JP2001311846A - Method for manufacturing electric wiring/optical wiring coexisting multilayer sheet and method for manufacturing electric wiring/optical wiring coexisting multilayer substrate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To manufacture an electric wiring/optical wiring coexisting multilayer sheet having a large area. SOLUTION: Electric wiring 54 made of a Cu thick film is provided on a substrate 50. Further, intermediate clad 60a, a core 68a and an upper clad layer 70 all consisting of high polymer material are provided and a copper foil sheet 90 is stuck onto the upper clad layer. Thereafter, the substrate is removed and a lower clad layer 72 is formed in a place where the substrate has existed. Next, after sticking the copper foil sheet 91 onto the lower clad layer, the electric wiring/optical wiring coexisting multilayer sheet wherein electric wiring 90a, 91a is formed on both of upper and lower surfaces of a flexible optical waveguide sheet incorporating electric wiring 54 by patterning theses copper foil sheets 90, 91 and forming electric wiring 90a, 91a is manufactured.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a method of manufacturing a multilayer sheet mixed with electric wiring and optical wiring and a method of manufacturing a multilayer board mixed with electric wiring and optical wiring suitable for use in an optical interconnect.

[0002]

2. Description of the Related Art Conventionally, a printed circuit board on which electric components such as ICs and resistors are mounted is exclusively provided with only electric components, and transmission and reception of signals between printed circuit boards and modules are performed by a flexible electric cable. I have been. However, recently, not only electrical components but also optical components are often mixed on the same printed circuit board,
In such a printed circuit board, optical wiring such as an optical fiber is used together with electric wiring. Also, transmission and reception of signals between printed circuit boards and modules have been performed using flexible optical fibers.

As described above, according to the optical interconnect for transmitting and receiving signals by light, the time delay is smaller than in the case where only electric wiring is used, and the speed of signal processing can be increased. In addition, the optical interconnect has an advantage that it is not affected by electric noise, which is a problem in electric wiring. Therefore, optical interconnects will be used more and more in the future, and in the future, not only performance and reliability but also cost reduction will be important.

Hitherto, a flexible optical waveguide made of a polymer material has been used as an optical wiring component for an optical interconnect, and its manufacturing method is disclosed in Japanese Patent Application Laid-Open No. Hei 8-304650.

[0005] The manufacturing method disclosed in the above document will be described with reference to FIGS. 11 and 12. 11 and 12 are cross-sectional views showing a conventional manufacturing process.

First, a copper (Cu) thin film 3 having a thickness of several tens nm to several hundreds nm is formed on a Si substrate 30 by sputtering.
2 is formed (FIG. 11A).

Next, a polymer optical waveguide material is deposited on the Cu thin film 32 to form a lower cladding layer 34 (FIG. 11).
(B)).

Next, a polymer optical waveguide material is deposited on the lower cladding layer 34 to form a core layer 36 (FIG. 11).
(C)). The material is adjusted so that the refractive index of the core layer 36 is higher than the refractive index of the lower cladding layer 34.

Next, after applying a resist on the core layer 36, photolithography and development are performed to obtain the core layer 3.
A resist pattern 38 is formed on 6 (FIG. 11)
(D)).

Next, reactive ion etching (RIE) using an oxygen (O ₂ ) gas is performed to form the core layer 36.
Is formed to form a core 36a having a pattern corresponding to the resist pattern 38. FIG.
(E)).

Next, the resist pattern 3 on the core 36a is
8 is removed (FIG. 12A).

Next, a polymer optical waveguide material is deposited on a portion where the lower cladding layer 34 is exposed and on the core 36a to form an upper cladding layer 40 (FIG. 12).
(B)). The refractive index of the upper cladding layer 40 is set to be the same as the refractive index of the lower cladding layer 34. By the above steps, the optical waveguide section 42 constituted by the upper cladding layer 40, the core 36a, and the lower cladding layer 34
It is formed on the u thin film 32.

Next, the optical waveguide chip is immersed in an aqueous hydrochloric acid (HCl) solution or an aqueous potassium hydroxide (KOH) solution 44 (FIG. 12C) to dissolve the Cu thin film 32,
The optical waveguide 42 is peeled off from the substrate 30 (FIG. 12).
(D)). As a result, the separated optical waveguide portion 42 is obtained as a flexible optical waveguide.

[0014]

However, according to the manufacturing method disclosed in the above document, the step of forming the Cu thin film 32 (FIG. 11A) and the step of RIE (FIG.
(E)) is a vacuum process performed in a vacuum chamber. Thus, the conventional method requires a vacuum device. Generally, vacuum equipment is expensive, and vacuum processes reduce productivity. Therefore, cost reduction is difficult.

In general, the size of the vacuum chamber is limited, and the size of the substrate that can be processed is also limited in view of the thickness of the Cu thin film on the substrate and the in-plane distribution of RIE processing accuracy. . For this reason, according to the conventional method, for example,
An optical waveguide having a size such as an m-square could not be manufactured. Further, when an optical waveguide sheet made of a conventional flexible optical waveguide is used for an optical interconnect, (1) the degree of freedom of electric wiring and optical wiring and (2) the increase in the density of mounting of electric parts and optical parts. There was a problem.

The present invention solves the above-mentioned problems, enables the manufacture of an optical waveguide that does not require a vacuum device, and enables the production of an optical waveguide having a large area, and furthermore, enables the freedom of electric wiring and optical wiring. It is an object of the present invention to provide a method for manufacturing a multilayer sheet with mixed electrical and optical wirings and a method for manufacturing a multilayered board with mixed electrical and optical wirings, which enable high-density mounting of electrical and optical components.

[0017]

In order to solve the above-mentioned problems, a method of manufacturing a multilayer sheet in which electric wiring and optical wiring are mixed according to the present invention comprises an optical waveguide comprising a core and a clad formed of a polymer material. A step of bonding a conductive sheet on at least one of the front and back surfaces of the flexible optical waveguide sheet, and a step of patterning the conductive sheet into a predetermined shape to form a pattern of electric wiring. And

In manufacturing a multilayer sheet containing both electric wiring and optical wiring, it is preferable to further include an electric wiring pattern in the flexible optical waveguide sheet in order to increase the number of electric wiring layers.

In manufacturing a multilayer sheet mixed with electric wiring and optical wiring, in order to increase the number of electric wiring layers, in the step of bonding conductive sheets, a conductive sheet is bonded to both the front and back surfaces of the flexible optical waveguide sheet. Preferably, in the step of forming an electric wiring pattern, electric wiring patterns are formed on both surfaces of the flexible optical waveguide sheet.

In order to improve the adhesiveness between the layers when manufacturing the above-mentioned multilayer sheet mixed with electric wiring and optical wiring,
Preferably, before the step of bonding the conductor sheets, the method further includes a step of roughening a surface to be bonded of each of the flexible optical waveguide sheet and the conductor sheet in advance.

