Opto-electric hybrid substrate, active optical cable, and method for manufacturing opto-electric hybrid substrate

Abstract

The opto-electric hybrid substrate (4) is provided with a metal support layer (12), a flexible wiring board (11), and an optical waveguide film (13). A flexible wiring board (11) is provided with a base insulating layer (14), a conductor layer (15), and a metal plating layer (31). The conductor layer (15) is provided with an electrical wiring (18) and a connector-side terminal (17). The opto-electric hybrid board (4) is provided with an electrical connection portion (7). The electrical connection portion (7) includes a metal support layer (12), a base insulating layer (14), and a connector-side terminal (17) and a metal plating layer (31). In the electrical connection portion (7), one end edge of the metal support layer (12) in the longitudinal direction protrudes further toward one side in the longitudinal direction than one end edges of the connector-side terminal (17) and the metal plating layer (31) in the longitudinal direction. One end edge of the base insulating layer (14) in the longitudinal direction protrudes further toward one side in the longitudinal direction than one end edge of the metal support layer (12) in the longitudinal direction.

Description

Technical Field

[0001] The present invention relates to an optoelectronic hybrid substrate, an active optical cable, and a method for manufacturing an optoelectronic hybrid substrate. Background Art

[0002] Conventionally, an optoelectronic hybrid substrate has been known. The optoelectronic hybrid substrate includes, for example, a flexible printed circuit board, a metal support layer, and an optical waveguide thin film. The optoelectronic hybrid substrate is connected to a printed circuit board via an electrical connector. More specifically, the optoelectronic hybrid substrate is inserted into an insertion port of the electrical connector, and the connector-side terminals of the optoelectronic hybrid substrate are brought into contact with the connector terminals of the electrical connector (for example, refer to Patent Document 1 below).

[0003] Prior Art Documents

[0004] Patent Documents

[0005] Patent Document 1: Japanese Patent Application Laid-Open No. 2021-028664 Summary of the Invention

[0006] Problems to be Solved by the Invention

[0007] There is a demand for further improvement in the connection reliability between the optoelectronic hybrid substrate and the electrical connector.

[0008] The present invention provides an optoelectronic hybrid substrate having excellent connection reliability, an active optical cable including the optoelectronic hybrid substrate, and a method for manufacturing the optoelectronic hybrid substrate.

[0009] Means for Solving the Problems

[0010] The present invention [1] includes an optoelectronic hybrid substrate that includes a metal support layer, a flexible printed circuit board, and an optical waveguide thin film. The flexible printed circuit board is disposed on one side in the thickness direction of the metal support layer and includes: a base insulating layer; a conductor layer disposed on one side in the thickness direction of the base insulating layer and including a wiring portion and a terminal portion continuous with the wiring portion; and a metal plating layer disposed on one side in the thickness direction of the terminal portion. The optical waveguide thin film is disposed on the other side in the thickness direction of the metal support layer. The optoelectronic hybrid substrate includes a connection portion disposed at one end in the length direction of the optoelectronic hybrid substrate. The connection portion includes the metal support layer, the base insulating layer, the terminal portion, and the metal plating layer. In the connection portion, one end edge in the length direction of the metal support layer protrudes more toward one side in the length direction than one end edge in the length direction of the terminal portion and the metal plating layer, and one end edge in the length direction of the base insulating layer protrudes more toward one side in the length direction than one end edge in the length direction of the metal support layer.

[0011] The present invention [2] includes the optoelectronic hybrid substrate described in [1] above. The connection part includes the optical waveguide thin film. In the connection part, one end edge in the length direction of the optical waveguide thin film protrudes more toward one side in the length direction than one end edge in the length direction of the terminal part and the metal plating layer. One end edge in the length direction of the metal support layer protrudes more toward one side in the length direction than one end edge in the length direction of the optical waveguide thin film.

[0012] The present invention [3] includes the optoelectronic hybrid substrate described in [1] or [2] above. In the connection part, the distance between one end edge in the length direction of the base insulating layer and one end edge in the length direction of the terminal part and the metal plating layer is longer than 0.10 mm.

[0013] The present invention [4] includes the optoelectronic hybrid substrate described in [3] above. In the connection part, the distance between one end edge in the length direction of the base insulating layer and one end edge in the length direction of the terminal part and the metal plating layer is 0.12 mm or more.

[0014] The present invention [5] includes the optoelectronic hybrid substrate described in [4] above. In the connection part, the distance between one end edge in the length direction of the base insulating layer and one end edge in the length direction of the terminal part and the metal plating layer is 0.12 mm or more and 0.30 mm or less.

[0015] The present invention [6] includes the optoelectronic hybrid substrate described in any one of [1] to [5] above. The connection part includes the optical waveguide thin film. In the connection part, the total of the thickness of the metal support layer, the thickness of the flexible printed circuit board, and the thickness of the optical waveguide thin film is 100 μm or more and 500 μm or less.

[0016] The present invention [7] includes the optoelectronic hybrid substrate described in any one of [1] to [6] above. The optical waveguide thin film is made of a photosensitive resin.

[0017] The present invention [8] includes an active optical cable, which includes: the optoelectronic hybrid substrate described in any one of [1] to [7] above; and an optical fiber cable, which is connected to the optoelectronic hybrid substrate.

[0018] The present invention [9] includes a method for manufacturing an optoelectronic hybrid substrate, which is a method for manufacturing the optoelectronic hybrid substrate described in any one of the above [1] to [7]. The method for manufacturing the optoelectronic hybrid substrate includes: a step of preparing a metal support layer; a step of disposing the base insulating layer having an opening on one surface in the thickness direction of the metal support layer; a step of disposing the wiring portion of the conductor layer on one surface in the thickness direction of the base insulating layer and disposing the terminal portion of the conductor layer on one surface in the thickness direction of the metal support layer exposed from the opening; a step of forming a metal plating layer on one surface in the thickness direction of the terminal portion by supplying power from the metal support layer to the terminal portion in the opening; a step of processing one end edge in the length direction of the metal support layer so that one end edge in the length direction of the metal support layer protrudes more toward one side in the length direction than the end edge in the length direction of the terminal portion and the metal plating layer, and one end edge in the length direction of the base insulating layer protrudes more toward one side in the length direction than the end edge in the length direction of the metal support layer; and a step of disposing an optical waveguide thin film on the other surface of the metal support layer opposite to the one surface in the thickness direction.

[0019] Advantages of the Invention

[0020] The optoelectronic hybrid substrate and the active optical cable of the present invention have excellent connection reliability.

[0021] The method for manufacturing an optoelectronic hybrid substrate of the present invention can efficiently manufacture an optoelectronic hybrid substrate having excellent connection reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 is a schematic side cross-sectional view of an embodiment of the optoelectronic hybrid substrate of the present invention (here, it refers to a mode in which the electrical connection portion includes an optical waveguide thin film).

[0023] Figure 2 is Figure 1 a top view of the optoelectronic hybrid substrate shown.

[0024] Figure 3A shows the step of preparing a metal support layer, Figure 3B shows the step of disposing the base insulating layer having an opening on one surface in the thickness direction of the metal support layer, Figure 3C shows the step of disposing the wiring portion of the conductor layer on one surface in the thickness direction of the base insulating layer and disposing the terminal portion of the conductor layer on one surface in the thickness direction of the metal support layer exposed from the opening, Figure 3D shows the step of disposing a covering insulating layer on one surface in the thickness direction of the wiring portion.

