JPH11194226A - Member for optical fiber fixation, optical fiber array, and optical waveguide module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the reliability by reducing the position shift of an optical fiber to be fixed and obtaining an optical fiber array which would be defective as a conforming article, although the structure is simple. SOLUTION: The member C for optical fiber fixation has plural optical fiber engagement parts C-1 for engaging optical fiber end parts molded by pressing. At this time, molded projection parts C-5 which stop an adhesive for fixing optical fiber end parts from slowing are formed outside both the sides of the array of optical fiber engagement parts C-1 at the same time. The molded projection parts C-5 are contiguous to the optical fiber engagement parts C-1 and arranged almost in parallel to the optical fiber engagement parts C-1. The height of the molded projection parts C-5 is equal to or higher than that of the molded mountain parts C-6 formed between the optical fiber engagement parts C-1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an optical fiber fixing member for engaging and positioning an optical fiber, an optical fiber array in which an optical fiber is positioned and fixed to the optical fiber fixing member, and an optical fiber array and an optical waveguide. Is fixed in an optically connected state.

[0002]

2. Description of the Related Art In the field of optical communication, optical measurement, and the like, when a plurality of optical fibers are connected to each other or a plurality of optical fibers are optically connected to another element (for example, an optical waveguide for branching an optical communication signal), each optical fiber is connected. A member for positioning and fixing the end of the device is required. In recent years, a method of manufacturing such an optical fiber fixing member by press molding with good mass productivity and reproducibility has been used.

For example, Japanese Patent Application Laid-Open No. Hei 6-201936 (hereinafter simply referred to as “publication”) discloses an optical fiber fixing member in which a groove-shaped optical fiber engaging portion for fixing an end of an optical fiber is formed by pressing. Are listed. According to the description of the above publication, two optical fiber fixing members are used, an optical fiber end is sandwiched in a groove of each member, and the optical fiber array is manufactured by bonding and fixing with a photocurable resin adhesive. ing.

[0004]

However, the above-mentioned prior art has the following problems.

(1) In the above-mentioned optical fiber array, an adhesive is filled and hardened between a pair of optical fiber fixing members sandwiching the optical fiber ends. When manufacturing the optical fiber array, the optical fiber is sandwiched in a state in which the adhesive is filled, so that the adhesive may flow and cause a positional shift of the optical fiber in the temporarily fixed state. If the adhesive is cured in this state, the optical fiber will be fixed in a state where displacement has occurred, resulting in a defective product.

(2) In order to optically connect an optical fiber array to another element (optical fiber array, optical waveguide element, etc.) with high precision, an alignment mark is required. Since the fiber array has no alignment mark, it is not easy to optically connect with high precision. In order to facilitate optical connection, alignment marks must be formed after molding the optical fiber fixing member or after fabricating the optical fiber array. The production process and structure are complicated because of the use.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and has a high reliability and a simple structure, an optical waveguide module using the optical fiber array, and a member used for those members. It is an object to provide a member for fixing an optical fiber.

[0008]

The means for solving the above problems will be described below.

An optical fiber fixing member according to the present invention comprises an optical fiber engaging portion for engaging an optical fiber end portion, and an adhesive for fixing the optical fiber end portion to the optical fiber engaging portion. An optical fiber fixing member having a flow preventing portion for preventing flow. The shape of the flow preventing portion is arbitrary as long as it can prevent the flow of the adhesive, and may be a convex portion, a concave portion, or an uneven portion.

[0010] More specifically, the optical fiber fixing member of the present invention is an optical fiber fixing member provided with an optical fiber engaging portion for engaging an optical fiber end. Part is formed in the surface, and the optical fiber engaging portion is at least one side of the optical fiber engaging portion when there is one optical fiber engaging portion, the said optical fiber engaging portion when there are a plurality of optical fiber engaging portions A projection is provided outside at least one of the arrangements of the optical fiber engaging portions and extending along the optical fiber engaging portion.

Here, the surface on which the optical fiber engaging portion is formed refers to the surface on which an adhesive for fixing the end of the optical fiber to the optical fiber engaging portion can be applied. The reason why the convex portion is used is that the flow of the adhesive can be effectively prevented, and at least one of the convex portions is provided so that even if the flow of the adhesive on one side can be effectively prevented, the displacement of the optical fiber is sufficiently reduced. It is because it can be reduced to. In addition, the reason for extending along the optical fiber engaging portion is that the adhesive is applied along the optical fiber engaging portion.

[0012] The optical fiber fixing member of the present invention satisfies the above requirements and has a convex portion adjacent to the optical fiber engaging portion. The optical fiber engaging portion has a peak portion between the optical fiber engaging portions, and the optical fiber engaging portion is arranged substantially in parallel with each other, and the convex portion and the peak portion have a pitch interval of the arrangement of the optical fiber engaging portion. What is characterized by being arranged at an equal pitch interval, a plurality of optical fiber engaging portions, and having a peak between the optical fiber engaging portion, the height of the convex portion of the peak portion A plurality of optical fiber engaging portions, having a peak portion between the optical fiber engaging portions, and a vertical cross-sectional shape and a convex portion of the peak portion. Characterized by the same or similar vertical cross-sectional shape Things, include those characterized by comprising the glass.

