JP2014085417A - Ferrule and optical waveguide assembly - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a ferrule which is easy to manufacture and suitable for mass production, and an optical waveguide assembly including the ferrule.SOLUTION: A ferrule 6A is attached, for use, to a tip part 31 of an optical waveguide 3 including core parts 34a to 34c and clad parts 35a to 35d provided so as to surround the core parts 34a to 34c, and having a belt-like shape as a whole. The ferrule 6A includes: a ferrule body 60 having an inner cavity 61 opened on the base end side and inserted with the tip part 31 of the optical waveguide 3, and a tip wall part 62 positioned at the tip side of the inner cavity 61; and lenses 4a to 4c provided on the tip wall part 62 and made of a light transmissive material having optical transparency. In the ferrule body 60, at least the tip wall part 62 is made of the light transmissive material and formed integrally with the lenses 4a to 4c.

Description

  The present invention relates to a ferrule and an optical waveguide assembly.

  In recent years, optical communications that transport data using optical frequency carriers have become increasingly important. In such optical communication, an optical fiber is used as a means for guiding signal propagating light propagating a signal from one point to another point.

  This optical fiber is composed of, for example, a linear core part and a clad part provided so as to surround the core part. This optical fiber is connected to another optical fiber in a state where a ferrule is attached to the tip (see, for example, Patent Document 1).

  The ferrule described in Patent Document 1 includes a ferrule body having a lumen portion into which a tip portion of an optical fiber is inserted, and a lens that is configured separately from the ferrule body and inserted into the lumen portion. Yes. The ferrule body and the lens are fixed via an adhesive.

  However, when manufacturing the ferrule described in Patent Document 1, since the ferrule body and the lens are separate, it has a process of manufacturing the ferrule body and a process of manufacturing the lens. A process of fixing and assembling the lens with an adhesive is required.

  These processes are time consuming and expensive to manufacture, and are problematic in mass production of inexpensive products.

Japanese Patent Laid-Open No. 5-113519

  An object of the present invention is to provide a ferrule that is easy to manufacture and suitable for mass production, and an optical waveguide assembly including the ferrule.

Such an object is achieved by the present inventions (1) to (15) below.
(1) A ferrule that has at least one core part and a clad part provided so as to surround the core part, and is used by being attached to a distal end part of an optical waveguide having a long overall shape. ,
A ferrule body that has a lumen portion that is open on the proximal end side and into which the distal end portion of the optical waveguide is inserted, and a distal end wall portion that is located on the distal end side of the lumen portion;
Including at least one lens provided on the tip wall portion and made of a light-transmitting material having light-transmitting properties;
The ferrule body has at least the tip wall portion made of the light transmissive material and is formed integrally with the lens.

(2) The optical waveguide has a strip shape as a whole,
The ferrule main body includes the tip wall portion, a top plate and a bottom plate facing in the thickness direction of the optical waveguide, and a pair of side wall portions facing in the width direction of the optical waveguide. The ferrule described in.

  (3) The ferrule according to (2), wherein the top plate, the bottom plate, and the pair of side wall portions are made of the light transmissive material.

  (4) The ferrule according to (2) or (3), wherein the tip wall portion, the top plate, the bottom plate, and the pair of side wall portions are integrally formed.

  (5) The ferrule according to any one of (1) to (4), wherein the lens has a convex surface that protrudes further toward the tip side than the tip surface of the tip wall portion.

(6) The optical waveguide has a plurality of the core portions,
The ferrule according to any one of (1) to (5), wherein one lens is provided corresponding to each of the core portions.

  (7) The ferrule according to any one of (1) to (6), wherein a surface on a proximal end side of the distal end wall portion is in contact with a distal end surface of the optical waveguide.

(8) The ferrule body and the optical waveguide are fixed via an adhesive,
In the vicinity of the boundary portion between the ferrule body and the tip wall portion, a through-hole is formed which communicates with the lumen portion and stores or discharges an excess of the adhesive. Ferrule according to any of the above.

  (9) The above (1) to (1), further comprising positioning means for positioning the connector so as to be separated from the lens in a connected state in which a connector having a light guide path optically connected to the optical waveguide is connected to the ferrule. The ferrule according to any one of (8).

  (10) The ferrule according to (9), wherein the positioning unit is formed to project from the distal end wall portion in the distal direction, and is configured by a projecting portion that contacts the connector in the connected state.

(11) The protruding portion has a plate shape,
The ferrule according to (10), wherein the protrusion is formed so as to surround the lens, and the thickness of the protrusion is gradually increased toward the proximal direction.

  (12) The ferrule according to (10) or (11), wherein the protruding portion is made of the light transmissive material and is formed integrally with the tip wall portion.

(13) The ferrule body is bonded to the optical waveguide via an adhesive,
The ferrule according to any one of (1) to (12), wherein the ferrule body is formed with an adhesive inlet that communicates with the lumen and injects the adhesive into the lumen.