[0025] Figure 4A Shows a process of forming a metal plating layer on one side surface in the thickness direction of a terminal portion by supplying power from a metal support layer to the terminal portion within the opening portion. Figure 4B Shows a process of processing one side edge in the length direction of the metal support layer, such that one side edge in the length direction of the metal support layer protrudes more toward one side in the length direction than one side edge in the length direction of the terminal portion and the metal plating layer, and such that one side edge in the length direction of the base insulating layer protrudes more toward one side in the length direction than one side edge in the length direction of the metal support layer. Figure 4C Shows a process of disposing an optical waveguide thin film on the other side in the thickness direction of the metal support layer.

[0026] Figure 5 Is a schematic diagram showing a state in which an optoelectronic hybrid substrate and an electrical connector are separated in one embodiment of an optoelectronic composite transmission module including the Figure 1 shown optoelectronic hybrid substrate.

[0027] Figure 6 Is a schematic diagram showing a state in which an optoelectronic hybrid substrate and an electrical connector are connected in one embodiment of the Figure 5 shown optoelectronic composite transmission module.

[0028] Figure 7 Is a schematic diagram showing one embodiment of an active optical cable of an optoelectronic composite transmission module including the Figure 5 shown optoelectronic hybrid substrate.

[0029] Figure 8 Is a schematic diagram of a side cross-section of another embodiment of the optoelectronic hybrid substrate of the present invention (here, referring to a mode in which an optical waveguide thin film is not provided in the electrical connection portion).

[0030] Symbol Explanation

[0031] 1 Optoelectronic Composite Transmission Module

[0032] 2 Printed Wiring Board

[0033] 3 Electrical Connector

[0034] 4 Optoelectronic Hybrid Substrate

[0035] 6 Connector Terminal

[0036] 7 Electrical Connection Portion

[0037] 8 Electrical Transmission Portion

[0038] 9 Optoelectronic Conversion Portion

[0039] 10 Optical Transmission Portion

[0040] 11 Flexible Wiring Board

[0041] 12 Metal support layer

[0042] 13 Optical waveguide thin film

[0043] 14 Substrate insulating layer

[0044] 15 Conductor layer

[0045] 16 Conversion side terminal

[0046] 17 Connector side terminal

[0047] 18 Electrical wiring

[0048] 19 Joining member

[0049] 20 Inner cladding

[0050] 21 Core layer

[0051] 22 Outer cladding

[0052] 23 Photoelectric conversion element

[0053] 24 Covering insulating layer

[0054] 25 Substrate

[0055] 26 First surface

[0056] 27 Second surface

[0057] 28 Through hole

[0058] 29 Mirror

[0059] 30 Third surface

[0060] 31 Metal plating layer

[0061] 32 Opening. Detailed implementation mode

[0062] 1. Optoelectronic hybrid substrate

[0063] 1) Overall structure

[0064] Hereinafter, with reference to Figures 1 - 2 an embodiment of the optoelectronic hybrid substrate of the present invention will be described. In Figures 1 - 2 , the optoelectronic hybrid substrate 4 has a long and flat plate shape.

[0065] The optoelectronic hybrid substrate 4 sequentially includes, in the length direction, an electrical connection portion 7 as a connection portion, an electrical transmission portion 8, an optoelectronic conversion portion 9, and an optical transmission portion 10. In addition, the optoelectronic hybrid substrate 4 includes a metal support layer 12, a flexible printed circuit board 11, and an optical waveguide thin film 13.

[0066] In addition, one side in the length direction of the optoelectronic hybrid substrate 4 is Figure 1 the left side of the paper surface in Figure 2 and the upper side of the paper surface in

[0067] In addition, the other side of the optoelectronic hybrid substrate 4 opposite to one side in the length direction (hereinafter, the other side in the length direction) is Figure 1 the right side of the paper surface in Figure 2 and the lower side of the paper surface in

[0068] The electrical connection portion 7 is disposed at one end portion in the length direction of the optoelectronic hybrid substrate 4. The electrical transmission portion 8 is disposed adjacent to the other side in the length direction of the electrical connection portion 7. The optoelectronic conversion portion 9 is disposed adjacent to the other side in the length direction of the electrical transmission portion 8. The optical transmission portion 10 is disposed adjacent to the other side in the length direction of the optoelectronic conversion portion 9.

[0069] The electrical connection portion 7, the electrical transmission portion 8, and the optoelectronic conversion portion 9 sequentially include, in the thickness direction, the flexible printed circuit board 11, the metal support layer 12, and the optical waveguide thin film 13. The optical transmission portion 10 does not include the metal support layer 12 and sequentially includes, in the thickness direction, the flexible printed circuit board 11 and the optical waveguide thin film 13.

[0070] Hereinafter, the metal support layer 12, the flexible printed circuit board 11, and the optical waveguide thin film 13 will be described in detail.

[0071] [Metal Support Layer]

[0072] The metal support layer 12 is disposed at the middle portion in the thickness direction of the optoelectronic hybrid substrate 4. That is, the metal support layer 12 is disposed between the flexible printed circuit board 11 and the optical waveguide thin film 13. In addition, the metal support layer 12 is not disposed in the optical transmission portion 10 and is disposed in the electrical connection portion 7, the electrical transmission portion 8, and the optoelectronic conversion portion 9.

[0073] The metal support layer 12 is disposed on the other side (the other surface) in the thickness direction of the flexible wiring board 11. Specifically, the metal support layer 12 contacts the other side (the other surface) in the thickness direction of the base insulating layer 14 (described later) without passing through an adhesive layer. In addition, the metal support layer 12 has a through hole 28 penetrating in the thickness direction. The through hole 28 is formed, for example, to face the light inlet / outlet of the photoelectric conversion element 23 described later.

[0074] As the material of the metal support layer 12, for example, metals can be cited. As the metal, more specifically, for example, 42 alloy, aluminum, beryllium copper, phosphor bronze, copper, silver, and aluminum can be cited. From the viewpoint of ensuring excellent rigidity and toughness, preferably, stainless steel can be cited. The thickness of the metal support layer 12 is, for example, 3 μm or more and 100 μm or less, and preferably 10 μm or more and 50 μm or less.

[0075] [Flexible Wiring Board]

[0076] The flexible wiring board 11 is disposed on one side (one surface) in the thickness direction of the metal support layer 12. The flexible wiring board 11 is disposed over the entire optoelectronic hybrid substrate 4 from one end to the other end in the length direction. Specifically, the flexible wiring board 11 is disposed at the electrical connection portion 7, the electrical transmission portion 8, the optoelectronic conversion portion 9, and the optical transmission portion 10.

[0077] The flexible wiring board 11 includes a base insulating layer 14, a conductor layer 15, a metal plating layer 31, and a covering insulating layer 24.

[0078] The top view shape of the base insulating layer 14 is the same as the top view shape of the flexible wiring board 11. The base insulating layer 14 is disposed at the electrical connection portion 7, the electrical transmission portion 8, the optoelectronic conversion portion 9, and the optical transmission portion 10. As the material of the base insulating layer 14, for example, insulating materials can be cited. As the insulating material, for example, polyimide can be cited. The thickness of the base insulating layer 14 can be set as appropriate.

[0079] The base insulating layer 14 has an opening 32 at the electrical connection portion 7. The opening 32 is a through hole penetrating the base insulating layer 14 in the thickness direction. In the opening 32, the metal support layer 12 is exposed from the base insulating layer 14.

[0080] The conductor layer 15 is disposed on one side (one surface) in the thickness direction of the base insulating layer 14. In addition, the conductor layer 15 is also disposed on one side (more specifically, inside the opening 32 (the same applies hereinafter)) in the thickness direction of the metal support layer 12 exposed from the base insulating layer 14. The conductor layer 15 is not disposed at the optical transmission portion 10, but is disposed at the electrical connection portion 7, the electrical transmission portion 8, and the optoelectronic conversion portion 9.

