Photoelectric wiring board and production method for photoelectric wiring board

Abstract

A photoelectric wiring board (1) comprises an optical waveguide core (2) that transmits optical signals, electrical wiring (3) that transmits electrical signals, and a metal part (4) that is positioned between the optical waveguide core (2) and the electrical wiring (3), which are adjacent to each other.

Description

Optical-electrical wiring board and method for manufacturing the same

[0001] The disclosed embodiments relate to an optical-electrical wiring board and a method for manufacturing the optical-electrical wiring board.

[0002] 2. Description of the Related Art Conventionally, an optoelectronic wiring board has been disclosed in which optical waveguide cores and electrical wiring are arranged on the same layer for the purpose of parallel transmission of optical signals and electrical signals (see, for example, Patent Document 1).

[0003] Japanese Patent Application Laid-Open No. 2007-293239

[0004] An optical-electrical wiring board according to one aspect of the embodiment includes an optical waveguide core for transmitting an optical signal, an electrical wiring for transmitting an electrical signal, and a metal portion located between the optical waveguide core and the electrical wiring that are adjacent to each other.

[0005] FIG. 1 is a cross-sectional view showing an example of the configuration of an opto-electrical wiring board according to an embodiment. FIG. 2 is a perspective view showing an example of the configuration of an opto-electrical wiring board according to an embodiment. FIG. 3 is a cross-sectional view showing an example of the configuration of an opto-electrical wiring board according to Alternative Embodiment 1. FIG. 4 is a cross-sectional view showing an example of the configuration of an opto-electrical wiring board according to Alternative Embodiment 2. FIG. 5 is a cross-sectional view showing an example of the configuration of an opto-electrical wiring board according to Alternative Embodiment 3. FIG. 6 is a cross-sectional view showing an example of the configuration of an opto-electrical wiring board according to Alternative Embodiment 4. FIG. 7 is a cross-sectional view showing an example of the configuration of an opto-electrical wiring board according to Alternative Embodiment 5. FIG. 8 is a cross-sectional view showing an example of the configuration of an opto-electrical wiring board according to Alternative Embodiment 6. FIG. 9 is a cross-sectional view showing an example of the configuration of an opto-electrical wiring board according to Alternative Embodiment 7. FIG. 10 is a diagram for explaining a manufacturing process of an opto-electrical wiring board according to Alternative Embodiment 4. FIG. 11 is a diagram for explaining a manufacturing process of an opto-electrical wiring board according to Alternative Embodiment 7.

[0006] Hereinafter, with reference to the accompanying drawings, embodiments of the optoelectronic wiring board and the method for manufacturing the optoelectronic wiring board disclosed in the present application will be described. Note that the present disclosure is not limited to the embodiments described below. Furthermore, each embodiment can be appropriately combined within a range that does not cause contradictions in the processing content. Furthermore, the same parts in each of the following embodiments are given the same reference numerals, and duplicated explanations will be omitted.

[0007] 2. Description of the Related Art Conventionally, an optoelectronic wiring board has been disclosed in which optical waveguide cores and electrical wiring are arranged on the same layer for the purpose of parallel transmission of optical signals and electrical signals.

[0008] However, the conventional technology has room for further improvement in terms of reducing signal interference between the optical waveguide core through which the optical signal flows and the electrical wiring through which the electrical signal flows.

[0009] Therefore, there is a need for a technology that can solve the above problems and reduce signal interference between the optical waveguide core and the electrical wiring.

[0010] 1 is a cross-sectional view showing an example of the configuration of an opto-electrical wiring board 1 according to an embodiment, and Fig. 2 is a perspective view showing an example of the configuration of an opto-electrical wiring board 1 according to an embodiment. For ease of understanding, the cladding layer 30 shown in Fig. 1 is omitted in Fig. 2.

[0011] 1, the optical-electrical wiring board 1 according to the embodiment includes a metal layer 10, a cladding layer 20, and a cladding layer 30. The cladding layer 30 is an example of another cladding layer.

