JP2015060133A - Photo-electric hybrid substrate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a photo-electric hybrid substrate capable of improving degree of freedom of the photo-electric hybrid substrate and improving yield.SOLUTION: A photo-electric hybrid substrate 1 comprises: a circuit board 7 which is a tabular shape; a light guide path 2 which is long, whose right end 21 is fixed to the circuit board 7, and which has flexibility; and a connector housing 10 attached to the right end 21 of the light guide path 2 and being fixed to the circuit board 7. An intermediate part 23 between the right end 21 and a left end 22 of the light guide path 2 is curved and is separated from the circuit board 7.

Description

  The present invention relates to an opto-electric hybrid board.

In recent years, optical communications that transport data using optical frequency carriers have become increasingly important. In such optical communication, an opto-electric hybrid board including an optical waveguide is known as a means for guiding signal propagation light from one point to another point (for example, see Patent Document 1). In the opto-electric hybrid board described in Patent Document 1, the optical waveguide has a layer shape, and the layer of the electrical wiring and the insulating layer constitute a laminate. The optical waveguide can be constituted by, for example, a pair of clad layers and a core layer provided between the pair of clad layers. The core layer has a linear core portion and a clad portion, which are alternately arranged.

  By the way, in the opto-electric hybrid board described in Patent Document 1, depending on the temperature change of the usage environment of the opto-electric hybrid board, if one end of the optical waveguide is fixed to the board via an adhesive, the fixed part In some cases, stress is generated in the optically mixed substrate and the optical waveguide at the fixed portion.

JP 2011-53269 A

    An object of the present invention is to provide an opto-electric hybrid board that can increase the design freedom of the opto-electric hybrid board and improve the yield.

Such an object is achieved by the present inventions (1) to (12) below.
(1) a plate-like substrate;
An elongated optical waveguide having one end fixed to the substrate, and a flexible optical waveguide;
A connector housing attached to the other end of the optical waveguide and fixed to the substrate;
An intermediate portion between the one end portion and the other end portion of the optical waveguide is spaced apart from the substrate and is curved.

  (2) The opto-electric hybrid board according to (1), wherein the intermediate portion includes two curved portions having different curved directions in a side view as viewed from a direction orthogonal to the surface direction of the substrate.

(3) A straight line passing through one end and the other end of the optical waveguide is inclined with respect to the substrate, and an angle formed between the straight line and the substrate is θ ₁ and is positioned between the two curved portions. The opto-electric hybrid board according to the above (2), which satisfies the relation θ ₁ <θ _{2, where} θ ₂ is an angle formed between a tangent line that touches the inflection point and the substrate.
(4) the angle theta _2, the opto-electric hybrid board according to the above (3) is 1 to 90 degrees.

  (5) The opto-electric hybrid board according to any one of (1) to (4), wherein the optical waveguide is disposed at a position where the other end is higher than the one end.

  (6) The optical waveguide according to any one of (1) to (5), wherein the one end and the other end are parallel in a side view as viewed from a direction orthogonal to the surface direction of the substrate. The opto-electric hybrid board described in 1.

(7) The opto-electric hybrid board according to any one of (1) to (6), wherein the intermediate portion functions as a buffer portion that relieves stress generated in the optical waveguide.

(8) At least one end of the optical waveguide is covered with a film made of a resin material, and the film is fixed to the substrate via an adhesive. The opto-electric hybrid board according to any one of the above.

(9) The opto-electric hybrid board according to any one of (1) to (8), wherein the connector housing is configured by a hollow body having a hollow portion into which the other end portion is inserted.

  (10) The opto-electric hybrid board according to any one of (1) to (9), wherein the one end portion and the other end portion are arranged on the same surface side with respect to the substrate.

  (11) The opto-electric hybrid board according to any one of (1) to (9), wherein the one end and the other end are disposed on opposite sides of the substrate.

(12) The opto-electric hybrid board according to any one of (1) to (11), further comprising an optical element that is disposed on the substrate and is optically connected to the optical waveguide and emits or receives light.

  The opto-electric hybrid board can be obtained with a high degree of design freedom and high yield.