  (14) The lumen portion according to any one of (1) to (13), wherein the lumen portion has an opening portion at a proximal end portion where a distance in the thickness direction of the optical waveguide gradually increases toward the proximal end direction. Ferrule.

(15) a long optical waveguide;
An optical waveguide assembly comprising: the ferrule according to any one of (1) to (14), which is attached to a distal end portion of the optical waveguide.

  According to the present invention, at least the tip wall portion of the ferrule body is made of a light transmissive material and is formed integrally with the lens. This configuration is relatively easy to manufacture and relatively inexpensive to manufacture, as compared to the case where the ferrule body and the lens are configured separately. Therefore, it is suitable for mass production.

  Further, when the tip wall portion, top plate, bottom plate, and the pair of side wall portions constituting the ferrule body are made of a light-transmitting material and these are integrally formed, the manufacture is easier. Cost is also cheaper. Therefore, it is more suitable for mass production.

  Further, when the lumen portion has an opening at the proximal end where the distance in the thickness direction of the optical waveguide gradually increases toward the proximal end, an external force is applied to the portion facing the opening of the optical waveguide. Even so, the portion facing the opening of the optical waveguide can be curved and deformed as much as the opening is formed. Thereby, sharp bending of the optical waveguide can be prevented. Therefore, the original high transmission characteristics of the optical waveguide can be maintained.

It is a perspective view which shows the optical transmission board | substrate provided with 1st Embodiment of the optical waveguide assembly (ferrule) of this invention. It is a longitudinal cross-sectional view which shows the optical transmission board | substrate provided with 1st Embodiment of the optical waveguide assembly (ferrule) of this invention. It is a longitudinal cross-sectional view which shows the optical transmission board provided with 2nd Embodiment of the optical waveguide assembly (ferrule) of this invention. It is a longitudinal cross-sectional view which shows the optical transmission board | substrate provided with 3rd Embodiment of the optical waveguide assembly (ferrule) of this invention.

  Hereinafter, the ferrule and optical waveguide assembly of the present invention will be described in detail based on preferred embodiments shown in the accompanying drawings.

<First Embodiment>
FIG. 1 is a perspective view showing an optical transmission board provided with a first embodiment of the optical waveguide assembly (ferrule) of the present invention, and FIG. 2 shows the first embodiment of the optical waveguide assembly (ferrule) of the present invention. It is a longitudinal cross-sectional view which shows the provided optical transmission board | substrate. 1 and 2, the upper side is referred to as “upper” or “upper”, and the lower side is referred to as “lower” or “lower”. In addition, the left side of FIGS. 1 and 2 is referred to as a “tip”, and the right side is referred to as a “base end”. 1 and 2, the vertical direction (thickness direction) of the optical transmission board is exaggerated.

  As shown in FIGS. 1 and 2, the optical transmission board 1 includes a board 5 and an optical waveguide assembly 2 </ b> A disposed on the board 5. The optical waveguide assembly 2 </ b> A includes an optical waveguide 3 having a long shape (band shape) and a ferrule 6 </ b> A attached to the optical waveguide 3. The ferrule 6 </ b> A is provided with lenses 4 a to 4 c corresponding to the core portions 34 a to 34 c of the optical waveguide 3. Further, the tip portion 31 of the optical waveguide 3 is inserted into the ferrule 6A, and the connector portion 7A is configured in the inserted state. The connector portion 7A is used by being connected to the connector portion 7B of the optical fiber assembly 2B which is a counterpart to be connected. Hereinafter, a state where the connector portion 7A is connected to the connector portion 7B is referred to as a “connected state”. In the present embodiment, light is directed from the optical waveguide assembly 2A to the optical fiber assembly 2B in the connected state.

Hereinafter, the configuration of each unit will be described.
First, the substrate 5 will be described. As shown in FIGS. 1 and 2, the substrate 5 has a function of supporting each part constituting the optical transmission substrate 1, and the optical waveguide 3 is installed on the upper surface 50.

  As shown in FIG. 2, the substrate 5 includes a first insulating layer 51, a first conductor pattern (conductor circuit) 52, a second insulating layer 53, and a second conductor pattern (conductor circuit) 54. And a third insulating layer 55, a third conductor pattern (conductor circuit) 56, and a coating layer (solder resist layer) 57, which are laminated (arranged) from below in this order. Consists of the body.

  In addition, the total thickness of the board | substrate 5 is not specifically limited, For example, it is preferable that it is 0.25-3.2 mm, and it is more preferable that it is 0.5-1.5 mm.

  Each of the first conductor pattern 52, the second conductor pattern 54, and the third conductor pattern 56 is made of a conductive metal material and is electrically connected to each other. Any one of the first conductor pattern 52, the second conductor pattern 54, and the third conductor pattern 56 is configured to be connected to a power source or a control device (not shown). ing.

