JPH10260321A - Manufacture of optical transmission member holding device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it hard to form a gap between an optical transmission member and a groove by securely fixing respective optical transmission members in grooves by using solder as to the holding device which fixes the optical transmission members such as optical fibers at specific positions. SOLUTION: The optical transmission member holding device is manufactured which is equipped with a hold substrate 3A holding optical transmission members 8 at specific positions respectively. Grooves 7 wherein the optical transmission members 8 are stored and fixed are formed on the hold substrate 3A. The optical transmission members 8 are put in the grooves 7 and a solder sheet 11 is set on the grooves 7 and optical transmission members 8. The solder sheet 11 while pressed against the grooves 7 is heated to make solder flow in the gaps between the grooves 7 and optical transmission members 8, which are fixed at the specific positions.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing an optical transmission member holding device for holding an optical transmission member such as an optical fiber at a predetermined position.

[0002]

2. Description of the Related Art Various substrates are known for fixing a plurality of optical fibers having a diameter of, for example, about 125 μm. Usually, a fixing groove such as a V-groove is formed in the holding substrate in order to fix the optical fiber at a predetermined position. After fixing a plurality of rows, for example, 16 rows of optical fibers to the holding substrate, the substrate is coupled to other optical components. At this time, each optical fiber is coupled to, for example, a light emitting diode or a light receiving element, or is optically coupled to another optical fiber or a rod lens.

As the material of the holding substrate, silicon, optical glass, ceramics and the like are known. As a method of forming the fixing groove as described above, an etching method is used for a silicon substrate, and a grinding method is used for a glass substrate or a ceramic substrate.

In any type of substrate, if the optical axis of the optical fiber fixed to the substrate is shifted from a predetermined position,
Transmission loss between the optical fiber and other optical transmission means increases. Therefore, as the processing accuracy of the fixing groove in the optical fiber holding substrate, an extremely high processing accuracy of, for example, 0.5 μm or less is required. Normally,
The optical fiber is fixed in the V-groove with a resin adhesive.

[0005]

However, in the case of such a holding device, an organic gas is generated from the resin adhesive, particularly when each optical fiber is connected to a light emitting diode or a light receiving element. There is a concern that the gas adheres to the light emitting interface of the light emitting diode and the light emitting characteristics are deteriorated.

In order to avoid such a problem, the present inventor studied fixing each optical fiber to the corresponding V-groove by soldering. However, the diameter of an optical fiber is currently usually about 125 μm, and V
Since the gap between the groove and the optical fiber is extremely small, it has been found that it is difficult to flow the solder into the V-groove from the end face of the holding substrate and to fill the gap without any gap. For this reason, a gap in which the solder does not flow easily occurs in the gap between the V-groove and the optical fiber.

The behavior of the void in the solder in such a groove is as follows:
Not clear. However, the optical fiber holding device as described above is housed in an airtight case or package, and is often provided at a key point of an optical cable. In this housing package, deterioration of an optical element such as a laser is prevented. For this reason, an inert gas such as nitrogen gas is often filled. However, when the package is sealed with the present optical fiber holding device, the solder is not sufficiently filled in the groove as described above, and a gap remains, and if this gap extends long along the groove, the groove may be formed in some cases. It has been found that the inert gas can leak through the internal space.

Further, the package containing the optical fiber holding device as described above is often placed in a severe outdoor environment, and is exposed to a high temperature of 60 ° C. to a low temperature of −40 ° C., or from a desert environment. Exposure to high humidity environment. The optical fiber holding device package must operate stably for a long period of time in such a harsh environment. However, if a void remains in the solder in the groove as described above, the air remaining in this void repeats expansion and contraction, or moisture invades into the void. The fixed position of the optical fiber sometimes fluctuated slightly. If the fixed position of the optical fiber fluctuates, the coupling loss increases or fluctuates even if the magnitude of the fluctuation is slight, because the optical axis is displaced.

