Optical / electrical hybrid board

Abstract

To provide a photoelectric hybrid substrate that is excellent in noise prevention.SOLUTION: A photoelectric hybrid substrate 1 comprises an optical waveguide 5 and an electric circuit board 6 in order toward one side in a thickness direction. The electric circuit board 6 includes a metal support layer 11, a base insulating layer 12 that is arranged on one side in the thickness direction of the metal support layer 11, a plurality of conductor layers 17, 18 that are arranged in order on one side in the thickness direction, and an intermediate insulating layer 14 that is arranged between the plurality of conductor layers 17, 18. At least one layer selected from the group consisting of the metal support layer 11 and the plurality of conductor layers 17, 18 is a shield layer that is electrically insulated from the rest of the layers.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an optical / electrical hybrid board. [Background technology]

[0002] 2. Description of the Related Art Conventionally, an optical / electrical hybrid board is known that includes an optical waveguide and a flexible printed circuit board in this order in a thickness direction.

[0003] For example, an optical / electrical hybrid board including an optical waveguide and a flexible printed circuit board including a plurality of wiring patterns has been proposed (see, for example, Patent Document 1 below). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2010-113102 A Summary of the Invention [Problem to be solved by the invention]

[0005] In recent years, there has been a demand for noise suppression in wiring patterns.

[0006] However, the optical / electrical hybrid board described in Patent Document 1 has a drawback in that it cannot satisfy the above-mentioned requirements.

[0007] The present invention provides an optical / electrical hybrid board that is excellent in noise suppression. [Means for solving the problem]

[0008] The present invention (1) includes an optical-electrical hybrid board comprising an optical waveguide and an electric circuit board in order toward one side in a thickness direction, the electric circuit board comprising a metal support layer, a base insulating layer arranged on one side in the thickness direction of the metal support layer, and a plurality of conductor layers arranged in order in the thickness direction, the plurality of conductor layers including a first conductor layer arranged on one side in the thickness direction of the base insulating layer, and an intermediate insulating layer arranged between the plurality of conductor layers, and at least one layer selected from the group consisting of the metal support layer and the plurality of conductor layers is a shielding layer electrically insulated from the remaining layers.

[0009] In the present invention, at least one layer selected from the group consisting of the metal support layer and the plurality of conductor layers is a shield layer, so that noise in the remaining layers can be suppressed.

[0010] The present invention (2) includes the optical-electrical hybrid board described in (1), in which at least one of the plurality of conductor layers further includes a terminal for mounting an optical element, the terminal being disposed on one thickness-wise surface of the base insulating layer.

[0011] However, if the terminal is arranged on one surface in the thickness direction of the intermediate insulating layer and an optical element is mounted thereon, the intermediate insulating layer and the base insulating layer are interposed between the optical element and the optical waveguide, and the distance between them in the thickness direction is relatively long.

[0012] In contrast, if, as in the present invention, an optical element is mounted on a terminal that is located on one side of the base insulating layer in the thickness direction, there is no intermediate insulating layer between the optical element and the optical waveguide, and only the base insulating layer is interposed, so that the distance between them in the thickness direction can be shortened.

[0013] Therefore, the optical coupling loss between the optical element and the optical waveguide can be reduced.

[0014] The present invention (3) includes the optical-electrical hybrid board according to (1) or (2), in which the shielding layer overlaps with the remaining layer in the thickness direction.

[0015] In this optical / electrical hybrid board, the shielding layer can reliably suppress noise from the remaining layers.

[0016] The present invention (4) includes the optical / electrical hybrid board according to any one of (1) to (3), in which the remaining layers include power supply wiring and signal wiring.

[0017] In this optical / electrical hybrid board, the power supply wiring and the signal wiring enable both signal transmission and electrical transmission.

[0018] The present invention (5) includes an optical-electrical hybrid board according to any one of (1) to (4), in which the first conductor layer includes power wiring and / or signal wiring, and the metal support layer and a second conductor layer adjacent to one side of the first conductor layer in the thickness direction among the conductor layers are all the shielding layer.

[0019] In this optical-electrical hybrid board, the first conductor layer, which is a power supply wiring and / or a signal wiring, can transmit signals and / or electricity. Moreover, since the first conductor layer is sandwiched from both sides in the thickness direction by the metal support layer, which is a shielding layer, and the second conductor layer, the noise suppression effect of the first conductor layer can be improved.

[0020] The present invention (6) includes the optical-electrical hybrid board according to (2), in which the metal support layer overlaps with the terminal in the thickness direction.