In manufacturing a multilayer sheet mixed with electric wiring and optical wiring, a through hole or a via hole is formed in the flexible optical waveguide sheet for interlayer connection, and a conductor is plated on the inner wall of the through hole or the via hole. It is preferable that the method further includes a step of performing.

In order to achieve optical coupling between an optical waveguide and an optical component when manufacturing a multilayer sheet in which electric wiring and optical wiring are mixed, the flexible optical waveguide sheet includes a predetermined position in a core forming region thereof. A step of providing an opening so as to open, a step of mounting a deflecting mirror in the opening, and a step of mounting the deflecting mirror on one of the front surface and the back surface of the flexible optical waveguide sheet located above the deflecting mirror. And mounting an optical component that is optically coupled to the core of the optical waveguide via the deflecting mirror.

[0023] The method for manufacturing a multilayer board mixed with electric wiring and optical wiring according to the present invention comprises the steps of: forming a flexible optical waveguide sheet having an optical waveguide comprising a core and a clad formed of a polymer material; and a printed board having electric wiring. Bonding and laminating via a prepreg, laminating and laminating a conductive sheet on a surface of at least one of the flexible optical waveguide sheet and the printed circuit board opposite to a surface facing the other, and Patterning the sheet into a predetermined shape to form an electric wiring pattern.

[0024] In manufacturing the multilayer board mixed with electric wiring and optical wiring, it is preferable that, in the step of bonding and laminating the conductor sheets, the conductor sheets are laminated and laminated via a prepreg.

In the production of a multi-layer substrate incorporating both electric wiring and optical wiring, it is preferable to further include an electric wiring pattern in the flexible optical waveguide sheet in order to increase the number of electric wiring layers.

[0026] In the production of a multi-layer board on which electric wiring and optical wiring are mixed, in order to make the electric wiring multi-layered, in the step of bonding and laminating a conductor sheet, the flexible optical waveguide sheet and the printed board are laminated. In the step of laminating and laminating a conductor sheet via a prepreg on the surface opposite to the surface facing each other and forming a pattern of electric wiring, the flexible optical waveguide sheet and the printed board are provided via the prepreg. It is preferable to form the electric wiring by patterning the conductor sheets laminated on each other.

In order to improve the adhesiveness between layers when manufacturing a multilayer board on which electric wiring and optical wiring are mixed, a flexible optical waveguide sheet and a printed board are laminated and laminated together with a conductive sheet via a prepreg. Preferably, before the step of laminating and laminating, the method further includes a step of preliminarily roughening the surfaces to be bonded of the flexible optical waveguide sheet, the printed circuit board, and the conductor sheet.

Further, in manufacturing a multilayer board on which electric wiring and optical wiring are mixed, a flexible optical waveguide sheet and a printed board are laminated and laminated together with a conductive sheet via a prepreg for interlayer connection. It is preferable that the method further includes a step of forming a through hole or a via hole in the laminate formed in the step, and plating a conductor on an inner wall of the through hole or the via hole.

A laminate formed by performing each step of the invention according to claim 7 in order to achieve optical coupling between an optical waveguide and an optical component when manufacturing a multilayer board mixed with electric wiring and optical wiring. Providing an opening so as to include a predetermined position in the core forming region of the flexible optical waveguide sheet, and mounting a deflecting mirror in the opening; and Mounted on one of the front and back surfaces of the laminate,
Mounting an optical component that is optically coupled to the core of the optical waveguide via the deflecting mirror.

[0030]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. It should be noted that the drawings merely schematically show the shapes, sizes, and arrangements so that the present invention can be understood. The conditions and materials such as numerical values described below are merely examples, and the present invention
The present invention is not limited to this embodiment.

[First Embodiment] In this first embodiment, an electric wiring / optical wiring mixed multilayer sheet, specifically, an electric wiring is provided on an upper clad layer of a flexible optical waveguide sheet in which electric wiring is embedded. A method of manufacturing a flexible optical waveguide sheet having a multilayer structure further provided with wiring (multilayer sheet mixed with electric wiring and optical wiring) will be described. The manufacturing process of the first embodiment will be described with reference to FIGS. First, a flexible optical waveguide sheet in which electric wiring is provided inside the flexible optical waveguide sheet is manufactured.
1 to 4 are cross-sectional views showing the steps of manufacturing this flexible optical waveguide sheet. Each figure shows the configuration of the main part.

First, a dry film 52, which is a photosensitive resin film, is laminated on the upper surface of the substrate 50 (FIG. 1).
(A)). The substrate 50 is made of stainless steel (SUS).
As a dry film 52, A made by Asahi Kasei Corporation
Q-5036 (model number) is used. The size of the dry film 52 is 200 mm square. Dry Life 5
2 has a thickness of 50 μm.

Subsequently, the dry film 52 is irradiated with UV using an exposure mask having an opening pattern having both a core and an electric wiring pattern. This allows
A latent image is formed on the dry film 52, and then the exposed dry film 52 is developed. As a result, a predetermined position of the dry film 52 is removed, and a dry film 52a having the removed portion as a recess is obtained on the substrate 50 (FIG. 1).
(B)). The pattern of the remaining dry film 52a matches the pattern of the intermediate cladding layer.

Next, a copper (Cu) thick film 54 is formed to a thickness of about 50 μm by an electroplating method so as to fill the concave portion of the dry film 52a (FIG. 1C). C
The pattern of the u-thick film 54 matches the pattern of the core and the electrical wiring. Subsequently, by immersing in a 3% aqueous sodium hydroxide solution and peeling off the dry film 52a, an uneven structure 56 in which a pattern of the Cu thick film 54 is formed at a predetermined position on the Cu substrate 50 is obtained (FIG. 1
(D)). The uneven structure 56 serves as a mold for the intermediate cladding layer.

Here, the surface of the Cu thick film 54 is roughened. In this roughening treatment, the surface of copper is oxidized to form minute irregularities and needle-like projections on the surface. The resin formed around the Cu thick film 54 is easily fixed by the unevenness and the small protrusions.

Next, the concave portion 58 of the formed concave-convex structure 56
Then, a solution of a fluorinated polyimide as a cladding material (OPIN-3205 (product name, manufactured by Hitachi Chemical)) is poured by a screen printing method, and a heat treatment is performed at a temperature of 350 ° C. for 1 hour. By this baking, the solvent of the fluorinated polyimide solution is volatilized or imidized, and the fluorinated polyimide film 60 is formed in the concave portion 58 (FIG. 2A). Since the volume shrinkage occurs during the imidization, the pouring and baking of the solution are repeated three times, and finally, the fluorinated polyimide film 6 having a thickness slightly larger than 50 μm is obtained.
I try to get 0.

Subsequently, the surfaces of the fluorinated polyimide film 60 and the Cu thick film 54 are polished so that the required dimensional accuracy as an optical waveguide is obtained, and the surfaces are flattened, and the thickness is reduced to about 50 μm. adjust. The fluorinated polyimide film after polishing becomes the intermediate cladding layer 60a (FIG. 2).
(B)).