SUMMARY OF THE INVENTION An object of the present invention is to provide a holding device for fixing an optical transmission member such as an optical fiber at a predetermined position, so that each optical transmission member can be securely fixed using solder in a groove. The purpose is to prevent a gap from being generated between the transmission member and the groove.

[0010]

SUMMARY OF THE INVENTION The present invention is a method for manufacturing an optical transmission member holding device having a holding substrate holding a plurality of optical transmission members at predetermined positions, respectively. A groove for accommodating and fixing the transmission member is provided, the optical transmission member is accommodated in the groove, a solder sheet is placed on the groove and the optical transmission member, and this solder sheet is directed toward the groove. By heating while applying pressure, solder flows into and fills the gap between the groove and the optical transmission member, and fixes the optical transmission member in a predetermined position. Things.

[0011] The present inventor, after accommodating the optical transmission member in the groove, installs a solder sheet on the groove and the optical transmission member, and heats this solder sheet while pressing it toward the groove. It has been conceived that the solder flows into and fills the gap between the groove and the optical transmission member. In this process, the solder sheet is crushed, preferentially flows into the groove, fills the gap between the light transmitting member and the groove, and the light transmitting member itself strongly presses against the surface of the groove. And fixed at a predetermined position. As a result, the error in the fixed position of the optical transmission member was minimized, and the gap between the groove and the optical transmission member was also minimized. Thus, the optical transmission member holding device in which the optical transmission member was fixed in the groove by soldering was successfully put to practical use.

Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings as appropriate. In the above, the optical transmission member is preferably an optical fiber, but may be a passive optical transmission member such as a rod lens. The light transmitting member can be optically coupled to another light transmitting member or optical element. The optical element is not particularly limited, but is preferably a laser light emitting element that oscillates laser light or a light receiving element that receives laser light.

FIG. 1A is a front view schematically showing an optical fiber holding device or array according to an embodiment of the present invention, and FIG. 1B is a plan view schematically showing this device. FIG. 1C is a front view of the apparatus of FIG. 1B when viewed from the left.

The optical fiber holding device 1 has an optical fiber holding substrate 3. The holding substrate 3 includes a coating mounting portion 3a for mounting the optical fiber coating, and the optical fiber coating 2 is fixed in the coating mounting portion 3a. A lid 5 is placed over the coating 2. A predetermined number of rows of grooves 7 are formed in the holding portion 3b of the holding substrate 3, and each groove 7 extends from the end face 6 of the holding portion 3b toward the coating placement portion 3a. A core wire 8 of an optical fiber is accommodated in each groove 7 and fixed with solder according to the present invention. The lid 4 is put on the holding part 3b.

According to the present invention, a method for manufacturing such an optical fiber array will be described. First, an optical fiber holding substrate is manufactured. It can be made of silicon, ceramics, glass. Each groove is fine, for example, having a depth of about 125 μm. The optical fibers 8 are accommodated in the respective grooves 7 and aligned.

As a method of forming a groove in the optical fiber holding substrate, there is a method of forming a groove by etching a silicon material. However, this method has a limitation in processing accuracy, and it has been difficult to form a V-groove with a high degree of accuracy. Therefore, a method of forming each groove by grinding a ceramic material such as alumina, agate, zirconia, or a glass material can be used. In this case, for example, a sintered body is manufactured by sintering a formed body of ceramics, and the sintered body is flat-ground to form a flat surface, and then the flat surface is ground with a diamond grindstone. Thereby, each groove is formed. Further, the fixing groove of the optical fiber holding substrate can be formed by a press molding method.

As the glass, BK-7: optical glass, borosilicate glass, soda-lime glass, ion exchange glass, LiO ₂ —Al ₂ O ₃ —SiO ₂ glass is particularly preferable.

When manufacturing an optical fiber holding device as shown in FIG. 1, a holding substrate 3 is used as shown in FIG.
A predetermined number of grooves 7 are formed on the holding portion 3b of A, and the core wires 8 of the respective optical fibers are accommodated in the grooves 7. Here, 10 is an upper side surface of the holding portion 3b, 33 is a side surface of the holding portion 3b, and 34 is the other end surface of the holding portion 3b.