It is a top view which shows 1st Embodiment of the opto-electric hybrid board | substrate of this invention. It is the figure (side view of the opto-electric hybrid board | substrate of this invention) seen from the arrow A direction in FIG. It is CC sectional view taken on the line in FIG. It is a side view which shows 2nd Embodiment of the opto-electric hybrid board | substrate of this invention. It is a longitudinal cross-sectional view which shows 3rd Embodiment of the opto-electric hybrid board | substrate of this invention.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an opto-electric hybrid board according to the present invention will be described in detail based on preferred embodiments shown in the accompanying drawings.

<First Embodiment>
FIG. 1 is a plan view showing a first embodiment of the opto-electric hybrid board according to the present invention, and FIG. 2 is a view seen from the direction of arrow A in FIG. 1 (side view of the opto-electric hybrid board according to the present invention). 3 is a cross-sectional view taken along the line CC in FIG. In the following, for convenience of explanation, the left side in FIGS. 1 to 3 (the same applies to FIG. 4) is referred to as “left”, and the right side is referred to as “right”. 2 to 3 (the same applies to FIGS. 4 and 5), the upper side is referred to as “upper (upper)” or “front”, and the lower side is referred to as “lower (lower)” or “back”. In FIG. 2 (the same applies to FIGS. 4 and 5), the vertical direction (thickness direction) of the opto-electric hybrid board is exaggerated.

  An opto-electric hybrid board 1 shown in FIGS. 1 and 2 includes a circuit board (substrate) 7 having a plate shape, an optical waveguide 2 having a strip shape (long shape), and a light emitting element (optical element) that emits light 111. 11 and a connector housing (hereinafter simply referred to as “housing”) 10.

In addition, the light traveling from the light emitting element 11 toward the optical waveguide is converted in the traveling direction by an optical path conversion unit (mirror) that converts the traveling direction of the optical path provided in the optical waveguide 2, and passes through the core portion of the optical waveguide 2. It may be transmitted. Furthermore, the light transmitted through the core portion of the optical waveguide 2 may be transmitted to the light receiving element by changing the direction of the optical path by a mirror provided in the optical waveguide 2.

  With the configuration shown in FIG. 1, since the intermediate portion 23 of the optical waveguide 2 having a strip shape (long shape) can be made easy, it can be easily attached to the circuit board 7 or the housing 10. Therefore, the opto-electric hybrid board 1 can be obtained with a high yield.

  When the right end portion 21 of the optical waveguide 2 is fixed to the circuit board 7 through an adhesive when the temperature change is significantly set, stress is applied to the fixed portion due to the temperature change. However, this stress is relieved by the intermediate portion 23, and peeling of the fixed portion can be prevented. Thereby, the adhesion state with respect to the right end part 21 is reliably maintained.

Even when the left end portion 22 of the optical waveguide 2 is fixed to the housing 10 via an adhesive, the intermediate portion 23 relieves stress generated in the fixing portion between the optical waveguide 2 and the housing 10. The adhesion state to the left end portion 22 is reliably maintained.

As described above, according to the present invention, it is possible to stably transmit light regardless of the temperature change of the use environment.

Hereinafter, the configuration of each unit will be described.
As shown in FIG. 3, the circuit board 7 includes a first insulating layer 71, a first conductor pattern (conductor circuit) 72, a second insulating layer 73, and a second conductor pattern (conductor circuit) 74. And a third insulating layer 75, a third conductor pattern (conductor circuit), and a coating layer (solder resist layer) 77, which are laminated (arranged) from below in this order. Consists of the body.

In addition, the total thickness of the circuit board 7 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.

  The first conductor pattern 72, the second conductor pattern 74, and the third conductor pattern 76 are each made of a conductive metal material and are electrically connected to each other. Any one of the first conductor pattern 72, the second conductor pattern 74, and the third conductor pattern 76 is connected to a power source and a control device.