Next, a dry film 62 is laminated on the upper surfaces of the intermediate cladding layer 60a and the Cu thick film 54 which have been planarized by polishing (FIG. 2C). Subsequently, the portion of the dry film 62 above the Cu thick film 54a at the position where the core is to be formed is removed (FIG. 2D). Therefore, the removal area of the dry film 62 is removed by exposure and development. Thus, an opening 64 is formed in the portion of the dry film 62 located above the Cu thick film 54a. Therefore, the upper surface of the Cu thick film 54a to be removed is exposed.

Next, the Cu thick film 54a exposed in the previous process is removed by immersion in an etching solution (FIG. 3A).
At this time, the other Cu thick film 54 is not removed because it is protected by the dry film 62. After the etching is completed, the unnecessary dry film 62 is peeled off (FIG. 3).
(B)). The removed portion 66 of the Cu thick film 54a serves as a core template.

Next, a core material is injected into the removed portion 66 of the Cu thick film. As the polymer material for the core, a solution of fluorinated polyimide having a smaller fluorine content than the cladding material (OPIN-3405 (product name) manufactured by Hitachi Chemical) is used. By reducing the fluorine content in this manner, the optical refractive index of the core becomes larger than the refractive index of the intermediate cladding layer 60a. As in the step of forming the intermediate cladding layer 60a, a fluorinated polyimide solution of the core material is poured into a predetermined portion, and then heat treatment is performed at 350 ° C. for one hour. As described above, since volume shrinkage occurs during imidization, the pouring and baking of the solution are repeated three times. And finally, 50 μm
A slightly thicker fluorinated polyimide film 68 is formed (FIG. 3C).

Subsequently, the surface of the fluorinated polyimide film 68 is puff-polished so as to obtain the required dimensional accuracy as an optical waveguide, and is adjusted to a thickness of about 50 μm. The fluorinated polyimide film after polishing becomes the core 68a (FIG. 3).
(D)).

Here, a roughening treatment of the polished upper surface of the Cu thick film 54 is performed. Subsequently, the upper surface of the Cu thick film 54,
On the upper surface of the core 68a and the intermediate cladding layer 60a, a fluorinated polyimide solution of the same polymer optical waveguide material as the intermediate cladding layer 60a (OPIN-3205 manufactured by Hitachi Chemical)
(Product name)) is applied. Then, by applying a heat treatment to the applied solution at a temperature of 350 ° C. for 1 hour,
A fluorinated polyimide film having a thickness of 30 μm is obtained as the upper cladding layer 70 (FIG. 4A).

Next, the substrate 50 is mechanically peeled off (FIG. 4).
(B)). Subsequently, a roughening process is performed on the exposed surface of the Cu thick film 54. Then, a fluorinated polyimide solution of the same polymer optical waveguide material as the intermediate cladding layer 60a (OPIN N-3205 manufactured by Hitachi Chemical Co., Ltd.)
(Product name)) is applied. The applied fluorinated polyimide solution is subjected to a heat treatment at 350 ° C. for one hour. By this firing, a fluorinated polyimide film having a thickness of 30 μm is formed as the lower cladding layer 72 (FIG. 4).
(C)).

In this way, as shown in FIG.
An optical waveguide (optical wiring) including an upper clad, an intermediate clad, a core and a lower clad, and an electric wiring formed of a Cu thick film are combined, and a flexible optical waveguide sheet 74 including the electric wiring is formed.

In the flexible optical waveguide sheet 74 thus formed, since a Cu thick film such as an electrical wiring can be formed in the transparent optical waveguide sheet, as shown in FIG. Sheet 74
An alignment mark 76 of a thick Cu film can be formed therein. FIG. 5 is a plan view showing an example of the configuration of the flexible optical waveguide sheet 74 in the electric wiring to be manufactured. In the flexible optical waveguide sheet 74 inside the electric wiring, an optical waveguide portion 78 made of a core and an electric wiring portion 80 made of a Cu thick film are formed. The alignment mark 76 is formed by a Cu thick film. By forming the alignment mark 76 in this manner, alignment that was difficult because the optical waveguide itself was originally transparent becomes easy. For example, when the flexible optical waveguide sheet 74 in the electric wiring is bonded on a printed circuit board, high-precision alignment can be performed.

Next, a step of forming an electric wiring on the surface of the flexible optical waveguide sheet existing in the electric wiring manufactured in the steps shown in FIGS. 1 to 4 will be described with reference to FIG. First, the surface of the upper clad layer 70 of the flexible optical waveguide sheet 74 in the electric wiring manufactured in the above-described process is subjected to a roughening treatment. In this roughening treatment, the surface of the upper cladding layer 70 is roughened by a roughening treatment method such as a chemical treatment to form minute irregularities on the surface. Further, a copper foil sheet 90 having a thickness of 20 μm is prepared as a conductor sheet to be bonded on the upper cladding layer 70, and a surface of the copper foil sheet 90 to be bonded to the upper cladding layer 70 is subjected to a roughening treatment. In this roughening treatment, the surface of copper is roughened by a roughening treatment method such as oxidation, and minute irregularities and needle-like projections are formed on the surface.

Next, the copper foil sheet 90 is placed on the upper clad layer 70 such that the roughened bonding surface of the copper foil sheet 90 faces the surface of the roughened upper clad layer 70. Then, the copper foil sheet 9 is pressed by heating using a heating / pressing means (not shown).
0 and the upper cladding layer 70 (FIG. 6
(A)). Since both surfaces to be bonded are roughened as described above, the bonding strength between the copper foil sheet 90 and the upper clad layer 70 can be increased.

Next, after applying and drying a resist on the surface of the copper foil 90 bonded to the upper clad layer 70, the resist is exposed using an exposure mask having a desired electric wiring pattern, and further developed to remove the resist pattern. After the etching mask is formed, it is immersed in an etching solution to dissolve and remove unnecessary copper foil, and further, the etching mask made of resist is removed, thereby forming a pattern of the electric wiring 90a made of copper ( FIG. 6 (B).

In this manner, the electric wiring pattern 90a is formed on the surface of the flexible optical waveguide sheet 74 inside the electric wiring.
Is completed, and the flexible optical waveguide sheet having a multilayer structure is completed. Optical components such as ICs and other electrical components and light receiving and emitting elements are mounted on the flexible optical waveguide sheet having a multilayer structure formed as described above, if necessary, and the electrical wiring pattern on the sheet surface and the like are used as necessary. The connection enables high-density mounting. Depending on the design, a via hole is formed in the upper cladding layer, the surface of the upper cladding layer is plated, or the like, so that any electric wiring 90a on the surface and any electric wiring 54 provided inside the optical waveguide sheet 74 are electrically connected. It is also possible to make the connection.

According to the present embodiment, the process of forming a Cu thin film by the sputtering method disclosed in the aforementioned document,
By omitting the vacuum process used in the IE process, a vacuum device is not required, so that a flexible optical waveguide sheet having a larger area can be manufactured. Further, productivity is remarkably improved because there is no vacuum process, and at the same time, cost can be reduced because expensive vacuum equipment is not used.