Here, the opening angle of each groove is not particularly limited. However, when each groove is formed by grinding, the cross-sectional shape of the groove is determined by the shape of a grindstone (usually a diamond grindstone) to be used. The shape of the grindstone changes little by little during the grinding process, and the tip of the grindstone becomes dull. At this time, the most important part of the groove shape is the shape of the inclined surface that directly contacts the optical fiber, and this inclined surface must be straight over the entire length of the groove. From this point of view, sharpen the whetstone,
It is preferable that the opening angle of the groove is reduced, specifically, 90 ° or less. On the other hand, if the opening angle of the groove is too small,
It becomes difficult for the optical fiber to enter the groove, and it becomes difficult for the solder to extremely flow into the bottom of the groove. Therefore, it is preferable that the opening angle of the groove is 60 ° or more.

The spacing or pitch between adjacent grooves is not particularly limited. Further, the number of optical fibers fixed to one optical fiber holding substrate is also determined by the number of optical elements to be optically coupled to each optical fiber. A particularly preferred application of the optical fiber holding device manufactured according to the present invention is a parallel transmission module, in which eight channels, typically corresponding to 8-bit signals, and other control signals such as clocks. Since a channel is required, it is conceivable to use a general tape fiber (12 rows or the like). In this case, the fiber pitch of the tape fiber is 250 μm
Therefore, the pitch between adjacent grooves is preferably 250 μm.

Next, as shown in FIG. 3, a solder sheet 11 is placed on the upper surface 10 of the holding portion 3b to cover the groove 7 and the optical fiber core 8 therein. As shown in FIG. 3, the lid 4 is placed on the solder sheet 11. Then, as shown in FIG. 4, the holding substrate 3A is placed on a predetermined heating source (for example, a hot plate 36), and at least a portion of the solder sheet 11 is heated. During this heating, a predetermined pressure is applied from above as shown by arrow A.

After the heat treatment, the entire holding device is removed from the hot plate to obtain the holding device 12 shown in FIG. The end face of the core wire 8 of each optical fiber is optically polished, and each end face is exposed on the end face 6 of the holding portion 3b of the holding substrate 3A.

Since the distance between the surface of each optical fiber and the surface of the groove is extremely small in the groove, it is necessary to use a solder made of a material that is particularly wettable on the surface of the groove. Normally, it is preferable to add a flux to the solder in order to improve the wettability of the solder. However, in the case of the optical fiber holding substrate which is the object of the present invention, it is desirable that the fixing position of the optical fiber in the groove is high and that the substrate is completely made of an inorganic material. For this reason, it is particularly preferable to use a gold-based eutectic solder having particularly good wettability.

As such solder, from the viewpoint of reliability, gold / tin solder, gold / germanium solder, and gold / silicon solder are preferable. It is particularly preferable because gold / tin solder flows easily.

When the material of the holding substrate is glass or ceramic, the solder does not directly wet the surface of the groove. Therefore, since the solder can be spread to the inside of the groove, it is preferable to form a metallized layer at least on the surface of the groove. Further, in order to fix the lid and the holding substrate, it is preferable to form a metallized layer on the mutual contact surfaces. The material of the metallized layer is not particularly limited. However, it is preferable that the metallized layer is formed of a plurality of metal layers, and the layer on the underside of the metallized layer is formed of a metal having a good adhesion to the material of the holding substrate. Further, the surface side of the metallized layer is preferably made of the same material as the material of the solder to be used, particularly preferably gold or a gold alloy.