[0021] In this optical-electrical hybrid board, even if vibration is applied when mounting an optical element on the terminal, the terminal overlaps the metal support layer, preventing the vibration from escaping to the outside. Therefore, the optical element can be reliably mounted on the terminal by the bonding member provided on the terminal. Effect of the Invention

[0022] The opto-electrical hybrid board of the present invention is excellent in noise suppression. [Brief description of the drawings]

[0023] [Figure 1]FIG. 1 is a cross-sectional view of an embodiment of an optical / electrical hybrid board of the present invention. [Diagram 2] Figures 2A to 2G are manufacturing process diagrams for the opto-electrical hybrid board shown in Figure 1, with Figure 2A showing the process of preparing a metal sheet, Figure 2B showing the process of forming a base insulating layer, Figure 2C showing the process of forming a first conductor layer, Figure 2D showing the process of forming an intermediate insulating layer, Figure 2E showing the process of forming a second conductor layer, Figure 2F showing the process of forming a cover insulating layer, and Figure 2G showing the process of forming a metal support layer. [Diagram 3] Figures 3H to 3K are manufacturing process diagrams for the opto-electrical hybrid substrate shown in Figure 1, following Figure 2G, in which Figure 3H is the process of forming an undercladding layer, Figure 3I is the process of forming a core layer, Figure 3J is the process of forming an overcladding layer, and Figure 3K is the process of forming a mirror. [Figure 4] FIG. 4 shows a modified example of the optical / electrical hybrid board shown in FIG. 1 (an optical / electrical hybrid board further provided with third to fifth conductor layers). [Diagram 5] FIG. 5 shows a modified example of the optical / electrical hybrid board shown in FIG. 1 (an optical / electrical hybrid board in which the first conductor layer and the second conductor layer in the first region are shield layers). [Figure 6] FIG. 6 shows another modified example of the optical / electrical hybrid board shown in FIG. 5 (an optical / electrical hybrid board in which a metal support layer is also disposed in the first region). [Figure 7] 7A to 7B are manufacturing process diagrams of a modified example of the optical-electrical hybrid board shown in FIG. 1 (an optical-electrical hybrid board further including a other-side conductor layer and a other-side insulating layer), in which FIG. 7A shows a process of forming the other-side conductor layer and the other-side insulating layer, and FIG. 7B shows a process of forming an optical waveguide. [Figure 8] FIG. 8 shows a modified example of the optical / electrical hybrid board shown in FIG. 1 (an optical / electrical hybrid board in which a metal support layer is disposed only in the mounting area). [Figure 9] FIG. 9 shows another modified example of the optical / electrical hybrid board shown in FIG. 5 (an optical / electrical hybrid board in which a power supply pattern is included in the first conductor layer and a signal pattern is included in the first conductor layer and the second conductor layer). [Figure 10] FIG. 10 shows a further modified example of the optical / electrical hybrid board shown in FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0024] <One embodiment> An embodiment of an opto-electrical hybrid board of the present invention will be described with reference to FIG.

[0025] The opto-electrical hybrid board 1 has a predetermined thickness and has a flat belt shape extending in a longitudinal direction perpendicular to the thickness direction. The opto-electrical hybrid board 1 mounts an optical element 31. The opto-electrical hybrid board 1 converts a transmitted optical signal into an electrical signal by the optical element 31 and transmits the signal, and / or converts a transmitted electrical signal into an optical signal (for example, weak power of less than 50 mW, or even less than 10 mW) by the optical element 31 and transmits the signal. The opto-electrical hybrid board 1 also transmits a power supply current (for example, a large current of 10 mA or more, or even 100 mA or more) in addition to the electrical signal.

[0026] The opto-electrical hybrid board 1 includes a mounting area 2, a first area 3, and a second area 4.

[0027] The mounting area 2 is an area for mounting an optical element 31. The mounting area 2 is located in the middle of the opto-electrical hybrid board 1 in the longitudinal direction.

[0028] The first area 3 is disposed on one longitudinal side of the mounting area 2. The first area 3 is continuous with one longitudinal end edge of the mounting area 2.

[0029] The second region 4 is disposed on the other longitudinal side of the mounting region 2. The second region 4 is continuous with the other longitudinal end edge of the mounting region 2.

[0030] Therefore, in this opto-electrical hybrid board 1, the second region 4, the mounting region 2, and the first region 3 are arranged in this order from the other side to one side in the longitudinal direction.

[0031] The optical / electrical hybrid board 1 also includes an optical waveguide 5 and an electric circuit board 6 arranged in this order toward one side in the thickness direction.

[0032] The optical waveguide 5 is the other side portion in the thickness direction of the opto-electrical hybrid substrate 1. The outer shape of the optical waveguide 5 is the same as that of the opto-electrical hybrid substrate 1. In other words, the optical waveguide 5 has a shape extending along the longitudinal direction. The optical waveguide 5 includes an undercladding layer 7, a core layer 8, and an overcladding layer 9.

[0033] The undercladding layer 7 has the same shape as the outer shape of the optical waveguide 5 in a plan view.

[0034] The core layer 8 is disposed at the center in the width direction (the direction perpendicular to the thickness direction and the longitudinal direction, that is, the paper thickness direction of FIG. 1) of the other surface in the thickness direction of the undercladding layer 7. The width of the core layer 8 is narrower than the width of the undercladding layer 7 in a plan view.