Further, in the present embodiment, since the flexible optical waveguide sheet in which electric wiring is provided has a multilayer structure in which electric wiring patterns are provided on the surface, (1) the degree of freedom of electric wiring and optical wiring is increased. (2) In addition, since the wiring length can be shortened, it is possible to reduce the strength reduction and delay of electric signals and optical signals, and to reduce the influence of noise.
The mounting density of optical components can be increased.

Various modifications of this embodiment will be described below. First, in this embodiment, the manufacturing process diagrams shown in FIGS. 1 to 4 and 6 show an example in which one core is used, that is, an example in which one optical waveguide is used. That is, the number of optical waveguides can be formed, and as shown in FIG. 5, a flexible optical waveguide sheet having a plurality of optical waveguides can be obtained.

Further, in this embodiment, a flexible optical waveguide sheet having electric wiring therein is used as a base.
Although the example in which the electric wiring is formed on the surface is shown, the flexible optical waveguide sheet serving as a base may be a flexible optical waveguide sheet having only an optical waveguide (optical wiring) having no electric wiring.

Further, in this embodiment, the patterning of the dry film 52 is performed by exposure and development, but this patterning may be performed by a laser ablation method. According to the laser ablation method,
By irradiating the laser beam, the dry film 52
Patterning can be performed. Therefore, patterning can be performed more easily.

Further, patterning by exposure and development and patterning by laser ablation may be used in combination. For example, it is preferable that the portion having a small pattern width is performed by a laser ablation method, and the other portion having a large pattern width is performed by exposure and development.

In this embodiment, an example is shown in which fluorinated polyimide is used as the polymer optical waveguide material. However, other polymer materials such as PMMA, silicone, and polycarbonate may be used. It is possible.
In the above description, when patterning the copper foil,
Although an example in which an etching mask made of a resist is used has been described, an etching mask formed by using a photosensitive resin such as a dry film or photosensitive ink and patterning the same by exposure and development may be used instead. Further, in the above description, an example in which the electric wiring made of copper is formed only on the surface of the upper cladding layer is shown. However, a similar electric wiring may be formed on the surface of the lower cladding layer. The electric wiring may be formed on both the surface and the lower clad layer surface.

[Second Embodiment] Next, a second embodiment of the present invention will be described.
An electric wiring / optical wiring mixed multilayer sheet according to the embodiment will be described with reference to the drawings. In the first embodiment described above, a method for manufacturing a flexible optical waveguide sheet having a multilayer structure in which electric wiring is provided on an upper clad layer of a flexible optical waveguide sheet having electric wiring therein has been described.
In the second embodiment, a flexible optical waveguide sheet having a multilayer structure in which electrical wiring is provided on an upper clad layer and a lower clad layer of a flexible optical waveguide sheet having an electrical wiring (a multilayer sheet mixed with electrical wiring and optical wiring). 7), that is, a method of manufacturing a flexible optical waveguide sheet having a multilayer structure in which electric wiring is provided on both upper and lower surfaces of a flexible optical waveguide sheet in an electric wiring will be described with reference to FIG. The same components as those in the first embodiment are described with the same reference numerals.

In the second embodiment, the steps up to the formation of the upper cladding layer 70 and the materials used are performed in the same manner as in the first embodiment. Therefore, a detailed description of the steps up to the formation of the upper cladding layer 70 is omitted, but the outline of the steps up to the formation of the upper cladding layer 70 will be described below with reference to the description of the first embodiment and the drawings. Will be explained.

First, in the same manner as in the steps described with reference to FIGS. 1A to 1D in the first embodiment, the concavo-convex structure 56 made of the Cu thick film 54 on the SUS substrate 50 is used. And roughening of the Cu thick film surface are performed. Next, the formation of the intermediate cladding layer 60a is performed in the same manner as in the steps described with reference to FIGS. 2A and 2B of the first embodiment. Next, FIG. 2C of the first embodiment,
The core 68a is formed in the same manner as the process described with reference to (D) and FIGS. 3A to 3D. Then the first
The upper cladding layer 70 is formed in the same manner as in the step described with reference to FIG. The steps up to the formation of the upper cladding layer 70 are the same as those of the first embodiment as described above, and the subsequent steps are different from those of the first embodiment.

Subsequently, the surface of the upper cladding layer 70 is roughened. In this roughening treatment, the surface of the upper cladding layer 70 is roughened by a roughening treatment method such as a chemical treatment to form minute irregularities on the surface. Further, as a conductive sheet to be bonded on the upper cladding layer 70, a film thickness of 20 μm
A copper foil sheet 90 of m is prepared, and the surface of the copper foil sheet 90 to be bonded to the upper cladding layer 70 is subjected to a roughening treatment.
In this roughening treatment, the surface of copper is roughened by a roughening treatment method such as oxidation, and minute irregularities and needle-like projections are formed on the surface. Next, after placing the copper foil sheet 90 on the upper clad layer 70 so that the roughened bonding surface of the copper foil sheet 90 faces the surface of the roughened upper clad layer 70. Then, the copper foil sheet 90 and the upper clad layer 70 are bonded to each other by applying pressure while heating using a heating / pressing means (not shown) (FIG. 7).
(A)). As described above, since both surfaces to be bonded are roughened, the bonding strength between the copper foil sheet 90 and the upper cladding layer 70 can be increased.

Next, the substrate 50 is mechanically peeled off (FIG. 7).
(B)). Subsequently, a roughening process is performed on the exposed surface of the Cu thick film 54. Then, a fluorinated polyimide solution of the same polymer optical waveguide material as the intermediate cladding layer 60a (OPIN N-3205 manufactured by Hitachi Chemical Co., Ltd.)
(Product name)) is applied. The applied fluorinated polyimide solution is subjected to a heat treatment at 350 ° C. for one hour. By this baking, a fluorinated polyimide film having a thickness of 30 μm is formed as the lower cladding layer 72 (FIG. 7).
(C)). As a result, a flexible optical waveguide sheet 84 in the electric wiring in which the copper foil sheet is stuck on the upper clad layer surface is completed.

Next, a copper foil sheet is attached to the surface of the lower clad layer 72 of the flexible optical waveguide sheet 84 manufactured as described above. Prior to this, first, the surface of the lower cladding layer 72 is roughened. In this roughening treatment, the surface of the lower cladding layer 72 is roughened by a roughening treatment method such as a chemical treatment to form minute irregularities on the surface. Further, a copper foil sheet 91 having a film thickness of 20 μm to be bonded on the lower cladding layer 72 is prepared, and a surface of the copper foil sheet 91 bonded to the lower cladding layer 72 is roughened. In this roughening treatment, the surface of copper is roughened by a roughening treatment method such as oxidation, and minute irregularities and needle-like projections are formed on the surface.