[0012] The metal layer 10 is located along one main surface of a flat substrate (not shown). The metal layer 10 is located, for example, on the main surface of the substrate. The metal layer 10 is connected, for example, to a ground potential. The metal layer 10 is made of a metal material containing, for example, copper, silver, aluminum, platinum, titanium, palladium, zinc, or chromium as a main component.

[0013] The cladding layer 20 is located on the surface 11 of the metal layer 10. The cladding layer 20 is located so as to cover all or part of the metal layer 10. The cladding layer 30 is located on the surface 21 of the cladding layer 20. The cladding layer 30 is located so as to cover all or part of the cladding layer 20. Here, in the present disclosure, the cladding layer 20 may be referred to as the first cladding layer 20, and the cladding layer 30 may be referred to as the second cladding layer 30.

[0014] The cladding layers 20, 30 are made of a material having a lower refractive index than the optical waveguide core 2, which will be described later. The refractive index of the cladding layers 20, 30 is set, for example, in the range of 1.45 to 1.8. The cladding layers 20, 30 can be made of, for example, epoxy resin, polyimide resin, phenol resin, or acrylic resin.

[0015] The optical-electrical wiring board 1 according to the embodiment further includes an optical waveguide core 2, an electrical wiring 3, and a metal portion 4. The optical waveguide core 2, the electrical wiring 3, and the metal portion 4 are located on a surface 21 of the cladding layer 20, for example.

[0016] If the cladding layer 20 is a flat structure each having a predetermined thickness and area, the optical waveguide core 2, the electrical wiring 3 and the metal part 4 may have portions arranged at a predetermined interval in one direction on the cladding layer 20.

[0017] In particular, the optical waveguide core 2, the electrical wiring 3 and the metal part 4 may have a portion on the cladding layer 20 that is arranged in a line substantially parallel to one another in one direction, and in particular, arranged in a line parallel to one another.

[0018] As shown in Fig. 2, the optical waveguide core 2 is formed in a predetermined pattern on the surface 21 of the cladding layer 20. Furthermore, as shown in Fig. 1, the optical waveguide core 2 is covered with the cladding layer 30. The optical waveguide core 2 has a higher refractive index than the cladding layers 20 and 30.

[0019] As a result, the light that has entered the optical waveguide core 2 travels through the optical waveguide core 2 while repeatedly being reflected at the interface between the optical waveguide core 2 and the cladding layer 20 and at the interface between the optical waveguide core 2 and the cladding layer 30. In other words, the optical waveguide core 2 has the function of transmitting an optical signal in the opto-electrical wiring board 1.

[0020] The refractive index of the optical waveguide core 2 is set, for example, in the range of 1.5 to 1.85. The refractive index of the optical waveguide core 2 may be, for example, 1% to 3% higher than the refractive index of the cladding layers 20, 30. The optical waveguide core 2 may be made of, for example, epoxy resin.

[0021] As shown in Fig. 2 , the electrical wiring 3 is formed in a predetermined pattern on the surface 21 of the cladding layer 20. Furthermore, as shown in Fig. 1 , the electrical wiring 3 is covered with the cladding layer 30. The electrical wiring 3 has a function of transmitting electrical signals in the optical-electrical wiring board 1.

[0022] The electrical wiring 3 is made of a metal material containing, as a main component, copper, silver, aluminum, platinum, titanium, palladium, zinc, chromium, or the like, for example.

[0023] 1 and 2, in this embodiment, a metal portion 4 is located between adjacent optical waveguide cores 2 and electrical wiring 3. This metal portion 4 is made of a metal material containing, as a main component, copper, silver, aluminum, platinum, titanium, palladium, zinc, chromium, or the like, for example.

[0024] As a result, of the noise radiated from the electrical wiring 3 due to the electrical signal flowing through the electrical wiring 3, the noise radiated toward the optical waveguide core 2 is suppressed by the metal part 4. That is, in the embodiment, it is possible to reduce the transmission of the noise radiated from the electrical wiring 3 to the optical waveguide core 2.