In a particularly preferred embodiment, the order of chromium layer / gold layer, titanium layer / platinum layer / gold layer is from the base material of the holding substrate. That is, the gold is exposed on the outermost surface. From the viewpoint of further improving the positional accuracy of the optical axis of the optical fiber in the groove,
The thickness is preferably 1.5 μm or less, and from the viewpoint of improving the wettability, it is preferably 0.5 μm or more. For example, a titanium layer having a thickness of 0.1 μm / a thickness of 0.1 μm.
A platinum layer of 1 μm / a gold layer of 1 μm thickness is sequentially laminated.

In an optical fiber array, a cover 4 that covers the holding portion 3b is usually used. In this case, since the pressure can be applied to the solder sheet by pressing the lid 4 as shown by the arrow A, it is preferable in that the pressure can be applied uniformly over the entire surface of the solder sheet. However, it is preferable that a metallized layer is formed at least on the bottom surface 4a of the cover 4 which is in contact with the solder sheet, so that a small void where solder does not exist is generated between the cover 4 and the optical fiber. Can be prevented.

Next, it is preferable to form a metallized layer also on the surface of an optical transmission member such as an optical fiber. For example, an optical fiber for communication is usually made of quartz, so that it is not easily wetted directly by solder. Then, when the solder contracts during cooling, the solder surrounding the outer peripheral surface of the optical fiber presses the optical fiber so as to strongly grasp the inside toward the inside. If the pressure is too high, the material of the optical fiber will have slight anisotropy due to the pressure from the solder, which may affect the optical signal propagating through the optical fiber. However, by forming the metallized layer on the surface of the optical fiber, the influence of the pressure due to the shrinkage of the solder hardly reaches the optical fiber.

Next, in the step of melting the solder,
Usually, a temperature of about 250 ° C. to 400 ° C. is required. When the core of the optical fiber is held by the holding substrate and the coating of the optical fiber is not held on the holding substrate, the entire holding substrate is housed in a furnace and heated to 250 ° C. to 400 ° C. No problem.

However, when the core wire of the optical fiber and the coating are supported by a holding substrate (for example, a pigtail type optical fiber array), it is necessary to prevent the coating from dissolving. In this case, it is preferable that the temperature around the optical fiber coating does not increase by locally heating only the holding portion holding the core wire. For this purpose, for example, there is a method in which a holding substrate is placed on a hot plate and only the periphery of the holding section is heated.

Further, if the solder is oxidized during heating, it becomes difficult to wet the metallized layer and the optical fiber. Therefore, it is preferable to keep at least the solder sheet under an inert atmosphere during heating. However, as described above, in order to locally heat only the holding portion of the core of the optical fiber,
When the holding substrate is placed on a hot plate, it is difficult to make the entire periphery of the holding substrate an inert atmosphere. For this reason, it is preferable that an inert gas, preferably a nitrogen gas, be continuously blown over the entire area of the locally heated portion at least during the heat treatment of the solder sheet.

The heating temperature of the solder sheet is the eutectic point of the solder +
It is particularly preferable that the temperature be 20 ° C. or higher and the eutectic point + 50 ° C. or lower. By setting the heating temperature of the solder sheet to be equal to or higher than the eutectic point of the solder + 20 ° C., the penetration of the solder around the optical fiber can be ensured. Further, by setting the heating temperature of the solder sheet to be equal to or lower than the eutectic point of the solder + 50 ° C., the disappearance of the metallized layer on the surface of the holding substrate or the lid can be prevented. For example,
In the case of gold / germanium solder (eutectic point 356 ° C),
The optimum working temperature was about 390 ° C.

In the present invention, it is essential to apply a load to the solder sheet toward the light transmitting member at the time of heating. Since the position of the light transmission member is not determined and moves in the molten solder, it is impossible to fix each optical transmission member at a predetermined position.

The magnitude of the load is preferably 500 g / cm ² or more so that the solder sheet being heated is securely crushed and the fiber is pressed into the V groove.
Further, from the viewpoint of preventing an adverse effect due to the load on the optical transmission member, the content is preferably 2500 g / cm ² or less.