Next, the copper foil sheet 91 is placed on the lower clad layer 72 such that the roughened bonding surface of the copper foil sheet 91 faces the surface of the roughened lower clad layer 72. Then, the copper foil sheet 9 is pressed by heating using a heating / pressing means (not shown).
1 and the lower cladding layer 72 (FIG. 7)
(D)). Since the surfaces to be bonded are roughened as described above, the bonding strength between the copper foil sheet 91 and the lower cladding layer 72 can be increased.

Next, a resist is applied and dried on the surface of the copper foil sheet 90 bonded to the upper cladding layer 70 and the surface of the copper foil sheet 91 bonded to the lower cladding layer 72, respectively. Exposure is performed using an exposure mask that is provided, and further developed to form an etching mask composed of a resist pattern, then immersed in an etching solution to dissolve and remove unnecessary copper foil, and further remove the etching mask composed of the resist. Thus, the patterns of the electric wires 90a and 91a made of copper are formed on the upper clad layer 70 and the lower clad layer 72, respectively (FIG. 7E).

In this way, a flexible optical waveguide sheet 92 having a multilayer structure in which electric wiring patterns 90a and 91a are formed on both upper and lower surfaces of the flexible optical waveguide sheet in the electric wiring is completed. Optical components such as ICs and other electrical components and light receiving and emitting elements are mounted on the flexible optical waveguide sheet having a multilayer structure formed as described above, if necessary, and the electrical wiring pattern on the sheet surface and the like are used as necessary. The connection enables high-density mounting. Depending on the design, a through hole may be formed to penetrate from the upper surface to the lower surface of the flexible optical waveguide sheet, or a via hole may be formed in the upper clad layer or the lower clad layer, and the inner wall surface of the through hole or the via hole may be plated. To electrically connect any electric wiring 90a or 91a on the upper surface or lower surface of the flexible optical waveguide sheet with any electric wiring (Cu thick film pattern) 54 provided inside the flexible optical waveguide sheet. You can also.

According to the present embodiment, the step of forming a Cu thin film by the sputtering method disclosed in the aforementioned document,
By omitting the vacuum process used in the IE process, a vacuum device is not required, so that a flexible optical waveguide sheet having a larger area can be manufactured. Further, productivity is remarkably improved because there is no vacuum process, and at the same time, cost can be reduced because expensive vacuum equipment is not used.

In the present embodiment, since the SUS substrate 50 exists at the time of attaching the copper foil sheet on the upper clad layer, when the copper foil is attached by heating and pressure bonding, the laminate including the substrate and the like is used. The entire body has a small amount of warpage and deflection, and it is easier to attach copper foil. Also, when laminating a copper foil sheet on the lower cladding layer, the copper foil sheet laminated on the upper cladding layer plays the role of a reinforcing body, and even in this case, warpage and deflection occur throughout the laminate. Small and easy to attach copper foil.

Further, in the present embodiment, since the flexible optical waveguide sheet in which electric wiring is provided has a multilayer structure in which electric wiring patterns are provided on both surfaces, (1) the degree of freedom of electric wiring and optical wiring is increased. (2) In addition, since the wiring length can be shortened, it is possible to reduce the strength reduction and delay of electric signals and optical signals, and to reduce the influence of noise.
The mounting density of optical components can be increased. Note that the various modifications described in the first embodiment can also be applied to the manufacturing method of the second embodiment.

[Third Embodiment] The first and second embodiments described above.
In the embodiment, basically, on one surface or both surfaces of the flexible optical waveguide sheet in the electric wiring,
Although the electric wiring pattern is added by bonding and patterning of a copper foil sheet, in the third embodiment, a conventional printed circuit board having only electric wiring and the above-described first embodiment are used. A method of manufacturing a multilayer board with mixed electric wiring and optical wiring manufactured by bonding the flexible optical waveguide sheet inside the electric wiring manufactured in the steps of FIGS. 1 to 4 will be described with reference to FIGS. I do.

In this embodiment, as an example, one flexible optical waveguide sheet in electric wiring, one printed board with double-sided electric wiring, one layer of electric wiring above the optical waveguide sheet, and one layer below the printed board A method of manufacturing a multilayer board on which electric wiring and optical wiring are mixed, which has a structure in which one electric wiring is laminated, will be described. In this case, the total number of electric wirings including the ones embedded in the optical waveguide sheet is five, but it is not limited to the use of each layer in a separated form. This is a structure for performing interlayer connection between the electric wirings. Hereinafter, FIG.
(C), and will be described in detail with reference to FIGS.

First, a flexible optical waveguide sheet having electric wiring therein is prepared. Although a detailed description of the manufacturing process of the flexible optical waveguide sheet in the electric wiring is omitted, FIGS. 1 to 4 (that is, FIGS. 1A to 1D) in the first embodiment described above. ), FIG.
(A) to (D), FIGS. 3 (A) to (D), and FIG. 4 (A)
To (C)). The structure is the flexible optical waveguide sheet 74 in the electric wiring shown in FIG.
In FIG. 8A used in the description of the present embodiment, the cladding layers are not shown, but the specific structure is as shown in FIG. 4C. As shown in FIG. 8A, the flexible optical waveguide sheet 7 in the electric wiring is provided.
Reference numeral 4 denotes a clad 70x (the clad 70x is composed of an upper clad layer 70, an intermediate clad layer 60a, and a lower clad layer 72, and these are collectively referred to), and a core 6
8a, an electrical wiring 54 made of copper. Although not shown, an alignment mark 76 of a Cu thick film is formed in the flexible optical waveguide sheet 74 as described with reference to FIG.

Next, the surface of the upper clad layer and the surface of the lower clad layer of the flexible optical waveguide sheet 74 in the electric wiring thus manufactured are roughened. In this roughening treatment, the surfaces of the upper cladding layer and the lower cladding layer are roughened by a roughening treatment method such as a chemical treatment to form minute irregularities on the surfaces. FIG. 8A does not clearly show the roughened state of the surface, but shows the flexible optical waveguide sheet 74 after the roughening process.

Similarly, the surface of one printed circuit board 94 with double-sided electric wiring and two copper foil sheets 96 and 98 are subjected to a roughening treatment to be brought into contact with other members when they are laminated.
In addition, these printed circuit board 94 and copper foil sheet 96,
Also in 98, alignment marks are respectively formed in advance at positions corresponding to the alignment marks 76 of the flexible optical waveguide sheet 74. Further, three prepregs 100a inserted between the respective layers for interlayer connection when laminating,
Similar alignment marks are also formed on 100b and 100c. Then, the flexible optical waveguide sheet 7
4. Printed circuit board 94 having copper electrical wiring 94a formed on both sides, copper foil sheets 96 and 98, prepreg 10
Each of the alignment marks 0a, 100b, and 100c is irradiated with laser light to form a circular hole having a predetermined diameter. Next, the copper foil sheet 96, prepreg 100a, printed board 94, prepreg 10
0b, flexible optical waveguide sheet 74, prepreg 1
00c and the copper foil sheet 98 in this order, the holes provided in each are passed through the pins 102, and the members are stacked while being positioned (FIG. 8B).