[0025] Furthermore, of the optical noise radiated from the optical waveguide core 2 due to the optical signal flowing through the optical waveguide core 2, the optical noise radiated toward the electrical wiring 3 is blocked by the metal portion 4. That is, in the embodiment, it is possible to reduce the transmission of the optical noise radiated from the optical waveguide core 2 to the electrical wiring 3.

[0026] Therefore, according to the embodiment, it is possible to reduce interference of signals between the optical waveguide core 2 and the electrical wiring 3 .

[0027] In addition, in the embodiment, the metal portion 4 may be connected to a ground potential. This allows the metal portion 4 to efficiently suppress noise radiated from the electrical wiring 3 toward the optical waveguide core 2. Therefore, according to the embodiment, it is possible to further reduce signal interference between the optical waveguide core 2 and the electrical wiring 3.

[0028] 1 and 2 show an example in which the metal portion 4 is located between the optical waveguide core 2 and the electrical wiring 3, but the present disclosure is not limited to such an example. For example, in the present disclosure, the metal portion 4 may be located between adjacent optical waveguide cores 2. This makes it possible to reduce signal interference between adjacent optical waveguide cores 2.

[0029] In the present disclosure, the metal portion 4 may be located between adjacent electrical wirings 3. This makes it possible to reduce signal interference between adjacent electrical wirings 3. Note that, when the optical waveguide core 2, electrical wirings 3, and metal portion 4 are arranged on the upper surface of the cladding layer 20 as shown in FIG. 1 , they may be located at the same height from the metal layer 10, with the cladding layer 20 interposed therebetween.

[0030] <Other Embodiments> Next, various other embodiments will be described with reference to Fig. 3 to Fig. 9. Fig. 3 is a cross-sectional view showing an example of the configuration of an opto-electrical wiring board 1 according to another embodiment 1. As shown in Fig. 3, in the opto-electrical wiring board 1 according to another embodiment 1, the position of the metal portion 4 differs from that of the above-described embodiment.

[0031] Specifically, in another embodiment 1, the distance L1 between the metal portion 4 and the electrical wiring 3 may be shorter than the distance L2 between the metal portion 4 and the optical waveguide core 2. This allows the noise radiated from the electrical wiring 3 toward the optical waveguide core 2 to be effectively suppressed by the metal portion 4 located close to the electrical wiring 3.

[0032] Therefore, according to the alternative embodiment 1, the interference of signals between the optical waveguide core 2 and the electrical wiring 3 can be further reduced.

[0033] Fig. 4 is a cross-sectional view showing an example of the configuration of an opto-electrical wiring board 1 according to another embodiment 2. As shown in Fig. 4, in the opto-electrical wiring board 1 according to another embodiment 2, the configuration of the metal part 4 differs from that of the above embodiment.

[0034] Specifically, in another embodiment 2, the thickness T1 of the metal part 4 may be greater than the thickness T2 of the electrical wiring 3. This allows the noise radiated from the electrical wiring 3 toward the optical waveguide core 2 to be effectively suppressed by the metal part 4, which has a large dimension in the height direction.

[0035] In this case, the opto-electrical wiring board 1 may have a structure in which the thickness T1 of the metal portion 4 is greater than the thickness T2 of the electrical wiring 3 in some portions. Also, the opto-electrical wiring board 1 may have a structure in which the thickness T1 of the metal portion 4 is greater than the thickness T2 of the electrical wiring 3 in multiple portions.

[0036] Furthermore, the metal portion 4, which has a large height dimension, can effectively shield optical noise radiated from the optical waveguide core 2 toward the electrical wiring 3. Therefore, according to another embodiment 2, signal interference between the optical waveguide core 2 and the electrical wiring 3 can be further reduced.

[0037] Fig. 5 is a cross-sectional view showing an example of the configuration of an opto-electrical wiring board 1 according to another embodiment 3. As shown in Fig. 5, in the opto-electrical wiring board 1 according to another embodiment 3, the configuration of the metal part 4 differs from that of the above-described another embodiment 2.