[0081] Specifically, the conductor layer 15 includes an electrical wiring 18 as a wiring portion, a connector-side terminal 17 as a terminal portion continuous with one side in the length direction of the electrical wiring 18, and a conversion-side terminal 16 continuous with the other side in the length direction of the electrical wiring 18.

[0082] The electrical wiring 18 is a portion in the conductor layer 15 that transmits an electrical signal. Refer to Figure 2 , in the width direction orthogonal to the length direction and the thickness direction, a plurality of electrical wirings 18 are arranged at intervals from each other.

[0083] Refer to Figure 1 , in the electrical transmission portion 8, each electrical wiring 18 is arranged along the length direction. In addition, each electrical wiring 18 connects the conversion-side terminal 16 and the connector-side terminal 17 respectively.

[0084] The connector-side terminal 17 is a portion in the conductor layer 15 that is electrically connected to a connector terminal 6 (described later). Refer to Figure 2 , in the width direction orthogonal to the length direction and the thickness direction, a plurality of connector-side terminals 17 are arranged at intervals from each other.

[0085] Refer to Figure 1 , each connector-side terminal 17 is arranged along the length direction in the electrical connection portion 7. In addition, each connector-side terminal 17 is arranged on one side (inside the opening portion 32) in the thickness direction of the metal support layer 12 exposed from the base insulating layer 14.

[0086] The conversion-side terminal 16 is a portion in the conductor layer 15 that is electrically connected to the photoelectric conversion element 23. Although not shown, a plurality of conversion-side terminals 16 are arranged at intervals from each other in the width direction orthogonal to the length direction and the thickness direction. Although not shown, each conversion-side terminal 16 is arranged along the length direction in the photoelectric conversion portion 9.

[0087] As the material of the conductor layer 15, known conductor materials can be cited. As the conductor material, for example, copper can be cited. The thickness of the conductor layer 15 can be set appropriately.

[0088] The metal plating layer 31 is arranged on one side (one surface) in the thickness direction of each connector-side terminal 17. The shape of the metal plating layer 31 in plan view is substantially the same as the shape of each connector-side terminal 17 in plan view. That is, one end face in the length direction of the metal plating layer 31 and one end face in the length direction of the connector-side terminal 17 are flush with each other. For example, as described later, the metal plating layer 31 is formed by using the metal support layer 12 as a plating lead and supplying power to the metal support layer 12.

[0089] As the material of the metal plating layer 31, for example, gold and nickel can be cited. The thickness of the metal plating layer 31 can be set appropriately.

[0090] The covering insulating layer 24 is disposed on one side in the thickness direction of the conductor layer 15. The covering insulating layer 24 is not disposed on the electrical connection portion 7, the optoelectronic conversion portion 9, and the optical transmission portion 10, but is disposed on the electrical transmission portion 8.

[0091] Specifically, the covering insulating layer 24 is in surface contact with one side surface in the thickness direction of the base insulating layer 14 around the electrical wiring 18, so as to cover the electrical wiring 18. The material of the covering insulating layer 24 is the same as that of the base insulating layer 14. The thickness of the covering insulating layer 24 can be set appropriately.

[0092] There is no particular limitation on the thickness of the flexible wiring board 11, which can be set appropriately. In particular, the thickness of the flexible wiring board 11 in the electrical connection portion 7 is set from the viewpoint of connection reliability. For example, the thickness of the flexible wiring board 11 in the electrical connection portion 7 is, for example, 20 μm or more and 250 μm or less, preferably 50 μm or more and 100 μm or less. In addition, the thickness of the flexible wiring board 11 in the electrical connection portion 7 is the sum of the thickness of the connector-side terminal 17 and the thickness of the metal plating layer 31.

[0093] [Optical waveguide thin film]

[0094] The optical waveguide thin film 13 is disposed on the other side (the other surface) in the thickness direction of the metal support layer 12. The optical waveguide thin film 13 is disposed over the entire optoelectronic hybrid substrate 4 from one end to the other end in the length direction. Specifically, the optical waveguide thin film 13 is disposed over the electrical connection portion 7, the electrical transmission portion 8, the optoelectronic conversion portion 9, and the optical transmission portion 10. The optical waveguide thin film 13 includes an inner cladding 20, a core layer 21, and an outer cladding 22.

[0095] The inner cladding 20 is disposed on the electrical connection portion 7, the electrical transmission portion 8, the optoelectronic conversion portion 9, and the optical transmission portion 10. The inner cladding 20 is disposed to be in surface contact with the other side surface in the thickness direction of the base insulating layer 14 of the flexible wiring board 11. In addition, the inner cladding 20 is disposed to be in surface contact with the other side surface in the thickness direction of the metal support layer 12. The thickness of the inner cladding 20 is, for example, 2 μm or more and 600 μm or less, preferably 3 μm or more and 100 μm or less, more preferably 4 μm or more and 60 μm or less, and still more preferably 5 μm or more and 45 μm or less.

[0096] The core layer 21 is not disposed in the electrical connection portion 7, but is disposed in the electrical transmission portion 8, the optoelectronic conversion portion 9, and the optical transmission portion 10. The core layer 21 is disposed on the surface on the other side in the thickness direction of the inner cladding 20. The core layer 21 is formed in a pattern with a width narrower than that of the inner cladding 20. The thickness of the core layer 21 is, for example, 5 μm or more and 100 μm or less, preferably 10 μm or more and 90 μm or less, more preferably 15 μm or more and 80 μm or less, and further preferably 20 μm or more and 60 μm or less.

[0097] In the optoelectronic conversion portion 9, a mirror 29 is formed in the core layer 21. The mirror 29 is opposed to the through hole 28 in the thickness direction. That is, the mirror 29 is opposed to the light entrance and exit (not shown) of the optoelectronic conversion element 23 in the thickness direction.

[0098] The outer cladding 22 is disposed at the same position as the inner cladding 20 in a plan view. Specifically, the outer cladding 22 is disposed in the electrical connection portion 7, the electrical transmission portion 8, the optoelectronic conversion portion 9, and the optical transmission portion 10. The outer cladding 22 is disposed on the surface on the other side in the thickness direction of the inner cladding 20 so as to cover the surface on the other side in the thickness direction and the side surface of the core layer 21. The thickness of the outer cladding 22 is, for example, 2 μm or more and 600 μm or less, preferably 3 μm or more and 100 μm or less, more preferably 4 μm or more and 60 μm or less, and further preferably 5 μm or more and 45 μm or less.

[0099] The thickness of the outer cladding 22 is the distance between the surface on the other side in the thickness direction of the inner cladding 20 and the surface on the other side in the thickness direction of the outer cladding 22. The ratio of the thickness of the outer cladding 22 to the thickness of the inner cladding 20 is, for example, 0.5 or more and 10 or less, preferably 1 or more and 5 or less.

[0100] As the material of the optical waveguide film 13, for example, resin can be cited, and preferably, photosensitive resin can be cited. That is, the optical waveguide film 13 is, for example, made of resin, and preferably made of photosensitive resin. As the photosensitive resin, for example, epoxy resin, acrylic resin, and silicone resin can be cited, and preferably, epoxy resin can be cited. The photosensitive resin can be appropriately selected so that the refractive index of the core layer 21 is higher than the refractive index of the inner cladding 20 and the refractive index of the outer cladding 22.

[0101] The thickness of the optical waveguide film 13 is not particularly limited and can be appropriately set. In particular, the thickness of the optical waveguide film 13 in the electrical connection portion 7 is set from the viewpoint of connection reliability.