When the solder sheet is heated while applying a load, a part of the molten solder is moved toward the peripheral direction of the upper surface 10 of the holding portion 3b in FIG.
Flow while wetting. At this time, in order to secure the flow on the upper side surface 10 of the solder, it is preferable to make the size of the solder sheet 11 smaller than that of the upper side surface 10 and to provide a metallized layer on the entire surface of the upper side surface 10. .

Next, preferred examples of details of the optical transmission member holding structure that can be manufactured according to the present invention will be further described.
FIG. 6 is a sectional view of a main part showing a state in which the optical fiber 8 is accommodated in a so-called V-groove 13 and the solder sheet 11 is set. FIG. FIG. 4 is a cross-sectional view of a main part showing a state where the display device is fixed to a position.

Each V-groove 13 is formed between substantially triangular projections 14 each having a sharp cross section. The bottom 16 of each V-groove is also quite sharp, but in reality, the bottom 16 has a slight radius because the tip of the grindstone is blunt. As described above, the optical fiber 8 is inserted into each V-groove 13.
To accommodate. At this time, the outer peripheral surface of each optical fiber 8 is in contact with the inclined surface 15 of each projection 14. 17
Is a contact portion between the optical fiber 8 and the inclined surface 15 of the projection 14.

Here, the plane C indicates that each optical fiber 8 is
This is a plane connecting the vertices of the optical fibers 8 when housed in the grooves 13. B denotes each projection 14 for forming a V-groove.
Is a plane connecting the vertices of. Hold the solder sheet 11 to the holding portion 3b
When placed on the top, it is preferable that the apex of each optical fiber be in contact with the solder sheet 11. That is, the plane C is preferably located above the plane B.

The height g of the portion of each optical fiber projecting from the projection is preferably -1 μm to 5 μm, and
-5 μm is particularly preferred. The whole of each optical fiber 8 is V
If the optical fiber 8 is accommodated in the groove and a part of the optical fiber does not protrude above the protrusion, the optical fiber 8 moves in the V groove regardless of the pressure when the solder sheet is crushed. This is because the accuracy tends to decrease. On the other hand, the height of each projection constituting each V-groove is determined by the spacing or pitch of each optical fiber and the opening angle θ of the V-groove, and the diameter of each optical fiber 8 is predetermined. For this reason, it is difficult in design to make g larger than 80 μm.

After heating the solder sheet while applying pressure,
As shown in FIG. 7, the bottom surface 4a of the lid 4 and the protrusion 14 approach each other, the thickness of the solder sheet decreases, and each optical fiber 8
Are held substantially at predetermined positions in the V-shaped groove 13. At this time, in the present invention, by applying pressure downward from the lid 4, each optical fiber 8 can be prevented from floating in the molten solder and rising upward.

In the heating and pressurizing process, a part of the solder constituting the solder sheet flows toward and fills a space 19 between the optical fiber 8 and the projection 14, and the other part is filled. 3, the air flows along the upper surface 10 of the holding portion 3b in the peripheral direction of the upper surface 10. Further, a part of the solder also flows into the space 18 below the optical fiber 8.

At this time, in FIG. 3, since no metallized layer is provided on the side surface 33 and the end surfaces 6 and 34 of the holding portion 3b, excess solder does not flow on them.
Since there is no place for the solder to escape, even when pressure is applied to the solder sheet, the thickness of the solder does not fall below a predetermined value (the reason will be described later). Therefore, in FIG. 7, the distance j between the plane B connecting the vertices of the protrusions 14 and the bottom surface 4a of the lid 4 does not become smaller than a certain value. When a solder sheet having a thickness of 50 μm is used, j is 8 to 3
0 μm.

In order to squeeze the solder sheet until j becomes 1 μm or less, the side face 33 and the end face 6,
A metallized layer can be formed at least on the portion of the upper surface 34 that is in contact with the upper side surface 10, so that the volume of the solder remaining around the groove and the optical fiber can be reduced. As a result, the volume of the solder around each optical fiber can be reduced, and the positional accuracy of each optical fiber can be further improved.