An optical fiber array according to the present invention further includes an optical fiber fixing member, an optical fiber whose end is aligned with an optical fiber engaging portion of the member, and a top portion of the optical fiber pressed and fixed. A holding member, and at least the periphery of the convex portion of the optical fiber fixing member is filled with an adhesive for bonding and fixing the optical fiber fixing member and the pressing member. is there.

Further, an optical waveguide module according to the present invention has at least the optical fiber array and an optical waveguide element.
The optical fiber of the optical fiber array and the optical waveguide of the optical waveguide element are fixed in an optically connected state.

According to the optical fiber fixing member of the present invention,
When the optical fiber is engaged with the optical fiber engaging portion and positioned, and the adhesive is fixed in a compressed state with the adhesive, the flow of the adhesive exceeding the convex portion is suppressed, and the positioned optical fiber shifts with the flow of the adhesive. Can be prevented. Therefore, a highly reliable optical fiber array can be obtained.

Further, since the convex portion of the optical fiber fixing member and the optical fiber engaging portion are simultaneously formed with high positional accuracy, the optical axis of the optical fiber precisely engaged with the optical fiber engaging portion can be formed. The projections have high positional accuracy with each other. Therefore, the optical fiber array can be optically connected to another element (optical fiber array, optical waveguide element, or the like) using the convex portion of the optical fiber fixing member as an alignment mark. Therefore, according to the present invention, a highly reliable optical waveguide module, in which the optical fiber array and the optical waveguide are optically connected, can be obtained.

[0017]

Embodiments of the present invention will be described below in detail.

The molding die is used for molding an optical fiber fixing member having an optical fiber engaging portion arranged in a plurality of grooves for engaging the ends of the optical fiber. As shown in FIG. 5, the molding die B of the embodiment has a plurality of (eight in the illustrated example) tips which are parallel and arranged at equal intervals so as to transfer and mold the optical fiber engaging portion on a flat surface. The inverted V-shaped mold ridge 112 and these mold ridges 1
12, a molding surface 114 composed of two planes formed on both outer sides of the array of the plurality of molding ridges 112, a molding surface 114 composed of two planes,
A mold concave portion 113 for molding a reference is provided between the mold convex and ridge portions 112 adjacent to these.

The shape of the vertical cross section of the mold recess 113 is close to the vertical cross section of the bottom of the mold recess 111 in the vertical cross section with respect to the longitudinal direction of the mold recess ridge 111. The mold concave portion 113 is formed in a streak like the mold concave ridge portion 111, and the mold concave ridge portion 111 and the mold convex ridge portion 112 are respectively located between two molding surfaces 114. The plurality of mold recesses 111 and the mold recesses 113 are arranged substantially in parallel with each other at substantially equal intervals, and the bottom of the mold recessed stripes 111 and the bottom of the mold recess 113 are located in substantially the same plane.

In other words, the shape of the molding surface of the molding die B is described as tracing the surface in a direction perpendicular to the longitudinal direction of the ridge 112 of the molding die. Crosses over a shallow V-groove-shaped mold recess 113, crosses a flat inverted V-shaped mold ridge 112 with a tip higher than the molding surface 114, and has the same bottom as the mold recess 113. It crosses over the V-shaped groove recess 111 having a depth, and repeats this plural times. Finally, it crosses over the shallow V-shaped mold recess 113 to reach the molding surface 114 formed of the other flat surface.

In order to manufacture the mold B as described above, first, a prototype thereof is formed. As shown in FIG. 6, while rotating the grindstone A, the grinding process is performed so that the depth becomes a position deeper than a predetermined depth Dmin with respect to the surface of the mold B perpendicular to the surface B-1 of the mold B '( FIG. 6 (a)). And a groove B-2 extending in the longitudinal direction while moving the grindstone A.
(FIG. 6 (b)), the grinding wheel A is pitched 2Y0.
And the relative position of the mold material B ′ is moved in a direction perpendicular to the longitudinal direction so that the grindstone A is again the same depth as the previously formed one, and is parallel to the previously formed groove B-2. (FIGS. 6C and 6D).
Such a process is repeated (FIG. 6E), and the number of optical fiber engaging portions to be produced by press molding is reduced by 1 to 8.
Is grinded to obtain the groove portion B-2 of several nines.

Here, the mold material B 'for the mold has oxidation resistance and non-reactivity with glass that can be used for press molding of glass, and does not cause structural change or plastic deformation in a high temperature environment. Are preferred, and specific examples thereof include silicon carbide,
Tungsten carbide, alumina, zirconia, crystallized glass, silicon, cermets of titanium carbide and titanium nitride, and the like. Examples of the grindstone A for grinding these mold materials include a resin-bonded diamond grindstone and a metal-bonded diamond grindstone. The grinding can be performed by using a dicing machine or another grinding machine for precision processing.

The depth at which the groove portion B-2 is ground, that is, the depth of the groove portion B-2 of the molding die B must be located at a position deeper than the predetermined depth Dmin. When the optical fiber is engaged with the optical fiber engaging portion to be transferred and molded if the depth is smaller than the predetermined depth Dmin, the optical fiber comes into contact with the bottom of the optical fiber engaging portion.
The optical fiber F rises from the two support points, and it becomes impossible to restrict the position of the optical fiber in the alignment direction of the optical fiber. When the optical fiber is engaged and aligned with the optical fiber engaging portion by the mold B that satisfies the above conditions, the cue of each optical fiber is possible, and the optical fiber is stably engaged with the optical fiber engaging portion. An optical fiber fixing member to be combined is obtained.