  Each conductor pattern is formed 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 71 is a layer that insulates the first conductor pattern 72 from the outside. The second insulating layer 73 is a layer that insulates a predetermined portion between the first conductor pattern 72 and the second conductor pattern 74. The third insulating layer 75 is a layer that insulates a predetermined portion between the second conductor pattern 74 and the third conductor pattern 76. By such each insulating layer, the unintentional short circuit (short circuit) of each conductor pattern can be prevented reliably.

  The covering layer 77 is formed so as to cover at least a part of the third conductor pattern 76. Thereby, the 3rd conductor pattern 76 can be protected, Therefore For example, degradation and the short circuit of the conducting 3rd conductor pattern 76 can be prevented.

  In addition, although it does not specifically limit as a constituent material of the 1st insulating layer 71, the 2nd insulating layer 73, the 3rd insulating layer 75, and the coating layer 77, For example, various resin materials are mentioned, Especially an epoxy type | system | group is mentioned. Resin materials such as resin, cyanate resin, phenol resin, polyimide resin, cyclic polyolefin resin, liquid crystal polymer resin, polyester resin, and fluorine resin are preferable.

  As shown in FIGS. 1 and 2, the strip-shaped optical waveguide 2 is arranged on the front side of the circuit board 7. Therefore, the right end portion (one end portion) 21 and the left end portion (other end portion) 22 of the optical waveguide 2 are disposed on the same surface side with respect to the circuit board 7.

  The optical waveguide 2 is not folded in the middle of the longitudinal direction, and the right end portion 21 and the left end portion 22 are arranged facing opposite directions. The right end 21 of the optical waveguide 2 is fixed to the circuit board 7, and the housing 10 is attached to the left end 22.

As shown in FIG. 3, the optical waveguide 2 includes a clad layer (first clad layer (cladding portion)) 3a, a core layer 4, and a clad layer (second clad layer (cladding portion)) 3b. These layers are laminated in this order from the lower side.

As shown in FIG. 1, the core layer 4 has a plurality of (for example, five in the present embodiment) core portions (waveguide channels) 41a, 41b, 41c, 41d, 41e that are elongated in plan view, A plurality of (for example, six in the present embodiment) side clad portions (cladding portions) 42 a, 42 b, 42 c, 42 d, 42 e, 42 f are formed, and these are alternately arranged in the width direction of the optical waveguide 2. Thus, the optical waveguide 2 is a multi-channel one having a plurality of core portions.

  The core portions 41a to 41e and the side cladding portions 42a to 42f 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 parts 41a to 41e are made of a material having a higher refractive index than the side clad parts 41a to 41f, and are made of a material having a higher refractive index than the cladding layers 3a and 3b.

  The constituent materials of the core portions 41a to 41e and the side clad portions 41a to 41f are not particularly limited, but in this embodiment, the core portion 41a and the side clad portion 42a are made of the same material. The difference in refractive index between the portions 41a to 41e and the side clad portions 41a to 41e is manifested by the difference in the chemical structure of the materials.

  Any material can be used as the constituent material of the core layer 4 as long as it is a material that is substantially transparent to light propagating through the core portions 41a to 41e. 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).

  Cladding layers 3a and 3b are disposed on both surfaces of the core layer 4, respectively. The clad layers 3 a and 3 b constitute clad portions located at the lower and upper portions of the core layer 4, respectively, and are in contact with the core layer 4. With such a configuration, each of the core portions 41a to 41e functions as a light guide path whose outer periphery is surrounded by the clad portion.

  As the constituent material of the cladding layers 3a and 3b, for example, the same material as the constituent material of the core layer 4 described above can be used, but a norbornene-based 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 4.

  Further, the norbornene-based polymer preferably contains an alkylnorbornene repeating unit. Since the norbornene-based polymer containing the alkylnorbornene repeating unit has high flexibility, high flexibility (flexibility) can be imparted to the optical waveguide 2 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 2 configured as described above is preferably used in data communication using light 111 in a predetermined (for example, about 600 to 1550 nm) wavelength region.

  In addition, the full length L1 of the optical waveguide 2 is not specifically limited, For example, it is preferable that it is 10-1500 mm, and it is more preferable that it is 20-1000 mm. Particularly in applications where low optical transmission loss is required, the total length L1 is preferably 20 mm or more and less than 60 mm.