[0038] Specifically, in another embodiment 3, the thickness T1 of the metal portion 4 may be greater than the thickness T2 of the electrical wiring 3 and greater than the width W of the metal portion 4 in a cross-sectional view. That is, in another embodiment 3, the shape of the metal portion 4 may be wall-like.

[0039] In this case, the wall-shaped metal portion 4 may be arranged on the cladding layer 20 so as to be along the extending direction of the optical waveguide core 2 and the electrical wiring 3. In particular, the wall-shaped metal portion 4 is preferably arranged on the cladding layer 20 so as to be parallel to at least one of the optical waveguide core 2 and the electrical wiring 3.

[0040] In addition, the portion of the metal portion 4 that is parallel to at least one of the optical waveguide core 2 and the electrical wiring 3 on the cladding layer 20 may be the entire area of ​​the metal portion 4, the optical waveguide core 2, and the electrical wiring 3 provided on the optical-electrical wiring board 1, or may be only a portion of the area.

[0041] When the optical-electrical wiring board 1 has a structure with a specific limited area, and there is a portion where at least one of the optical waveguide core 2 and the electrical wiring 3 is forced to have a curved shape rather than a straight shape, the metal part 4 may not be parallel near this curved portion, but may have a structure that is close to parallel.

[0042] When at least one of the optical waveguide core 2 and the electrical wiring 3, particularly both the optical waveguide core 2 and the electrical wiring 3, are linear and parallel to each other, the metal portion 4 is preferably arranged parallel to them.

[0043] In this way, by making the thickness T1 of the metal part 4 thicker than the thickness T2 of the electrical wiring 3, the noise radiated from the electrical wiring 3 toward the optical waveguide core 2 can be effectively suppressed by the metal part 4, which has a larger dimension in the height direction.

[0044] Furthermore, the metal portion 4, which has a large height, can effectively shield optical noise radiated from the optical waveguide core 2 toward the electrical wiring 3. Therefore, according to another embodiment 3, signal interference between the optical waveguide core 2 and the electrical wiring 3 can be further reduced.

[0045] In another embodiment 3, by forming the metal portion 4 in a wall shape, the area occupied by the metal portion 4 in the optical-electrical wiring board 1 can be reduced, thereby increasing the degree of freedom in designing the optical-electrical wiring board 1.

[0046] Fig. 6 is a cross-sectional view showing an example of the configuration of an opto-electrical wiring board 1 according to another embodiment 4. As shown in Fig. 6, in the opto-electrical wiring board 1 according to another embodiment 4, the configuration of the metal part 4 differs from that of the above-described embodiment.

[0047] Specifically, in another embodiment 4, the metal portion 4 may have an inverted U-shape in cross section. In this case, for example, the metal portion 4 may be positioned so as to cover the top and side surfaces of the dummy core 2A. This dummy core 2A is made of the same material as the optical waveguide core 2, but unlike the optical waveguide core 2, it is a portion that does not transmit optical signals.

[0048] Here, the inverted U-shape is a representation of the arrangement of the open portion of the U-shaped metal portion 4 when viewed with the metal layer 10 side facing the ground (-Z direction) and the opposite side facing the sky (+Z direction) in Figure 6. This is used to conveniently indicate that the open portion of the metal portion 4 faces the metal layer 10 and clad layer 20.

[0049] When the metal layer 10 and the cladding layer 20 are located on the +Z direction side of the metal portion 4, they may be seen as a U-shape rather than an inverted U-shape. In this disclosure, the term "U-shape" does not only refer to a shape in which the opening is curved like the letter U, but also includes a metal portion 4 in which the portion located on the top surface of the dummy core 2A has a linear shape (a flat shape when the depth is taken into account), as shown in FIG.

[0050] In this way, by forming the metal part 4 in an inverted U shape, the thickness T1 of the metal part 4 can be made thicker than the thickness T2 of the electrical wiring 3. As a result, noise radiated from the electrical wiring 3 toward the optical waveguide core 2 can be effectively suppressed by the inverted U-shaped metal part 4, which has a large dimension in the height direction.