[0102] For example, the thickness of the optical waveguide thin film 13 in the electrical connection portion 7 is, for example, 20 μm or more and 250 μm or less, preferably 50 μm or more and 100 μm or less. In addition, the thickness of the optical waveguide thin film 13 in the electrical connection portion 7 is the sum of the thickness of the inner cladding 20 and the thickness of the outer cladding 22.

[0103] [Opto - electric conversion element]

[0104] The opto - electric hybrid substrate 4 can be provided with an opto - electric conversion element 23. The opto - electric conversion element 23 is an element that can convert an optical signal into an electrical signal and / or can convert an electrical signal into an optical signal. The opto - electric conversion element 23 is electrically connected to the conversion - side terminal 16 of the flexible wiring board 11 via a known bonding member 19.

[0105] [Positional relationship in the electrical connection portion]

[0106] In the above - mentioned opto - electric hybrid substrate 4, the electrical connection portion 7 includes a metal support layer 12, a base insulating layer 14, a connector - side terminal 17, a metal plating layer 31, and an optical waveguide thin film 13.

[0107] Moreover, the metal support layer 12, the base insulating layer 14, the connector - side terminal 17, the metal plating layer 31, and the optical waveguide thin film 13 are arranged to have a given positional relationship.

[0108] More specifically, as will be described in detail below, in the electrical connection portion 7, one - side edge in the length direction of the metal support layer 12, one - side edge in the length direction of the base insulating layer 14, one - side edge in the length direction of the connector - side terminal 17 and the metal plating layer 31, and one - side edge in the length direction of the optical waveguide thin film 13 have a given positional relationship as follows.

[0109] That is, in the electrical connection portion 7, referring to Figure 1 and Figure 2 , among one - side edge in the length direction of the metal support layer 12, one - side edge in the length direction of the base insulating layer 14, one - side edge in the length direction of the optical waveguide thin film 13, and one - side edge in the length direction of the connector - side terminal 17 and the metal plating layer 31, one - side edge in the length direction of the connector - side terminal 17 and the metal plating layer 31 is arranged at the position closest to the other side in the length direction.

[0110] In other words, in the electrical connection portion 7, one - side edge in the length direction of the base insulating layer 14, one - side edge in the length direction of the metal support layer 12, and one - side edge in the length direction of the optical waveguide thin film 13 all protrude more toward one side in the length direction than one - side edge in the length direction of the connector - side terminal 17 and the metal plating layer 31.

[0111] In addition, in the electrical connection portion 7, among one side edge in the longitudinal direction of the metal support layer 12, one side edge in the longitudinal direction of the base insulating layer 14, one side edge in the longitudinal direction of the optical waveguide thin film 13, and one side edge in the longitudinal direction of the connector-side terminal 17 and the metal plating layer 31, one side edge in the longitudinal direction of the optical waveguide thin film 13 is disposed at the second-nearest position to the other side in the longitudinal direction.

[0112] That is, in the electrical connection portion 7, both one side edge in the longitudinal direction of the base insulating layer 14 and one side edge in the longitudinal direction of the metal support layer 12 protrude more toward one side in the longitudinal direction than one side edge in the longitudinal direction of the optical waveguide thin film 13.

[0113] Furthermore, referring to Figure 1 and Figure 2 , among one side edge in the longitudinal direction of the metal support layer 12, one side edge in the longitudinal direction of the base insulating layer 14, one side edge in the longitudinal direction of the optical waveguide thin film 13, and one side edge in the longitudinal direction of the connector-side terminal 17 and the metal plating layer 31 in the electrical connection portion 7, one side edge in the longitudinal direction of the metal support layer 12 is disposed at the third-nearest position to the other side in the longitudinal direction.

[0114] In other words, in the electrical connection portion 7, one side edge in the longitudinal direction of the base insulating layer 14 protrudes more toward one side in the longitudinal direction than one side edge in the longitudinal direction of the metal support layer 12.

[0115] As described above, in the electrical connection portion 7, one side edge in the longitudinal direction of the base insulating layer 14 is disposed at the position closest to one side in the longitudinal direction. In addition, in the electrical connection portion 7, one side edge in the longitudinal direction of the connector-side terminal 17 and the metal plating layer 31 is disposed at the position closest to the other side in the longitudinal direction.

[0116] From the viewpoint of connection reliability, the distance (in other words, the shortest distance in the longitudinal direction (the same applies hereinafter)) between one side edge in the longitudinal direction of the base insulating layer 14 (more specifically, the edge of the base insulating layer 14 disposed at the position closest to one side in the longitudinal direction (the same applies hereinafter)), and one side edge in the longitudinal direction of the connector-side terminal 17 and the metal plating layer 31 (more specifically, the edge of the connector-side terminal 17 and the metal plating layer 31 disposed at the position closest to one side in the longitudinal direction (the same applies hereinafter)) is, for example, 0.05 mm or more, preferably longer than 0.10 mm (in other words, exceeding 0.10 mm), and more preferably 0.12 mm or more.

[0117] In addition, in the electrical connection portion 7, the upper limit of the distance (the shortest distance in the longitudinal direction) between one end edge in the longitudinal direction of the base insulating layer 14 and one end edge in the longitudinal direction of the connector-side terminal 17 and the metal plating layer 31 is set according to, for example, the terminal size of the electrical connector 3. For example, in the electrical connection portion 7, from the perspective of the terminal size, the upper limit of the distance between one end edge in the longitudinal direction of the base insulating layer 14 and one end edge in the longitudinal direction of the connector-side terminal 17 and the metal plating layer 31 is, for example, 0.50 mm or less, preferably 0.40 mm or less, and more preferably 0.30 mm or less.

[0118] That is, in the electrical connection portion 7, from the perspectives of connection reliability and terminal size, the distance (the shortest distance in the longitudinal direction) between one end edge in the longitudinal direction of the base insulating layer 14 and one end edge in the longitudinal direction of the connector-side terminal 17 and the metal plating layer 31 is, for example, 0.05 mm or more and 0.50 mm or less, preferably longer than 0.10 mm (in other words, exceeding 0.10 mm) and 0.40 mm or less, and more preferably 0.12 mm or more and 0.30 mm or less.

[0119] Hereinafter, the distance (the shortest distance in the longitudinal direction) between one end edge in the longitudinal direction of the base insulating layer 14 and one end edge in the longitudinal direction of the connector-side terminal 17 and the metal plating layer 31 is referred to as the "marginal distance".

[0120] Moreover, in the longitudinal direction, between one end edge in the longitudinal direction of the base insulating layer 14 (the end edge disposed at the position closest to one side in the longitudinal direction) and one end edge in the longitudinal direction of the connector-side terminal 17 and the metal plating layer 31 (the end edge disposed at the position closest to one side in the longitudinal direction), one end edge in the longitudinal direction of the metal support layer 12 and one end edge in the longitudinal direction of the optical waveguide thin film 13 are disposed.

[0121] For example, the distance (the shortest distance in the longitudinal direction) between one end edge in the longitudinal direction of the base insulating layer 14 and one end edge in the longitudinal direction of the metal support layer 12 is, for example, 0.01 mm or more and 0.2 mm or less, preferably 0.02 mm or more and 0.1 mm or less.

[0122] Hereinafter, the distance (the shortest distance in the longitudinal direction) between one end edge in the longitudinal direction of the base insulating layer 14 and one end edge in the longitudinal direction of the metal support layer 12 is referred to as the "first distance".

[0123] The ratio of the first distance to the above-mentioned marginal distance is, for example, 7% or more and 80% or less, preferably 13% or more and 67% or less.

