JP2003195063A - Optical fiber component for connection and method of manufacturing the same - Google Patents

Abstract

(57) Abstract: The present invention aims to prevent an increase in light loss, a decrease in flexibility, a decrease in mechanical strength, and an increase in weight, which occur when reinforcing a connection portion of an optical fiber. The present invention provides an optical fiber component for connection. A connection optical fiber component and a method of manufacturing the same according to the present invention cover a substrate on which a connection portion of an optical fiber is mounted and an optical fiber on the substrate with a foamable silicone resin.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical fiber component for connecting optical components, boards, and frames with an optical fiber.

[0002]

2. Description of the Related Art Up to now, various connecting optical fiber parts for connecting optical parts, boards, and racks have been constructed by preliminarily designing an optical fiber on a flexible resin film substrate. Wiring is the mainstream. As a method of fixing the optical fiber after wiring, a sandwich type in which the optical fiber is sandwiched between the substrate films, an embedded type in which the optical fiber arranged on the substrate is embedded with a thermoflexible resin, etc. It is an optical fiber component for connection.

However, the sandwich type is
The difference in the amount of expansion due to bending between the upper and lower films centering on the optical fiber, that is, when the connecting optical fiber component is bent, the inner side of the bend contracts and the outer side applies force in the extending direction, making it difficult to bend Also, stress is applied to the optical fiber, which causes an increase in optical loss.

Further, in the sandwich type proposed so far, since a material having a small elasticity is used for the substrate film, when stress is applied in a direction perpendicular to the connecting optical fiber component, the stress is directly applied to the optical fiber. In particular, when stress is applied to the intersection of the optical fibers, it causes an increase in optical loss.

Further, the embedded type has the drawbacks that stress is applied to the optical fiber when the resin is cured, loss variation is likely to occur due to temperature changes, and there is no flexibility with respect to bending. The optical fiber parts for implantable connection using a silicone resin as an embedding material, which the inventors invented to improve the drawbacks of the conventional implantable type, have a small curing shrinkage and have flexibility even after curing. Have the advantages of.

However, the optical fiber parts for embedded connection using a silicone resin are not necessarily high in mechanical strength against external forces such as scratches and cuts. Further, in the case of the embedded type optical fiber component using the silicone resin, if the structure is such that the optical fiber is completely embedded, the weight of the resin is large and the A4 size (210 mm × 2
(97 mm) for connecting optical fiber parts, when resin is embedded in a thickness of 2 mm, the weight is about 120 g. Therefore, it is necessary to consider the weight and take measures to support the weight and prevent bending due to its own weight.

It is also assumed that the connecting optical fiber component is wired in a limited space and that the connecting optical fiber component body is mounted in a bent state. Therefore,
An increase in bending loss and a decrease in flexibility are major problems.

In the inter-board wiring, the connecting optical fiber parts are installed outside the rack housing the boards for connecting the boards, so that the connecting optical fiber parts are accidentally hooked or pushed during the work. It is assumed that the mechanical strength is weak, which is a problem. Furthermore, if a large-sized optical fiber component for connection in the wiring between the frames or the wiring between the boards is embedded, the weight becomes large, which is a mounting problem.

As described above, the above-mentioned problems are important to be solved in all aspects of optical characteristics, reliability, and mountability in the connecting optical fiber component. The connection optical fiber parts proposed so far have not realized all of these problems.

[0010]

DISCLOSURE OF THE INVENTION The present invention is applied to a sandwich type in which an increase in light loss due to stress during curing found in an embedded type, a decrease in flexibility, a mechanical strength against a notch, an adverse effect due to the weight of resin, and a sandwich type. In order to solve the increase in optical loss due to the bending stress and the increase in optical loss due to the stress applied in the direction perpendicular to the substrate, we have developed a connecting optical fiber component that achieves good optical characteristics, high reliability, and high mountability. The purpose is to provide.

[0011]

In order to achieve the above-mentioned object, in the invention described in claim 1, the substrate of the connecting optical fiber component and the optical fiber wired on the substrate are covered with a foaming silicone resin. It is characterized by that.

According to a second aspect of the invention, in the connecting optical fiber component according to the first aspect, the optical fiber is wired on one side of the substrate, and both sides of the substrate and the wired optical fiber are made of a foaming silicone resin. Characterized by being covered.