[0051] Furthermore, optical noise radiated from the optical waveguide core 2 toward the electrical wiring 3 can be effectively shielded by the inverted U-shaped metal portion 4, which is large in the height direction. Therefore, according to another embodiment 4, signal interference between the optical waveguide core 2 and the electrical wiring 3 can be further reduced.

[0052] Fig. 7 is a cross-sectional view showing an example of the configuration of an opto-electrical wiring board 1 according to another embodiment 5. As shown in Fig. 7, in the opto-electrical wiring board 1 according to another embodiment 5, the configuration of the metal part 4 differs from that of the above-described another embodiment 4.

[0053] Specifically, in another embodiment 5, the downward extending extension portion 4 a in the inverted U-shaped metal portion 4 may extend from the surface 21 of the cladding layer 20 to the inside of the cladding layer 20. This allows the noise radiated from the electrical wiring 3 toward the optical waveguide core 2 to be effectively suppressed by the inverted U-shaped metal portion 4, which has a large dimension in the height direction.

[0054] Furthermore, optical noise radiated from the optical waveguide core 2 toward the electrical wiring 3 can be effectively shielded by the inverted U-shaped metal portion 4, which is large in the height direction. Therefore, according to another embodiment 5, signal interference between the optical waveguide core 2 and the electrical wiring 3 can be further reduced.

[0055] Fig. 8 is a cross-sectional view showing an example of the configuration of an opto-electrical wiring board 1 according to another embodiment 6. As shown in Fig. 8, in the opto-electrical wiring board 1 according to another embodiment 6, the configuration of the metal part 4 differs from that of the above-described other embodiments 4 and 5.

[0056] Specifically, in another embodiment 6, the extending portion 4 a extending downward in the inverted U-shaped metal portion 4 may extend through the cladding layer 20 to the metal layer 10. This allows the noise radiated from the electrical wiring 3 toward the optical waveguide core 2 to be effectively suppressed by the inverted U-shaped metal portion 4, which has a large dimension in the height direction.

[0057] Furthermore, optical noise radiated from the optical waveguide core 2 toward the electrical wiring 3 can be effectively shielded by the inverted U-shaped metal portion 4, which is large in the height direction. Therefore, according to another embodiment 6, signal interference between the optical waveguide core 2 and the electrical wiring 3 can be further reduced.

[0058] In another embodiment 6, the metal layer 10 connected to the ground potential and the metal portion 4 are electrically connected at the extending portion 4 a, so that the metal portion 4 can be stabilized at the ground potential, thereby improving the transmission quality of the electrical signal in the electrical wiring 3.

[0059] 9 is a cross-sectional view showing an example of the configuration of an opto-electrical wiring board 1 according to another embodiment 7. As shown in FIG. 9, in the opto-electrical wiring board 1 according to another embodiment 7, the configuration around the metal portion 4 differs from that of the above-described another embodiment 6.

[0060] Specifically, in Alternative Embodiment 7, a metal layer 40 may be located on the surface 31 of the cladding layer 30. Such a metal layer 40 is an example of an alternative metal layer.

[0061] The metal layer 40 is connected to, for example, a ground potential and is made of a metal material containing, for example, copper, silver, aluminum, platinum, titanium, palladium, zinc, chromium, or the like as a main component.

[0062] The presence of such a metal layer 40 can reduce external noise from being transmitted to the optical waveguide core 2 and the electrical wiring 3. Therefore, according to another embodiment 7, an optoelectronic wiring board 1 that is resistant to external noise can be realized.

[0063] In another embodiment 7, the metal portion 4 may be connected to the metal layer 40 through the via 5. In this way, the metal layer 40 connected to the ground potential and the metal portion 4 are electrically connected through the via 5, so that the metal portion 4 can be further stabilized at the ground potential.

[0064] Therefore, according to the seventh embodiment, the transmission quality of the electrical signal in the electrical wiring 3 can be further improved.

