JP5696538B2 - Manufacturing method of opto-electric hybrid board - Google Patents

Description

The present invention relates to a method for manufacturing an opto-electric hybrid board .

  In recent years, with the wave of computerization, wideband lines (broadband) capable of communicating a large amount of information at high speed have been spreading. Also, as devices for transmitting information to these broadband lines, transmission devices such as router devices and WDM (Wavelength Division Multiplexing) devices are used. In these transmission apparatuses, a large number of signal processing boards in which arithmetic elements such as LSIs and storage elements such as memories are combined are installed, and each line is interconnected.

  Each signal processing board has a circuit in which arithmetic elements, storage elements, etc. are connected by electrical wiring. However, with the increase in the amount of information to be processed in recent years, each board has a very high throughput. It is required to transmit. However, with the speeding up of information transmission, problems such as generation of crosstalk and high frequency noise and deterioration of electric signals are becoming apparent. For this reason, electrical wiring becomes a bottleneck, making it difficult to improve the throughput of the signal processing board. Similar problems are also becoming apparent in supercomputers and large-scale servers.

  On the other hand, an optical communication technique for transferring data using an optical carrier wave has been developed, and in recent years, an optical waveguide is becoming popular as a means for guiding the optical carrier wave from one point to another point. This optical waveguide has a linear core part and a clad part provided so as to cover the periphery thereof. The core part is made of a material that is substantially transparent to the light of the optical carrier wave, and the cladding part is made of a material having a refractive index lower than that of the core part.

  In the optical waveguide, light introduced from one end of the core portion is transmitted (conveyed) to the other end while being reflected at the boundary with the cladding portion. A light emitting element such as a semiconductor laser is disposed on the incident side of the optical waveguide, and a light receiving element such as a photodiode is disposed on the emission side. Light incident from the light emitting element propagates through the optical waveguide, is received by the light receiving element, and performs communication based on the flickering pattern of the received light or its intensity pattern.

  By replacing the electric wiring in the signal processing board with such an optical waveguide, it is expected that the problem of the electric wiring as described above is solved and the signal processing board can be further increased in throughput.

  For example, in Patent Document 1, a plurality of optical waveguides arranged on a support substrate in a signal processing substrate (an opto-electric hybrid substrate), and a light emitting element and a light receiving element corresponding to the optical waveguide are provided on the optical waveguide. Arranged ones have been proposed.

  In this signal processing board, a plurality of optical waveguides are formed in the signal processing board by disposing clad parts that are in contact with each other between adjacent core parts. In this optical waveguide, light from the light emitting element arranged on the upper side is transmitted to one end of the optical waveguide, and light from the other end of the optical waveguide is also transmitted to the light receiving element arranged on the upper side. It is required to form a mirror (optical path changing unit) for the purpose.

  Therefore, in order to form a signal processing substrate having an optical waveguide provided with such a mirror, first, an optical waveguide is prepared, and after the mirror is formed in the optical waveguide, the optical waveguide is bonded onto the support substrate. In addition, it is necessary to go through a process of joining the light emitting element and the light receiving element on the optical waveguide, which causes a problem that the manufacturing process of the signal processing board becomes complicated.

JP 2008-122908 A

An object of the present invention is to provide a manufacturing how the opto-electric hybrid board which is capable of manufacturing an optical waveguide hybrid board by a simple process without increasing the complexity of the manufacturing process.

Such an object is achieved by the present invention described in the following (1) to ( 2 ).
(1) A first support substrate having a hole portion for transmitting laser light and a sheet material having a sheet shape are prepared, and the sheet material is bonded to the support substrate so as to cover the hole portion. Process,
A liquid film is formed by supplying a liquid material containing an optical waveguide forming material for forming an optical waveguide onto the support substrate in a state where the sheet material is interposed using a coating method. And the process of
A third step of drying the liquid film to form a layer containing the optical waveguide forming material;
A fourth step of forming the optical waveguide by applying a predetermined treatment to the layer ;
A part of the sheet material and the optical waveguide is removed using the laser light through the hole portion, thereby forming a defect portion including an optical path changing mirror that changes the direction of the optical path, and a light emitting element and And a fifth step of bonding a wiring board on which the light receiving element is mounted on the optical waveguide .

( 2 ) In the second step, the optical waveguide forming material includes a polymer and a monomer having a refractive index different from that of the polymer. The active radiation is irradiated to the layer, and the active radiation is irradiated. In the irradiated region, the reaction of the monomer proceeds to diffuse the unreacted monomer from the unirradiated region that is not irradiated with the actinic radiation to the irradiated region, and as a result, the irradiated region and the unirradiated region. A core layer in which one of the irradiated region and the non-irradiated region is used as the core portion and the other is used as the cladding portion having a lower refractive index than the core portion by causing a difference in refractive index between the core portion and the irradiated portion. The method for producing an opto-electric hybrid board according to ( 1 ), wherein the optical waveguide is provided.