  Further, in the case where the optical waveguide 2 is required to have a degree of design freedom in the opto-electric hybrid board 1, the total length L1 is preferably 60 mm or more and 1000 mm or less. Further, when a low optical transmission loss is required, 70 mm or more and 500 mm or less are especially preferable. Moreover, the width w1 is not specifically limited, For example, it is preferable that it is 1.0-10.0 mm, and it is more preferable that it is 1.5-5.0 mm. Moreover, thickness t1 is not specifically limited, For example, it is preferable that it is 0.01-2 mm, and it is more preferable that it is 0.03-1.00 mm. By setting in such a numerical range, the optical waveguide 2 can suppress the loss of the transmitted light 111 as much as possible in combination with the constituent material used.

  As shown in FIG. 3, the optical waveguide 2 is covered (sandwiched) with the two films 17a and 17b from the top and bottom in the entire direction, that is, from the right end portion 21 to the left end portion 22. The films 17a and 17b support and reinforce the optical waveguide 2 and protect the optical waveguide 2, respectively.

The optical waveguide 2 and the films 17a and 17b are joined together by a method such as thermocompression bonding, adhesion with an adhesive or a pressure sensitive adhesive.

  Moreover, it does not specifically limit as a constituent material of the films 17a and 17b, For example, various resin materials, such as polyethylene terephthalate (PET), polyolefins, such as polyethylene and a polypropylene, a polyimide, a polyamide, can be used. In addition, metal materials such as copper, aluminum, and silver can also be used.

  Moreover, the thickness of film 17a, 17b is not specifically limited, For example, 5-200 micrometers is preferable and 5-30 micrometers is more preferable. Accordingly, the films 17a and 17b each have appropriate rigidity, so that the optical waveguide 2 can be reliably supported and the flexibility of the optical waveguide 2 is hardly hindered. Further, the thickness of the film 17a and the thickness of the film 17b may be the same or different.

As shown in FIG. 2, at the right end portion 21 of the optical waveguide 2, a film 17 b that covers the surface on the back side is fixed to the circuit board 7 via an adhesive layer.

The adhesive layer can be composed of, for example, an acrylic adhesive, a urethane adhesive, a silicone adhesive, or various hot melt adhesives (polyester or modified olefin). The adhesive layer made of such a material is a relatively flexible layer. Thereby, for example, even if the temperature of the usage environment of the opto-electric hybrid board 1 changes and the shape of the right end portion 21 changes, the adhesive layer can follow the change. As a result, it is possible to reliably prevent the film 17b (right end portion 21) and the adhesive layer from peeling off due to the shape change.

  The thickness of an adhesive bond layer is not specifically limited, For example, it is preferable that it is 1-100 micrometers, and it is more preferable that it is 5-60 micrometers.

  As shown in FIGS. 1, 2, and 3, a housing 10 (ferrule) is attached to the left end portion 22 of the optical waveguide 2. In the opto-electric hybrid board 1, the housing 10 and the left end portion 22 constitute a connector portion 8 to which the optical cable 20 is connected.

Light enters the connected optical cable 20. Thereby, light transmission can be reliably performed between the opto-electric hybrid board 1 and the optical cable 20, and thus data communication using the light 111 can be suitably performed.

  The housing 10 is fixed to the circuit board 7 via an adhesive layer 19 from the front side. The adhesive layer 19 can be made of the same material as the adhesive layer described above, and can have the same thickness as the adhesive layer.

  Further, the housing 10 is configured by a hollow body having a hollow portion (slit) 101 formed so as to penetrate the central portion of the outer shape of the block 10. In the housing 10, the left end portion 22 of the optical waveguide 2 is inserted into the hollow portion 101, and the housing 10 is attached to the left end portion 22 by this insertion. Note that the left end portion 22 is bonded to the housing 10 through an adhesive (not shown) in the hollow portion 101.