Normally, in FIG. 7, i is 5 to 20 μm
The solder sheet is crushed to a degree, and h is 3 to 10 μm.
Here, D is a plane connecting the vertices of the optical fibers 8, and E is a plane connecting the bottoms 16 of the V grooves 13. Among these dimensions, k and j depend on the thickness and area of the solder sheet and the amount of excess solder that may be present on the side surface. In FIG. 7, reference numeral 21 denotes solder between the optical fiber and the projection.

Next, the present inventor has conceived the following embodiment in the case of the structure shown in FIG. This embodiment will be described. FIG. 8 is a cross-sectional view showing a state before each optical fiber is set in a groove and fixed with solder, and FIG. 9 is a cross-sectional view showing a state where each optical fiber is fixed in the groove with solder. .

The cross section of each groove 26 has a substantially trapezoidal shape.
In each case, a straight inclined surface 15 is formed. In each groove 26, a flat portion 25 is formed between a pair of inclined surfaces 15 of each projection 23. A flat portion 24 is formed at the top of each projection. Such a plane portion 24
Can be formed by grinding the vicinity of the top of each projection 14 as shown in FIG. 7, or can be formed by press molding. Hold the solder sheet 11 to the holding portion 3b
When placed on top, it is preferable that the apex of each optical fiber 8 be in contact with the solder sheet 11.
At this stage, the distance g between the plane B connecting the plane portions 24 of the projections and the plane C connecting the vertices of the optical fibers 8 when each optical fiber 8 is accommodated in the groove 23 is preferably 10 μm or more. , 20 μm to 30 μm.

By subjecting the assembly shown in FIG. 8 to processing according to the present invention, the microstructure shown in FIG. 9 is obtained. However, the reference numerals shown in FIG. 9 are the same as those shown in FIG. The solder melts, flows on the protrusions 23, flows along the inclined surface 15, and flows between the lower side of the optical fiber 8 and the flat portion 25.

As a result, as shown in FIG. 9, each optical fiber 8 is accommodated in the groove 26, and a part of the optical fiber 8 projects on the plane portion 24. Here, in the present embodiment, the solder flows into the space 30 on the flat portion 24 of each projection 23 while the solder flows into the region 29 beside the optical fiber. As a result, the distance j between the bottom surface 4a of the lid 4 and the plane B connecting the vertices of the projections has the same value as described above, and the height h of the protruding portion of the optical fiber with respect to the plane B is 8 μm to 30 μm. We were able to.

When the melting of the solder is completed, the solder 20
Each optical fiber 8 is in a floating state, and the optical fiber tends to be fixed at a position substantially equidistant from the bottom surface 4a and the pair of inclined surfaces 15. According to the present embodiment, the tip of each projection 23 is deleted, the flat portion 24 is formed, and the solder flows into the space 30 above the flat portion 24, so that the embodiment shown in FIGS. In comparison, the solder sheet can be thinly crushed to a position closer to the optical fiber. As a result, the distance i of each optical fiber to the bottom surface 4a can be made extremely small, for example, 1 μm or less, and the displacement of the fixed position of each optical fiber can be made extremely small.

This will be described in more detail. FIG. 10 shows a further extension to the side surfaces 33 and 42 in FIG. Since the side surfaces 33 and 42 are not provided with a metallized layer, the side surfaces 42 and 33 are not wet by the solder. As the solder flows into the region 29 beside the optical fiber, the space 30 on the flat portion 24 of each protrusion 23 is formed.
At this time, the excess solder having no place to go flows between the substrate 3b and the lid 4, and the side surfaces 33 and 4
It flows out between two.

At this time, since the side surfaces 33 and 42 are not metallized, the solder does not wet the side surfaces and swells with a surface tension from the solder layer. 43 is the surplus solder. However, the surface of this surplus solder is oxidized,
The surface tension increases, and more than a certain amount cannot exist. Even in the case of a nitrogen atmosphere, the oxidation of the surplus solder 43 cannot be completely avoided because oxygen content is inevitable to some extent. The surplus solder that can exist is solder that can be deformed (volume change) after melting and solidification from the solder sheet.