  According to the method for manufacturing an opto-electric hybrid board of the present invention, it is possible to manufacture an opto-electric hybrid board by a relatively simple process, and to manufacture an opto-electric hybrid board having an optical waveguide with excellent reliability. it can.

It is a longitudinal cross-sectional view which shows the outline of 1st Embodiment of a photoelectric hybrid board | substrate . It is a top view which shows the support substrate and sheet | seat material with which the opto-electric hybrid board shown in FIG. 1 is provided. It is a fragmentary longitudinal cross-sectional view for demonstrating the manufacturing process of the optical waveguide board | substrate with which an opto-electric hybrid board is provided. It is a fragmentary longitudinal cross-sectional view for demonstrating the manufacturing process of the optical waveguide board | substrate with which an opto-electric hybrid board is provided. It is a fragmentary longitudinal cross-sectional view for demonstrating the manufacturing process of the optical waveguide board | substrate with which an opto-electric hybrid board is provided. It is a longitudinal cross-sectional view which shows the outline of 2nd Embodiment of a photoelectric hybrid board | substrate . It is a top view which shows the support substrate and sheet material with which the opto-electric hybrid board shown in FIG. 6 is provided. It is a top view which shows the support substrate and sheet material with which 3rd Embodiment of an opto-electric hybrid board is equipped.

Hereinafter, a method for manufacturing 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, prior to describing the method for manufacturing an opto-electric hybrid board according to the present invention, the opto-electric hybrid board manufactured by the method for manufacturing an opto-electric hybrid board according to the present invention will be described.

<First Embodiment>
First, a first embodiment of the opto-electric hybrid board will be described.

FIG. 1 is a longitudinal sectional view schematically showing a first embodiment of the opto-electric hybrid board , and FIG. 2 is a plan view showing a support substrate and a sheet material provided in the opto-electric hybrid board shown in FIG. In the following description, the upper side in FIG. 1 is referred to as “upper” and the lower side is referred to as “lower”. Moreover, in FIG. 2, the optical waveguide joined on a sheet | seat material is shown with the dashed-two dotted line.

  The opto-electric hybrid board 1 mainly includes a support substrate 81, a sheet material 82 bonded to the support substrate 81, an optical waveguide 20 bonded on the support substrate 81 via the sheet material 82, and the optical waveguide 20. The wiring board 3 bonded to the upper surface, the light emitting element 4 and the light emitting element IC 40 mounted on the wiring board 3, respectively, and the light receiving element 5 and the light receiving element IC 50 are provided.

  In the opto-electric hybrid board 1 having such a configuration, the light L from the light emitting element 4 is transmitted through the optical waveguide (optical circuit) 20 and received by the light receiving element 5. That is, optical communication is performed between the light emitting element 4 and the light receiving element 5 via the optical waveguide 20.

  The support substrate 81 supports the sheet material 82 and the optical waveguide 20 placed on the support substrate 81.

  In this embodiment, the support substrate 81 has a flat plate shape as a whole, and further has two holes 83 for transmitting light.

  In addition, in the method for manufacturing the opto-electric hybrid board 1 described later, the hole 83 is provided corresponding to a region including these so that the defect portions 28a and 28b can be formed in the optical waveguide 20 and the sheet material 82. As shown in FIG. 2, two rectangular shapes in plan view are formed on the end portion side of the core portion 211 in the optical path direction.

  Further, the constituent material of the support substrate 81 is not particularly limited as long as it has a strength that can support the sheet material 82 and the optical waveguide 20. For example, a ceramic material such as alumina, polyethylene terephthalate, polypropylene, Examples include resin materials such as cycloolefin polymer, polymethyl methacrylate, polycarbonate, and polyarylate, glass materials such as quartz glass and soda glass, and metal materials such as aluminum and stainless steel. Alternatively, two or more kinds can be used in combination.

  For example, the support substrate 81 may have a wiring formed on the upper surface thereof, thereby providing a function as an electric wiring substrate. Further, when the support substrate 81 is made of aluminum or the like, a function as a heat dissipation substrate can be given.

  Further, the average thickness of the support substrate 81 is not particularly limited, but is preferably about 0.01 to 20 mm, and more preferably about 0.1 to 10 mm.

  The sheet material 82 has a function of supporting the optical waveguide 20 and protecting the lower surface of the optical waveguide 20 and is a liquid material used for forming the optical waveguide 20 in the method of manufacturing the opto-electric hybrid board 1 described later. (Liquid coating film 75) has a function of preventing leakage to the hole 83 side.

  The sheet material 82 has a flat plate shape (sheet shape). In this embodiment, the sheet material 82 is disposed on the support substrate 81 so as to cover almost the entire surface (the entire surface) except for the edge of the support substrate 81. Has been.

  The constituent material of the sheet material 82 is not particularly limited, and examples thereof include polyimide, polyimide amide, polyimide amide ether, polyester imide, and polyimide ether.

  The average thickness of the sheet material 82 is not particularly limited, but is preferably about 5 to 200 μm, and more preferably about 10 to 100 μm. Thereby, the sheet | seat material 82 fully exhibits the said function.