Then, after removing the pin 102 in a state where the above-described members are stacked, the above-mentioned stacked members are attached to each other by applying pressure while heating using a heating / pressing means (not shown). Then, a laminated body is formed (FIG. 8C). In addition, the prepregs 100a, 100
b and 100c are glass fibers impregnated with an epoxy resin and dried. The resin is cured by being sandwiched between the layers and heated and pressed, so that the resin has sufficient strength and can be bonded together. it can.

Next, in the laminated body, for example, a columnar through hole 104 is formed by processing with a carbide drill at a position at which electrical connection is established by electric wiring between different layers (FIG. 9A). FIG. 9A is a cross-sectional view at a position where the through hole 104 is formed. When the through hole 104 is formed, the resin may adhere to the perforated inner wall. In order to remove the resin, a permanganese desmear process is performed. Further, in order to improve the adhesion of the chemical copper plating in the next step, the surface of the through hole 104 where the fluorinated polyimide is exposed is roughened. In this roughening treatment, the exposed surface is roughened by a roughening treatment method such as a chemical treatment to form minute irregularities on the surface.

After this roughening treatment, in order to make the inner wall of the portion where the through hole 104 is opened conductive, the portion where the resin is exposed is subjected to electroless copper plating, and further to electrolytic copper plating. As a result, a through-hole / plated portion consisting of an electroless copper plating layer of about 0.5 μm and an electroplating layer of several μm to several tens μm is formed. The mutual electrical connection between the wirings can be reliably performed (FIG. 9B). FIG.
9B shows a cross section at the same position as FIG. 9A, and in this figure, the electroless plating layer and the electroplating layer are shown together as the plating layer 106.

In the plating layer 106, a portion formed on the inner wall of the through hole 104 and in the vicinity of the substrate surface becomes a through hole plated portion 106a. In addition, although the electroless copper plating has some problems in terms of cost and reliability, since the electrolytic copper plating is further performed, the copper plating can be performed reliably and the film thickness can be made sufficient. Also, when performing plating by electroless copper plating and electroplating,
A similar copper plating layer 106 is also formed on the uppermost copper foil sheet 98 and the lowermost copper foil sheet 96 of the laminate,
Together with the copper foil sheets 96 and 98, the thickness of copper in these layers increases, and the electrical resistance can be reduced.

Finally, electric wiring patterns are formed on the upper and lower surfaces of the laminate. Here, first, in order to form an electric wiring pattern on the upper surface of the laminate, a resist is applied to the plating layer 106 on the copper foil sheet 98 on the upper surface side, and dried. At this point, the copper foil sheet 96 on the lower surface side of the laminate, on which the electric wiring pattern has not been formed yet, and the plating layer 106 thereon are formed on the lower surface of the laminate in order to prevent etching. A resist is applied and dried to cover the entire surface of the plating layer 106 on the copper foil sheet 96 on the side. Then, after exposing and developing the resist on the plating layer 106 on the upper surface side of the laminate using an exposure mask having a desired electric wiring pattern, it is immersed in an etching solution to remove unnecessary copper foil on the upper surface side. 98 and the plating layer 106 are dissolved and removed. Next, the copper foil 98 and the plating layer 10 are removed by removing the resist remaining on the upper surface side and the resist covering the lower surface side.
6 are formed on the upper surface of the laminate. Next, the copper foil sheet 9 on the lower surface side of the laminate
6 and the plating layer 106 thereon are patterned by the same procedure as the above-described step of forming an electric wiring pattern on the upper surface side of the laminate, so that the copper foil 96 and the plating layer 106 are patterned.
Is formed on the lower surface of the laminate (FIG. 9C). Further, when the resist is applied, the resist enters the through hole 104, but the resist in the through hole can be removed at the time of the above-described resist removal. In addition, this electric wiring 1
The method of forming the patterns 08 and 109 is not limited to the method described above, and for example, the method described in the second embodiment can be used.

Through the above steps, an electric wiring / optical wiring mixed multilayer substrate in which one optical wiring layer and five electric wiring layers (the first optical wiring layer and the electric wiring layer 1 are the same layer) is completed. . According to this embodiment, one optical wiring layer and five electric wiring layers (however, one optical wiring layer and one electric wiring layer are the same layer)
Can realize a multi-layered substrate in which electrical wiring and optical wiring are mixed, and (1) the degree of freedom of electrical wiring and optical wiring is increased, and (2)
Also, since the wiring length can be shortened, it is possible to reduce the strength reduction and delay of electric signals and optical signals, and to reduce the influence of noise.
(3) The mounting density of electrical components and optical components can be increased.

Further, it is also possible to establish an electrical connection between the electric wires between the layers by forming through holes and forming a through hole / plated portion, so that the wires can be shortened, and the wires can be commonly set to the ground potential between the layers. And electrical noise can be reduced. In addition, since a printed circuit board whose technology has already been established is used as the electric wiring, the performance and reliability of the electric wiring portion can be secured.

In this embodiment, the conductor sheet (copper foil sheet) is bonded via the prepreg, but the heating is performed in the same manner as in the first and second embodiments. It is also possible to directly bond to the flexible optical waveguide sheet by crimping.

Further, in this embodiment, an example is shown in which no electric wiring is provided on the surface of the flexible optical waveguide sheet. However, the method is the same as that of the first and second embodiments. Then, a flexible optical waveguide sheet in which an electric wiring pattern is formed on one side or both sides of the flexible optical waveguide sheet may be used. By doing so, higher density wiring can be obtained. In addition, it is also possible to form a via hole and perform plating or the like on the surface of the via hole for electrical wiring connection between the layers, so that electrical connection between any electrical wiring between any layers can be performed. .

[Fourth Embodiment] Next, a fourth embodiment of the present invention will be described. In the fourth embodiment, an optical waveguide in an electric wiring / optical wiring mixed multilayer substrate manufactured in the third embodiment and an optical component such as a light receiving element or a light emitting element mounted on the surface of the multilayer substrate are used. A method of manufacturing a multilayer board on which electric wiring and optical wiring are mixed, which is configured to achieve optical coupling, will be described. Hereinafter, the fourth embodiment will be described.
This will be described with reference to FIG.

First, an electric wiring / optical wiring mixed multilayer substrate manufactured according to the manufacturing process described in the third embodiment is manufactured. The structure of this multilayer substrate is the structure shown in FIG. 9C described in the third embodiment. This figure 9
FIG. 10A shows a cross section in a direction perpendicular to the paper surface along the cutting line XX in FIG. As shown in FIG. 10A, the optical waveguide portion includes a core 68a and a clad 70x.
(As 70x, in this cross-sectional view, the upper clad 70
And the lower clad 72).