According to a third aspect of the invention, in the connecting optical fiber component according to the first or second aspect, the foaming silicone resin has a foaming ratio of 1.1 to 15 times, preferably 1.1 times. It is characterized by being 7 times.

According to the invention described in claim 4,
In the optical fiber component for connection described in 2 or 3, the sheet body of the foamable silicone resin molded to cover the substrate and the optical fiber wired on the substrate has a skin layer on both sides or one side. And, it is characterized in that it is a closed cell.

According to a fifth aspect of the invention, in the connecting optical fiber component according to the first or second aspect, a flexible material or an elastic material is adhered and formed at the intersection of the optical fibers wired on the substrate. It is characterized by having done.

According to a sixth aspect of the invention, in the connecting optical fiber component of the fifth aspect, the flexible material or the elastic material is liquid or paste at room temperature before curing, and after curing, It is characterized by being adhered or adhered to a foamable silicone resin.

In a seventh aspect of the present invention, a foaming silicone resin composed of a main agent and an auxiliary agent is mixed and stirred, and then the substrate and the optical fiber wired on the substrate are covered with the foaming silicone resin to form the foaming agent. 7. The method for producing an optical fiber component for connection according to claim 1, wherein the silicone resin is foamed and cured at room temperature.

In the invention described in claim 8, after the foamable silicone resin composed of the main agent and the auxiliary agent is mixed and stirred, the substrate and the optical fiber wired on the substrate are covered with the foamable silicone resin to form the foamable silicone resin. 7. The method of manufacturing an optical fiber component for connection according to claim 1, wherein the silicone resin is foamed and cured by heating.

According to a ninth aspect of the invention, in the method of manufacturing the connecting optical fiber component according to the seventh or eighth aspect,
It is characterized in that the main agent and the auxiliary agent, which are liquid, are mixed and stirred between −50 degrees Celsius and 100 degrees Celsius.

The respective configurations can be combined as much as possible. The composition of the foamable silicone resin is composed of polyorganosiloxane, a filler, water, a catalyst, and an additive, which forms the skeleton of the resin, and is a so-called liquid silicone foam. The expansion ratio refers to the ratio of the volume after foaming to the volume of silicone resin before foaming. Closed bubbles are bubbles having a wall between adjacent bubbles. The skin layer means a smooth skin-like layer, rather than the surface of the silicone resin having an uneven surface in which bubbles are broken. Foam hardening refers to hardening the foamable silicone resin in a foamed state. In the present invention, normal temperature refers to 5 degrees Celsius to 45 degrees Celsius, and heating refers to 50 degrees Celsius to 100 degrees Celsius.
It means to make a degree.

[Operation] When a plurality of optical fibers are wired on a substrate in accordance with a predesigned pattern and the optical fibers wired to the substrate are covered with a foamable silicone resin,
Since the flexibility is extremely high, the stress applied to the optical fiber when the connecting optical fiber component is bent can be suppressed to be small, and the excess optical loss at the time of bending can be reduced. In addition, since the expandable silicone resin is composed of small cells configured to surround a gas such as air, that is, cells in which so-called bubbles are hardened, the shearing property of a normal silicone resin is improved, and a sharp angle is obtained. Even if the connecting optical fiber parts are bent, cracks are hardly seen. The fact that the bubbles are closed cells also has the effect of improving the shearing property. Further, even if a crack should occur, the cracks do not spread widely because the cells existing on the surface or in the vicinity are crushed to suppress the progress of the crack.

Further, since this cell plays the role of a cushion, it has a characteristic that elasticity is very large, and also has a function of protecting the optical fiber from external force when external force is applied to the connecting optical fiber component. ing. In addition, the fact that the surface of the silicone resin is not the surface of the bumpy and broken uneven surface but is covered with a smooth skin layer also has a great effect in suppressing the occurrence of cracks.

By using the foamable silicone resin, it is possible to expect an effect that the weight becomes smaller than that of an ordinary resin. For example, when the density of the foamable silicone resin after curing is about 0.2 g / cm ³ (5 times foaming assuming the liquid specific gravity is 1), the weight of the foamed silicone resin is smaller than that of a silicone resin of the same thickness. It becomes about 1/5. Foaming ratio is 1.1
It is suitable to be double to fifteen times. Preferably 1.1 to 7
Double. When the expansion ratio is 1.1 to 15 times, the mechanical strength that can stand by itself is maintained, and when the expansion ratio is 1.1 to 7 times, the strength that can withstand the applied pressure can be further maintained. As described above, by using the foamable silicone resin, the weight can be reduced while maintaining the mechanical characteristics. Therefore, a large area connecting optical fiber component such as a connecting optical fiber component applied for connecting between racks can be obtained. Then, the effect becomes larger. In this way, the expansion ratio is 1.1 to 15 times, so that the above weight saving is realized.