[0124] In addition, for example, the distance (the shortest distance in the length direction) between one side edge in the length direction of the metal support layer 12 and one side edge in the length direction of the optical waveguide thin film 13 is, for example, 0.01 mm or more and 0.7 mm or less, preferably 0.05 mm or more and 0.5 mm or less.

[0125] Hereinafter, the distance (the shortest distance in the length direction) between one side edge in the length direction of the metal support layer 12 and one side edge in the length direction of the optical waveguide thin film 13 is referred to as the "second distance".

[0126] The ratio of the second distance to the above-mentioned marginal distance is, for example, 7% or more and 60% or less, preferably 33% or more and 50% or less.

[0127] In addition, for example, the distance (the shortest distance in the length direction) between one side edge in the length direction of the optical waveguide thin film 13 and one side edge in the length direction of the connector-side terminal 17 and the metal plating layer 31 is, for example, 0.01 mm or more and 0.5 mm or less, preferably 0.05 mm or more and 0.2 mm or less.

[0128] Hereinafter, the distance (the shortest distance in the length direction) between one side edge in the length direction of the optical waveguide thin film 13 and one side edge in the length direction of the connector-side terminal 17 and the metal plating layer 31 is referred to as the "third distance".

[0129] The ratio of the third distance to the above-mentioned marginal distance is, for example, 7% or more and 60% or less, preferably 33% or more and 50% or less.

[0130] In addition, the sum of the ratios of the first distance, the second distance, and the third distance to the above-mentioned marginal distance is 100%.

[0131] In addition, for example, the distance (the shortest distance in the length direction) between one side edge in the length direction of the metal support layer 12 and one side edge in the length direction of the connector-side terminal 17 and the metal plating layer 31 is, for example, 0.01 mm or more and 0.5 mm or less, preferably 0.05 mm or more and 0.3 mm or less.

[0132] Hereinafter, the distance (the shortest distance in the length direction) between one side edge in the length direction of the metal support layer 12 and one side edge in the length direction of the connector-side terminal 17 and the metal plating layer 31 is referred to as the "fourth distance".

[0133] The ratio of the fourth distance to the above-mentioned marginal distance is, for example, 7% or more and 90% or less, preferably 33% or more and 80% or less.

[0134] In addition, for example, the distance (the shortest distance in the length direction) between one end edge in the length direction of the base insulating layer 14 and one end edge in the length direction of the optical waveguide thin film 13 is, for example, 0.01 mm or more and 0.5 mm or less, preferably 0.05 mm or more and 0.4 mm or less.

[0135] Hereinafter, the distance (the shortest distance in the length direction) between one end edge in the length direction of the base insulating layer 14 and one end edge in the length direction of the optical waveguide thin film 13 is referred to as the "fifth distance".

[0136] The ratio of the fifth distance with respect to the above-mentioned marginal distance is, for example, 7% or more and 90% or less, preferably 33% or more and 80% or less.

[0137] In the electrical connection portion 7, the thickness of the optoelectronic hybrid substrate 4 is set from the viewpoint of connection reliability. For example, in the electrical connection portion 7, the thickness of the optoelectronic hybrid substrate 4 is adjusted to be the same as the distance between the first surface 26 (described later) of the electrical connector 3 and the connector terminal 6 (described later). The thickness of the optoelectronic hybrid substrate 4 is the sum of the thickness of the metal support layer 12, the thickness of the flexible wiring board 11, and the thickness of the optical waveguide thin film 13.

[0138] More specifically, in the electrical connection portion 7, the sum of the thickness of the metal support layer 12, the thickness of the flexible wiring board 11, and the thickness of the optical waveguide thin film 13 is, for example, 50 μm or more, preferably 100 μm or more, and more preferably 150 μm or more. In addition, the sum of the thickness of the metal support layer 12, the thickness of the flexible wiring board 11, and the thickness of the optical waveguide thin film 13 is, for example, 1000 μm or less, preferably 500 μm or less, and more preferably 400 μm or less.

[0139] That is, from the viewpoint of connection reliability, the sum of the thickness of the metal support layer 12, the thickness of the flexible wiring board 11, and the thickness of the optical waveguide thin film 13 is, for example, 50 μm or more and 1000 μm or less, preferably 100 μm or more and 500 μm or less, and more preferably 150 μm or more and 400 μm or less.

[0140] 2) Manufacturing method of the optoelectronic hybrid substrate

[0141] Hereinafter, with reference to Figures 3A - 4C the manufacturing method of the optoelectronic hybrid substrate 4 will be described in detail.

[0142] In this method, first, with reference to Figure 3A , the metal support layer 12 is prepared.

[0143] Next, in this method, with reference to Figure 3B , on one surface in the thickness direction of the metal support layer 12, the base insulating layer 14 having the opening 32 is formed.

[0144] There is no particular limitation on the method for forming the base insulating layer 14. For example, a varnish of the above resin for forming the base insulating layer 14 is applied to the surface on one side in the thickness direction of the metal support layer 12. After exposure and development to form a given pattern of the opening 32, the resin varnish is cured. Thus, the base insulating layer 14 having a given pattern is formed.

[0145] Next, in this method, referring to Figure 3C , a conductor layer 15 including the electrical wiring 18, the connector-side terminal 17, and the conversion-side terminal 16 is formed.

[0146] More specifically, the electrical wiring 18 and the conversion-side terminal 16 of the conductor layer 15 are disposed on the surface on one side in the thickness direction of the base insulating layer 14. In addition, in this method, the connector-side terminal 17 of the conductor layer 15 is disposed on the surface on one side in the thickness direction of the metal support layer 12 exposed from the opening 32. There is no particular limitation on the method for forming the conductor layer 15, and known methods can be adopted. For example, an additive method, a semi-additive method, and a subtractive method can be cited. Preferably, an additive method can be cited. In the additive method, for example, a seed film is formed by a known method, the seed film is immersed in a plating solution, and an external device supplies power to the seed film from the metal support layer 12. Thus, the conductor layer 15 having a given pattern is formed on the seed film.

[0147] Next, in this method, referring to Figure 3D , a covering insulating layer 24 is disposed on one side in the thickness direction of the electrical wiring 18.

[0148] There is no particular limitation on the method for forming the covering insulating layer 24. For example, a resin varnish for forming the covering insulating layer 24 is applied to the surfaces on one side in the thickness directions of the base insulating layer 14 and the conductor layer 15, and after exposure and development to form a given pattern covering the electrical wiring 18, the resin varnish is cured. Thus, the covering insulating layer 24 having a given pattern is formed.

[0149] Next, in this method, referring to Figure 4A , a metal plating layer 31 is formed on the surface on one side in the thickness direction of the connector-side terminal 17.

[0150] More specifically, the connector-side terminal 17 in the opening 32 is immersed in a plating solution, and an external device supplies power to the connector-side terminal 17 in the opening 32 via the metal support layer 12. That is, the metal support layer 12 is used as a plating lead to supply power to the connector-side terminal 17. Thus, the metal plating layer 31 is formed on the surface on one side in the thickness direction of the connector-side terminal 17.

[0151] Next, in this method, referring to Figure 4B, at the electrical connection portion 7, one end edge in the longitudinal direction of the metal support layer 12 is processed so that the metal support layer 12 satisfies the above-mentioned given positional relationship.

[0152] More specifically, in this process, by processing one end edge in the longitudinal direction of the metal support layer 12, the length in the longitudinal direction of the metal support layer 12 is shortened, and one end edge in the longitudinal direction of the base insulating layer 14 protrudes more toward one side in the longitudinal direction than one end edge in the longitudinal direction of the metal support layer 12.