Here, the grinding depth of the groove portion B-2 will be further described. It is desirable that the grinding depth, that is, the depth of the groove portion B-2 is set at a position shallower than a certain depth Dmax. The reason is that the surface of the mold B to be subjected to the groove grinding is flat, so that when the grinding depth is set as described above, a part of the flat surface B-1 of the mold B is sandwiched between the grooves B-2. This is because it remains as the transfer molding surface. In such a molding die B, the gap between the groove portions B-2 is flat and does not have a sharp and thin edge, so that the handling of the molding die B becomes easy without fear of chipping of the tip of the groove portion B-2 of the molding die B. On the other hand, if the depth of the groove is deeper than a certain depth Dmax, a problem that a sharp and thin edge is generated between the grooves and chipping tends to occur easily occurs.

As shown in FIG. 1C, such a molding die B transfers a flat surface to the bottom of the optical fiber engaging portion when the optical fiber fixing member C is press-molded. In the glass press molding for forming such a flat bottom, after the optical fiber engaging portion 21 is transferred and formed, the optical fiber engaging portion 21 is generated at the tip between the grooves of the mold or at the bottom of the optical fiber engaging portion 21 in a cooling process. The resulting stress is dispersed, and has a function of reducing chipping and cracking at the tip between the grooves of the mold.

A further description will be given with reference to FIG. After performing the grinding of the grooves (# 1 to # 9) as described above on the mold member B '(FIG. 7A), the outermost groove B-2- out of the plurality of grooves B-2. 1, the outermost grooves B-2-1 and B-2-2 located outside of B-2-2.
And the groove B-2-1 and the groove B-2.
-2 is removed so as to form a molding surface 114 which is a plane slightly higher than the bottom of the groove B-2, leaving the bottoms of the two outermost grooves as mold recesses 113, and the remaining grooves B- 2 is a mold concave streak portion 111 (FIG. 7B).
Such processing is referred to as double-side processing. A molding die B having a mold concave portion 113 between both side processed portions of the molding die and an outermost mold convex ridge portion 112 by this both-side processing, and having # to # mold convex ridge portions 112. Is obtained (FIG. 7 (c)). The height of the molding surfaces 114 on both sides with respect to the bottom of the groove B-2 may be higher than the bottom of the mold ridge 111 and lower than the mold ridge 112 between the grooves B-2.

After the shaping of the mold B as described above, a release film is formed on at least the transfer molding surface 100 of the mold B to facilitate release of the press-formed object after molding. Examples of the release film include a carbon-based film and a platinum alloy-based film.

Using such a molding die B, a glass molding preform as a material to be molded is hot press-molded at a temperature at which press molding is possible. Using the molding die B, for example, a molding die for transferring and molding the pedestal portion of the optical fiber fixing member for mounting the coating portion of the optical fiber and the molding die B is integrated with a fixing frame to form a lower die. Using a body mold and an upper mold, a glass forming preform (material to be molded) is arranged in a space surrounded by the lower mold, the body mold and the upper mold, and press-molded at a temperature at which press molding is possible.

The manner in which the molding material B is being filled into the molding die B will be described with reference to FIG. Molded material 1
20 is filled from the part with the smallest flow resistance, and the part with the largest flow resistance is filled last. That is, before filling in FIG. 8, the portion 231 (FIG. 8) that should be the bottom of the optical fiber engaging portion, the inclined surface 232 that should be the support surface of the optical fiber end of the optical fiber engaging portion, and the optical fiber engaging portion Part 2 to be a molding surface located outside the array of parts
26 (FIG. 8) so that the molding die B
Is pressed uniformly to cause the molding material 120 to flow.

Next, the material 12 to be molded is
After filling with 0 (FIG. 8), the remaining slope 232 of the optical fiber engaging portion and the portion 222 corresponding to the crest located between the optical fiber engaging portions are formed into the material to be molded 120.
(FIG. 8). At this stage, the material to be molded 120 has not yet come into contact with the molding surface of the concave groove portion 111 of the molding die B, so that the molded product mountain portion 222 of the optical fiber fixing member located between the optical fiber engaging portions. Is a free surface that does not come into contact with the bottom of the mold concave ridge 111 of the mold B. When pressure is further applied, the material to be molded 120
Is brought into contact with the bottom of the mold concave ridge 111 to completely fill the mold concave ridge 111, and the filling is completed (FIG. 8).

It is not preferable to continue applying pressure even after the filling is completed, since burrs are generated. The optical fiber engaging portion 221 is transferred to the glass, which is a material to be molded thus formed, and the optical fiber fixing member C is obtained. The vertical cross-sectional shape of the molded product peak of the optical fiber fixing member C obtained in this way and the vertical cross-sectional shape of the molded product convex portion serving as the convex portion of the present invention are free from the molded product peak. If it is a surface, it will be similar, and if it is a transfer molding surface, it will be the same.