[0035] The overclad layer 9 is disposed on the other thickness-wise surface of the underclad layer 7 so as to cover the core layer 8. In a plan view, the overclad layer 9 has the same shape as the outer shape of the underclad layer 7. Specifically, the overclad layer 9 is disposed on the other thickness-wise surface and both width-wise side surfaces of the core layer 8, and on both width-wise outer sides of the core layer 8 on the other thickness-wise surface of the underclad layer 7. The refractive index of the core layer 8 is higher than the refractive index of the underclad layer 7 and the refractive index of the overclad layer 9.

[0036] Furthermore, in the core layer 8, a mirror 10 is formed in the mounting region 2.

[0037] The material of the optical waveguide 5 may be, for example, a transparent material such as epoxy resin. The thickness of the optical waveguide 5 is, for example, 10 μm or more, and, for example, 200 μm or less.

[0038] The electric circuit board 6 is disposed on one surface in the thickness direction of the optical waveguide 5. The electric circuit board 6 includes a metal support layer 11, a base insulating layer 12, a plurality of conductor layers 17, 18, an intermediate insulating layer 14, and a cover insulating layer 15.

[0039] The metal support layer 11 is disposed in the mounting region 2 and the second region 4. The metal support layer 11 is located at the other extreme side in the thickness direction in the mounting region 2 and the second region 4 of the opto-electrical hybrid board 1. The metal support layer 11 has a generally flat plate shape extending in the longitudinal direction. The metal support layer 11 also has an opening 16 penetrating in the thickness direction. The opening 16 is formed in the mounting region 2.

[0040] The metal supporting layer 11 also includes a grounding portion (not shown) at the other end in the longitudinal direction that can be grounded to an external grounding member, so that the metal supporting layer 11 functions as a shield layer.

[0041] Examples of materials for the metal support layer 11 include metals such as 42 alloy, aluminum, copper-beryllium, phosphor bronze, copper, silver, aluminum, and stainless steel. From the viewpoint of ensuring excellent rigidity and toughness, stainless steel is preferable. The thickness of the metal support layer 11 is, for example, 3 μm or more, preferably 10 μm or more, and, for example, 100 μm or less, preferably 50 μm or less.

[0042] The base insulating layer 12 is disposed across the mounting region 2, the first region 3, and the second region 4. The base insulating layer 12 is disposed on one surface in the thickness direction of the metal support layer 11 in the mounting region 2 and the second region 4. The base insulating layer 12 is disposed on one surface in the thickness direction of the undercladding layer 7 in the first region 3. The base insulating layer 12 has a generally flat plate shape extending in the longitudinal direction. Examples of materials for the base insulating layer 12 include resins such as polyimide. The thickness of the base insulating layer 12 is, for example, 2 μm or more and, for example, 50 μm or less.

[0043] The multiple conductor layers 17, 18 are located on one side in the thickness direction of the base insulating layer 12. The multiple conductor layers 17, 18 are a first conductor layer 17 and a second conductor layer 18. The first conductor layer 17 and the second conductor layer 18 are arranged in order from the other side to one side in the thickness direction.

[0044] The first conductor layer 17 is disposed on one surface in the thickness direction of the base insulating layer 12. The first conductor layer 17 is disposed on one side in the thickness direction of the metal support layer 11, with the base insulating layer 12 interposed therebetween. Therefore, the first conductor layer 17 is electrically insulated from the metal support layer 11. The first conductor layer 17 includes, for example, a signal pattern 41 and a power supply pattern 42.

[0045] The signal pattern 41 is disposed in the mounting area 2 and the second area 4. The signal pattern 41 integrally includes a signal wiring 43, a first terminal 44 as an example of a terminal, and a second terminal (not shown).

[0046] The signal line 43 connects the first terminal 44 and a second terminal (not shown).

[0047] The first terminal 44 is disposed in the mounting region 2. The first terminal 44 overlaps with the metal support layer 11 in the thickness direction. For example, a plurality of the first terminals 44 are disposed facing each other at intervals in the longitudinal direction. One end of the signal wiring 43 is connected to the first terminal 44. In addition, an electrode 33 (described later) of the optical element 31 is joined to the first terminal 44 via a bump 34 (described later).

[0048] The second terminal (not shown) is disposed in the second region 4, and is connected to the other end of the signal wiring 43. The second terminal is connected to an external substrate (not shown) (for example, a printed wiring board).

[0049] The power supply pattern 42 is disposed across the second region 4, the mounting region 2, and the first region 3. Note that the manner in which the power supply pattern 42 is disposed in the second region 4 and the mounting region 2 is not depicted in Fig. 1, but in a plan view, the power supply pattern 42 bypasses the optical element 31 in the mounting region 2 and the second region 4.

[0050] The power supply pattern 42 is spaced apart from the signal pattern 41 in the planar direction (a direction perpendicular to the thickness direction, including the longitudinal direction and width direction). This allows the power supply pattern 42 to be insulated from the signal pattern 41.