  Each conductor pattern can be formed, for example, by etching a metal foil into a predetermined pattern. Moreover, it does not specifically limit as metal foil, For example, copper foil can be used suitably. Thereby, each conductor pattern has a relatively small resistance value.

  The first insulating layer 51 is a layer that insulates the first conductor pattern 52 from the outside. The second insulating layer 53 is a layer that insulates the first conductor pattern 52 and the second conductor pattern 54. The third insulating layer 55 is a layer that insulates the second conductor pattern 54 and the third conductor pattern 56. By such each insulating layer, the unintentional short circuit (short circuit) of each conductor pattern can be prevented reliably.

  The covering layer 57 is formed so as to cover at least a part of the third conductor pattern 56. Thereby, the 3rd conductor pattern 56 can be protected, Therefore For example, degradation and the short circuit of the 3rd conductor pattern 56 can be prevented.

  In addition, although it does not specifically limit as a constituent material of the 1st insulating layer 51, the 2nd insulating layer 53, the 3rd insulating layer 55, and the coating layer 57, For example, various resin materials are mentioned, Especially an epoxy resin is mentioned. Phenol resin is preferred.

  Moreover, in this embodiment, although the board | substrate 5 is comprised by the above laminated bodies, it is not restricted to this, A single layer structure may be sufficient.

  As shown in FIGS. 1 and 2, the optical waveguide 3 is disposed on the upper surface 50 of the substrate 5. The optical waveguide 3 has a strip shape as a whole.

  The optical waveguide 3 includes a clad layer (first clad layer (clad part)) 33a, a core layer 32, and a clad layer (second clad layer (clad part)) 33b. They are laminated in order from the bottom.

  As shown in FIG. 1, the core layer 32 includes a plurality of (three in the present embodiment) core portions (waveguide channels) 34a, 34b, 34c, and a plurality (in the present embodiment). There are four side clad portions (cladding portions) 35 a, 35 b, 35 c, and 35 d, which are alternately arranged in the width direction of the optical waveguide 3. Thus, the optical waveguide 3 constitutes a multichannel type having a plurality of core portions.

  The core portions 34a to 34c and the side clad portions 35a to 35d have different light refractive indexes, and the difference in the refractive indexes is not particularly limited, but is preferably 0.5% or more, and 0.8%. The above is more preferable. The upper limit value may not be set, but is preferably about 5.5%.

  The core portions 34a to 34c are made of a material having a higher refractive index than the side clad portions 35a to 35d, and are also made of a material having a higher refractive index than the cladding layers 33a and 33b.

  The constituent materials of the core portions 34a to 34c and the side clad portions 35a to 35d are not particularly limited. In the present embodiment, the core portions 34a to 34c and the side clad portions 35a to 35d are made of the same material, and the difference in refractive index between them is expressed by the difference in the chemical structure of the material constituting each portion. Yes.

  Any material can be used as a constituent material of the core layer 32 as long as it is a material that is substantially transparent to light passing through the core portions 34a to 34c. In addition to various resin materials such as olefin resin, polycarbonate, polystyrene, epoxy resin, polyamide, polyimide, polybenzoxazole, polysilane, polysilazane, and cyclic olefin resin such as benzocyclobutene resin and norbornene resin, quartz glass A glass material such as borosilicate glass can be used.

  Among these, in order to express a difference in refractive index due to a difference in chemical structure as in the present embodiment, the refractive index changes by irradiation with active energy rays such as ultraviolet rays and electron beams (or by further heating). Preferably it is a material.

  As such a material, for example, the chemical structure changes due to, for example, at least part of the bond being cut or bound or at least part of the functional group being desorbed and modified by irradiation with active energy rays or heating. Possible materials are listed.

  Specifically, silane-based resins such as polysilane (eg, polymethylphenylsilane), polysilazane (eg, perhydropolysilazane), and the resin serving as a base for materials with structural changes as described above include molecules on the molecular side. The following resins (1) to (6) having a functional group at the chain or terminal may be mentioned. (1) Addition (co) polymer of norbornene type monomer obtained by addition (co) polymerization of norbornene type monomer, (2) Addition copolymer of norbornene type monomer and ethylene or α-olefins, (3) An addition copolymer of a norbornene-type monomer and a non-conjugated diene and, if necessary, another monomer, (4) a ring-opening (co) polymer of a norbornene-type monomer, and, if necessary, the (co) polymer A hydrogenated resin, (5) a ring-opening copolymer of a norbornene monomer and ethylene or α-olefins, and a resin in which the (co) polymer is hydrogenated, if necessary, (6) a norbornene monomer Ring-opening copolymers with non-conjugated dienes or other monomers, and norbornene-based resins such as resins obtained by hydrogenating the (co) polymers if necessary, other photo-curing reactive monomers An acrylic resin or an epoxy resin obtained by polymerizing a polymer.