As described above, since the expandable silicone resin has a small weight and is flexible, it is possible to cover both surfaces of the connecting optical fiber component with the expandable silicone resin.
As a result, by using the same material for both surfaces of the substrate of the connecting optical fiber component, the bendability of the entire connecting optical fiber component is improved and the stress applied to the optical fiber is relaxed.

Further, among various foaming resins, silicone foam is flame retardant, weather resistant, heat resistant, solvent resistant,
It has excellent properties in compression set and harmlessness of combustion gas. For example, the compression set is 70 degrees Celsius, which is 30% and 60% for chloroprene foam and fluororubber foam, respectively, while silicone foam is as small as several%. Even if a halogen-based, phosphorus-based, or inorganic flame-retardant is used for phenol foam and urethane foam, the oxygen index, which is a measure of flame retardancy, is about 32% and 30% at the maximum, respectively. On the other hand, silicone foam is the largest with a maximum of 35% and has high flame retardancy. Flame retardancy is an essential item when connecting optical fiber parts are used in communication devices. Further, environmental resistance, heat resistance, and solvent resistance are also very important from the viewpoint of ensuring the reliability of the connecting optical fiber component. Further, mechanical strength and flexibility are also important items from the viewpoint of mountability and workability. Therefore, the connecting optical fiber component covered with the foaming silicone resin satisfying these requirements is very practical.

The method for producing the connecting optical fiber component is characterized in that the foamable silicone resin is foamed and cured at room temperature. However, curing at room temperature does not require a constant temperature bath and can reduce the manufacturing cost. it can. Furthermore, since the connecting optical fiber component has a multilayer structure of a protective layer made of silicone and a substrate having an adhesive property, the temperature difference between the curing temperature during production and the temperature during use is reduced,
Unnecessary bending of the connecting optical fiber component body can be reduced, leading to stabilization of optical characteristics.

If there are no such concerns, there is a feature that the product can be manufactured in a short time by curing at a high temperature. Since it can be manufactured in a short time, the manufacturing cost can be reduced.

It is also within the scope of the present invention that the main agent and auxiliary agent of the foamable silicone resin are liquid at temperatures between -50 ° C and 100 ° C, and particularly at room temperature. The fact that the foamable silicone is liquid at room temperature is practically useful in that it enables mounting in accordance with the complicated shape of the connecting optical fiber component. In addition, by dividing the product into two packaging types, by mixing a highly foamable material immediately before use, it is possible to shorten the foaming time and to optimize the amount of the material used, thus reducing the product cost. It becomes possible to price.
The two-pack type means that the materials are initially stored in two packages and are mixed at the time of use.

In the connecting optical fiber component, when a flexible material or an elastic material is adhered and formed on a portion where a plurality of wired optical fibers intersect and overlap each other, the optical fiber is protected from external force or stress. Therefore, the optical fiber can be doubly protected by the protection by the flexible material or the elastic material and the protection by the foaming silicone resin.

The composition of the flexible material or the elastic material to be adhered and formed is composed of polyorganosiloxane forming a resin skeleton, a filler, a catalyst, and an additive, which is so-called liquid silicone rubber. It is what

When a plurality of optical fibers are wired on the substrate of the connecting optical fiber component, there is a portion where the optical fibers intersect and overlap with each other. However, since the optical fibers are in contact with each other at the overlapping portion, external force or stress is not generated. The optical loss is increased in the optical fiber by concentrating at the intersection and generating microbends.
If a flexible material or an elastic material is adhered and formed on this portion, microbending will not occur due to external force or stress, and the increase in optical loss of the optical fiber can be further alleviated.

The flexible or elastic material deposited is
The fact that it is liquid or paste at room temperature before curing makes it easy to adhere and form it at the intersection of the optical fibers.
Furthermore, when the adhered or formed flexible material or elastic material adheres or adheres to the foamable silicone resin covering the same, it is possible to prevent external force or stress from concentrating on one place.