  The optical waveguide 20 has a layered core layer 21 and a layered clad layer 22 provided on each of the upper and lower surfaces of the core layer 21, and light L incident on one end of the core layer 21 is incident on the optical waveguide 20. , Transmitted (propagated) to the other end.

  The core layer 21 includes a core portion 211 having a predetermined pattern (in the present embodiment, a strip shape long in the longitudinal direction of the optical waveguide 20), and a clad portion 212 (side clad portion) adjacent to the core portion (waveguide channel) 211. It consists of and.

  In the present embodiment, as shown in FIG. 2, four core portions 211 are provided, and a cladding portion 212 is provided adjacent to the core portions 211 so as to be interposed between the core portions 211. .

  The clad part 212 is a part that performs the same function as the clad layer 22, and the clad part 212 (low refractive index region 215) and the clad layer 22 have an average refractive index (hereinafter simply referred to as the core part 211). Sometimes called "refractive index").

  Thereby, the core part 211 formed by being surrounded by the clad part 212 and the clad layer 22 transmits the light L incident from the defect part 28a described later at the interface between the core part 211, the clad part 212, and the clad layer 22. An optical path that is reflected and transmitted (propagated) to the defect portion 28b is formed.

  In the present embodiment, the core section 211 has a quadrangular shape such as a square or a rectangle (rectangle) in cross section.

  Furthermore, the core portion 211 preferably has a width in the direction of the optical path of the light L of about 10 to 100 μm, and more preferably about 15 to 80 μm in plan view as shown in FIG. As a result, the light L incident from the core part 211 is reflected at the interface between the core part 211, the clad part 212, and the clad layer 22 and reliably functions as an optical path for transmission (propagation) to the end part. To come.

  The difference in refractive index between the core part 211, the clad part 212, and the clad layer 22 is not particularly limited, but is preferably 0.5% or more, and more preferably 0.8% or more. On the other hand, the upper limit value may not be set, but is preferably about 5.5%. If the difference in refractive index is less than the lower limit, the effect of transmitting light may be reduced, and even if the upper limit is exceeded, no further increase in light transmission efficiency can be expected.

The difference in refractive index is expressed by the following equation, where A is the refractive index of the core portion 211 and B is the refractive index of the cladding portion 212 and the cladding layer 22.
Refractive index difference (%) = | A / B-1 | × 100

  In addition, in this embodiment, although the core part 211 is each formed in strip shape (straight line shape) by planar view, you may curve and branch in the middle and the shape is arbitrary. In addition, if the manufacturing method of the optical waveguide 20 which is mentioned later is used, the core part 211 of a complicated and arbitrary shape can be formed easily and with sufficient dimensional accuracy.

  On the other hand, the two clad layers 22 constitute a clad portion located below and above the core portion 211. With such a configuration, the core portion 211 functions as a light guide path whose outer periphery is surrounded by the clad portion.

  The average thickness of the clad layer 22 is preferably about 0.1 to 1.5 times the average thickness of the core layer 21, and more preferably about 0.3 to 1.25 times. Specifically, the average thickness of the clad layer 22 is not particularly limited, but is usually preferably about 1 to 200 μm, and more preferably about 5 to 100 μm. Thereby, the function as a clad layer is suitably exhibited while preventing the optical waveguide 20 from becoming unnecessarily large (thickened).

  Each constituent material of the core layer 21 and the clad layer 22 is not particularly limited as long as the above-described refractive index difference is generated. Specifically, acrylic resin, methacrylic resin, polycarbonate, polystyrene, epoxy resin, Various resin materials such as polyamide, polyimide, polybenzoxazole, polysilane, polysilazane, and cyclic olefin resins such as benzocyclobutene resin and norbornene resin, and glass materials such as quartz glass and borosilicate glass Can be used.

  In this embodiment, the sheet material 82 and the optical waveguide 20 extend from the lower surface of the sheet material 82 to the upper cladding layer 22 beyond the lower cladding layer 22 and the core layer 21 (core portion 211). Defects 28a and 28b formed by removing (removing) portions are provided. As a result, at least the surfaces of the core layer 21 that face the defect portions 28a and 28b are mirrors that reflect light based on the refractive index difference between the core layer 21 and the air in the defect portions 28a and 28b, respectively. Optical path changing section 23a, 23b to be changed.

  In addition, by setting it as this structure, the area | region in which the mirrors 23a and 23b of the core part 211 were formed comprises the edge part of the core part 211. FIG.

  Further, the defect portions 28 a and 28 b are formed so as to form a right triangle in the longitudinal section of the optical waveguide 20, and the mirrors (optical path changing portions) 23 a and 23 b are approximately 45 with respect to the central axis of the core layer 21. Inclined at °. Therefore, as indicated by the arrow in FIG. 1, the light L emitted downward from the light emitting element 4 is changed (bent) by 90 ° by the mirror 23a immediately below the light L, and then the core The light is transmitted through the layer 21 (core portion 211), and the light path is changed upward by about 90 ° by the mirror 23 b directly below the light receiving element 5, and then enters the light receiving element 5.