  Of these, norbornene resins are particularly preferred. These norbornene-based polymers include, for example, ring-opening metathesis polymerization (ROMP), combination of ROMP and hydrogenation reaction, polymerization by radical or cation, polymerization using a cationic palladium polymerization initiator, and other polymerization initiators ( For example, it can be obtained by any known polymerization method such as polymerization using a polymerization initiator of nickel or another transition metal).

  As shown in FIGS. 1 and 2, clad layers 33a and 33b are disposed on both surfaces of the core layer 32, respectively. The clad layers 33 a and 33 b constitute clad portions located below and above the core layer 32, respectively, and are in contact with the core layer 32. Thereby, core part 34a-34c becomes a structure by which all the outer peripheral surfaces are each enclosed by a clad part. Therefore, each of the core portions 34a to 34c functions as a light guide path.

  As a constituent material of the clad layers 33a and 33b, for example, the same material as that of the core layer 32 described above can be used, but a norbornene polymer is particularly preferable. For example, the norbornene-based polymer having a relatively low refractive index is preferably one containing a norbornene repeating unit having a substituent containing an epoxy structure at the terminal. Such a norbornene-based polymer has a particularly low refractive index and good adhesion to the core layer 32.

  Further, the norbornene-based polymer preferably contains an alkylnorbornene repeating unit. Since a norbornene-based polymer containing a repeating unit of alkylnorbornene has high flexibility, high flexibility (flexibility) can be imparted to the optical waveguide 3 by using such norbornene-based polymer.

  Examples of the alkyl group that the alkylnorbornene repeating unit has include a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, and a decyl group, and a hexyl group is particularly preferable. These alkyl groups may be either linear or branched.

  By including the repeating unit of hexyl norbornene, it is possible to prevent the refractive index of the entire norbornene-based polymer from increasing.

The optical waveguide 3 configured as described above is preferably used in data communication using light in a predetermined wavelength region (for example, about 600 to 1550 nm).
The optical waveguide 3 may have a cover film (not shown) on the lower surface of the cladding layer 33a and the upper surface of the cladding layer 33b. Examples of the constituent material of the cover film include various resin materials such as polyethylene terephthalate (PET), polyolefin such as polyethylene and polypropylene, polyimide, and polyamide.

  Moreover, although the average thickness of a cover film is not specifically limited, It is preferable that it is about 5-200 micrometers, and it is more preferable that it is about 10-100 micrometers.

  Further, the cover film and the clad layer 33a, and the cover film and the clad layer 33b are bonded. Examples of this method include thermocompression bonding, adhesion with an adhesive or a pressure-sensitive adhesive, and the like.

The optical waveguide 3 is fixed to the substrate 5 via, for example, an adhesive layer (not shown).
The optical waveguide 3 having such a configuration is used with the ferrule 6A attached to the tip 31 thereof.

  As shown in FIGS. 1 and 2, the ferrule 6 </ b> A has a ferrule having a lumen portion 61 into which the tip portion 31 of the optical waveguide 3 is inserted and a tip wall portion 62 located on the tip side of the lumen portion 61. A main body 60 and lenses 4a, 4b, and 4c provided on the tip wall portion 62 are provided.

  The ferrule body 60 includes a top plate 601, a bottom plate 602, and a pair of side wall portions 603 and 604 that connect them. The top plate 601 and the bottom plate 602 are each composed of a plate member and are disposed to face each other in the thickness direction of the optical waveguide 3. The side wall portions 603 and 604 are each made of a plate member and are disposed to face each other in the width direction of the optical waveguide 3. The tip wall portion 62 is a tip of the top plate 601, the bottom plate 602, and the side wall portions 603, 604 so as to block a portion opened to the tip side of the space surrounded by the top plate 601, the bottom plate 602, and the side wall portions 603, 604 It is the board member provided in the side.

  The lumen portion 61 is a space that is surrounded by the top plate 601, the bottom plate 602, the side wall portions 603 and 604, and the distal end wall portion 62 and opens to the proximal end side. The distal end portion 31 of the optical waveguide 3 is inserted into the lumen portion 61. In this inserted state, the distal end surface 36 of the optical waveguide 3 is in contact with the proximal end surface 621 of the distal end wall portion 62.

  As shown in FIGS. 1 and 2, the top plate 601 is formed with an adhesive injection port 66 that penetrates in the thickness direction and injects the adhesive 9 into the lumen portion 61. The adhesive injection port 66 communicates with the lumen portion 61.

  The adhesive 9 is not particularly limited, and for example, a silicone-based, epoxy-based, acrylic-based, cyanoacrylate-based, polyurethane-based, or the like thermosetting, ultraviolet curable, visible light curable, or electron beam curable adhesive. An agent can be suitably used.