  As shown in FIG. 1, the housing 10 is provided with guide holes 104 on both sides of the hollow portion 101 into which the respective guide pins 203 of the optical cable 20 are inserted. By inserting the guide pin 203 of the optical cable 20 into the guide hole 104 of the housing 10, the core portions 41 a to 41 e of the optical waveguide 2 and the optical fibers 201 a to 201 e of the optical cable 20 are positioned. Thereby, the core part 41a and the optical fiber 201a are reliably optically connected, the core part 41b and the optical fiber 201b are reliably optically connected, and the core part 41c and the optical fiber 201c are reliably optically connected. The core portion 41d and the optical fiber 201d are surely optically connected, and the core portion 41e and the optical fiber 201e are reliably optically connected.

  The length L3 of the housing 10 along the longitudinal direction of the optical waveguide 2 is not particularly limited. For example, the length L3 is preferably 1.0 to 10.0 mm, and more preferably 2.0 to 8.0 mm. . Moreover, the maximum width w3 of the housing 10 is not particularly limited, and is preferably 2.0 to 10.0 mm, and more preferably 4.5 to 8.0 mm, for example. The thickness (height) t3 of the housing 10 is not particularly limited, and is preferably 1.0 to 10.0 mm, and more preferably 2.0 to 8.0 mm, for example.

  The constituent material of the housing 10 is not particularly limited, and examples thereof include a resin material filled with an inorganic filler. As this resin material, for example, a thermosetting epoxy resin or PPS (polyphenylene sulfide) is used. . Moreover, as an inorganic filler, granular silica, a glass filler, an alumina, white carbon, bentonite etc. are used, for example.

  Next, the optical cable 20 connected to the connector portion 8 of the opto-electric hybrid board 1 will be described.

  As shown in FIG. 1, the optical cable 20 bundles together optical fibers 201 a to 201 e that are linearly arranged in a line along the vertical direction in FIG. 1 and the right ends of the optical fibers 201 a to 201 e. Connector housing (hereinafter simply referred to as “housing”) 202 and two guide pins 203 fixed to the housing 202.

  Each of the optical fibers 201a to 201e is one through which the light 111 passes. In a connected state in which the optical cable 20 is connected to the connector portion 8 of the opto-electric hybrid board 1, the right end of the optical fiber 201a is optically connected to the left end of the core portion 41a of the optical waveguide 2, and the right end of the optical fiber 201b is optical waveguide 2 The optical fiber 201c is optically connected to the left end of the core portion 41b, the right end of the optical fiber 201c is optically connected to the left end of the core portion 41c of the optical waveguide 2, and the optical fiber 201d is optically connected to the left end of the core portion 41d of the optical waveguide 2. The right end of the optical fiber 201e is optically connected to the left end of the core portion 41e of the optical waveguide 2. Thereby, the data communication using the light 111 can be performed between the opto-electric hybrid board 1 and the optical cable 20 as described above.

  The connector housing 202 is comprised by the cylinder, and can fix the right end part of the optical fibers 201a-201e inside it.

  Each guide pin 203 protrudes from the right end surface of the housing 202 and is inserted into the guide hole 104 of the housing 10 of the opto-electric hybrid board 1. Each guide pin 203 is a cylindrical member made of a metal material such as stainless steel.

  As described above, the right end portion 21 of the optical waveguide 2 is fixed to the circuit board 7 via the adhesive layer, and the housing 10 is attached to the left end portion 22 of the optical waveguide 2. 10 is fixed to the circuit board 7 through an adhesive layer 19. Since the housing 10 is thicker than the adhesive layer, the right end portion 21 and the left end portion 22 have different positions in the thickness direction with respect to the circuit board 7, that is, the left end portion 22 is the right end portion. It arrange | positions in the position higher than the part 21 (refer FIG. 2). When a straight line 25 passing through the intersection (one end) 212 between the center line 24 of the optical waveguide 2 and the right end surface 211 and the intersection (the other end) 222 between the center line 24 of the optical waveguide 2 and the left end surface 221 is assumed. The straight line 25 is inclined with respect to the circuit board 7.

  Note that the right end portion 21 and the left end portion 22 are parallel in a side view as viewed from a direction orthogonal to the surface direction of the circuit board 7.

  As shown in FIG. 2, the intermediate portion 23 between the right end portion 21 and the left end portion 22 of the optical waveguide 2 is separated from the circuit board 7.