Next, the portion where the light is extracted from the multi-layer board on which the electric wiring and the optical wiring are mixed is processed by laser light irradiation.
125 μm diameter cylindrical opening 110 penetrating through the substrate
Is formed (FIG. 10B). On the other hand, a 90 ° deflection mirror is manufactured using a quartz-based multimode optical fiber. This quartz multimode optical fiber has an outer shape of 1.
A core having a core of 25 μmφ and a central portion of 50 μmφ is used. Then, the tip of the fiber is cut so that the angle of the cross section becomes 45 °, and the cut surface is optically polished. Subsequently, aluminum (Al) was evaporated to a thickness of 0.1 μm on the cut surface by vacuum evaporation.
By forming the mirror section 114, a 90 ° deflection mirror 112 including the fiber section and the mirror section is completed.

Next, the above-described 90 made of optical fiber was used.
を The light deflection mirror 112 (the mirror unit is 114)
After being inserted into the opening 110 and the height of the center of the mirror surface and the height of the center of the core 68a of the optical waveguide are matched, the periphery of the fiber portion of the 90 ° deflection mirror 112 is fixed with an adhesive. As a result, the optical signal L that has propagated through the core of the optical waveguide of the multilayer board on which electric wiring and optical wiring are mixed can be deflected by 90 ° and emitted upward (ie, toward the surface of the multilayer substrate).

Next, a light receiving element 120 such as a photodiode or a phototransistor is mounted on the surface of the multilayer board in which electric wiring and optical wiring are mixed so as to cover the opening 110 and to be located above the deflection mirror 112 by 90 °. (FIG. 10C). The light receiving element 120 is electrically connected to the electric wiring 108 on the surface of the multilayer substrate. By providing the opening 110 and mounting the 90 ° deflecting mirror 112 and the light receiving element 120 in this manner, the core 6 of the optical waveguide is provided.
The optical signal L that has propagated through the 8a
The light enters the light receiving element 120 via the (mirror unit 114).

According to this embodiment, the optical signal that has propagated through the core of the optical waveguide of the multilayer board on which electric wiring and optical wiring are mixed is deflected by 90 °, emitted upward, and mounted on the upper part. It can be optically coupled with components, which enables not only electrical components but also optical components such as light receiving elements to be mounted. A wiring / optical wiring mixed multilayer substrate can be manufactured. Also, in this embodiment,
The third embodiment has the same effects as those described in the third embodiment.

In this embodiment, an example in which a light receiving element is used as an optical component has been described. Instead, a light emitting element such as a laser diode can be used. In this case, the optical signal emitted from the light emitting element is 90
The light is deflected by 90 ° by the ゜ deflection mirror 112, is incident on the core 68a of the optical waveguide, and propagates through the core 68a.

In the fourth embodiment, an opening is formed, a 90 ° deflecting mirror is mounted, a light receiving element, a light emitting element is formed on a multilayer board on which electric wiring and optical wiring are mixed by the method according to the third embodiment. The example in which the optical coupling such as the element is mounted to perform the optical coupling has been described. However, the electric wiring / optical wiring mixed multilayer sheet (formed on the upper clad layer) formed by the method according to the first embodiment described above. A flexible optical waveguide sheet having a multilayer structure provided with electric wiring) or an electric wiring / optical wiring mixed multilayer sheet prepared by the method according to the second embodiment described above (an electric wiring is formed on the upper clad layer and the lower clad layer). For the provided flexible optical waveguide sheet having a multilayer structure, the opening 110 is formed and the 90 ° deflection mirror 112 is mounted in the same manner as in the fourth embodiment. It may be configured to implement the optical components such as a light-emitting element, improve the optical coupling of the optical waveguide and the optical component.

In the third embodiment described above,
A through hole is opened in an electric wiring / optical wiring mixed multilayer substrate in which one optical wiring layer and five electric wiring layers (where the first optical wiring layer and the first electric wiring layer 1 are the same layer) are laminated. Although the case where the through-hole / plated portion is formed on the inner wall and the surface of the substrate in the vicinity thereof has been described, even in the multilayered electric and optical wiring hybrid sheet according to the first and second embodiments described above, By the same method as that of the third embodiment, the formation of the through-hole and the formation of the through-hole / plated portion can enable the electrical connection of the electric wiring between the layers.

Further, in each of the above-described embodiments, an example in which a copper foil sheet is used as the conductor sheet has been described, but a sheet made of another conductive metal may be used instead.

[0093]

As described above in detail, according to the method for manufacturing a multilayer sheet with mixed electrical / optical wiring of the present invention according to the first and second embodiments, the vacuum process can be performed. By eliminating the need for a vacuum device, a large-area flexible optical waveguide sheet can be manufactured because no vacuum device is required. In addition, productivity is significantly improved because there is no vacuum process, and at the same time, cost is reduced because expensive vacuum devices are not used. This has the effect of enabling the conversion.

Further, since the flexible optical waveguide sheet in which electric wiring is embedded has a multilayer structure in which electric wiring patterns are provided on the surface, (1) the degree of freedom of electric wiring and optical wiring is increased, and (2) Since the wiring length can be shortened, it is possible to reduce the strength reduction and delay of electric and optical signals, reduce the influence of noise, and (3) have the effect of increasing the mounting density of electric and optical components. .

Further, according to the method of manufacturing the multilayer board with mixed electric wiring and optical wiring of the present invention according to the third and fourth embodiments, an electric wiring having a large number of optical wiring layers and electric wiring layers is laminated. A multi-layer board with mixed wiring and optical wiring can be realized (1)
The degree of freedom of electric wiring and optical wiring is increased. (2) In addition, since the wiring length can be shortened, reduction in strength and delay of electric and optical signals can be reduced, and the influence of noise can be reduced. This has the effect that the mounting density of optical components can be further increased.

Further, according to the method for manufacturing a multilayer sheet with mixed electric wiring and optical wiring and the method for manufacturing a multi-layer substrate mixed with electric wiring and optical wiring according to the present invention, a conductor is formed on the inner wall of the through hole or via hole. It is also possible to make electrical connection between the electric wiring between the layers by plating, it is also possible to shorten the wiring and to make the wiring a common ground potential between the layers, and it is also possible to reduce the electric noise Has an effect.

Further, according to the method for producing a multilayer board with mixed electric wiring and optical wiring or the multilayer sheet mixed with electric wiring and optical wiring of the present invention, an opening is provided, a deflection mirror, and an optical component such as a light receiving element or a light emitting element. , Optical coupling between the optical waveguide and the optical component can be achieved, the electrical wiring and the optical wiring are mixed, and the electric component and the optical component are mixed. Substrates or multilayer sheets can be made.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a manufacturing process according to a first embodiment.

FIG. 2 is a view showing a manufacturing step of the first embodiment, following FIG. 1;

FIG. 3 is a view illustrating a manufacturing step of the first embodiment, following FIG. 2;

FIG. 4 is a view illustrating a manufacturing step of the first embodiment following FIG. 3;

FIG. 5 is a diagram showing an example of a configuration of a flexible optical waveguide sheet with electric wiring.