[0065] <Manufacturing Process> Next, a manufacturing process of the opto-electrical wiring board 1 according to the above-described Alternative Embodiment 4 and Alternative Embodiment 7 will be described with reference to Fig. 10 and Fig. 11. Fig. 10 is a diagram for explaining the manufacturing process of the opto-electrical wiring board 1 according to Alternative Embodiment 4.

[0066] 10A, first, a metal layer 10 and a cladding layer 20 are laminated in this order along the main surface of a substrate (not shown). In another embodiment 4, for example, the metal layer 10 is formed by a known dry method (e.g., chemical vapor deposition (CVD), physical vapor deposition (PVD), etc.) or a known wet method (e.g., plating, etc.).

[0067] The cladding layer 20 is formed, for example, by applying a resin having a predetermined refractive index to a predetermined thickness on the surface 11 of the metal layer 10 and curing the resin with heat, light, or the like.

[0068] 10(b), the optical waveguide core 2 and the dummy core 2A are formed on the surface 21 of the cladding layer 20. In another embodiment 4, for example, the optical waveguide core 2 and the dummy core 2A are formed in the same process.

[0069] For example, the optical waveguide core 2 and the dummy core 2A are formed by applying a resin having a predetermined refractive index to a predetermined thickness on the surface 11 of the metal layer 10, hardening the resin with heat or light, and then patterning the hardened resin into a predetermined planar shape using a known method.

[0070] In this way, by forming the optical waveguide cores 2 and the dummy cores 2A in the same process, the manufacturing process of the opto-electrical wiring board 1 can be simplified, and the manufacturing cost of the opto-electrical wiring board 1 can be reduced.

[0071] 10(c), electrical wiring 3 is formed on the surface 21 of the cladding layer 20, and metal portions 4 are formed on the upper and side surfaces of the dummy core 2A. In another embodiment 4, for example, the electrical wiring 3 and the metal portions 4 are formed in the same process.

[0072] For example, a resist film is selectively formed by a known method on locations other than the locations where the electrical wiring 3 and metal portion 4 are to be formed. Next, a metal film including the electrical wiring 3 and metal portion 4 is formed on the surface of the intermediate product during the manufacturing process by plating or the like, and finally the resist film is peeled off by a known method, thereby forming the electrical wiring 3 and metal portion 4.

[0073] Here, the same process refers to a process in which the metal film that will become the electrical wiring 3 and the metal film that will become the metal portion 4 are deposited simultaneously in one plating process. In other words, the simultaneous deposition can also be expressed as deposition at the same timing.

[0074] In this way, by forming the electrical wiring 3 and the metal part 4 in the same process, the manufacturing process of the opto-electrical wiring board 1 can be simplified, and the manufacturing cost of the opto-electrical wiring board 1 can be reduced.

[0075] In another embodiment 4, by forming the metal portion 4 on the upper and side surfaces of the dummy core 2A, the thickness T1 (see Figure 6) of the metal portion 4, which is formed in the same process as the electrical wiring 3, can easily be made thicker than the thickness T1 (see Figure 6) of the electrical wiring 3.

[0076] Next, as shown in FIG. 10( d ), a cladding layer 30 is formed on the surface 21 of the cladding layer 20 so as to cover the optical waveguide core 2 , the electrical wiring 3 and the metal portion 4 .

[0077] The cladding layer 30 is formed, for example, by applying a resin having a predetermined refractive index to a predetermined thickness on the surface 21 of the cladding layer 20 and curing the resin by treating it with heat, light, etc. The formation of the cladding layer 30 completes the manufacturing process for the optical-electrical wiring board 1 according to another embodiment 4.

[0078] 11 is a diagram illustrating a manufacturing process of an optoelectronic wiring board 1 according to another embodiment 7. In another embodiment 7, first, as shown in (a) of FIG. 11, a metal layer 10 and a cladding layer 20 are laminated in this order along the main surface of a base material (not shown). This process is similar to the process described above in (a) of FIG. 10, and therefore a detailed description thereof will be omitted.