[0153] In addition, in this process, the length in the longitudinal direction of the metal support layer 12 is not overly shortened, and one end edge in the longitudinal direction of the metal support layer 12 protrudes more toward one side in the longitudinal direction than one end edge in the longitudinal direction of the connector-side terminal 17 and the metal plating layer 31.

[0154] Furthermore, in this process, for example, a part of the metal support layer 12 of the photoelectric conversion portion 9 is removed to form a through hole 28. In addition to this, in this process, the metal support layer 12 of the optical transmission portion 10 is removed. Additionally, the method for processing the metal support layer 12 is not particularly limited, and known methods can be used.

[0155] Next, in this method, referring to Figure 4C , on the other side surface of the metal support layer 12 opposite to one side surface in the thickness direction, the optical waveguide thin film 13 is disposed.

[0156] More specifically, for example, on the other side in the thickness direction of the metal support layer 12, an inner cladding layer 20, a core layer 21, and an outer cladding layer 22 are sequentially formed. Thus, the optical waveguide thin film 13 can be disposed on the other side in the thickness direction of the metal support layer 12. In addition, in this process, the optical waveguide thin film 13 is processed (here, more specifically, it means cutting (the same hereinafter)), and a mirror 29 is formed in the core layer 21.

[0157] In addition, in this process, the optical waveguide thin film 13 is disposed to satisfy the above-mentioned given positional relationship.

[0158] That is, the size and position of the optical waveguide thin film 13 are adjusted so that one end edge in the longitudinal direction of the optical waveguide thin film 13 protrudes more toward one side in the longitudinal direction than one end edge in the longitudinal direction of the connector-side terminal 17 and the metal plating layer 31.

[0159] In addition, the size and position of the optical waveguide thin film 13 are adjusted so that one end edge in the longitudinal direction of the metal support layer 12 protrudes more toward one side in the longitudinal direction than one end edge in the longitudinal direction of the optical waveguide thin film 13.

[0160] The optoelectronic hybrid substrate 4 is manufactured through the above steps.

[0161] Specifically, the above-mentioned optoelectronic hybrid substrate 4 has excellent connection reliability as described later. Therefore, the optoelectronic hybrid substrate 4 can be suitably used as a component of the optoelectronic composite transmission module 1.

[0162] 3) Optoelectronic composite transmission module

[0163] Hereinafter, with reference to Figures 5 - 6 The optoelectronic composite transmission module 1 will be described. With reference to Figures 5 - 6 , the optoelectronic composite transmission module 1 has a long strip shape.

[0164] The optoelectronic composite transmission module 1 includes the above-mentioned optoelectronic hybrid substrate 4, a printed wiring board 2, and an electrical connector 3 that connects them.

[0165] The printed wiring board 2 is disposed at one end portion in the length direction of the optoelectronic composite transmission module 1. The printed wiring board 2 includes a substrate 25 and terminals (not shown).

[0166] The substrate 25 has a flat plate shape. As the material of the substrate 25, for example, a hard material can be cited. As the hard material, for example, glass fiber reinforced epoxy resin can be cited. Terminals (not shown) are provided on one surface in the thickness direction of the substrate 25. The substrate 25 and the electrical connector 3 are connected via the terminals (not shown).

[0167] The electrical connector 3 is a connector that electrically connects the printed wiring board 2 and the optoelectronic hybrid substrate 4. As the electrical connector 3, for example, an FPC connector, a ZIF connector, and a board connector can be cited. Preferably, a ZIF connector can be cited.

[0168] The electrical connector 3 is disposed on one surface in the thickness direction of the printed wiring board 2. The electrical connector 3 has a substantially U-shaped (or U-shaped) shape in a cross-sectional view, for example. The electrical connector 3 has an insertion port 5 and connector terminals 6 provided in the insertion port 5.

[0169] The insertion port 5 is configured such that the electrical connection portion 7 of the above-mentioned optoelectronic hybrid substrate 4 can be inserted. The insertion port 5 includes a first surface 26, a second surface 27, and a third surface 30. The first surface 26, the second surface 27, and the third surface 30 are all inner walls of the insertion port 5.

[0170] The first surface 26 and the second surface 27 are arranged in the length direction so as to face each other in the thickness direction. The third surface 30 is the innermost wall surface in the insertion direction of the insertion port 5 (here, the length direction (the same applies hereinafter)). More specifically, the third surface 30 is arranged in the thickness direction between one end edge in the length direction of the first surface 26 and one end edge in the length direction of the second surface 27. One end edge in the thickness direction of the third surface 30 is connected to one end edge in the length direction of the first surface 26. In addition, the other end edge in the thickness direction of the third surface 30 is connected to one end edge in the length direction of the second surface 27.

[0171] The connector terminal 6 is provided on the second surface 27. The connector terminal 6 is provided corresponding to the connector-side terminal 17 of the electrical connection portion 7.

[0172] The distance between the first surface 26 and the connector terminal 6 can be appropriately set according to the specifications of the electrical connector 3 (in other words, the type (the same applies hereinafter)). Specifically, the distance between the first surface 26 and the connector terminal 6 is, for example, 10 μm or more and 2,000 μm or less, preferably 100 μm or more and 500 μm or less.

[0173] Moreover, for example, the optical and electrical hybrid substrate 4 and the printed wiring board 2 are electrically connected to manufacture the optical and electrical composite transmission module 1.

[0174] More specifically, as Figure 5 shown, a printed wiring board 2 and an electrical connector 3 that are electrically connected to each other are prepared. In addition, the optical and electrical hybrid substrate 4 is manufactured by the above method.

[0175] Next, as Figure 6 shown, the electrical connection portion 7 of the optical and electrical hybrid substrate 4 is inserted into the electrical connector 3 so that the connector-side terminal 17 of the optical and electrical hybrid substrate 4 contacts the connector terminal 6 of the electrical connector 3.

[0176] Through the above, the optical and electrical hybrid substrate 4 and the printed wiring board 2 are electrically connected via the electrical connector 3. As a result, the optical and electrical composite transmission module 1 can be manufactured.

[0177] 4) Function and effect

[0178] The above-mentioned optical and electrical hybrid substrate 4 and optical and electrical composite transmission module 1 have excellent connection reliability.

[0179] More specifically, as described above, the electrical connection portion 7 includes a metal support layer 12, a base insulating layer 14, a connector-side terminal 17 as a terminal portion, a metal plating layer 31, and an optical waveguide thin film 13.

[0180] In the conventional electrical connection portion 7, one end edge in the longitudinal direction of the connector-side terminal 17 and the metal plating layer 31 is sometimes disposed at one end edge in the longitudinal direction of the optoelectronic hybrid substrate 4.

[0181] More specifically, in the above description, the metal support layer 12 is used as a plating lead to supply power to the connector-side terminal 17. However, in the conventional electrical connection portion 7, a convex plating lead is formed without using the metal support layer 12 as a plating lead (refer to Figure 2 the virtual line B). That is, in the conventional electrical connection portion 7, the connector-side terminal 17 is disposed on one surface in the thickness direction of the base insulating layer 14. Further, the convex plating lead for forming the metal plating layer 31 (refer to Figure 2 the virtual line B) is connected to the connector-side terminal 17. Then, the convex plating lead is disposed such that one end edge in the longitudinal direction of the convex plating lead is flush with one end edge in the longitudinal direction of the optoelectronic hybrid substrate 4. Then, by supplying power to the convex plating lead, the metal plating layer 31 is formed on one surface in the thickness direction of the connector-side terminal 17.

[0182] In such a case, one end edge in the longitudinal direction of the convex plating lead (refer to Figure 2 the virtual line B) and the metal plating layer 31 are disposed at one end edge in the longitudinal direction of the optoelectronic hybrid substrate 4. Further, in the conventional electrical connection portion 7, the metal support layer 12, the base insulating layer 14, the convex plating lead (refer to Figure 2 the virtual line B), the metal plating layer 31, and the optical waveguide thin film 13 are sometimes disposed flush in one side in the thickness direction.