The thickness of the solder sheet 11 has a lower limit, and it is difficult to reduce the thickness to 40 μm or less by the current processing technology. As a result of the lower limit of the thickness of the solder sheet 11, it is difficult to reduce the distance between the surface of the fixing substrate and the surface 4a of the lid 4 to a certain extent or more. For example, in FIG. 7, a plane B connecting the vertices of the protrusion 14 and a bottom surface 4 a
Is usually not less than a certain value, and is usually 8 to 30 μm. As a result, in the structure of FIG.
Since the optical fiber floats in the solder toward the bottom surface 4a when the solder is melted, the accuracy of the fixing position of the optical fiber tends to decrease as compared with the structure of FIG.

On the other hand, in the structure shown in FIG.
Since the optical fiber 8 protrudes from the groove 26 by the height h, j is the same as that shown in FIG.
Even if it is about 30 μm, the distance i between the bottom surface 4a of the lid 4 and the optical fiber 8 becomes small. As a result, the accuracy of the fixed position of the optical fiber 8 is significantly improved as compared with the structure shown in FIG.

At the same time, the flat portion 2
Providing 5 makes it easy for the solder to wet the bottom of the groove 26 as well, and the rarely generated void 45 as shown in FIG. 7 is eliminated. As a result, a thin, substantially uniform thickness solder layer was formed between the optical fiber 8 and the projection 23. From the viewpoint that the solder is sufficiently wetted to the bottom of the groove, the width of the flat portion 25 at the bottom is set to 10 μm.
It is preferable to make the above. The maximum value of the width dimension is not particularly limited, but is usually 60 μm or less. Although there is no particular limitation on the depth of the groove, as shown in FIG. 8, in a state where the optical fiber 8 is installed in the groove, the surface of the optical fiber is prevented from directly contacting the flat portion 25, and the optical fiber is placed on the inclined surface 15. It is preferable to hold at two points 17.

In the microstructure shown in FIG. 9, a thin solder layer 28 having a substantially uniform thickness is formed between the optical fiber 8 and the projection 23, and an integrated large solder is provided between the adjacent optical fibers 8. A pool 40 is formed. The solder pool 40 is formed of solder filled in the spaces 29 and 30.

As described above, the entire space between the top surface 10 and the bottom surface 4a of the board is filled with the solder, and the strength is high.
The position stability of the optical fiber is excellent even with temperature changes. This is equivalent to the fact that the optical propagation characteristics during coupling with the optical element are excellent.

Moreover, each optical fiber is securely held down against the wall surface of the groove, and the alignment accuracy of the optical fiber is ensured. This is also sufficient for applications requiring high alignment accuracy such as a single mode optical fiber. Has characteristics.

In the structure shown in FIG. 9, the optical fiber is projected from the plane B, the projections 23 are not sharp, and the gap through which the molten solder flows is large. Until the space between B and the bottom surface 4a is filled, the flow of the solder is easy to flow without being impaired.
The time required until the melting and filling of the solder can be shortened.

In the present invention, it is preferable to fill the entire surface of the substrate upper surface 10 shown in FIG. 3 with solder when the joining of the lid and the substrate with the solder is completed. This maintains the airtightness between the substrate upper surface 10 and the lid bottom surface 4a, and is particularly suitable for an optical component having a structure in which the optical fiber array maintains the airtightness of the package.

[0060]

As described above, according to the present invention, in a holding device for fixing an optical transmission member such as an optical fiber at a predetermined position, each optical transmission member can be reliably used by using solder in a groove. It can be fixed, and in this case, it is possible to prevent a gap from being generated between the optical transmission member and the groove.

[Brief description of the drawings]

FIG. 1A is a front view schematically illustrating an example of a holding device including an optical fiber holding substrate, and FIG.
FIG. 1 is a plan view schematically showing this device, and FIG.
It is the front view when the apparatus of (b) is seen from the left side.