When molding the optical fiber fixing member C having the free surface 230 at the top of the molded product peak portion 222, make sure that the material to be molded 120 is not completely filled in the portion to be the top of the molded product peak portion 222. To In order to mold the optical fiber fixing member C having such a free surface 230, FIG. 8 or FIG.
Stop at the stage of. For that purpose, the optical fiber fixing member C obtained by molding is inspected, and a predetermined pressing force,
It is necessary to find a filling completion point at a predetermined heating temperature. In the present embodiment, the mold recess 113 of the mold B is used.
With reference to the shape of the molded product convex portion 224 molded by
The filling completion point is found by optically inspecting the shape or degree of filling of the molded article peak portion 222 between the optical fiber engaging portions 221 of the optical fiber fixing member C.

That is, after press molding, a molded product (optical fiber fixing member) serving as a pilot is taken out of the mold,
Place the convex part of the molded part and the convex part of the molded part between the optical fiber engaging parts in the same field of view of the optical microscope, or compare and observe the optically enlarged image at the same magnification, and , The shape or filling degree of the molded product peak is relatively measured. There are three methods for measuring the degree of filling of the V-groove shaped article peak. This will be described with reference to FIGS.

[0034] (1) the radius of curvature of the top portion of the molded article ridges 222 for the curvature radius R _ref of the molded product protruding portion 224 as the top portion of the molded article crests is shown in represented if Figure 9 with a radius of curvature with an arc R ₁ or R
It represents ₂ ratio R ₁ / R _ref or R ₂ / R _ref. Incidentally, FIG. 9 (a) If the radius of curvature R ₁ is larger, FIG (b) shows a case where the radius of curvature R ₂ is less, respectively.

(2) A case in which the top of the crest is curved but not arcuate and cannot be represented by the radius of curvature As shown in FIG.
The ratio d ₁ of the height d ₁ or d ₂ of the top of the molded article peak 222 to the height d _ref of the molded article projection 224 based on 0.
/ D _ref or d ₁ / d _ref or molded article peak 22
Expressed in 2 of the difference d ₁ -d _ref or d ₂ -d _ref between the height d ₁ or d ₂ of the top and the height d _ref of the molded product protruding portion 224. FIG. 10A shows the case where the curvature of the top of the molded article is small, and FIG. 10B shows the case where the curvature is large.

(3) Method of Measuring by Area or Cross Section As shown in FIG.
0, the slope from the molded product convex portion 224 toward the bottom 220, and the flat portion 214 from the top of the molded product convex portion 224.
Tangent to the bottom 220 of the optical fiber engaging portion 221 with respect to the area _Sref in a substantially triangular region surrounded by the slope toward the bottom and an extension line extending this slope, and the bottom 220 on both sides from the molded product mountain 222 Ratio S ₁ / S of the area S ₁ or S ₂ in the mountain area surrounded by the two slopes toward
_ref or S ₂ / S _ref or their difference S ₁ -S
represented by _ref or S ₂ -S _ref. FIG. 11 (a)
Fig. 11B shows a case where the curvature of the top of the molded article is small, and Fig. 11B shows a case where the curvature is large.

As a result of inspecting the degree of filling of the material to be molded by using any of the above methods (1) to (3), if the desired free surface is obtained, the information is fed back to the pilot. Thus, the press forming conditions at which the filling is completed are determined, and thereafter, mass-produced products are formed under the same conditions.

In the case where the peak of the molded product is used as a free surface, the shape of the bottom of the concave portion of the concave portion of the molding die for forming the molded product peak 222 (FIGS. 9 to 11)
(Shown by a dashed-dotted line in FIG. 2) does not become a transfer surface and disappears, so that it is not possible to inspect the shape of the molded product peak by referring to the shape of the bottom of the concave portion of the molding die. In this regard, in the embodiment, the molded article convex portion 224 serving as a reference is provided on the same molded article on which the molded article mountain portion 222 to be inspected is formed.
Are formed together, and the shape or the degree of filling of the molded product peak portion 222 is relatively measured with reference to the molded product convex portion 224. Therefore, both errors are cancelled, and in the absolute measurement, Difficult shape dimensions of 30 μm to 50 μm or less can be measured with high accuracy.

Further, the molded product convex portion 22 serving as a reference is provided.
4 has a stable shape because it is formed by completely filling the mold concave portion with the material to be molded. On the other hand, the molded product mountain portion 222 between the optical fiber engaging portions does not completely fill the molding concave portion with the material to be molded, and therefore has an unstable element in its shape. Due to the structure of the mold, the molded product convex portion 224 is always formed after filling is completed before the molded product mountain portion 222.
The molded product convex portion 224 serves as a reference. Since the degree of filling of the molded product peak 222 can be accurately measured by relative measurement with the molded product convex portion 224 serving as a reference, it becomes easy to detect the filling completion point of the molding material in the molding die,
The molding control can be performed with high accuracy, and the optical fiber fixing member can be manufactured with high accuracy.

In the present embodiment, the molded product convex portion serving as a reference is particularly useful for obtaining a free surface in which the transition of filling is difficult to grasp. Even in the case of complete filling without obtaining a surface (Fig. 8
), It is useful not to pass through the point of complete filling and to prevent overfilling, and the degree of filling can be measured accurately and quickly.

In the above-described embodiment, the molded article is taken out of the mold during or after molding, and measured, and the result is fed back to the next molding condition. It is a method of seeking.

On the other hand, a method is also possible in which the result is fed back to the molding conditions in real time by measuring without removing the molded product from the mold during the molding to control the filling state.