[0051] The power supply pattern 42 integrally includes a power supply wiring 45, a third terminal (not shown), and a fourth terminal (not shown).

[0052] The power supply wiring 45 connects a third terminal and a fourth terminal (not shown). The third terminal (not shown) and the fourth terminal (not shown) are disposed in the first area 3 and the second area 4, respectively. A separate power supply line is connected to the third terminal. An external board (e.g., a printed wiring board, etc.) is connected to the fourth terminal. The external board is configured to receive power from the outside.

[0053] The second conductor layer 18 is adjacent to one side in the thickness direction of the first conductor layer 17. The second conductor layer 18 is disposed on one side in the thickness direction of the first conductor layer 17 via an intermediate insulating layer 14, which will be described next. This allows the second conductor layer 18 to be insulated from the first conductor layer 17.

[0054] The second conductor layer 18 overlaps the signal wiring 43 and the power supply wiring 45 in the thickness direction, but does not overlap the first terminal 44, the second terminal (not shown), the third terminal (not shown), and the fourth terminal (not shown). Each of the signal wiring 43 and the power supply wiring 45 includes an overlapping portion 47 that overlaps with the second conductor layer 18 and a non-overlapping portion 48 that does not overlap with the second conductor layer 18.

[0055] The second conductor layer 18 and the metal support layer 11 sandwich the above-mentioned overlapping portion 47 of the first conductor layer 17 in the thickness direction.

[0056] The second conductor layer 18 includes a ground portion at an end portion (not shown) that can be grounded to an external ground member. Therefore, the second conductor layer 18 is also a shield layer. Therefore, the second conductor layer 18 includes a shield pattern 50.

[0057] Therefore, the two shield layers (metal support layer 11 and second conductor layer 18) sandwich the overlapping portion 47 of the first conductor layer 17 in the thickness direction.

[0058] An example of the material of each of the multiple conductor layers 17, 18 is a conductor such as copper. Each of the multiple conductor layers 17, 18 has a thickness of, for example, 2 μm or more, preferably 4 μm or more, and for example, 50 μm or less, preferably 25 μm or less.

[0059] The intermediate insulating layer 14 is disposed between the multiple conductor layers 17, 18. Specifically, it is interposed between the first conductor layer 17 and the second conductor layer 18. The intermediate insulating layer 14 is in contact with one thickness direction surface and both side surfaces of the signal wiring 43 and the power wiring 45, and one thickness direction surface of the base insulating layer 12 surrounding the first conductor layer 17. The intermediate insulating layer 14 is also in contact with the other thickness direction surface of the second conductor layer 18. Therefore, the second conductor layer 18 is disposed on one thickness direction surface of the intermediate insulating layer 14.

[0060] Furthermore, the intermediate insulating layer 14 insulates the two patterns in the first conductor layer 17, namely, the power supply pattern 42 and the signal pattern 41. Specifically, the intermediate insulating layer 14 is interposed between the power supply wiring 45 and the signal wiring 43.

[0061] It should be noted that intermediate insulating layer 14 exposes a first terminal 44, a second terminal (not shown), a third terminal (not shown), and a fourth terminal (not shown).

[0062] Examples of materials for the intermediate insulating layer 14 include resins such as polyimide. The thickness of the intermediate insulating layer 14 is, for example, not less than 2 μm and not more than 50 μm.

[0063] The cover insulating layer 15 is disposed on one thickness-wise surface of the intermediate insulating layer 14 so as to cover the second conductor layer 18. The cover insulating layer 15 is in contact with one thickness-wise surface and both side surfaces of the second conductor layer 18 and one thickness-wise surface of the periphery of the second conductor layer 18 in the intermediate insulating layer 14. The cover insulating layer 15 exposes a first terminal 44, a second terminal (not shown), a third terminal (not shown), and a fourth terminal (not shown). Examples of materials for the cover insulating layer 15 include resins such as polyimide. The thickness of the cover insulating layer 15 is, for example, 2 μm or more and, for example, 50 μm or less.

[0064] Next, a method for manufacturing this opto-electrical hybrid board 1 will be described with reference to FIGS. 2A to 3I.

[0065] 2A, in this method, first, a metal sheet 49 is prepared. The metal sheet 49 is a sheet for forming the metal support layer 11.

[0066] 2B, the insulating base layer 12 is then formed on one surface in the thickness direction of the metal sheet 49. For example, a photosensitive resin composition containing a resin is applied to the entire surface of one surface in the thickness direction of the metal sheet 49 to form a photosensitive film, which is then subjected to photolithography to form the insulating base layer 12.

[0067] 2C, next, the first conductor layer 17 is formed on one surface in the thickness direction of the base insulating layer 12. Examples of a method for forming the first conductor layer 17 include an additive method and a subtractive method.