[0033]

EXAMPLES Examples of the present invention will be described below, but in any of the examples, the action and effect of the invention do not depend on the wiring pattern of the optical fiber of the connecting optical fiber component. (Example 1) Fig. 1 shows a schematic view of a connecting optical fiber component according to this example. Optical fiber wiring device
-119034), the substrate 12 of the lowermost layer is installed, and the optical fibers 11 are wired one by one. Here, the substrate has a thickness of 50
A polyethylene terephthalate (PET) or polyimide film having a thickness of 50 μm coated with a rubber adhesive was used. Next, a foamable silicone resin before foaming (TOSFOAM 53 manufactured by GE Toshiba Silicone Co., Ltd.)
10 (A) and (B)) are mixed at a predetermined mixing ratio, and then applied so as to cover the optical fiber 11 on the substrate 12 with a commercially available injection device (shot master 3 manufactured by Musashi Engineering Co., Ltd.) and uniformly. did. After application, the temperature was set to 40 degrees Celsius and foaming was performed for 20 minutes. By the above manufacturing method, a connecting optical fiber component covered with the foamable silicone resin 13 was obtained.

The characteristics of the resulting connecting optical fiber component covered with the foamable silicone resin are shown in Table 1. As a comparative example, a sandwich type measurement result of the same wiring pattern using a polyimide film is shown.

[Table 1] From the results shown in Table 1, although the connecting optical fiber component covered with the foamable silicone resin of the present invention is equivalent to the conventional sandwich type connecting optical fiber component in the environmental test, the bending stress test and the vertical stress test are performed. Showed good characteristics.
Further, this result is almost the same as the conventional embedded type using a flexible resin, but the weight of the connecting optical fiber component is about 1
Since it is less than / 2, the weight is greatly reduced.

Example 2 In this example, a foaming silicone resin before being foamed by an injection device was applied and foamed on both surfaces of the connecting optical fiber component. FIG. 2 shows a connecting optical fiber component obtained by covering the both surfaces with a foamable silicone resin. As shown in FIG.
Both sides of the substrate 12 are covered with a foamable silicone resin. Table 2 shows the result of the same test as in Example 1 performed on the optical fiber part for connection. The comparative example is the same as the example 1. As shown in Table 2, even when the foamable silicone resin was applied to both surfaces of the connecting optical fiber component, good results could be obtained.

Further, it has been found that the stress required for bending the connecting optical fiber component is about 10% smaller than that for the case where the foamable silicone resin is applied on one side. As a result, when the connecting optical fiber component is mounted while being bent, the work force is improved because the force required for bending is small.

[Table 2]

(Embodiment 3) The connecting optical fiber component in which the optical fiber 11 is wired on the flexible substrate 12 is dipped in a foamable silicone resin solution before foaming, and both surfaces are coated in the same manner as in Embodiment 2. A foamable silicone resin was applied. Then, an optical fiber component for connection was obtained, which was heat-foamed and had a silicone resin foamed on both sides as a protective film. FIG. 3 shows the optical fiber component for connection, the both surfaces of which thus obtained are covered with the foaming silicone resin. As shown in FIG. 3, both sides of the substrate 12 are covered with a foamable silicone resin. The results of the environment resistance test, the bending stress test, and the vertical stress test were similar to those of Example 2. Further, the foamable silicone resin on both sides is seamlessly connected in the thickness direction and has a structure that covers the entire both sides, and the effect of protecting against external force and stress is further enhanced.

(Example 4) The optical fiber 11 was wired on the flexible substrate 12, and a foamable silicone resin sheet having a thickness of 2 mm cut according to the shape of the substrate 12 was adhered thereon by an adhesive. An optical fiber component for connection covered with the foamable silicone resin sheet thus obtained is shown in FIG. As the adhesive used at this time, a silicone adhesive sealant (GE Toshiba Silicone Co., Ltd., TSE3843-W) that retains elasticity after curing was used.

The same results as in Example 1 were obtained for the environment resistance test, bending stress resistance test, and vertical stress resistance test of the optical fiber part for connection thus produced. Further, instead of adhering with an adhesive, a foaming silicone resin having a thickness of 2 mm is provided with an adhesive layer on one side, and the same effect can be obtained by covering the substrate 12.