[0079] 11(b), a plurality of recesses 22 are formed at predetermined locations in the cladding layer 20. The recesses 22 are formed at locations corresponding to the extensions 4a of the metal portion 4 (see FIG. 9) so as to penetrate the cladding layer 20 and reach the metal layer 10.

[0080] The recesses 22 are formed, for example, by etching the cladding layer 20 using a known technique.

[0081] Next, as shown in Fig. 11(c), the optical waveguide core 2 and the dummy core 2A are formed on the surface 21 of the cladding layer 20. In another embodiment 7, for example, the optical waveguide core 2 and the dummy core 2A are formed in the same process as in the above-mentioned another embodiment 4. This process is the same as the process described in Fig. 10(b) above, and therefore a detailed description thereof will be omitted.

[0082] Next, as shown in Figure 11(d), electrical wiring 3 is formed on the surface 21 of the cladding layer 20, and metal portions 4 are formed on the upper surface, side surfaces, and recesses 22 of the dummy core 2A. In another embodiment 7, for example, similar to the above-mentioned another embodiment 4, the electrical wiring 3 and metal portions 4 are formed in the same process. This process is similar to the process described in Figure 10(c) above, and therefore a detailed description thereof will be omitted.

[0083] 11(e), a cladding layer 30 is formed on the surface 21 of the cladding layer 20 so as to cover the optical waveguide core 2, the electrical wiring 3, and the metal portion 4. Furthermore, a plurality of recesses 32 are formed in predetermined locations in the cladding layer 30.

[0084] The cladding layer 30 is formed, for example, by applying a resin having a predetermined refractive index to a predetermined thickness on the surface 21 of the cladding layer 20 and curing the resin by treating it with heat, light, etc. The plurality of recesses 32 are formed, for example, by etching the cladding layer 30 using a known method.

[0085] 11(f), the via 5 is formed in the recess 32 of the cladding layer 30, and the metal layer 40 is formed on the surface 31 of the cladding layer 30. In another embodiment 7, for example, the via 5 and the metal layer 40 are formed in the same process.

[0086] In another embodiment 7, for example, the via 5 and the metal layer 40 are formed by a known dry method (e.g., chemical vapor deposition (CVD), physical vapor deposition (PVD), etc.) or a known wet method (e.g., plating, etc.).

[0087] In this way, by forming the vias 5 and the metal layer 40 in the same process, the manufacturing process of the optoelectronic wiring board 1 can be simplified, thereby reducing the manufacturing cost of the optoelectronic wiring board 1. Then, when the vias 5 and the metal layer 40 are formed, the manufacturing process of the optoelectronic wiring board 1 according to another embodiment 7 is completed.

[0088] Although the embodiments of the present disclosure have been described above, the present disclosure is not limited to the above embodiments, and various modifications are possible without departing from the spirit of the present disclosure. For example, in the above embodiments, an example was shown in which the optical waveguide cores 2, the electrical wiring 3, and the metal portion 4 are all located in a plane on the surface 21 of the cladding layer 20, but the present disclosure is not limited to such an example, and the optical waveguide cores 2, the electrical wiring 3, and the metal portion 4 may be arranged three-dimensionally.

[0089] Even in this case, by positioning the metal portion 4 between the optical waveguide core 2 and the electrical wiring 3 adjacent to each other, it is possible to reduce signal interference between the optical waveguide core 2 and the electrical wiring 3.

[0090] Further advantages and other aspects may readily occur to those skilled in the art. Therefore, the disclosure in its broader aspects is not limited to the specific details and representative embodiments shown and described above. Accordingly, various modifications may be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims and their equivalents.