  By providing such mirrors 23 a and 23 b, the main surface (upper surface and / or lower surface) of the optical waveguide 20 can be used as a region for mounting the light emitting element 4 and the light receiving element 5 through the wiring substrate 3. The opto-electric hybrid board 1 can be downsized and contributes to high-density mounting.

  The wiring board 3 is bonded to the upper surface of the optical waveguide 20, and the light emitting element 4 and the light emitting elements are formed on the upper surface of the wiring board 3 so as to correspond to a core portion 211 provided in the core layer 21 described later. The element IC 40, the light receiving element 5 and the light receiving element IC 50 are mounted.

The wiring board 3 has a wiring part (not shown) formed in a predetermined pattern.
The light emitting element (optical element) 4 includes an element main body 41 including a light emitting portion and a bump 42, and the bump 42 is bonded to a terminal included in the wiring portion (conductor portion). The light emitting element IC 40 includes an element body 401 and a bump 402 on which a predetermined circuit is formed, and the bump 402 is bonded to a terminal included in the wiring portion. As a result, the light emitting element 4 is electrically connected to the light emitting element IC 40 via the wiring substrate 3, and its operation is controlled by the light emitting element IC 40.

  Furthermore, the light receiving element (optical element) 5 includes an element body 51 including a light receiving portion and a bump 52, and the bump 52 is bonded to a terminal included in the wiring portion. The light receiving element IC 50 includes an element body 501 on which a predetermined circuit is formed and a bump 502, and the bump 502 is joined to a terminal of the wiring portion. As a result, the light receiving element 5 is electrically connected to the light receiving element IC 50 via the wiring board 3, and the light receiving element IC 50 operates to amplify the detection signal from the light receiving element 5.

  As a result, an electric circuit is constructed in the opto-electric hybrid board 1. In the opto-electric hybrid board 1, these optical elements (light emitting element 4 and light receiving element 5) and electric elements (light emitting element IC 40 and light receiving element IC 50). ) In cooperation with each other, the mutual conversion between the optical signal and the electric signal is performed reliably, and the signal processing with high speed and low noise can be easily performed.

  Further, in such a wiring board 3, the portion corresponding to the optical path of the light L from the light emitting element 4 and the portion corresponding to the optical path of the light L to the light receiving element 5 are allowed to transmit the light L, respectively. As shown in FIG.

  In the present embodiment, the optical waveguide substrate 2 is constituted by the support substrate 81, the sheet material 82, and the optical waveguide 20 among such an opto-electric hybrid substrate 1.

  In the present embodiment, the sheet material 82 is made of the same material as that of the cladding layer 22, so that the sheet material 82 has a refractive index lower than that of the core portion 211. You may make it exhibit the function as 22. FIG. In this case, the formation of the lower clad portion 22 of the optical waveguide 20 can be omitted.

  Furthermore, although the case where the longitudinal sections of the defect portions 28a and 28b have a right triangle shape has been described, the present invention is not limited to such a case, and if the mirrors 23a and 23b are formed by providing the defect portions, the defect The part may have any shape, for example, the longitudinal section thereof may have a trapezoidal shape.

  The opto-electric hybrid board 1 as described above is manufactured, for example, as follows using the opto-electric hybrid board manufacturing method of the present invention.

  In the following, a case where the core layer 21 provided in the optical waveguide 20 is formed using the photosensitive resin composition 70 whose refractive index is lowered by the action of the photosensitive light will be described as an example.

  3 to 5 are partial vertical cross-sectional views for explaining the manufacturing process of the optical waveguide substrate provided in the opto-electric hybrid board. 3 to 5 are partial longitudinal sectional views taken along the line AA of FIG. 2, and the right diagrams of FIGS. 3 to 5 are partial longitudinal sectional views taken along the line BB of FIG. FIG. In the following description, the upper side in FIGS. 3 to 5 is referred to as “upper”, and the lower side is referred to as “lower”.

  <1> First, a support substrate 81 having a hole 83 and a sheet material 82 having a sheet shape are prepared, and the sheet material 82 is joined to the support substrate (support base material) 81 (first step).

  In the present embodiment, the sheet material 82 is bonded onto the support substrate 81 so as to cover almost the entire surface excluding the edge portion of the support substrate 81, whereby the hole 83 is covered with the sheet material 82.

  The sheet material 82 can be bonded to the support substrate 81 using, for example, an adhesive such as polyolefin, polyamide, polyester, or polyurethane.

  <2> Next, the optical waveguide substrate 2 is obtained by forming the optical waveguide 20 on the support substrate 81 with the sheet material 82 interposed therebetween.

  <2-1> First, by the action of the photosensitive resin composition (core layer forming resin composition) 70 that changes so that the refractive index is lowered by the action of the photosensitive light EL (active radiation) and the photosensitive light EL. A non-photosensitive resin composition (clad layer forming resin composition) 71 whose refractive index does not change is prepared.