In this method, the ratios R / R _ref and H / R shown in FIGS. 9 to 11 are monitored by optically monitoring the molding state of the peaks between the optical fiber engaging portions of the optical fiber fixing member.
H _{re f,} determined such as a continuous S / S _ref, as shown in FIG. 12, the pressing time will draw the plot such as the ratio (pressure, a is a function of the heating temperature), the ratio is 1 This is a method of finding the point at which it becomes as a complete filling completion point. In FIG. 12, a region where the ratio is increasing forms a free surface, and a region where the ratio is saturated indicates a filling completed region. From this plot, it is easy to accurately detect the filling state of the molding material in each part. Therefore, good molding conditions can be obtained, and the allowable range of the molding conditions is widened.
Improves transferability, releasability, and burr controllability.

By the way, the appropriate range of the shape of the molded product peak portion controlled by the molded product peak portion serving as the reference is such that the optical fiber contact point E (see FIG. 13) of the molded product is a plane (a straight line in a sectional view). It is determined by the following geometric conditions. In mathematical formulas, it can be expressed as follows.

The critical fiber contact distance t ≧ 0 (1) Here, the critical fiber contact distance t is a distance from the contact point E to a point at which a straight line from the contact point E toward the top of the molded article peak becomes a curve or an angle. 13 can be described as follows.

T = DE = CE-CD = (AE−BD) / tan (θ / 2) = (R _Vmax −R _V ) / tan (θ / 2) (2) The C point is R _{V in the} above equation. It is the bottom of the mold ridge when = 0, and the shape of the mold ridge when R _V = 0 is the same as the shape of the molded product protrusion serving as a reference for the molded product. Further, the apex of the molded product convex portion is located on the line segment CB or CA.
Therefore, hereinafter, the point C will be described with the top of the convex part of the molded product. R _Vmax is the radius of a circle having the central point A, which is inscribed in the molded product convex portion serving as the vertex C and in contact with the optical fiber contact point E. The radius R _V is the radius of a circle inscribed at the vertex C and having the center point B, and the arc above the inner contact points represents the top shape of the molded product peak.

As can be seen, when the fiber contact critical distance t takes the lower limit value t = 0, the radius R _{V of} the circle
Becomes maximum and R _Vmax -R _V = 0. That is, the circle having the radius R _V having the center point B moves downward in FIG. 13 and coincides with the circle having the radius R _Vmax having the center point A, and the top of the molded product peak has the radius R _Vmax . It overlaps with the circle, and the height is the lowest within the appropriate range. An increase in the value of the fiber contact critical distance t means that the value of the radius R _V decreases and the circle moves toward the vertex C while inscribed in the convex part of the molded product. When the radius R _V is minimized, the height of the molded product peak is highest within an appropriate range.

The above equation (1) is obtained by subtracting the inverse V
In the case of using the character-shaped molded article mountain shape parameters, the following can be specifically expressed.

(A) When the molded product peak can be represented by a radius of curvature 0 ≦ R ≦ R _Vmax (3) (b) When the molded product peak is represented by height d ₀ −S _Rvmax ≦ d ≦ d ₀ ( 4) Here, as can be seen from FIG. 14, R _Vmax = P / (2 cos (θ / 2)) − R _f (5) d _RVmax = d ₀ −S _Rvmax = d ₀ −R _Vmax (1 / sin (θ / 2) -1) (6) where P is the pitch of the optical fiber engaging portion, and R _f is the radius of the optical fiber.

[0050] Examples 13 and 14 described above, when referred to in FIG. 15 in which the optical fiber see how that is engaged to the optical fiber engagement portion of an optical fiber fixing member from its cross-sectional direction, a ₁ ~b ₂ but will be described the case of FIG. (a) located on the straight line contours, it can be applied to a case located on the contour of the curve as shown in FIG. (b). In FIG. 15, F _A and F _B are the optical axes of the optical fibers, a ₁ , a ₂ ,
b ₁ and b ₂ indicate optical fiber contact points, respectively.

After the molded product convex portion of the optical fiber fixing member C manufactured as described above functions as the reference, when an optical fiber array is manufactured, the end of the optical fiber is positioned and fixed. It functions as a flow blocking part for the adhesive to be applied. That is, as shown in FIG. 2, the optical fiber engaging portion C-1 of the optical fiber fixing member C is used.
Then, the optical fiber F is engaged and aligned, and the pressing surface M-1 of the pressing block M presses the side surface of the optical fiber F where the optical fiber F is caught, and is adhesively fixed. At this time, the flow of the adhesive beyond the convex part C-5 of the molded product is suppressed, and the positioned optical fiber F
Can be prevented from shifting with the flow of the adhesive.
Looking at the cross section perpendicular to the optical axis of the optical fiber in this state, the side of the optical fiber is at two points by the optical fiber engaging portion C-1, and at one point by the pressing surface M-1 of the pressing block M.
An optical fiber array Y supported by a total of three points is obtained,
The distance between the bonding surfaces of the optical fiber fixing member C and the holding block M can be made uniform in each portion. The optical input / output end faces of the optical fiber array Y are optically polished and put to practical use, and a highly reliable optical fiber array Y is obtained.