  As shown in FIG. 1, lenses 4 a to 4 c are provided on the distal end surface 620 of the distal end wall portion 62. Specifically, the lens 4a is provided at a portion facing the core portion 34a, the lens 4b is provided at a portion facing the core portion 34b, and the lens 4c is provided at a portion facing the core portion 34c. Since the lenses 4a to 4c have the same configuration, the lens 4b will be described as a representative.

  As shown in FIGS. 1 and 2, the lens 4 b is configured by a convex lens having a convex surface 41 that protrudes further to the distal end side than the distal end surface 620 of the distal end wall portion 62. The convex surface 41 of the lens 4b is configured by a curved surface having a convex shape, and the bottom surface 42 of the lens 4b is configured by a plane. The lens 4b has a circular shape when viewed from the front end side. The focal point of the lens 4b coincides with the position of the base end face 82 of the optical fiber 81b in the connected state.

  By providing the lens 4b having such a configuration, the light emitted from the core portion 34b is converged and enters the optical fiber 81b. Thereby, more light can enter into the optical fiber 81b, and the loss of light can be suppressed.

  Further, the ferrule 6A further includes positioning means 63 for positioning the connector portion 7B so as to be separated from the lenses 4a to 4c in the connected state. As shown in FIGS. 1 and 2, the positioning means 63 is formed to protrude from the edge of the distal end surface 620 of the distal end wall portion 62 in the distal direction, and abuts against the proximal end surface 82 of the connector portion 7B in the connected state. 64.

  The protrusion 64 has a plate shape and is provided so as to surround the lenses 4a to 4c. The protruding portion 64 includes an upper plate 641, a lower plate 642, and side plates 643 and 644 that connect them. The thickness of the projecting portion 64 constituted by these four plate members gradually increases toward the base end. Thereby, even if a comparatively strong external force is applied to the protruding portion 64, the protruding portion 64 can be prevented from being broken.

  Moreover, the protrusion part 64 has the contact surface 640 which contact | abuts the base end surface 82 of the connector part 7B at the front-end | tip. The contact surface 640 is parallel to the tip wall portion 62.

  By the positioning means 63 having such a configuration, the connector portion 7B is positioned apart from the lenses 4a to 4c. In this positioning state, as described above, the focal point of the lens 4a coincides with the position of the proximal end surface 82 of the optical fiber 81a, and the focal point of the lens 4b coincides with the position of the proximal end surface 82 of the optical fiber 81b. The focal point of 4c coincides with the position of the base end face 82 of the optical fiber 81c. Thereby, more light can enter into the optical fiber 81b more reliably, and the loss of light can be more reliably suppressed. In addition, since the lenses 4a to 4c are located on the base end side with respect to the contact surface 640, damage to the surfaces of the lenses 4a to 4c can be prevented. Further, even when the cleaning operation is performed by mistake, the cleaning is performed without contact with the convex surface 41 of the lenses 4a to 4c. Therefore, damage to the convex surface 41 is prevented.

  As shown in FIG. 1, the ferrule 6 </ b> A is formed with a pair of guide holes 65 opened in the contact surface 640. The guide hole 65 is circular when viewed from the distal end side, and is arranged in the width direction of the optical waveguide 3. In the guide hole 65, a guide pin 86 used when connecting to the connector portion 7B of the optical fiber assembly 2B is inserted.

  In the ferrule 6A in the present embodiment, the top plate 601, the bottom plate 602, the side wall portions 603 and 604, the tip wall portion 62, the lenses 4a to 4c and the protruding portion 64 are made of a light transmissive material, and These are integrally formed. Thereby, in the ferrule 6A, the top plate 601, the bottom plate 602, the side wall portions 603 and 604, the tip wall portion 62, the lenses 4a to 4c, and the projecting portion 64 are configured as separate bodies, respectively. Compared to the case of being made of different materials, the manufacturing is easier and the manufacturing cost is lower. Therefore, the ferrule 6A of this embodiment is more suitable for mass production.

  Examples of the light transmissive material include acrylic resins, methacrylic resins, polycarbonates, polystyrenes, cyclic ether resins such as epoxy resins and oxetane resins, polyamides, polyimides, polybenzoxazoles, polysilanes, polysilazanes, and benzocyclones. In addition to various resin materials such as cyclic olefin resin such as butene resin and norbornene resin, various glass materials such as quartz glass and borosilicate glass, various crystal materials such as sapphire and quartz can be used. In particular, it is preferable to use an epoxy resin or a polyamide resin. Teralink ("Teralink" is a registered trademark) is preferable as the material composed of epoxy resin and polyamide resin.

  The refractive index of the light transmissive material is preferably a value between the refractive index of the core portions 83 a to 83 c of the optical fibers 81 a to 81 c and the refractive index of the core portions 34 a to 34 c of the optical waveguide 3. The refractive index is preferably, for example, 1.420 to 1.780, more preferably 1.450 to 1.580.