[0068] 2D, the intermediate insulating layer 14 is then formed on the surfaces (including one surface in the thickness direction) of the base insulating layer 12 and the first conductor layer 17. For example, a photosensitive resin composition containing a resin is applied to the surfaces of the base insulating layer 12 and the first conductor layer 17 to form a photosensitive film, which is then subjected to photolithography to form the intermediate insulating layer 14.

[0069] 2E, the second conductor layer 18 is formed on one surface in the thickness direction of the intermediate insulating layer 14. Examples of a method for forming the second conductor layer 18 include an additive method and a subtractive method.

[0070] 2F, the cover insulating layer 15 is formed on the surfaces (including one surface in the thickness direction) of the intermediate insulating layer 14 and the second conductor layer 18. For example, a photosensitive resin composition containing a resin is applied to the surfaces of the intermediate insulating layer 14 and the second conductor layer 18 to form a photosensitive film, which is then subjected to photolithography to form the cover insulating layer 15.

[0071] As shown in FIG. 2G, a metal sheet 49 is contoured, for example by etching, to form a metal support layer 11 having an opening 16 therein.

[0072] In this way, the electric circuit board 6 is formed.

[0073] Thereafter, as shown in FIGS. 3H to 3J, the optical waveguide 5 is formed on the other surface in the thickness direction of the electric circuit board 6.

[0074] Specifically, as shown in Fig. 3H, a photosensitive resin composition containing a material for the undercladding layer 7 is first applied to the other thickness-wise surfaces of the metal supporting layer 11 and the insulating base layer 12 in the electric circuit board 6 to form a photosensitive coating. Then, the photosensitive coating is subjected to photolithography to form the undercladding layer 7.

[0075] 3I, a photosensitive resin composition containing a material for the core layer 8 is then applied to the other surface in the thickness direction of the undercladding layer 7 to form a photosensitive coating. The photosensitive coating is then subjected to photolithography to form the core layer 8.

[0076] 3J, a photosensitive resin composition containing a material for the overcladding layer 9 is then applied to the other thickness-wise surfaces of the undercladding layer 7 and the core layer 8 to form a photosensitive coating. The photosensitive coating is then subjected to photolithography to form the overcladding layer 9.

[0077] A mirror 10 is then formed on the core layer 8, as shown in FIG. 3K.

[0078] In this way, the optical waveguide 5 is formed.

[0079] In this way, the optical / electrical hybrid board 1 is manufactured.

[0080] Thereafter, the optical element 31 is mounted on the electric circuit board 6 of the optical / electrical hybrid board 1, as shown in FIG.

[0081] The optical element 31 has a generally rectangular cross section and includes an electrode 33 and an input / output port 32 located on the other surface in the thickness direction.

[0082] Two electrodes 33 are disposed at an interval in the longitudinal direction. The electrodes 33 have a shape extending in the thickness direction.

[0083] The incident / exit opening 32 is disposed between the two electrodes 33, and specifically, is located at the center in the longitudinal direction on the other surface in the thickness direction of the optical element 31. The incident / exit opening 32 is configured to allow light to enter and exit.

[0084] To mount the optical element 31 on the electric circuit board 6, first, the bumps 34 are arranged (placed) on one surface in the thickness direction of the first terminals 44 of the signal pattern 41. Examples of the bumps 34 include a meltable material, and specific examples include gold, solder, etc.

[0085] Next, the electrode 33 and the first terminal 44 are bonded via the bump 34. Examples of the bonding method include ultrasonic bonding in which ultrasonic vibration is applied to the first terminal 44 to melt the bump 34, and thermocompression bonding using a conductive adhesive.

[0086] As a result, the optical element 31 is electrically connected to the signal wiring 43 .

[0087] In addition, a second terminal (not shown) of the signal pattern 41 is connected to an external board (not shown).

[0088] Furthermore, a third terminal and a fourth terminal (not shown) of the power supply pattern 42 are connected to a power supply line and an external board (not shown), respectively.

[0089] Furthermore, the respective grounded portions of the metal support layer 11 and the second conductor layer 18 (shield layer) are electrically connected to an external ground member, so that the metal support layer 11 and the second conductor layer 18 each serve as a shield layer.

[0090] In this optical / electrical hybrid board 1, light is transmitted through core layer 8 from one side in the longitudinal direction, and has its optical path changed by mirror 10. Light enters input / output port 32 and is converted into an electrical signal by optical element 31. The electrical signal is input to an external board via signal pattern 41.

[0091] In addition, in this optical / electrical hybrid board 1, an electrical signal input from an external board to the optical element 31 via the signal pattern 41 is converted into an optical signal by the optical element 31. The optical signal is output from the input / output port 32 toward the mirror 10, and after the optical path is converted by the mirror 10, it is transmitted toward one side in the thickness direction.

[0092] Furthermore, the power supply current input from the power supply device is input to the external board via the power supply pattern 42.