(Embodiment 5) The optical fiber 11 is wired on the flexible substrate 12, and a silicone adhesive seal having excellent flexibility and elasticity is provided at a position where the optical fibers intersect and a position where the optical fibers overlap each other. Agent (GE Toshiba Silicone,
TSE3843-W) was adhered and formed so that the height was about the same (500 μm or more) as the overlapping height of the optical fibers.
After that, the foamable silicone resin sheet having the adhesive layer of Example 4 on one surface was cut wider than the shape of the substrate 12, and bonded from above the silicone adhesive sealant to produce a connecting optical fiber component. FIG. 5 shows a connecting optical fiber component covered with the foamable silicone resin sheet thus obtained. In FIG. 5, the adhesive layer is not shown.

Since the connecting optical fiber component manufactured in this manner covers the crossing portion of the optical fiber with a silicone resin having high flexibility and elasticity, it has higher reliability against external force and stress. . The same results as in Example 2 were obtained for the environment resistance test, bending stress resistance test, and vertical stress resistance test of the optical fiber component for connection thus manufactured.

[0042]

As described above, according to the present invention, by using the foamable silicone resin, it is possible to reduce the weight, flexibility, and mechanical strength of the connecting optical fiber component, and It is possible to realize a connecting optical fiber component having high reliability, mountability, and reliability.

[Brief description of drawings]

FIG. 1 An example of a connecting optical fiber component in which a foamable silicone resin is applied only to the surface on which the optical fiber is wired.

[Fig. 2] Example of connecting optical fiber parts coated with expandable silicone resin on both sides

[Fig. 3] Example of optical fiber component for connection completely wrapped with foamable silicone resin by dipping

FIG. 4 is an example of an optical fiber component for connection in which a foamable silicone resin sheet is bonded with an adhesive.

FIG. 5 is an example of an optical fiber component for connection in which a silicone adhesive sealant having elasticity is adhered to an intersection of optical fibers and a foamable silicone resin sheet is adhered.

[Explanation of symbols] 11 Optical fiber or tape optical fiber 12 Optical fiber component substrate for connection 13 Expandable silicone resin 14 Adhesive 15 Flexible or elastic material

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Yoshi Kurosawa             1-12-1 Dogenzaka, Shibuya-ku, Tokyo             Titi Electronics Co., Ltd. (72) Inventor Takashi Yoshida             1-12-1 Dogenzaka, Shibuya-ku, Tokyo             Titi Electronics Co., Ltd. (72) Inventor Fumihiro Arai             6-2-1 Roppongi, Minato-ku, Tokyo GE             Within Toshiba Silicone Co., Ltd. F-term (reference) 2H038 CA52

Claims (9)

[Claims] 1. An optical fiber component for connection, characterized in that a substrate and an optical fiber wired on the substrate are covered with a foaming silicone resin. 2. The optical fiber component for connection according to claim 1, wherein an optical fiber is wired on one surface of the substrate, and both surfaces of the substrate and the wired optical fiber are covered with a foaming silicone resin. 3. The optical fiber for connection according to claim 1, wherein the foaming silicone resin has a foaming ratio of 1.1 times to 15 times, preferably 1.1 times to 7 times. parts. 4. The sheet body of the foamable silicone resin molded to cover the substrate and the optical fiber wired on the substrate has skin layers on both sides or one side, and is a closed cell. The optical fiber component for connection according to claim 1, 2, or 3. 5. The connecting optical fiber component according to claim 1, wherein a flexible material or an elastic material is adhered and formed at an intersecting portion of the optical fiber wired on the substrate. 6. The flexible material or the elastic material according to claim 5, wherein the flexible material or the elastic material is liquid or paste at room temperature before curing, and adheres or adheres to the foamable silicone resin after curing. Optical fiber parts for connection. 7. A foamable silicone resin comprising a main agent and an auxiliary agent is mixed and stirred, and then the substrate and the optical fiber wired on the substrate are covered with the foamable silicone resin, and the foamable silicone resin is foamed and cured at room temperature. The method for manufacturing a connecting optical fiber component according to claim 1, wherein 8. A foaming silicone resin comprising a main agent and an auxiliary agent is mixed and stirred, and then the substrate and the optical fiber wired on the substrate are covered with the foaming silicone resin, and the foaming silicone resin is heated and foamed and cured. The method for manufacturing a connecting optical fiber component according to claim 1, wherein 9. The method for producing an optical fiber component for connection according to claim 7, wherein the main agent and the auxiliary agent, which are liquid, are mixed and stirred between −50 degrees Celsius and 100 degrees Celsius. .