  Here, as the photosensitive resin composition 70, for example, a resin composition having a special composition can be used.

  This resin composition contains a base polymer and a monomer having a refractive index lower than that of the base polymer, and the reaction of the monomer proceeds in the irradiation region irradiated with the photosensitive light EL, whereby the photosensitive light EL. In some cases, unreacted monomer is diffused into the irradiated region from the unirradiated region where no irradiation is performed, and as a result, the refractive index of the unirradiated region becomes higher than the refractive index of the irradiated region.

  Examples of the base polymer include cyclic olefin resins such as norbornene resins and benzocyclobutene resins, acrylic resins, methacrylic resins, polycarbonates, polystyrenes, epoxy resins, polyamides, polyimides, polybenzoxazoles, and silicone resins. , Fluorine resins and the like, and one or more of these can be used in combination (polymer alloy, polymer blend (mixture), copolymer, etc.).

  Among these, those mainly composed of cyclic olefin resins are preferable. By using a cyclic olefin-based resin as the base polymer, the core layer 21 having excellent optical transmission performance and heat resistance can be formed.

  Furthermore, as the cyclic olefin-based resin, it is preferable to use a norbornene-based resin from the viewpoints of heat resistance and transparency. Moreover, since norbornene-type resin has high hydrophobicity, the core layer 21 which is hard to produce the dimensional change by water absorption, etc. can be formed.

  On the other hand, as the monomer, for example, a norbornene monomer, an acrylic acid (methacrylic acid) monomer, an epoxy monomer, an oxetane monomer, a vinyl ether monomer, a styrene monomer, or the like having a lower refractive index than the base polymer is selected. Of these, one or two or more of these can be used in combination.

  Among these, as the monomer, it is preferable to use a monomer or oligomer having a cyclic ether group such as an oxetanyl group or an epoxy group. By using a monomer or oligomer having a cyclic ether group, the cyclic ether group is likely to be opened, so that a monomer capable of reacting quickly can be obtained.

  Specifically, as a monomer having an oxetanyl group and having a refractive index lower than that of the base polymer, for example, a monofunctional oxetane (3- (cyclohexyloxy) methyl-3-ethyloxetane represented by the following formula (1): CHOX) and the like.

  Moreover, as the non-photosensitive resin composition 71, what contains the said base polymer which has a refractive index lower than the core part 211 formed in a post process as a main material, for example can be used.

  In the present embodiment, the photosensitive resin composition 70 and the non-photosensitive resin composition 71 constitute an optical waveguide forming material for forming the optical waveguide 20.

  <2-2> Next, the non-photosensitive resin composition 71, the photosensitive resin composition 70, and the non-photosensitive resin composition 71 are supported on the support substrate 81 with the sheet material 82 interposed therebetween. A liquid film 75 having a three-layer structure laminated in this order from the side is formed (second step).

  In addition, such a liquid coating 75 makes each of the photosensitive resin composition 70 and the non-photosensitive resin composition 70 varnish (liquid), and these varnish-like materials (liquid materials), for example, It can be formed by supplying the sheet material 82 individually or collectively.

  Further, when the photosensitive resin composition 70 and the non-photosensitive resin composition 71 are varnished, each resin composition 70, 71 can be obtained by dissolving or dispersing in a solvent or a dispersion medium, The solvent or dispersion medium is not particularly limited, and examples thereof include those described in JP 2010-90328 A.

  Further, as a method for supplying the photosensitive resin composition 70 and the non-photosensitive resin composition 71 onto the cladding layer 22, various coating methods can be used, for example, a doctor blade method, a spin coating method, a dipping method, Examples of the method include a table coating method, a spray method, an applicator method, a curtain coating method, and a die coating method. The curtain coating method is preferably used.

  According to the curtain coating method, by using the head H1 that can supply three kinds of liquid materials in a laminated state, as shown in FIG. 3A, the non-photosensitive resin composition 71, the photosensitive resin composition, Since the product 70 and the non-photosensitive resin composition 71 can be supplied on the support substrate 81 in a state of being laminated in this order, the liquid coating 75 having a three-layer structure can be easily formed collectively. it can. As a result, the process for forming the liquid film 75 can be simplified.

  Here, the support substrate 81 is configured to include the hole portion 83 so that the defect portions 28a and 28b can be formed in the optical waveguide 20 in the post-process <3>. Therefore, when the liquid film 75 is formed on the support substrate 81 without bonding the sheet material 82 to the support substrate 81, a part of the liquid film 75 is formed inside the hole 83 depending on the viscosity of the liquid film 75. Leakage (embedding) may cause a problem that the liquid film 75 having a uniform film thickness, and hence the optical waveguide 20 (particularly, the lower clad layer 22) having a uniform film thickness cannot be formed. . On the other hand, in the present invention, the sheet material 82 is bonded to the support substrate 81 so as to cover the hole 83. Therefore, since the sheet material 82 is interposed between the liquid film 75 and the support substrate 81, it is possible to reliably prevent the liquid film 75 from leaking into the hole 83.