[0093] On the other hand, noise in the signal wiring 43 and the power supply pattern 42 is suppressed by the metal support layer 11 and the second conductor layer 18 (shield pattern 50).

[0094] <Effects of one embodiment> In this optical / electrical hybrid board 1, since the metal support layer 11 and the second conductor layer 18 are shield layers, noise from the first conductor layer 17 can be suppressed.

[0095] Furthermore, although not shown, the first terminal 44 is arranged on one surface in the thickness direction of the intermediate insulating layer 14, and when the optical element 31 is mounted thereon, the intermediate insulating layer 14 and the base insulating layer 12 are interposed between the input / output port 32 and the mirror 10, so that the distance therebetween in the thickness direction is relatively long.

[0096] In contrast, if the optical element 31 is mounted on the first terminal 44 arranged on one surface in the thickness direction of the base insulating layer 12 as in this opto-electrical hybrid board 1, there is no intermediate insulating layer 14 between the optical element 31 and the mirror 10, and only the base insulating layer 12 is interposed as an insulating layer. Therefore, the distance L between the input / output opening 32 and the mirror 10 (the center in the longitudinal direction) in the thickness direction can be shortened.

[0097] Therefore, the optical coupling loss between the optical element 31 and the optical waveguide 5 can be reduced.

[0098] Furthermore, in this optical-electrical hybrid board 1, when projected in the thickness direction, the metal support layer 11 and the second conductor layer 18 overlap with the overlapping portion 47 of the first conductor layer 17, so that the metal support layer 11 and the second conductor layer 18 can reliably suppress noise in the first conductor layer 17.

[0099] Furthermore, in this optical-electrical hybrid board 1, signal transmission and electrical transmission can be achieved simultaneously through the signal wiring 43 and the power supply wiring 45, and these noises can be suppressed by the two shielding layers (the metal support layer 11 and the second conductor layer 18).

[0100] Furthermore, according to this optical-electrical hybrid board 1, even if ultrasonic vibration is applied to the first terminal 44 when mounting the optical element 31 on the first terminal 44, the first terminal 44 overlaps the metal support layer 11, so that the metal support layer 11, which has high rigidity, can absorb the ultrasonic vibration energy, thereby ensuring that the bumps 34 melt, and therefore the optical element 31 can be reliably mounted on the first terminal 44 via the bumps 34.

[0101] <Modification> In the following modifications, the same reference numerals are used for the same components and steps as those in the above-described embodiment, and detailed descriptions thereof will be omitted. In addition, each modification can achieve the same effects as those in the above-described embodiment, unless otherwise specified. Furthermore, the embodiment and its modifications can be appropriately combined.

[0102] In one embodiment, both the metal support layer 11 and the second conductor layer 18 are shield layers, but for example, although not shown, either one may be a shield layer. For example, the metal support layer 11 is a shield layer, and the second conductor layer 18 includes a power supply wiring and / or a signal wiring. Alternatively, the second conductor layer 18 is a shield layer, and the metal support layer 11 includes a power supply wiring and / or a signal wiring.

[0103] Preferably, as in one embodiment, both the metal support layer 11 and the second conductor layer 18 are shield layers. With this configuration, the first conductor layer 17 is sandwiched between two shield layers from both sides in the thickness direction, so that the noise suppression effect of the first conductor layer 17 can be improved.

[0104] In one embodiment, the first terminal 44 and the signal wiring 43 are arranged on the same plane, that is, on one surface in the thickness direction of the base insulating layer 12, and both are included in the first conductor layer 17. However, although not shown, the first terminal 44 may be arranged on one surface in the thickness direction of the base insulating layer 12, while the signal wiring 43 may be arranged on one surface in the thickness direction of the intermediate insulating layer 14 and included in the second conductor layer 18. In this modification, the first terminal 44 and the signal wiring 43 are connected in the thickness direction by a connecting line (not shown) extending in the thickness direction.

[0105] In this modification, the first terminal 44 is also disposed on one surface in the thickness direction of the base insulating layer 12, so that the above-mentioned distance L can be shortened. Therefore, the optical coupling loss between the optical element 31 and the optical waveguide 5 can be reduced.

[0106] In the embodiment, ultrasonic bonding is exemplified as a method for connecting the electrodes 33 of the optical element 31 and the first terminals 44, but the present invention is not limited to this, and reflow or the like can also be used.

[0107] Ultrasonic bonding is preferable. In reflow bonding, the optical element 31 is easily damaged by heat. However, ultrasonic bonding as in one embodiment can prevent such damage.

[0108] On the other hand, in ultrasonic bonding, the vibration energy is easily transmitted to the flexible optical waveguide 5 and escapes to the other side in the thickness direction, but in this embodiment, since the metal support layer 11 overlaps with the first terminal 44, the metal support layer 11, which has high rigidity, can absorb the vibration energy of the ultrasonic waves, and therefore the bump 34 can be reliably melted. Therefore, the optical element 31 can be reliably mounted on the first terminal 44 while preventing damage to the optical element 31.