The length _{L 2} of the intermediate portion 23 is not particularly limited, for example, is preferably from 3-97% of the total length _{L 1} of the optical waveguide 2, and more preferably 5 to 95%.

  Furthermore, as shown in FIG. 2, the intermediate portion 23 is curved so as to form an “S” shape in a side view as viewed from a direction orthogonal to the surface direction of the circuit board 7, that is, the bending direction is It has the 1st bending part 231 and the 2nd bending part 232 which are two different bending parts. The first bending portion 231 positioned on the right end side is curved “convex downward”. On the other hand, the second bending portion 232 located on the left end side is curved “convex upward”. Note that the average curvature of the first bending portion 231 and the average curvature of the second bending portion 232 may be the same or different.

The inflection point 233 where the bending direction changes is located between the first bending portion 231 and the second bending portion 232 in the intermediate portion 23. Then, the angle between the straight line 25 and the circuit board 7 and theta _1, when the angle between the tangent 26 and the circuit board 7 in contact with the inflection point 233 and a theta _2, satisfies θ _{1 <θ 2} the relationship . The angle θ ₂ is not particularly limited, and is preferably 1 to 90 degrees, for example, and more preferably 10 to 90 degrees.

  When the right end portion 21 of the optical waveguide 2 is fixed to the circuit board 7 through an adhesive when the temperature change is significantly set, stress is applied to the fixed portion due to the temperature change. However, this stress is relieved by the intermediate portion 23, and peeling of the fixed portion can be prevented. Thereby, the adhesion state with respect to the right end part 21 is reliably maintained.

  Even when the left end portion 22 of the optical waveguide 2 is fixed to the housing 10 via an adhesive, the intermediate portion 23 relieves stress generated in the fixing portion between the optical waveguide 2 and the housing 10. The adhesion state to the left end portion 22 is reliably maintained.

  Further, the left end portion 22 of the optical waveguide 2 is likely to be peeled off from the adhesive in the hollow portion 101, but the stress generated in the optical waveguide 2 is relieved by the intermediate portion 23, so that the peeling is reliably performed. Can be prevented. Thereby, the adhesion state with respect to the left end part 22 is reliably maintained.

  Further, when the optical waveguide 2 is formed, a tensile force acts on each of the core portions 41a to 41e. On the other hand, when the optical waveguide 2 contracts, a compressive force acts on the core portions 41a to 41e. In any case, the diameters of the core portions 41a to 41e are likely to change involuntarily, but the optical waveguide 2 is provided with the intermediate portion 23 having the above-described configuration. The stress generated in the optical waveguide 2 (intermediate portion 23) is relieved, and thus the unintentional change can be surely prevented. Thereby, transmission of the light 111 in the core parts 41a-41e can be performed stably.

  Accordingly, the intermediate portion 23 functions as a buffer portion (buffer) that relieves stress generated in the optical waveguide 2 when an external force is applied to the optical waveguide 2.

  As described above, the opto-electric hybrid board 1 can stably perform light transmission regardless of the temperature change of the environment (use environment) in which it is used.

  Note that the opto-electric hybrid board 1 can be mounted on, for example, a mobile device such as a super computer, a personal computer, or a mobile phone, a video device, a measuring device, or the like.

The opto-electric hybrid board 1 is assembled as follows.
[1] A circuit board 7, an optical waveguide 2, a housing 10, and a light emitting element 11 are prepared. The optical waveguide 2 is covered with films 17a and 17b in advance.

  [2] First, the left end 22 of the optical waveguide 2 is inserted into the housing 10 and the housing 10 is mounted. Thereby, an assembly of the optical waveguide 2 and the housing 10 is obtained.

[3] Next, the housing 10 of the assembly is fixed to the circuit board 7.
[4] Next, the right end portion 21 of the optical waveguide 2 of the assembly in which the housing 10 is fixed to the circuit board 7 is fixed to the circuit board 7. As described above, the intermediate portion 23 is installed so as to bend, that is, bend, so that, for example, the fixing work at this time is compared with the case where the intermediate portion 23 is installed with tension so that the intermediate portion 23 is pulled. Can be easily performed.
[5] Next, the light emitting element 11 is fixed on the right end portion 21 of the optical waveguide 2.