  Thereby, the difference in refractive index between the core portions 34a to 34c, the tip wall portion 62 and the lenses 4a to 4c can be reduced, and thus the loss of light emitted from the core portions 34a to 34c can be suppressed. Can do.

  Such a ferrule 6A can be manufactured by various methods such as an injection molding method.

  The optical transmission board 1 having the optical waveguide assembly 2A composed of the optical waveguide 3 and the ferrule 6A as described above includes, for example, a router device, a WDM device, a mobile phone, an automobile, a game machine, a personal computer, and a television. , Home servers, and other various electrical appliances.

  The connector portion 7B of the optical fiber assembly 2B is connected to the connector portion 7A of the optical waveguide assembly 2A. As shown in FIG. 1, the optical fiber assembly 2 </ b> B includes a plurality of (three in this embodiment) optical fibers 81 a, 81 b, 81 c and a ferrule 83. Moreover, the connector part 7B has the base end part of optical fiber 81a-81c, and the ferrule 83 which hold | maintains the front-end | tip part of optical fiber 81a-81c collectively.

  The ferrule 83 is configured by a housing, and the base ends of the optical fibers 81a to 81c are fixed inside thereof.

  The optical fiber 81a has a core part 84a through which light passes and a clad part 85a surrounding the core part 84a. The optical fiber 81b has a core part 84b through which light passes and a clad part 85b surrounding the core part 84b. The optical fiber 81c has a core part 84c through which light passes and a clad part 85c surrounding the core part 84c.

  In the connected state, the base end surface of the core portion 84a is disposed so as to face the lens 4a, the base end surface of the core portion 84b is disposed so as to face the lens 4b, and the base end surface of the core portion 84c is disposed so as to face the lens 4c. Has been. For this reason, in the connected state, the core portion 84a of the optical fiber 81a and the core portion 34a of the optical waveguide 3 are optically connected via the lens 4a and the tip wall portion 62, and the core portion 84b of the optical fiber 81b and the optical waveguide are connected. 3 core part 34b is optically connected via lens 4b and tip wall part 62, and core part 84c of optical fiber 81c and core part 34c of optical waveguide 3 are connected via lens 4c and tip wall part 62. Optically connected. Thereby, data communication using light can be performed between the optical transmission board 1 and the optical fiber assembly 2B.

  As shown in FIG. 1, the base end surface 82 of the ferrule 83 is provided with a pair of guide pins 86 having a columnar shape (bar shape) protruding in the base end direction. The pair of guide pins 86 are respectively inserted into the pair of guide holes 65 of the ferrule 6A. Thereby, connector part 7A and 7B are hold | maintained in a connection state.

  Next, a method for manufacturing the optical waveguide assembly 2A by attaching the ferrule 6A to the distal end portion 31 of the optical waveguide 3 will be described. The manufacturing method of the optical waveguide assembly 2A includes an insertion process, an adhesive injection process, and an adhesive curing process. In the following, a case where an ultraviolet curable adhesive is used as the adhesive 9 will be described.

[1] Insertion process (assembly process)
The distal end portion 31 of the optical waveguide 3 is inserted into the inner cavity portion 61 of the ferrule 6 </ b> A, and the distal end surface 36 of the optical waveguide 3 is abutted against the proximal end surface 621 of the distal end wall portion 62.

[2] Adhesive Injection Step Next, the adhesive 9 is injected into the lumen 61 through the adhesive injection port 66 while maintaining the abutted state (contact state). The adhesive 9 injected into the lumen 61 flows between the inner peripheral portion 69 of the ferrule 6A and the outer peripheral portion 37 of the distal end portion 31 of the optical waveguide 3 by capillary action.

[3] Adhesive curing step Next, ultraviolet rays are irradiated toward the ferrule 6A. The ultraviolet rays pass through the ferrule 6 </ b> A made of a light transmissive material and are applied to the adhesive 9. As a result, the adhesive 9 is cured and the optical waveguide 3 and the ferrule 6A are fixed.

  Further, in the adhesive injection step, the distal end surface 36 of the optical waveguide 3 and the proximal end surface 621 of the distal end wall portion 62 are held in abutting state (contact state). Inflow between the distal end surface 36 of the optical waveguide 3 and the proximal end surface 621 of the distal end wall portion 62 is prevented. Thereby, it can prevent that the adhesive agent 9 adheres to the front end surface 36 of the optical waveguide 3. FIG. Therefore, it is possible to omit the step of polishing and removing the adhesive adhering to the front end surface of the optical waveguide together with the front end surface of the optical waveguide, which has been performed in the conventional manufacturing process of the optical waveguide assembly. Therefore, the ferrule 6A of this embodiment is suitable for mass production.

Second Embodiment
FIG. 3 is a longitudinal sectional view showing an optical transmission board provided with the second embodiment of the optical waveguide assembly (ferrule) of the present invention.