  Furthermore, when the substantially upper surface of the support substrate 81 is covered with the sheet material 82 as in this embodiment, the liquid coating 75 is formed on the sheet material 82 without contacting the support substrate 81. It becomes. Therefore, in such a configuration, even when the support substrate 81 having a relatively rough surface property is used, the optical waveguide 20 having a uniform film thickness can be reliably formed.

  <2-3> Next, by drying the liquid film 75 having a three-layer structure formed on the support substrate 81, as shown in FIG. 3B, the clad layer forming film 73 and the core layer forming film are formed. An optical waveguide forming film (layer) 76 in which the film 72 and the clad layer forming film 73 are laminated in this order is formed (third step).

  Among the films 76, the core layer forming film 72 becomes the core layer 21 including the core part 211 and the clad part 212 by irradiation with photosensitive light (active radiation) EL described later.

  In addition, the refractive index of the clad layer forming film 73 does not change even when irradiated with photosensitive light (active radiation) EL. By forming the core layer 21 including the core part 211 and the clad part 212, The function as the cladding layer 22 is exhibited.

  Therefore, the film 76 having the three-layer structure forms a layer containing the optical waveguide forming material.

  <2-4> Next, the optical waveguide 20 is formed by performing a predetermined process on the film 76 (fourth step).

  In the present embodiment, this predetermined processing is performed by selectively irradiating the region for forming the clad portion 212 in the core layer forming film 72 with photosensitive light EL (for example, ultraviolet rays). .

  At this time, as shown in FIG. 4A, a mask M having an opening corresponding to the shape of the clad portion 212 to be formed above the core layer forming film 72 (film 76) is disposed. Through this mask M, the core layer forming film 72 is irradiated with the photosensitive light EL. In other words, the region where the core part 211 is to be formed is masked using the mask M.

  Examples of the photosensitive light EL used include those having a peak wavelength in a wavelength range of 200 to 450 nm. Thereby, the refractive index in the area | region where the photosensitive light EL of the film 72 for core layer formation was irradiated can be made comparatively easily low.

The irradiation amount of the photosensitive optical EL is not particularly limited, and is preferably about 0.1~9J / cm ^2, more preferably about 0.2~6J / cm ^2, 0.2 More preferably, it is about ˜3 J / cm ² .

  Note that the use of the mask M can be omitted in the case where photosensitive light EL having high directivity such as laser light is used.

  Here, in the irradiation region of the core layer forming film 72 irradiated with the photosensitive light EL, monomer reaction (crosslinking of the pace polymer, polymerization of the monomer, etc.) starts. Further, no monomer reaction occurs in the non-irradiated region where the photosensitive light EL is not irradiated.

  Therefore, in the irradiation region, the remaining amount of monomer decreases as the reaction of the monomer proceeds. In response, the monomer in the unirradiated region diffuses toward the irradiated region, thereby causing a refractive index difference between the irradiated region and the unirradiated region.

  Here, in this embodiment, since the refractive index of the monomer is lower than the refractive index of the base polymer, the monomer in the unirradiated region diffuses into the irradiated region, so that the refractive index of the irradiated region continuously decreases. The refractive index of the unirradiated region is continuously increased.

  Through this process, as shown in FIG. 4B, the unirradiated region of the core layer forming film 72 becomes the core portion 211, and the irradiated region of the core layer forming film 72 becomes the cladding portion 212. 21 is formed.

  In addition, since the clad layer forming film 73 has no change in the refractive index even when irradiated with the photosensitive light EL, and the base material having a lower refractive index than that of the core portion 211 is used as a main material, The clad layer 22 is constituted by the clad layer forming film 73.

  Accordingly, the pair of clad layers 22 are arranged so as to sandwich the core portion 211 from a direction different from that of the clad portion 212, that is, from the vertical direction of the core portion 211, and therefore, as shown in FIG. A waveguide 20 is formed.

  As described above, the optical waveguide substrate 2 in which the optical waveguide 20 is formed on the support substrate 81 is manufactured through the sheet material 82. However, the optical waveguide substrate 2 is directly formed on the support substrate 81 through the above-described steps. The optical waveguide 20 can be formed. Therefore, the manufacturing process is simplified compared with the case where the optical waveguide 20 is manufactured on the dummy substrate, and then the optical waveguide 20 separated from the dummy substrate is bonded to the support substrate 81 to obtain the optical waveguide substrate 2. Can be planned.

  <3> Next, the defective parts 28a and 28b are formed by removing a part of the sheet material 82 and the optical waveguide 20 (fifth step).

  More specifically, in the present embodiment, the missing portions 28 a and 28 b extend from the lower surface of the sheet material 82 to the upper cladding layer 22 beyond the lower cladding layer 22 and the core layer 21 (core portion 211). It is formed by deleting (removing) the previous part.