  In the assembly process of the opto-electric hybrid board 1, the order of the process [3] and the process [4], that is, the fixing order of the housing 10 and the right end portion 21 of the optical waveguide 2 to the circuit board 7 is reversed. May be.

Second Embodiment
FIG. 4 is a side view showing a second embodiment of the opto-electric hybrid board according to the present invention.

Hereinafter, the second embodiment of the opto-electric hybrid board according to the present invention will be described with reference to this figure. However, the difference from the above-described embodiment will be mainly described, and the description of the same matters will be omitted.

  This embodiment is the same as the first embodiment except that the arrangement position of the connector housing with respect to the board is different.

As shown in FIG. 4, in the opto-electric hybrid board 1 of the present embodiment, a housing 10 is arranged and fixed on the back surface of the circuit board 7.

The circuit board 7 is formed with a through hole 78 that penetrates in the thickness direction.
The optical waveguide 2 is inserted through the through-hole 78, the right end 21 is disposed on the front side of the circuit board 7, and the left end 22 is disposed on the back side, that is, the right end 21 and the left end 22 are The circuit boards 7 are arranged on opposite sides of each other. The intermediate portion 23 of the optical waveguide 2 arranged in this manner is separated from the circuit board 7, and the first curved portion 231 curved “convex upward” and the second curved “convex downward”. The curved portion 232 is formed.

<Third Embodiment>
FIG. 5 is a longitudinal sectional view showing a third embodiment of the opto-electric hybrid board according to the present invention.

Hereinafter, a third embodiment of the opto-electric hybrid board according to the present invention will be described with reference to this figure, but the description will focus on differences from the above-described embodiment, and the description of the same matters will be omitted.

  This embodiment is the same as the first embodiment except that the configuration (shape) of the connector housing is different.

  As shown in FIG. 5, in the opto-electric hybrid board 1 of the present embodiment, the housing 10 has an inclined surface 103 a formed on the right end portion of the upper surface 102 a among the surfaces defining the hollow portion 101. An inclined surface 103b is also formed at the right end of the surface 102b. The inclined surface 103a and the inclined surface 103b are inclined so as to be separated from each other toward the right side.

  Further, each of the inclined surfaces 103a and 103b is rounded, that is, curved, and its curvature gradually increases toward the right side.

By the way, in the optical waveguide 2, the part (proximal part 27) which protrudes from the housing 10 and is close to the 10 housing is a part which is relatively easily bent. However, since the inclined surfaces 103a and 103b are formed, the proximal portion 27 can be curved relatively gently along the curvature of the inclined surfaces 103a and 103b. Can be suppressed or prevented. Therefore, the opto-electric hybrid board 1 has excellent kink resistance at the proximal portion 27.
In addition, in the opto-electric hybrid board 1 of this embodiment, the inclined surface 103a may be omitted.

  The opto-electric hybrid board 1 having the above-described configuration, like the opto-electric hybrid board 1 of the first embodiment, can perform light transmission stably regardless of the temperature change of the usage environment. There are the following advantages.

  For example, as shown in FIG. 5, when the device on which the opto-electric hybrid board 1 is to be mounted has a projecting part 300 formed to project, the projecting part 300 is not the same as the opto-electric hybrid board 1 of the first embodiment. Although interfering with the housing 10, the opto-electric hybrid board 1 of this embodiment can prevent the interference because the housing 10 is located on the back side. Thereby, the opto-electric hybrid board 1 can be reliably mounted.

  As mentioned above, although the opto-electric hybrid board of the present invention has been described with respect to the illustrated embodiment, the present invention is not limited to this, and each part constituting the opto-electric hybrid board is an arbitrary one that can exhibit the same function. It can be replaced with the configuration of Moreover, arbitrary components may be added.

  Moreover, the opto-electric hybrid board of the present invention may be a combination of any two or more configurations (features) of the above embodiments.