[0109] In one embodiment, the number of layers of the plurality of conductor layers is two, but it may be three or more. Fig. 4 illustrates a modified example in which the number of layers is five.

[0110] In this modification, the multiple conductor layers include a first conductor layer 17, a second conductor layer 18, a third conductor layer 23, a fourth conductor layer 24, and a fifth conductor layer 25. The first conductor layer 17, the second conductor layer 18, the third conductor layer 23, the fourth conductor layer 24, and the fifth conductor layer 25 are arranged in order toward one side in the thickness direction.

[0111] The intermediate insulating layer 14 includes a first intermediate insulating layer 51 to a fourth intermediate insulating layer 54.

[0112] The first region 3 includes a portion (laminated structure) in which the first conductor layer 17, the first intermediate insulating layer 51, the second conductor layer 18, the second intermediate insulating layer 52, the third conductor layer 23, the third intermediate insulating layer 53, the fourth conductor layer 24, the fourth intermediate insulating layer 54 and the fifth conductor layer 25 are arranged in sequence toward one side in the thickness direction.

[0113] In this modification, the first conductor layer 17 does not include, for example, the power supply pattern 42 (see FIG. 1).

[0114] The first conductor layer 17 includes a shield pattern 50 in the first region 3. The shield pattern 50 is included in the first conductor layer 17, the third conductor layer 23, and the fifth conductor layer 25 in the first region 3.

[0115] On the other hand, in the first region 3, the signal pattern 41 is included in the second conductor layer 18 and the fourth conductor layer 24.

[0116] That is, the signal patterns 41 and the shield patterns 50 are alternately arranged toward one side in the thickness direction in the first region 3. Furthermore, each signal pattern 41 is sandwiched between the shield patterns 50 arranged on both sides in the thickness direction.

[0117] 5, the shield pattern 50 included in the second conductor layer 18 in the second region 4 overlaps, in the thickness direction, all of the signal wirings 43 in the second region 4. That is, in the modification shown in Fig. 5, one longitudinal end edge of the shield pattern 50 is closer to the mounting region 2 than one longitudinal end edge of the shield pattern 50 of the embodiment shown in Fig. 1.

[0118] In this modification, the first conductor layer 17 does not include the non-overlapping portion 48 (see FIG. 1) that does not overlap with the shield pattern 50.

[0119] Moreover, in this modification, in the first region 3, the shield pattern 50 is included in the first conductor layer 17 and the second conductor layer 18.

[0120] In the first region 3, the first conductor layer 17 including the shielding pattern 50 extends from one side in the longitudinal direction to a midpoint.

[0121] The intermediate insulating layer 14 has an insulating opening 21 that corresponds to the other longitudinal end of the first conductor layer 17. The insulating opening 21 penetrates the intermediate insulating layer 14 in the thickness direction.

[0122] The second conductor layer 18 in the first region 3 contacts one thickness direction surface of the intermediate insulating layer 14, an inner surface defining the insulating opening 21, and one thickness direction surface of the first conductor layer 17 on the inner side than the insulating opening 21.

[0123] In this modification, since the shield pattern 50 in the second region 4 is adjacent to the first region 3, the region that can be shielded can be expanded to the vicinity of the optical element 31.

[0124] 6, a metal support layer 11 constituting a shielding layer may be disposed in the first region 3. That is, the metal support layer 11 is disposed across the mounting region 2, the first region 3, and the second region 4.

[0125] As shown in FIG. 7B, the electric circuit board 6 further includes an other-side conductor layer 55 and an other-side insulating layer 56.

[0126] The other-side conductor layer 55 is disposed on the other surface in the thickness direction of the base insulating layer 12 in the first region 3. The other-side conductor layer 55 functions as, for example, a shield layer.

[0127] In the first region 3, the other-side insulating layer 56 contacts the other thickness direction surface of the base insulating layer 12 and the other thickness direction surface and the peripheral side surface of the other-side conductor layer 55. The back surface (including the other thickness direction surface) of the other-side insulating layer 56 is in contact with the undercladding layer 7.

[0128] To manufacture this optical-electrical hybrid board 1, after manufacturing the electric circuit board 6 shown in Fig. 2G, the other-side conductor layer 55 and the other-side insulating layer 56 are formed in this order as shown in Fig. 7A. Then, as shown in Fig. 7B, the optical waveguide 5 is formed on the back surface (including the other surface in the thickness direction) of the metal support layer 11, the base insulating layer 12, the other-side conductor layer 55, and the other-side insulating layer 56.

[0129] 8, in this modification, the other-side conductor layer 55 and the other-side insulating layer 56 are further arranged in the second region 4. On the other hand, the metal support layer 11 is not present in the second region 4. In other words, the metal support layer 11 is not arranged in the first region 3 and the second region 4, but is arranged only in the mounting region 2.