Hereinafter, a ferrule and an optical waveguide assembly according to a second embodiment of the present invention will be described with reference to this figure. However, differences from the above-described embodiment will be mainly described, and description of similar matters will be omitted. .
The present embodiment is the same as the first embodiment except that the ferrule has a different shape.

  As shown in FIG. 3, the lumen 61 of the ferrule 6B of the present embodiment has an opening 67 at the proximal end thereof where the distance in the thickness direction of the optical waveguide 3 gradually increases in the proximal direction. Yes. In addition, an inclined surface 68 a is formed at a portion facing the opening 67 of the top plate 601, and an inclined surface 68 b is formed at a portion facing the opening 67 of the bottom plate 602.

  The inclined surfaces 68a and 68b are surfaces curved toward the central axis 610 of the lumen portion 61, respectively. Further, the curvature R of the inclined surfaces 68a and 68b may be constant or may gradually increase in the proximal direction.

  For example, the average curvature R of the inclined surfaces 68a and 68b is preferably 1 to 4, and more preferably 2 to 3.

  By providing such inclined surfaces 68a and 68b, even if an external force is applied to the portion facing the opening 67 of the optical waveguide 3, the portion facing the opening 67 of the optical waveguide 3 Since 67 is formed, it can be curved and deformed until it comes into contact with the inclined surfaces 68a and 68b. Thereby, sharp bending of the optical waveguide 3 can be prevented. Therefore, the original high transmission characteristics of the optical waveguide 3 can be maintained.

<Third Embodiment>
FIG. 4 is a longitudinal sectional view showing an optical transmission board provided with a third embodiment of the optical waveguide assembly (ferrule) of the present invention.

Hereinafter, the third embodiment of the ferrule and the optical waveguide assembly of the present invention will be described with reference to this figure, but the description will focus on the differences from the above-described embodiment, and the description of the same matters will be omitted. .
The present embodiment is the same as the first embodiment except that the ferrule has a different shape.

  As shown in FIG. 3, the ferrule 6 </ b> C of the present embodiment communicates with the inner cavity portion 61 at the boundary portion (the ferrule main body 60 in the present embodiment) between the ferrule main body 60 and the tip wall portion 62, and the adhesive 9 A through hole 670 for storing or discharging the surplus is provided. The through hole 670 is formed through the tip of the top plate 601 and the bottom plate 602 in the respective thickness directions, and the outer peripheral surface opened to the inner peripheral portion 61 and the outer peripheral surface of the ferrule body 60. Side opening 672. The through hole 670 is provided on the same plane as the distal end surface 36 of the optical waveguide 3.

  Further, the width of the lumen side opening 671 of the through hole 670 is smaller than the width of the optical waveguide 3. Thereby, it is possible to prevent the optical waveguide 3 or the cover film from being caught on the edge of the lumen-side opening 671 of the through hole 670 in the insertion step of inserting the optical waveguide 3 into the lumen 61.

  In the adhesive injection step of injecting the adhesive 9 into the lumen 61, the adhesive 9 injected from the adhesive injection port 66 is caused by a capillary phenomenon, and the inner peripheral portion 69 of the ferrule 6C and the distal end portion 31 of the optical waveguide 3. Between the outer peripheral portion 37 and the outer peripheral portion 37. Part of the adhesive 9 that has flowed in is directed toward the tip. Then, the adhesive 9 flows into the through hole 670 and is stored through the lumen side opening 671. Further, when the injection of the adhesive 9 is further continued, the surplus portion of the adhesive 9 is discharged to the outside of the ferrule body 60 through the outer peripheral surface side opening 672.

  As described above, the adhesive 9 is stored or discharged in the through hole 670, so that the adhesive 9 is reliably prevented from adhering to the distal end surface 36 of the optical waveguide 3.

  Further, when the adhesive 9 flows into the through hole 670, air between the inner peripheral portion 69 of the ferrule 6 </ b> C and the outer peripheral portion 37 of the distal end portion 31 of the optical waveguide 3 passes through the through hole 670. Discharged to the outside. Accordingly, the adhesive 9 can surely flow into the tip between the inner peripheral portion 69 of the ferrule 6C and the outer peripheral portion 37 of the tip portion 31 of the optical waveguide 3.

  The embodiment of the ferrule and optical waveguide assembly of the present invention has been described above, but the present invention is not limited to this, and each part constituting the ferrule and optical waveguide assembly has the same function. It can be replaced with any configuration that can be exhibited. Moreover, arbitrary components may be added.

  In each embodiment, light is directed from the optical waveguide assembly to the optical fiber assembly in the connected state. However, the present invention is not limited to this, and light is transmitted from the optical fiber assembly to the optical waveguide assembly in the connected state. The structure may be suitable for a three-dimensional object.