FIG. 2 is a perspective view showing a state in which a predetermined number of grooves 7 are formed on a holding portion 3b of the holding substrate 3 and cores 8 of optical fibers are accommodated in the grooves 7;

FIG. 3 shows an upper surface 10 and an optical fiber 8 of a holding portion 3b.
FIG. 4 is a perspective view showing a state where a solder sheet 11 is placed thereon.

FIG. 4 is a perspective view showing a state in which pressure is applied from above the lid 4 to melt the solder sheet.

FIG. 5 is a perspective view showing an optical fiber holding device obtained by the present invention.

FIG. 6 is a cross-sectional view showing details of a groove shape in the optical fiber holding device according to the embodiment of the present invention.

FIG. 7 is a cross-sectional view showing a state where an optical fiber is fixed in a groove of FIG.

FIG. 8 is a cross-sectional view showing details of a groove shape in an optical fiber holding device according to another embodiment of the present invention.

FIG. 9 is a cross-sectional view showing a state where an optical fiber is fixed in a groove in FIG.

10 is a cross-sectional view for explaining the flow of excess solder 43 in the structure as shown in FIG.

[Explanation of symbols]

Reference Signs List 1 optical fiber holding device, 2 coating of optical fiber, 3, 3A optical fiber holding substrate, 3a coating mounting portion, 3b holding portion of holding substrate 3, 6, 34 end face of holding portion 3b, 7 groove, 8 optical fiber (core wire), 10 Top surface of holding portion 3b, 11 solder sheet, 13 V groove, 14 protrusion, 15 inclined surface of protrusion, 16 bottom of V groove 13, 17 optical fiber 8
Contact portion with the inclined surface 15 of the projection, 20 solder, 2
3 Projection, 24, 25 flat part, 26 groove, 30
33 space on the plane portion 24 of each projection 23, 33 holding portion 3
b side surface, 36 hot plate, 40 solder pool, 43 surplus solder, A pressure application direction, plane connecting the apexes of each protrusion for forming B groove, C when each optical fiber 8 is accommodated in V groove A plane connecting the vertices of the optical fibers 8; g the height of the portion of each optical fiber projecting from the protrusion; j a plane B connecting the vertices of the protrusion
, The gap between the lid 4 and the bottom surface 4a, the opening angle of the θ V groove

Claims (7)

[Claims] 1. A method for manufacturing an optical transmission member holding device including a holding substrate holding a plurality of optical transmission members at predetermined positions, wherein the optical transmission member is accommodated in the holding substrate, A groove for fixing is provided, the optical transmission member is accommodated in the groove, a solder sheet is placed on the groove and the optical transmission member, and the solder sheet is applied toward the groove. A method of manufacturing an optical transmission member holding device, characterized in that by heating while pressing, solder flows into and fills a gap between the groove and the optical transmission member, and fixes the optical transmission member at a predetermined position. . 2. The method according to claim 1, wherein said solder sheet is made of a gold-based eutectic solder. 3. A method for manufacturing an optical transmission member according to claim 1, wherein a metallized layer is formed on a surface of said optical transmission member. 4. The optical transmission according to claim 1, wherein a lid is provided on the solder sheet, and pressure is applied to the solder sheet from the lid. A method for manufacturing a member holding device. 5. The apparatus according to claim 5, wherein said lid and a surface of said holding substrate,
The method for manufacturing an optical transmission member holding device according to claim 4, wherein a metallized layer is formed at least in each of the portions where the two are in contact with each other. 6. The optical transmission member is an optical fiber, and the holding substrate holds a core wire of the optical fiber in the groove, and a coating mounting portion mounting a coating of the optical fiber. The method according to any one of claims 1 to 5, further comprising: locally heating the holding unit. 7. The method according to claim 1, wherein the heating of the solder sheet is performed in an inert gas atmosphere.