Further, the molded product convex portion C-5 also functions as an alignment mark when an optical waveguide module is manufactured. That is, since the molded product convex portion and the optical fiber engaging portion of the optical fiber fixing member C are simultaneously molded with high positional accuracy to each other, the optical axis of the optical fiber precisely engaged with the optical fiber engaging portion and the optical axis of the optical fiber. The molded product has high positional accuracy with the convex portion. Therefore, the molded product convex portion of the optical fiber fixing member is used as an alignment mark as shown in FIG.
As shown in (2), the optical fiber array Y and the optical waveguide element W can be optically connected, and a highly reliable optical waveguide module in which the optical fiber array Y and the optical waveguide W are optically connected can be obtained. When the convex part of the molded product is used as the alignment mark in this manner, coupling using the alignment mark can be performed. An optical fiber array or another element may be connected instead of the optical waveguide element W.

The mold according to the embodiment is not limited to the above-described example of the use of the optical fiber fixing member. For example, an optical fiber for positioning a light emitting element and a light receiving element in addition to an optical fiber with high precision. The present invention can be applied to transfer molding of an optical fiber engaging portion such as a component mounting substrate or an optical component fixing member.

As the glass to be molded, any glass that can be press-molded can be used, but those having a low coefficient of thermal expansion, a material having a yield point of 600 ° C. or less, and a material having excellent ultraviolet transmittance are preferred. For example, SiO ₂ , B ₂ O ₃ and Z
Glass containing nO can be used. In addition, commercially available press glass can be used.

[0055]

EXAMPLES Specific examples will be described below.

Embodiment 1 A molding die for press-molding an optical fiber fixing member for positioning and fixing an optical input / output end of a silica glass single mode fiber widely used in the fields of optical communication, optical measurement, etc. Produced. The number of optical fibers to be engaged with the optical fiber engaging portion of the optical fiber fixing member is eight, and the radius of the optical fiber is 62.5 μm. The shape of the cross section of the groove (cross section of the grindstone) of this embodiment is V-shaped, and the cross section of the bottom (cross section of the tip of the grindstone) is arc-shaped.

A cemented carbide base material containing tungsten carbide as a main component was precision machined to obtain a cemented carbide block having a base dimension of 5 mm in width, 5 mm in length and 14 mm in height. The surface roughness of only the upper surface of the cemented carbide block is 0.04 μm in Ra.
The surface was processed so that On the upper surface of this carbide block,
Using a dicing saw and a diamond grindstone, V-grooves with an opening angle of 70 ° are 250 μm so as to be aligned with the center of 5 mm in width.
Nine pieces were processed at intervals. In processing, the V-groove depth was set such that an unprocessed surface having a width of about 20 μm remained between the V-grooves.

After nine grooves are formed in this way,
Using a dicing machine, the outer portions of the V-grooves at both ends are removed, and both sides are machined to form a flat surface at a depth slightly smaller than the depth of the V-groove.
A V-groove forming mold B having a concave and convex groove in which two reference mold concave portions and an inverted V-shaped convex portion 112 having eight flat ends were arranged therebetween was obtained. The depth of both side processing was set to 1/6 of the V groove depth.

Example 2 The V-groove forming mold obtained in Example 1 was combined with other mold parts to form an optical fiber fixing member forming die as shown in FIG. That is, the above-described V-groove forming die B, the forming die D for transferring and forming a pedestal portion on which the optical fiber coating portion is placed,
The groove forming die B and the forming die D are integrated with a fixing frame E to form an upper die, and a trunk die K for forming the side surface of the optical fiber fixing member and a lower die for forming the bottom surface of the optical fiber fixing member. The cavity Z was formed using G. Note that a carbon-based release film H was previously formed on the molding surface of each mold by 500 angstrom by an ion plating method in order to impart mold release properties.

Next, 13.3 wt% of SiO ₂ and B ₂ O
₃ at 32.2 wt%, ZnO at 44.5 wt%, Al ₂
A glass material containing 5.5% by weight of O ₃ and 4.5% by weight of Li ₂ O, and further containing 0.1% by weight of SnO ₂ on an external basis is preliminarily hot-formed, and the width at which the ridge exhibits a curved surface is formed. A glass preform J having a size of 3.8 mm, a length of 10.5 mm, and a thickness of 2.05 mm was obtained. This glass preform J
Is placed in the mold cavity Z as shown in FIG.
While heating the mold to 560 ° C in an inert atmosphere,
A pressure of 50 kgf / m ² was applied to press-mold the glass preform J for 90 seconds. At this time, a pilot is flowed in advance, the pilot is taken out of the mold, and press molding is performed after finding the press conditions in which the shape of the molded product peak portion falls within an appropriate range constituting the free surface with reference to the pilot molded product convex portion. went. After press molding, the molded product C was taken out of the mold by cooling to room temperature while reducing the pressing force.

On the upper surface of the optical fiber fixing member C which is the removed molded product, as shown in FIG.
8, eight V-grooves C-2 are formed at a pitch of 250 μm, and on both sides thereof, a convex part C-5 for reference is formed. Further, a step surface C-3, which is one step lower than the plane portion C-4, is formed for mounting the optical fiber coating portion. The above-mentioned molded product convex portion C-5 is provided with an optical fiber engaging portion C.
-1 and substantially parallel to the optical fiber engaging portion C-1. The height of the molded product convex portion C-5 is the optical fiber engaging portion C.
The height is equal to or higher than the height of the molded product peak portion C-6 formed between -1.