FIG. 6 is a view illustrating a manufacturing step of the first embodiment, following FIG. 4;

FIG. 7 is a diagram illustrating a manufacturing process according to a second embodiment.

FIG. 8 is a diagram illustrating a manufacturing process according to a third embodiment.

FIG. 9 is a view illustrating a manufacturing step of the third embodiment following FIG. 8;

FIG. 10 is a diagram illustrating a manufacturing process according to a fourth embodiment.

FIG. 11 is a diagram showing a conventional manufacturing process.

FIG. 12 is a view showing a conventional manufacturing process following FIG. 11;

[Explanation of symbols]

 50: substrate 52, 52a: dry film 54: thick Cu film 54a: thick Cu film at a position where a core is to be formed 56: uneven structure 58: concave portion 60, 68: fluorinated polyimide film 60a: intermediate cladding layer 64, 110: opening Portion 66: Removed portion of Cu thick film 54a 68a: Core 70: Upper cladding layer 70x: Cladding 72: Lower cladding layer 74: Flexible optical waveguide sheet embedded in electric wiring 76: Alignment mark 78: Optical waveguide section 80: Electric wiring Part 84: Flexible optical waveguide sheet with copper foil sheet 90, 91, 96, 98: Copper foil sheet 90a, 91a: Electric wiring pattern 92: Flexible optical waveguide sheet with double-sided electric wiring 94: Printed circuit board 94a: Electricity on printed circuit board Wirings 100a, 100b, 100c: prepreg 102: pin 1 4: through hole 106: plated layer 106a: through-hole plating portion 108 and 109: electric wiring pattern 112: 90 ° deflecting mirror 114: mirror portion 120: light-receiving element

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor: Noboru Fujimaki, Fukuda-cho, Joetsu, Niigata Pref., Oki Printed Circuit Co., Ltd. (72) Inventor: Masahiko Suzuki 1, Fukuda-cho, Joetsu, Niigata, Oki Printed Circuit Co., Ltd. (72) Inventor Mitsuro Mita 1-7-12 Toranomon, Minato-ku, Tokyo Oki Electric Industry Co., Ltd. (72) Inventor Masahiro Kamikawa 1-7-12 Toranomon, Minato-ku, Tokyo Oki Electric Industry Co., Ltd. 72) Inventor Hitori Maeno 1-7-12 Toranomon, Minato-ku, Tokyo Oki Electric Industry Co., Ltd. (72) Inventor Hiroki Miyamoto 1-7-112 Toranomon, Minato-ku, Tokyo F-term (Oki Electric Industry Co., Ltd.) Reference) 2H047 KA04 KB08 KB09 LA09 PA21 PA24 PA28 QA05 QA07 TA43 TA47

Claims (13)

[Claims] 1. A step of bonding a conductive sheet to at least one of a front surface and a back surface of a flexible optical waveguide sheet having an optical waveguide formed of a core and a clad formed of a polymer material; Forming a pattern of electric wiring by patterning into a shape of the electric wiring. 2. The method according to claim 1, wherein a pattern of electric wiring is further provided in the flexible optical waveguide sheet. 3. In the step of bonding the conductive sheet, the conductive sheet is bonded to both the front and back surfaces of the flexible optical waveguide sheet to form an electric wiring pattern. 3. The method for producing a multilayer sheet in which electric wiring and optical wiring are mixed according to claim 1 or 2, wherein a pattern of electric wiring is formed on the sheet. 4. The method according to claim 1, further comprising, before the step of bonding the conductor sheets, a step of roughening a surface to be bonded of each of the flexible optical waveguide sheet and the conductor sheet in advance. Claim 3
The method for producing a multilayer sheet mixed with electric wiring and optical wiring according to any one of claims 1 to 4. 5. The flexible optical waveguide sheet according to claim 1, further comprising a step of forming a through hole or a via hole in the flexible optical waveguide sheet and plating a conductor on an inner wall of the through hole or the via hole. A method for manufacturing a multilayer sheet mixed with electric wiring and optical wiring according to any one of claims. 6. A step of providing an opening in the flexible optical waveguide sheet so as to include a predetermined position in a core formation region thereof; a step of mounting a deflection mirror in the opening; A step of mounting an optical component that is located above and is mounted on either one of the front surface or the back surface of the flexible optical waveguide sheet, and is optically coupled to the core of the optical waveguide via the deflecting mirror. The method according to claim 1, further comprising the step of manufacturing a multilayer sheet in which electrical wiring and optical wiring are mixed. 7. A flexible optical waveguide sheet comprising an optical waveguide formed of a polymer material and comprising a core and a clad, and a printed circuit board having electric wiring are laminated via a prepreg and laminated. Bonding and laminating a conductive sheet on a surface of at least one of the sheet and the printed circuit board opposite to a surface facing the other, and patterning the conductive sheet into a predetermined shape to form a pattern of electric wiring And a method for manufacturing a multilayer board mixed with electric wiring and optical wiring. 8. The multi-layer board according to claim 7, wherein in the step of bonding and laminating the conductor sheets, the conductor sheets are laminated and laminated via a prepreg. Production method. 9. The method according to claim 7, wherein a pattern of an electric wiring is further provided in the flexible optical waveguide sheet. 10. In the step of laminating and laminating conductive sheets, laminating and laminating conductive sheets is performed via prepregs on the surfaces of the flexible optical waveguide sheet and the printed circuit board opposite to the surfaces facing each other. In the step of forming an electric wiring pattern, an electric wiring is formed by patterning a conductive sheet laminated on the flexible optical waveguide sheet and the printed board via the prepreg. 10. The method for manufacturing a multilayer board mixed with electric wiring and optical wiring according to claim 7. 11. The flexible optical waveguide sheet, the printed board, and the conductive sheet before the step of bonding and laminating a flexible optical waveguide sheet and a printed board via a prepreg and bonding and laminating a conductive sheet. 11. The method for manufacturing a multilayer sheet in which electric wiring and optical wiring are mixed according to any one of claims 7 to 10, further comprising a step of preliminarily roughening the surfaces to be bonded. 12. A through hole or a via hole is formed in the laminate formed by the step of laminating and laminating a flexible optical waveguide sheet and a printed board via a prepreg and laminating and laminating a conductor sheet,
12. The method for producing a multilayer sheet with mixed electrical / optical wiring according to claim 7, further comprising a step of plating a conductor on the inner wall of the through hole or the via hole. . 13. A step of providing an opening so as to open including a predetermined position in a core forming region of the flexible optical waveguide sheet in a laminate formed by performing the steps according to claim 7. A step of mounting a deflecting mirror in the opening; and a step of mounting the deflecting mirror above the deflecting mirror, being mounted on one of the front surface and the back surface of the multilayer body, and connecting the optical waveguide core and the light via the deflecting mirror. 13. The method for manufacturing an electric wiring / optical wiring mixed multilayer sheet according to claim 7, further comprising: mounting an optical component capable of being coupled.