[0183] In such a case, one end edge in the longitudinal direction of the metal support layer 12, one end edge in the longitudinal direction of the base insulating layer 14, one end edge in the longitudinal direction of the metal plating layer 31, and one end edge in the longitudinal direction of the optical waveguide thin film 13 are all disposed at one end edge in the longitudinal direction of the optoelectronic hybrid substrate 4.

[0184] In such a case, when the electrical connection portion 7 of the optoelectronic hybrid substrate 4 is inserted into the insertion port 5 of the electrical connector 3, the third surface 30 of the insertion port 5 and the metal plating layer 31 sometimes come into contact. As a result, the metal plating layer 31 is sometimes damaged, and the connection reliability between the optoelectronic hybrid substrate 4 and the electrical connector 3 sometimes decreases.

[0185] In contrast, in the above-described optoelectronic hybrid substrate 4 and the optoelectronic composite transmission module 1, in the electrical connection portion 7, the metal support layer 12, the base insulating layer 14, the connector-side terminal 17, the metal plating layer 31, and the optical waveguide thin film 13 have the above-described positional relationship.

[0186] More specifically, the above-described connector-side terminal 17 is disposed on one side surface of the metal support layer 12 within the opening 32, and a metal plating layer 31 is formed by supplying power to the connector-side terminal 17. That is, a convex plating lead (refer to the virtual line B in Figure 2 ) is not required.

[0187] Therefore, in the above-described optoelectronic hybrid substrate 4 and optoelectronic composite transmission module 1, the positional relationship between one side edge in the length direction of the metal support layer 12, the connector-side terminal 17, and one side edge in the length direction of the metal plating layer 31 can be adjusted as described above.

[0188] That is, one side edge in the length direction of the metal support layer 12 can protrude more toward one side in the length direction than one side edge in the length direction of the connector-side terminal 17 and the metal plating layer 31. In addition, one side edge in the length direction of the base insulating layer 14 can protrude more toward one side in the length direction than one side edge in the length direction of the metal support layer 12.

[0189] As a result, in the above-described optoelectronic hybrid substrate 4 and optoelectronic composite transmission module 1, when the electrical connection portion 7 of the optoelectronic hybrid substrate 4 is inserted into the insertion port 5 of the electrical connector 3, before the third surface 30 of the insertion port 5 contacts the connector-side terminal 17 and the metal plating layer 31, first, the third surface 30 of the insertion port 5 contacts the base insulating layer 14, and the insertion stops. Further, even when the insertion does not stop when the third surface 30 of the insertion port 5 has contacted the base insulating layer 14, next, the third surface 30 of the insertion port 5 will also contact the metal support layer 12, thereby stopping the insertion.

[0190] That is, according to the above-described optoelectronic hybrid substrate 4 and optoelectronic composite transmission module 1, contact between the third surface 30 of the insertion port 5 and the connector-side terminal 17 and the metal plating layer 31 can be suppressed.

[0191] As a result, damage to the connector-side terminal 17 and the metal plating layer 31 is suppressed, and the connection reliability between the optoelectronic hybrid substrate 4 and the electrical connector 3 is improved.

[0192] Further, in the above-described optoelectronic hybrid substrate 4 and optoelectronic composite transmission module 1, one side edge in the length direction of the optical waveguide thin film 13 protrudes more toward one side in the length direction than one side edge in the length direction of the connector-side terminal 17 and the metal plating layer 31. In addition, one side edge in the length direction of the metal support layer 12 protrudes more toward one side in the length direction than one side edge in the length direction of the optical waveguide thin film 13.

[0193] Therefore, even when the insertion does not stop even though the third surface 30 of the insertion port 5 has come into contact with the metal support layer 12, the third surface 30 of the insertion port 5 and the optical waveguide thin film 13 will come into contact next, causing the insertion to stop.

[0194] That is, according to the above-mentioned optoelectronic hybrid substrate 4 and optoelectronic composite transmission module 1, it is possible to particularly well suppress the contact between the third surface 30 of the insertion port 5 and the connector-side terminal 17 and the metal plating layer 31. As a result, damage to the connector-side terminal 17 and the metal plating layer 31 is suppressed, and the connection reliability between the optoelectronic hybrid substrate 4 and the electrical connector 3 is improved.

[0195] As described above, the above-mentioned optoelectronic hybrid substrate 4 and optoelectronic composite transmission module 1 have excellent connection reliability with respect to the electrical connector 3. In addition, according to the manufacturing method of the above-mentioned optoelectronic hybrid substrate 4, it is possible to efficiently manufacture an optoelectronic hybrid substrate 4 having excellent connection reliability.

[0196] Therefore, the above-mentioned optoelectronic hybrid substrate 4 and the above-mentioned optoelectronic composite transmission module 1 can be suitably used as components of the active optical cable 100, for example.

[0197] 2. Active Optical Cable

[0198] Hereinafter, with reference to Figure 7 the active optical cable 100 will be described. With reference to Figure 7 , the active optical cable 100 has a long strip shape.

[0199] The active optical cable 100 includes the above-mentioned optoelectronic composite transmission module 1, the optical fiber cable 101, and the optical connector 102 that connects them.

[0200] As described above, the optoelectronic composite transmission module 1 includes the printed wiring board 2, the electrical connector 3, and the optoelectronic hybrid substrate 4. In other words, the active optical cable 100 includes the above-mentioned optoelectronic hybrid substrate 4, the optical fiber cable 101 connected to the optoelectronic hybrid substrate 4, and the optical connector 102.

[0201] Moreover, in the optoelectronic hybrid substrate 4, the optical waveguide thin film 13 of the optical transmission portion 10 (refer to Figure 1 ) is optically connected to the optical fiber cable 101.

[0202] More specifically, for one active optical cable 100, two (more specifically, a pair (the same applies hereinafter)) optoelectronic composite transmission modules 1 are provided. Moreover, one optoelectronic composite transmission module 1 is optically connected to one side in the length direction of the optical fiber cable 101. The other optoelectronic composite transmission module 1 is optically connected to the other side in the length direction of the optical fiber cable 101.

[0203] The optical fiber cable 101 is a cable capable of transmitting and receiving optical signals. The optical fiber cable 101 has, for example, a plastic optical fiber through which an optical signal passes and an outer skin covering the plastic optical fiber.

[0204] With respect to one active optical cable 100, for example, one optical fiber cable 101 is provided. More specifically, as described above, one end portion in the length direction of the optical fiber cable 101 is optically connected to one optoelectronic hybrid transmission module 1. In addition, the other end portion in the length direction of the optical fiber cable 101 is optically connected to another optoelectronic hybrid transmission module 1.

[0205] The optical connector 102 is a connector that connects the optoelectronic hybrid transmission module 1 and the optical fiber cable 101. The optical connector 102 is interposed at the connection portion between the optoelectronic hybrid transmission module 1 and the optical fiber cable 101 by a known method.

[0206] More specifically, with respect to one active optical cable 100, for example, two (a pair of) optical connectors 102 are provided. Moreover, one optical connector 102 is interposed between one end portion in the length direction of the optical fiber cable 101 and one optoelectronic hybrid transmission module 1. In addition, the other optical connector 102 is interposed between the other end portion in the length direction of the optical fiber cable 101 and another optoelectronic hybrid transmission module 1.