FIG. 17 shows an enlarged cross section near the optical fiber engaging portion of the optical fiber fixing member C.
The cross section is a cross section perpendicular to the optical axis of the optical fiber F when the optical fiber F is engaged with the optical fiber engaging portion 221. The cross-sectional shape of the optical fiber engaging portion 221 is substantially V-shaped, and the V-shaped opening angle is 70 °. Between the optical fiber engaging portions 221, a molded product mountain portion 2 that partitions between the engaging portions.
22 are formed.

The surface of the optical fiber engaging portion 221 that supports the optical fiber side surface f when the optical fiber F is engaged is a mold transfer surface 225 transferred by a molding die. The top surface of the molded article peak portion 222 located between 221 comprises a free surface 230 which does not contact the molding die, and has a rounded and substantially arcuate cross section. The width of the free surface 230 in the cross section is preferably 10 to 80 μm, and the radius of curvature of the arc is 25 to 50 μm.
m is desirable. When the width of the free surface is 10 μm or less, the releasability of the molded product is deteriorated, and molding burrs are easily generated. If it is 80 μm or more, the amount of free shrinkage of the glass increases, and the molding accuracy deteriorates. When the radius of curvature is 25 μm or less, the area with minute irregularities on the mold transfer surface becomes large, so that when arranging and fixing the fibers, the fiber side surface is easily damaged. As the amount increases, the polishing characteristics and durability of the end face decrease.

The molded product convex portion 224 formed on the flat portion 214 adjacent to the outermost optical fiber engaging portion 221 is
The surface is a mold transfer surface transferred by a molding die, and the cross section is a pointed inverted V-shape.

The above is the case where glass is used as the material, but the same applies to the case where a moldable and transparent polymer material in a cured state is used.

Embodiment 3 Using the optical fiber fixing member of Embodiment 2, as shown in FIG.
In FIG. 1, an 8-core quartz glass single mode optical fiber F whose coating was peeled off was engaged and arranged, and the optical fiber coating portion was arranged on a step surface C-3. Then, an optical fiber engaged with the optical fiber engaging portion C-1 was clamped by using a holding block M made of transparent glass. At this time, the optical fiber F is sandwiched while being filled with an adhesive made of an ultraviolet curable resin. However, the adhesive is blocked by the convex portion C-5 of the molded product and does not flow outward. There was no displacement. When the adhesive was cured in this state, the optical fiber was fixed at the correct position, and a good product was obtained.

Next, the optical fiber end face on the side fixed by the optical fiber fixing member C and the holding block M was polished together with the optical fiber fixing member end face and the holding block end face to produce an optical fiber array Y. In addition, N is a pressing block that presses the optical fiber coating portion to the step surface C-3 of the optical fiber fixing member.

When the vicinity of the optical fiber fixed from the end face after polishing was observed with a microscope, it was confirmed that each of the eight optical fibers was supported at three points. Further, when a thermal cycle test was performed on this optical fiber array, the total width of the optical connection loss fluctuation was within 0.3 dB, and no change was observed in the positional accuracy of the optical fiber after the test.
Also, no change was observed in the state where each optical fiber was held and fixed by three-point support. Similar good results were obtained by using the above-mentioned materials and the like other than tungsten carbide as the mold material.

Further, as shown in FIG. 3, the optical fiber array Y and the optical waveguide device W were connected so that the optical fiber and the optical waveguide were optically connected to each other to obtain an optical waveguide module. At the time of this connection, since the molded product convex portion C-5 of the optical fiber fixing member constituting the optical fiber array functions as an alignment mark, an alignment mark including the molded product convex portion and an optical waveguide (not shown) The device W was connected so as to match the alignment mark of the device W. The optical fiber array and the optical waveguide module obtained in the present embodiment have an optical axis exactly along the direction of the optical fiber engaging portion not only at the end face of the optical fiber but also at least near the end face of the optical fiber connected to the end face. Met.

[0070]

According to the optical fiber fixing member of the present invention, since the flow preventing portion or the protruding portion is provided, the displacement of the optical fiber to be fixed can be reduced, and the light which would have become defective in the prior art can be reduced. A good fiber array can be obtained, and a highly reliable optical fiber fixing member and an optical fiber array can be obtained.

According to the optical fiber array of the present invention, when the optical fiber is engaged with the optical fiber engaging portion and the optical fiber side surface is pressed and fixed by the pressing member, the optical fiber engaging portion is used when the adhesive is used. The flow of the adhesive to the molding parts on both sides of the optical fiber engaging part, the flow in the opposite direction is suppressed,
The displacement of the positioned optical fiber due to the flow of the adhesive can be suppressed.

Further, according to the optical fiber array of the present invention, the convex portion of the optical fiber fixing member can be used as an alignment mark, so that the coupling using the alignment mark can be performed with a simple structure. Optical connection with other elements is facilitated.

Further, according to the optical waveguide module including the optical fiber array, a highly reliable module can be obtained.

[Brief description of the drawings]

FIG. 1 is a perspective view of an optical fiber fixing member according to an embodiment.

FIGS. 2A and 2B are explanatory views showing an optical fiber array according to the embodiment, wherein FIG. 2A is a perspective view and FIG. 2B is a front view.

FIG. 3 is a perspective view of the optical waveguide module of the embodiment.