  In the ferrule of each of the embodiments, the top plate, the bottom plate, the pair of side wall portions, the tip wall portion, the lens and the protruding portion are made of a light transmissive material and are integrally formed. However, the present invention is not limited to this, and it is sufficient that at least the tip wall portion and the lens are made of a light-transmitting material and are integrally formed.

DESCRIPTION OF SYMBOLS 1 Optical transmission board | substrate 2A Optical waveguide assembly 2B Optical fiber assembly 3 Optical waveguide 31 Tip part 32 Core layer 33a Clad layer (1st clad layer (clad part))
33b Clad layer (second clad layer (clad part))
34a, 34b, 34c Core part (waveguide channel)
35a, 35b, 35c, 35d Side cladding (cladding)
36 Front end surface 37 Outer peripheral portions 4a, 4b, 4c Lens 41 Convex surface 42 Bottom surface 5 Substrate 50 Top surface 51 First insulating layer 52 First conductor pattern (conductor circuit)
53 Second insulating layer 54 Second conductor pattern (conductor circuit)
55 Third insulating layer 56 Third conductor pattern (conductor circuit)
57 Coating layer (solder resist layer)
6A, 6B, 6C Ferrule 60 Ferrule body 601 Top plate 602 Bottom plate 603, 604 Side wall portion 61 Lumen portion 610 Center shaft 62 Tip wall portion 620 Tip surface 621 Base end surface 63 Positioning means 64 Projection portion 640 Contact surface 641 Top plate 642 Lower plate 643, 644 Side plate 65 Guide hole 66 Adhesive injection port 67 Opening portion 670 Through hole 671 Lumen side opening 672 Outer peripheral surface side opening 68a, 68b Inclined surface 69 Inner peripheral portion 7A, 7B Connector portions 81a, 81b, 81c Optical fiber 82 Base end face 83 Ferrule 84a, 84b, 84c Core part 85a, 85b, 85c Clad part 86 Guide pin 9 Adhesive R Curvature

Claims (15)

A ferrule having at least one core portion and a clad portion provided so as to surround the core portion, and being used by being attached to a distal end portion of an optical waveguide having a long overall shape,
A ferrule body that has a lumen portion that is open on the proximal end side and into which the distal end portion of the optical waveguide is inserted, and a distal end wall portion that is located on the distal end side of the lumen portion;
Including at least one lens provided on the tip wall portion and made of a light-transmitting material having light-transmitting properties;
The ferrule body has at least the tip wall portion made of the light transmissive material and is formed integrally with the lens. The optical waveguide has a strip shape as a whole,
The ferrule body is configured by the tip wall portion, a top plate and a bottom plate facing in the thickness direction of the optical waveguide, and a pair of side wall portions facing in the width direction of the optical waveguide. The described ferrule.   The ferrule according to claim 2, wherein the top plate, the bottom plate, and the pair of side wall portions are made of the light transmissive material.   The ferrule according to claim 2 or 3, wherein the tip wall portion, the top plate, the bottom plate, and the pair of side wall portions are integrally formed.   The ferrule according to any one of claims 1 to 4, wherein the lens has a convex surface that protrudes further toward the distal end side than the distal end surface of the distal end wall portion. The optical waveguide has a plurality of the core parts,
The ferrule according to claim 1, wherein one lens is provided corresponding to each of the core portions.   The ferrule according to any one of claims 1 to 6, wherein a surface on a proximal end side of the distal end wall portion is in contact with a distal end surface of the optical waveguide. The ferrule body and the optical waveguide are fixed via an adhesive,
8. A through hole is formed in the vicinity of the boundary between the ferrule main body and the tip wall portion so as to communicate with the lumen portion and store or discharge excess of the adhesive. The ferrule described in.   9. The positioning apparatus according to claim 1, further comprising positioning means for positioning the connector so as to be separated from the lens in a connected state in which a connector having a light guide path optically connected to the optical waveguide is connected to the ferrule. The ferrule described in.   The ferrule according to claim 9, wherein the positioning means is formed to protrude from the distal end wall portion in the distal end direction, and is configured by a protruding portion that contacts the connector in the connected state. The protrusion is plate-shaped,
The ferrule according to claim 10, wherein the protrusion is formed so as to surround the lens, and the thickness of the protrusion is gradually increased in the proximal direction.   The ferrule according to claim 10 or 11, wherein the protrusion is made of the light transmissive material and is formed integrally with the tip wall. The ferrule body is bonded to the optical waveguide via an adhesive,
The ferrule according to any one of claims 1 to 12, wherein the ferrule body is formed with an adhesive injection port that communicates with the lumen portion and injects the adhesive into the lumen portion.   The ferrule according to any one of claims 1 to 13, wherein the lumen portion has an opening portion at a proximal end portion of which the distance in the thickness direction of the optical waveguide gradually increases toward the proximal end direction. An elongated optical waveguide;
An optical waveguide assembly, comprising: the ferrule according to any one of claims 1 to 14, which is attached to a distal end portion of the optical waveguide.

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