  In the opto-electric hybrid board, a light receiving element that receives light can be used instead of the light emitting element. In this case, the light receiving element is not particularly limited, and examples thereof include a photodiode (PD, APD), an LSI integrated element including an optical element, and a silicon photonics.

In addition, the intermediate portion of the optical waveguide has two curved portions in each of the above embodiments, but is not limited to this, and has, for example, one curved portion so as to form a mountain shape or a valley shape. Alternatively, three or more curved portions may be provided so as to form a waveform. When the intermediate portion of the optical waveguide has three or more curved portions, the angle θ ₂ is the inflection point closest to the optical element.

1 Opto-electric hybrid board 2 Optical waveguide 21 Right end (one end)
211 Right end face 212 Intersection (one end)
22 Left end (other end)
221 Left end face 222 Intersection (other end)
23 intermediate part 231 first curved part 232 second curved part 233 inflection point 24 center line 25 straight line 26 tangent 27 proximal part 3a clad layer (first clad layer (clad part))
3b cladding layer (second cladding layer (cladding portion))
4 Core layer 41a, 41b, 41c, 41d, 41e Core part (waveguide channel)
42a, 42b, 42c, 42d, 42e, 42f Side cladding (cladding)
7 Circuit board (board)
71 1st insulating layer 72 1st conductor pattern (conductor circuit)
73 Second insulating layer 74 Second conductor pattern (conductor circuit)
75 Third insulating layer 77 Cover layer (solder resist layer)
78 Through-hole 8 Connector part 10 Connector housing (housing)
101 Hollow part (slit)
102a Upper surface 102b Lower surface 103a, 103b Inclined surface 104 Guide hole 11 Light emitting element (optical element)
111 Optical 17a, 17b Film 19 Adhesive layer 20 Optical cable 201a, 201b, 201c, 201d, 201e Optical fiber 202 Connector housing 203 Guide pin 300 Protruding part L1 Total length L2, L3 Length t1, t3 Thickness w1 Width w3 Maximum width θ ₁ , θ ₂ angle

Claims (12)

A plate-shaped substrate;
An elongated optical waveguide having one end fixed to the substrate, and a flexible optical waveguide;
A connector housing attached to the other end of the optical waveguide and fixed to the substrate;
An intermediate portion between the one end portion and the other end portion of the optical waveguide is spaced apart from the substrate and is curved.   2. The opto-electric hybrid board according to claim 1, wherein the intermediate portion includes two curved portions having different curved directions in a side view as viewed from a direction orthogonal to the surface direction of the substrate. A straight line passing through one end and the other end of the optical waveguide is inclined with respect to the substrate,
An angle between the straight line and the substrate and theta _1, when the angle formed by the tangent line and said substrate in contact with the inflection point located between the two curved portions and theta _2, comprising theta _{1 <theta 2} The opto-electric hybrid board according to claim 2 satisfying the relationship. The opto-electric hybrid board according to claim 3, wherein the angle θ ₂ is 1 to 90 degrees.   5. The opto-electric hybrid board according to claim 1, wherein the other end portion of the optical waveguide is disposed at a position higher than the one end portion.   6. The opto-electric hybrid device according to claim 1, wherein the one end portion and the other end portion of the optical waveguide are parallel in a side view as viewed from a direction orthogonal to the surface direction of the substrate. substrate.   The opto-electric hybrid board according to claim 1, wherein the intermediate portion functions as a buffer portion that relieves stress generated in the optical waveguide.   The light according to claim 1, wherein at least one end of the optical waveguide is covered with a film made of a resin material, and the film is fixed to the substrate via an adhesive. Electric mixed board.   The opto-electric hybrid board according to any one of claims 1 to 8, wherein the connector housing is constituted by a hollow body having a hollow portion into which the other end portion is inserted.   The opto-electric hybrid board according to claim 1, wherein the one end and the other end are arranged on the same surface side with respect to the substrate.   The opto-electric hybrid board according to claim 1, wherein the one end and the other end are arranged on opposite sides of the board.   The opto-electric hybrid board according to claim 1, further comprising an optical element that is disposed on the substrate and is optically connected to the optical waveguide and emits or receives light.

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