[0207] The method for manufacturing the active optical cable 100 is not particularly limited. For example, one optical fiber cable 101 and two (a pair of) optoelectronic hybrid transmission modules 1 are connected via the optical connector 102 by a known method. Through the above, the active optical cable 100 can be manufactured. According to the above active optical cable 100, an optical signal can be transmitted between a pair of optoelectronic hybrid transmission modules 1.

[0208] Moreover, the above active optical cable 100 includes the above optoelectronic hybrid transmission module 1. Therefore, the above active optical cable 100 has excellent connection reliability between the optoelectronic hybrid substrate 4 and the electrical connector 3.

[0209] 3. Modification

[0210] In the following respective modification examples, the same reference numerals are assigned to the same components and processes as those in the above-described one embodiment, and the detailed description thereof is omitted. In addition, unless otherwise specified, each modification example can exhibit the same effects as those of one embodiment. Further, one embodiment and its modification examples can be appropriately combined.

[0211] As Figure 8 shown, the electrical connection portion 7 may not include the optical waveguide thin film 13. In addition, the electrical transmission portion 8 may not include the optical waveguide thin film 13.

[0212] More specifically, in Figure 8In [the structure], the optoelectronic hybrid substrate 4 sequentially has an electrical connection portion 7, an electrical transmission portion 8, an optoelectronic conversion portion 9, and an optical transmission portion 10 as connection portions in the longitudinal direction.

[0213] Moreover, the optoelectronic conversion portion 9 sequentially includes a flexible wiring board 11, a metal support layer 12, and an optical waveguide thin film 13 in the thickness direction. The electrical connection portion 7 and the electrical transmission portion 8 do not include the optical waveguide thin film 13, and sequentially include the flexible wiring board 11 and the metal support layer 12 in the thickness direction. The optical transmission portion 10 does not include the metal support layer 12, and sequentially includes the flexible wiring board 11 and the optical waveguide thin film 13 in the thickness direction.

[0214] In such a case, in the electrical connection portion 7, one end edge in the longitudinal direction of the metal support layer 12 also protrudes more toward one side in the longitudinal direction than one end edge in the longitudinal direction of the connector-side terminal 17 and the metal plating layer 31. In addition, one end edge in the longitudinal direction of the base insulating layer 14 also protrudes more toward one side in the longitudinal direction than one end edge in the longitudinal direction of the metal support layer 12. Therefore, the above-described optoelectronic hybrid substrate 4 has excellent connection reliability.

[0215] From the viewpoints of the rigidity and connection reliability of the electrical connection portion 7, preferably, the electrical connection portion 7 includes the optical waveguide thin film 13. That is, as long as the electrical connection portion 7 includes the optical waveguide thin film 13, the rigidity of the electrical connection portion 7 can be improved, and in addition, the connection reliability is further improved.

[0216] In addition, in the above description, in the formation of the base insulating layer 14 and the covering insulating layer 24, after exposing and developing the resin varnish, it is cured. On the other hand, for example, the resin varnish may be cured without exposing and developing it, and then the cured product of the resin varnish may be cut into a given pattern.

[0217] In addition, in the above description, an inner cladding 20, a core layer 21, and an outer cladding 22 are sequentially formed on the other side in the thickness direction of the metal support layer 12. On the other hand, for example, the optical waveguide thin film 13 can be formed in advance, and the optical waveguide thin film 13 can be bonded to the other side in the thickness direction of the metal support layer 12 via an adhesive.

[0218] In addition, the above invention is provided as an exemplary embodiment of the present invention, and these are merely examples and should not be construed in a limiting manner. Modification examples of the present invention that are obvious to those skilled in the art in this technical field are also included within the scope of the appended patent claims.

[0219] Industrial Applicability

[0220] The optoelectronic hybrid substrate, active optical cable, and manufacturing method of the optoelectronic hybrid substrate of the present invention can be used in the field of signal transmission.

Claims

1. An optoelectronic hybrid substrate comprising a metal support layer, a flexible printed circuit board, and an optical waveguide thin film, wherein the flexible printed circuit board is disposed on one side in the thickness direction of the metal support layer, and the flexible printed circuit board includes: a base insulating layer; a conductor layer disposed on one side in the thickness direction of the base insulating layer, having a wiring portion and a terminal portion continuous with the wiring portion; and a metal plating layer disposed on one side in the thickness direction of the terminal portion, wherein the optical waveguide thin film is disposed on the other side in the thickness direction of the metal support layer, the optoelectronic hybrid substrate has a connection portion disposed at one end portion on one side in the length direction of the optoelectronic hybrid substrate, the connection portion includes the metal support layer, the base insulating layer, the terminal portion, and the metal plating layer, in the connection portion, one end edge in the length direction of the metal support layer protrudes more toward one side in the length direction than one end edge in the length direction of the terminal portion and the metal plating layer, one end edge in the length direction of the base insulating layer protrudes more toward one side in the length direction than one end edge in the length direction of the metal support layer.

2. The optoelectronic hybrid substrate according to claim 1, wherein the connection portion includes the optical waveguide thin film, in the connection portion, one end edge in the length direction of the optical waveguide thin film protrudes more toward one side in the length direction than one end edge in the length direction of the terminal portion and the metal plating layer, one end edge in the length direction of the metal support layer protrudes more toward one side in the length direction than one end edge in the length direction of the optical waveguide thin film.

3. The optoelectronic hybrid substrate according to claim 1, wherein in the connection portion, the distance between one end edge in the length direction of the base insulating layer and one end edge in the length direction of the terminal portion and the metal plating layer is longer than 0.10 mm.

4. The optoelectronic hybrid substrate according to claim 3, wherein in the connection portion, the distance between one end edge in the length direction of the base insulating layer and one end edge in the length direction of the terminal portion and the metal plating layer is 0.12 mm or more.

5. The optoelectronic hybrid substrate according to claim 4, wherein in the connection portion, the distance between one end edge in the length direction of the base insulating layer and one end edge in the length direction of the terminal portion and the metal plating layer is 0.12 mm or more and 0.30 mm or less.

6. The optoelectronic hybrid substrate according to claim 1, wherein the connection portion includes the optical waveguide thin film, in the connection portion, the sum of the thickness of the metal support layer, the thickness of the flexible printed circuit board, and the thickness of the optical waveguide thin film is 100 μm or more and 500 μm or less.

7. The optoelectronic hybrid substrate according to claim 1, wherein the optical waveguide thin film is made of a photosensitive resin.

8. An active optical cable comprising: the optoelectronic hybrid substrate according to any one of claims 1 to 7; and an optical fiber cable connected to the optoelectronic hybrid substrate.

9. A method for manufacturing an optoelectronic hybrid substrate, which is a method for manufacturing the optoelectronic hybrid substrate according to any one of claims 1 to 7, The method for manufacturing the optoelectronic hybrid substrate comprises: a step of preparing a metal support layer; a step of disposing the base insulating layer having an opening on a surface on one side in the thickness direction of the metal support layer; a step of disposing the wiring portion of the conductor layer on a surface on one side in the thickness direction of the base insulating layer, and disposing the terminal portion of the conductor layer on a surface on one side in the thickness direction of the metal support layer exposed from the opening; a step of forming a metal plating layer on a surface on one side in the thickness direction of the terminal portion by supplying power from the metal support layer to the terminal portion in the opening; a step of processing one side edge in the length direction of the metal support layer so that one side edge in the length direction of the metal support layer protrudes more toward the length direction than one side edge in the length direction of the terminal portion and the metal plating layer, and one side edge in the length direction of the base insulating layer protrudes more toward the length direction than one side edge in the length direction of the metal support layer; and a step of disposing an optical waveguide thin film on the other surface of the metal support layer opposite to the surface on one side in the thickness direction.

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