  Such formation of the defect portions 28a and 28b is performed, for example, by subjecting the optical waveguide 20 to laser processing, grinding processing, or the like.

  Therefore, for example, when the defect portions 28a and 28b are formed by laser processing, the present invention includes the regions where the optical waveguide 20 and the defect portions 28a and 28b of the sheet material 82 are to be formed as described above. A hole 83 is provided. Therefore, as shown in FIG. 5A, the head H <b> 2 provided in the laser device is disposed at a position corresponding to the hole 83 below the support substrate 81, so that the laser is transmitted through the hole 83 to the sheet material. 82 and the optical waveguide 20 can be directly irradiated. Therefore, even if the optical waveguide 20 is directly formed on the support substrate 81, the defect portions 28a and 28b can be easily formed (see FIG. 5B).

  It should be noted that an alignment mark may be provided in advance on the lower surface of the sheet material 82 at a position where the missing portions 28a and 28b are to be formed. Thereby, even if the sheet material 82 is made of a material having no transparency, the sheet material 82 and a part of the optical waveguide 20 are removed without causing displacement, and the defective portions 28a and 28b are formed. Can be formed.

<4> Next, the wiring board 3 is prepared.
For each wiring board 3, for example, a laminated board (for example, a double-sided copper-clad board) in which a metal layer is formed on both sides of a flat base is prepared, and subjected to etching, laser processing, etc., so that the metal layer has a predetermined shape. It is manufactured by patterning to form a wiring part.

  <5> Next, the light-emitting element 4 and the light-emitting element IC 40, the light-receiving element 5 and the light-receiving element IC 50 are respectively prepared and mounted (bonded) at predetermined positions on the wiring board 3.

  <6> Next, while positioning the wiring board 3 such that the light emitting part of the light emitting element 4 corresponds to the mirror 23a of the missing part 28a, and the light receiving part of the light receiving element 5 corresponds to the mirror 23b of the missing part 28b. The upper surface of the optical waveguide 20 is bonded using an adhesive.

The opto-electric hybrid board 1 is manufactured through the steps as described above.
In the present embodiment, the case where the core layer 21 including the core part 211 and the clad part 212 is formed using a resin composition containing a monomer having a refractive index lower than that of the base polymer has been described. The core layer 21 may be formed using a resin composition containing a monomer having a higher refractive index than that of the base polymer.

  When such a resin composition is used, the refractive index in the irradiated region of the core layer forming film 72 where the monomer diffuses by irradiation with the photosensitive light EL is higher than that in the unirradiated region of the core layer forming film 72. Therefore, in such a form, the core layer 21 is formed in which the irradiated region and the non-irradiated region of the core layer forming film 72 become the core part 211 and the clad part 212, respectively.

Second Embodiment
Next, a second embodiment of the opto-electric hybrid board will be described.

FIG. 6 is a longitudinal sectional view showing an outline of the second embodiment of the opto-electric hybrid board , and FIG. 7 is a plan view showing a support substrate and a sheet material provided in the opto-electric hybrid board shown in FIG. In the following description, the upper side in FIG. 6 is referred to as “upper” and the lower side is referred to as “lower”. Moreover, in FIG. 7, the optical waveguide joined on a sheet | seat material is shown with the dashed-two dotted line. Furthermore, the hatching in FIG. 7 is included in the sheet material for easy understanding of the difference between the support substrate and the sheet material, and does not indicate a cross section.

  Hereinafter, although the opto-electric hybrid board 1 according to the present embodiment will be described, differences from the opto-electric hybrid board 1 according to the first embodiment will be mainly described, and description of similar matters will be omitted.

  The opto-electric hybrid board 1 according to the present embodiment is the same as that of the first embodiment except that the shape of the sheet material 82 joined to the support substrate 81 so as to cover the hole 83 is different.

  The sheet material 82 shown in FIGS. 6 and 7 is formed so that the planar view shape thereof substantially matches the planar view shape of the hole 83, and is provided selectively with respect to the hole 83. As shown in FIG. 6, a flat surface is formed by the upper surface of the support substrate 81 and the upper surface of the sheet material 82 by being unevenly distributed above the hole 83.

  Also by joining the sheet material 82 having such a configuration to the support substrate 81, the operation and effect obtained by providing the sheet material 82 can be obtained in the same manner as described in the first embodiment.

  That is, in the step <2-2>, it is possible to prevent a part of the liquid coating 75 from leaking into the hole 83 and form the optical waveguide 20 with a uniform film thickness. Formation of the defect | deletion parts 28a and 28b via the hole 83 in <3> is realizable.

<Third Embodiment>
Next, a third embodiment of the opto-electric hybrid board will be described.

FIG. 8 is a plan view showing a support substrate and a sheet material provided in the third embodiment of the opto-electric hybrid board . In the following description, the front side of the paper in FIG. 8 is referred to as “upper”, and the rear side of the paper is referred to as “lower”. Moreover, in FIG. 8, the optical waveguide joined on a sheet | seat material is shown with the dashed-two dotted line.