FIGS. 4A and 4B are explanatory diagrams showing the configuration of the present invention, wherein FIG. 4A shows a prototype of a molding die, FIG. 4B shows a molding die obtained by processing both sides of the prototype, and FIG. It is an optical fiber fixing member as the molded product shown.

FIG. 5 is a perspective view of a molding die according to the embodiment.

FIG. 6 is a perspective view showing a processing step of manufacturing a molding die from a mold material by grinding using a grindstone according to the embodiment.

FIG. 7 is an explanatory diagram of both-side processing according to the embodiment;
(A) shows a prototype of a grooved molding die, (b) shows both side processing, and (c) shows an obtained molding die.

FIG. 8 shows the order of filling using the molding die according to the embodiment, before filling, completion of bottom filling, progress of filling of both side surfaces and slopes of V-groove, completion of filling of convex portions of molded product and flat portions of both sides, slope of V-groove. Filling is completed and filling of the molded part is in progress,
It is a flowchart explaining completion of filling of a peak part of a molded article.

FIG. 9 is an explanatory view in which the degree of filling of a molded product peak is measured by a radius of curvature with reference to a completely filled molded product convex portion, and FIG. 9A illustrates a case where the radius of curvature of the molded product peak is large;
(B) shows the case where the radius of curvature of the peak of the molded product is small.

10A and 10B are explanatory diagrams in which the degree of filling of a molded product peak is measured by height using a completely filled molded product convex portion as a reference, and FIG. 10A shows a case where the curvature of the molded product peak is large, and FIG. Indicates the case where the curvature of the peak of the molded article is small.

11A and 11B are explanatory diagrams illustrating measurement of a degree of filling of a molded product peak by a cross-sectional area using a completely filled molded product convex portion as a reference, and FIG. 11A illustrates a case where the curvature of the molded product peak is large; Indicates the case where the curvature of the peak of the molded article is small.

FIG. 12 is a filling characteristic diagram showing a filling degree with respect to molding conditions.

FIG. 13 is an explanatory diagram showing an allowable range of a peak shape measured with reference to a reference according to the embodiment.

FIG. 14 is a supplementary explanatory diagram of a fiber contact critical distance using a molded article peak shape parameter according to the embodiment.

FIG. 15 is a diagram showing a state in which the optical fiber according to the embodiment is engaged with the optical fiber engaging portion of the optical fiber fixing member when viewed from the cross-sectional direction, and FIG. (B) shows the case where the optical fiber is on the contour of the curve, respectively.

16A to 16C are process diagrams illustrating a method for manufacturing an optical fiber fixing member using a press mold according to an embodiment, wherein FIG. 16A is a front sectional view before pressing, FIG. 16B is a sectional side view thereof, and FIG. Is a front sectional view during pressing, and (d) is a side sectional view of the same.

FIG. 17 is a diagram showing a cross section near the optical fiber engaging portion of the optical fiber fixing member of the embodiment.

[Explanation of symbols]

 C Optical fiber fixing member C-1 Optical fiber engaging portion C-5 Molded product convex portion C-6 Molded product peak Y Optical fiber array M Holding member W Optical waveguide element

Claims (9)

[Claims] An optical fiber engaging portion for engaging an optical fiber end; and a flow preventing portion for preventing a flow of an adhesive for fixing the optical fiber end to the optical fiber engaging portion. An optical fiber fixing member having: 2. An optical fiber fixing member provided with an optical fiber engaging portion for engaging an end of an optical fiber, wherein the optical fiber is located in a plane where the optical fiber engaging portion is formed, and When there is one engaging portion, it is on at least one side of the optical fiber engaging portion, and when there are a plurality of optical fiber engaging portions, it is outside at least one of the arrangement of the optical fiber engaging portions. An optical fiber fixing member having a convex portion extending along the optical fiber engaging portion. 3. The optical fiber fixing member according to claim 2, wherein said convex portion is adjacent to said optical fiber engaging portion. 4. A plurality of optical fiber engaging portions, and a crest portion between the optical fiber engaging portions, wherein the optical fiber engaging portions are arranged substantially in parallel with each other, and 4. The optical fiber fixing member according to claim 2, wherein the peaks are arranged at a pitch interval equal to a pitch interval of the arrangement of the optical fiber engaging portions. 5. A plurality of optical fiber engaging portions and a peak portion between the optical fiber engaging portions, and a height of the convex portion is equal to or higher than a height of the peak portion. The optical fiber fixing member according to any one of claims 2 to 4, wherein: 6. A plurality of optical fiber engaging portions and a peak portion between the optical fiber engaging portions, and a vertical cross-sectional shape of the peak portion and a vertical cross-sectional shape of the convex portion are the same or approximate. The optical fiber fixing member according to any one of claims 2 to 5, wherein: 7. The method according to claim 1, wherein the glass is made of glass.
7. The optical fiber fixing member according to any one of claims 6 to 6. 8. An optical fiber fixing member according to claim 2, an optical fiber whose end is aligned with an optical fiber engaging portion of said member, and a top portion of said optical fiber. A pressing member for pressing and fixing, wherein at least a periphery of the convex portion of the optical fiber fixing member is filled with an adhesive for bonding and fixing the optical fiber fixing member and the pressing member. An optical fiber array. 9. An optical fiber array according to claim 8, and an optical waveguide element, wherein the optical fiber of the optical fiber array and the optical waveguide of the optical waveguide element are fixed in an optically connected state. Optical waveguide module.