[0091] The present technology may also have the following configurations. (1) An opto-electrical wiring board comprising: an optical waveguide core for transmitting an optical signal; an electrical wiring for transmitting an electrical signal; and a metal portion located between the adjacent optical waveguide core and the electrical wiring. (2) The opto-electrical wiring board according to (1), wherein the metal portion is connected to a ground potential. (3) The opto-electrical wiring board according to (1) or (2), wherein the thickness of the metal portion is greater than the thickness of the electrical wiring. (4) The opto-electrical wiring board according to (3), wherein the shape of the metal portion is wall-like. (5) The opto-electrical wiring board according to any one of (1) to (4), wherein the distance between the metal portion and the electrical wiring is shorter than the distance between the metal portion and the optical waveguide core. (6) The opto-electrical wiring board according to any one of (1) to (5), wherein the metal portion is in an inverted U-shape in cross section. (7) The optical-electrical wiring board according to (6), further comprising: a flat substrate; a metal layer located along a main surface of the substrate; and a clad layer located between the metal layer and the optical waveguide core and the electrical wiring, wherein the metal layer extends through the clad layer to reach the metal layer. (8) The optical-electrical wiring board according to (7), further comprising: another clad layer located on the surface of the clad layer and covering the optical waveguide core and the electrical wiring, and another metal layer located on the surface of the another clad layer, wherein the metal portion is connected to the another metal layer through a via. (9) A method for manufacturing an optical-electrical wiring board, comprising: a step of stacking a metal layer and a clad layer along a main surface of the substrate; a step of forming an optical waveguide core that transmits an optical signal on the surface of the clad layer; a step of forming an electrical wiring that transmits an electrical signal on the surface of the clad layer; and a step of forming a metal portion made of metal between the optical waveguide core and the electrical wiring adjacent to each other on the surface of the clad layer. (10) The method for manufacturing an optical-electrical wiring board according to (9), wherein the step of forming the electrical wiring and the step of forming the metal portion are carried out at the same time.

[0092] REFERENCE SIGNS LIST 1 Optical-electrical wiring board 2 Optical waveguide core 2A Dummy core 3 Electrical wiring 4 Metal portion 4a Extension portion 5 Via 10 Metal layer 20 Cladding layer 21 Surface 30 Cladding layer (an example of another cladding layer) 31 Surface 40 Metal layer (an example of another metal layer)

Claims

1. an optical waveguide core for transmitting an optical signal; an electrical wiring for transmitting an electrical signal; a metal portion located between the optical waveguide core and the electrical wiring adjacent to each other; An optical-electrical wiring board comprising:

2. The metal part is connected to a ground potential. The optical-electrical wiring board according to claim 1 .

3. The thickness of the metal portion is greater than the thickness of the electrical wiring. The optical-electrical wiring board according to claim 1 .

4. The metal part has a wall-like shape. The optical-electrical wiring board according to claim 3 .

5. The distance between the metal portion and the electrical wiring is shorter than the distance between the metal portion and the optical waveguide core. The optical-electrical wiring board according to any one of claims 1 to 4.

6. The metal portion has an inverted U-shape in cross section. The optical-electrical wiring board according to any one of claims 1 to 4.

7. A flat substrate; a metal layer located along a major surface of the substrate; a clad layer located between the metal layer and the optical waveguide core and the electrical wiring; Furthermore, The metal layer extends through the cladding layer to the metal layer. The optical-electrical wiring board according to claim 6 .

8. another cladding layer located on the surface of the cladding layer and covering the optical waveguide core and the electrical wiring; another metal layer located on the surface of the another cladding layer; Furthermore, The metal portion is connected to the other metal layer through a via. The optical-electrical wiring board according to claim 7 .

9. laminating a metal layer and a clad layer along a major surface of the substrate; forming an optical waveguide core for transmitting an optical signal on a surface of the cladding layer; forming electrical wiring for transmitting electrical signals on the surface of the cladding layer; forming a metal portion made of metal between the optical waveguide core and the electrical wiring adjacent to each other on the surface of the cladding layer; A method for manufacturing an optical / electrical wiring board, comprising:

10. The step of forming the electrical wiring and the step of forming the metal portion are carried out at the same time. The method for manufacturing the optical-electrical wiring board according to claim 9 .