  Hereinafter, although the opto-electric hybrid board 1 according to the present embodiment will be described, differences from the opto-electric hybrid board 1 according to the first embodiment will be mainly described, and description of similar matters will be omitted.

  The opto-electric hybrid board 1 according to the present embodiment is the same as the first embodiment except that the configuration of the hole 83 formed in the support substrate 81 is different.

  In the support substrate 81 shown in FIG. 8, the hole 83 is formed in a substantially square shape in a plan view, and eight holes 83 are provided, and are formed separately so as to correspond to the respective defective portions 28a and 28b. .

  Also in the support substrate 81 including the hole 83 having such a configuration, it is possible to obtain the operation and effect by providing the sheet material 82 on the support substrate 81 as described in the first embodiment.

  That is, in the step <2-2>, it is possible to prevent a part of the liquid coating 75 from leaking into the hole 83 and form the optical waveguide 20 with a uniform film thickness. Formation of the defect | deletion parts 28a and 28b via the hole 83 in <3> is realizable.

  In addition, the shape in plan view of the defect portions 28a and 28b is not particularly limited, and other than the case where it is a square shape as in the present embodiment, for example, a circular shape such as a perfect circle, an ellipse, an ellipse, a triangle, a rectangle It may be a polygonal shape such as a hexagon or an octagon.

The opto-electric hybrid board can be applied to any electronic device that performs signal processing of both optical signals and electric signals. For example, a router device, a WDM device, a mobile phone, a game machine, a personal computer, a television, and a home server. Application to electronic devices such as these is preferable. In any of these electronic devices, it is necessary to transmit a large amount of data at high speed between an arithmetic device such as an LSI and a storage device such as a RAM. Therefore, by providing such an electronic device with the opto-electric hybrid board , problems such as noise and signal degradation peculiar to the electric wiring are eliminated, and a dramatic improvement in performance can be expected.

  In addition, the amount of heat generated in the optical waveguide portion is greatly reduced compared to electrical wiring. For this reason, the degree of integration in the substrate can be increased, the power required for cooling can be reduced, and the power consumption of the entire electronic device can be reduced.

As mentioned above, although embodiment of the manufacturing method of the opto-electric hybrid board | substrate of this invention was described, this invention is not limited to this.

  For example, each part constituting the opto-electric hybrid board can be replaced with any part having a similar function. Moreover, arbitrary components may be added.

Further, in the opto-electric hybrid board , any configuration of the first to third embodiments can be combined.

  In each of the above embodiments, the case where the longitudinal cross-sectional shape of the core portion and the core portion are rectangular has been described, but the present invention is not limited to this. An elliptical shape, an oval shape, a triangular shape, etc. may be sufficient as the longitudinal cross-sectional shape of a core part.

DESCRIPTION OF SYMBOLS 1 Opto-electric hybrid board 2 Optical waveguide board 20 Optical waveguide 21 Core layer 211 Core part 212 Clad part 22 Clad layer 23a, 23b Mirror 28a, 28b Defect part 3 Wiring board 4 Light emitting element 41 Element main body 42 Bump 40 Light emitting element IC
401 Element body 402 Bump 5 Light receiving element 51 Element body 52 Bump 50 Light receiving element IC
501 Element body 502 Bump 70 Photosensitive resin composition 71 Non-photosensitive resin composition 72 Core layer forming film 73 Clad layer forming film 75 Liquid coating 76 Film 81 Support substrate 82 Sheet material 83 Hole H1 head H2 head M mask L light EL light for light exposure

Claims (2)

A first step of preparing a support substrate including a hole for transmitting laser light and a sheet material in a sheet shape, and bonding the sheet material to the support substrate so as to cover the hole;
A liquid film is formed by supplying a liquid material containing an optical waveguide forming material for forming an optical waveguide onto the support substrate in a state where the sheet material is interposed using a coating method. And the process of
A third step of drying the liquid film to form a layer containing the optical waveguide forming material;
A fourth step of forming the optical waveguide by applying a predetermined treatment to the layer ;
A part of the sheet material and the optical waveguide is removed using the laser light through the hole portion, thereby forming a defect portion including an optical path changing mirror that changes the direction of the optical path, and a light emitting element and And a fifth step of bonding a wiring board on which the light receiving element is mounted on the optical waveguide . In the second step, the optical waveguide forming material includes a polymer and a monomer having a refractive index different from that of the polymer. The irradiation region is irradiated with the active radiation and irradiated with the active radiation. In the above, by allowing the reaction of the monomer to proceed, the unreacted monomer is diffused into the irradiated region from the unirradiated region that is not irradiated with the actinic radiation, and as a result, the irradiated region and the unirradiated region By providing a difference in refractive index between them, one of the irradiated region and the non-irradiated region is used as the core portion, and the other is provided with a core layer serving as the cladding portion having a refractive index lower than that of the core portion. The method for manufacturing an opto-electric hybrid board according to claim 1 , wherein an optical waveguide is formed.

Images