[0130] However, the metal support layer 11 in the mounting region 2 overlaps with the first terminals 44 in the thickness direction. Although the metal support layer 11 is a shielding layer, it can absorb vibration energy during ultrasonic bonding to the first terminals 44 of the optical element 31, and can reliably melt the bumps 34.

[0131] 9, the power supply pattern 42 is included in the first conductor layer 17. Meanwhile, the signal pattern 41 is included in the first conductor layer 17 and the second conductor layer 18. In this modification, the metal support layer 11 is a shield layer.

[0132] 10, the optical / electrical hybrid board 1 includes a plurality of (for example, two) optical elements 31. The optical elements 31 are arranged at intervals in the longitudinal direction.

[0133] The multiple optical elements 31 are, for example, a first optical element 31A and a second optical element 31B.

[0134] This opto-electrical hybrid board 1 includes two mounting areas 2, one first area 3, and two second areas 4.

[0135] The two mounting areas 2 are a one-side mounting area 2A arranged on one side in the longitudinal direction and an other-side mounting area 2B arranged on the other side in the longitudinal direction. The one-side mounting area 2A and the other-side mounting area 2B sandwich the first area 3 in the longitudinal direction. A first optical element 31A is mounted in the one-side mounting area 2A. A second optical element 31B is mounted in the other-side mounting area 2B.

[0136] The two second regions 4 are a one-side second region 4A arranged on one side in the longitudinal direction and an other-side second region 4B arranged on the other side in the longitudinal direction. The one-side second region 4A is arranged contiguous to one side in the longitudinal direction of the one-side mounting region 2A. The other-side second region 4B is arranged contiguous to the other side in the longitudinal direction of the other-side mounting region 2B.

[0137] The opto-electrical hybrid board 1 shown in Fig. 10 is formed by connecting the opto-electrical hybrid board 1 shown in Fig. 9 with an opto-electrical hybrid board 1 that has been moved in line symmetry around the other longitudinal end of the opto-electrical hybrid board 1. In this opto-electrical hybrid board 1, one longitudinal end of the power supply wiring 45 of the power supply pattern 42 is connected to one external board (not shown), and the other longitudinal end of the power supply wiring 45 is connected to another external board (not shown).

[0138] The above invention is provided as an exemplary embodiment of the present invention, but this is merely an example and should not be interpreted as being limited. Modifications of the present invention that are obvious to those skilled in the art are included in the scope of the following claims. [Industrial Applicability]

[0139] The optical / electrical hybrid board is used for optical and electrical applications. [Explanation of symbols]

[0140] 1. Optical / electrical hybrid board 5 Optical waveguide 6 Electrical Circuit Board 11 Metal support layer (an example of a shield layer) 12 Base insulation layer 14 Intermediate insulation layer 17 First conductor layer 18 Second conductor layer (an example of a shielding layer) 23 Third conductor layer 24 4th conductor layer 25 5th conductor layer 31 Optical elements 43 Signal wiring 44 1st terminal 45 Power wiring 51 First intermediate insulating layer 52 Second intermediate insulating layer 53 Third intermediate insulating layer 54 4th intermediate insulating layer 55 Other side conductor layer (an example of a shield layer)

Claims

1. an optical waveguide and an electric circuit board are provided in this order toward one side in a thickness direction; The electric circuit board includes: A metal support layer; a base insulating layer disposed on one surface of the metal supporting layer in a thickness direction; A plurality of conductor layers arranged in order in a thickness direction, the plurality of conductor layers including a first conductor layer arranged on one surface in the thickness direction of the base insulating layer; an intermediate insulating layer disposed between the plurality of conductor layers; at least one layer selected from the group consisting of the metal support layer and the plurality of conductor layers is a shield layer electrically insulated from the remaining layers; At least one of the plurality of conductor layers further includes a terminal for mounting an optical element; An optical / electrical hybrid board, characterized in that the terminal is disposed on one surface in a thickness direction of the base insulating layer.

2. The optical / electrical hybrid board according to claim 1 , wherein the metal support layer overlaps with the terminal in the thickness direction.

3. A semiconductor device comprising an optical waveguide and an electric circuit board in that order toward one side in a thickness direction, The electric circuit board includes: A metal support layer; a base insulating layer disposed on one surface of the metal supporting layer in a thickness direction; A plurality of conductor layers arranged in order in a thickness direction, the plurality of conductor layers including a first conductor layer arranged on one surface in the thickness direction of the base insulating layer; an intermediate insulating layer disposed between the plurality of conductor layers; at least one layer selected from the group consisting of the metal support layer and the plurality of conductor layers is a shield layer electrically insulated from the remaining layers; the first conductor layer includes a power supply wiring and / or a signal wiring, An optical-electrical hybrid board, characterized in that the metal support layer and a second conductor layer among the plurality of conductor layers adjacent to one thickness-wise side of the first conductor layer are both the shielding layer.

4. 4. The optical-electrical hybrid board according to claim 1, wherein the shielding layer overlaps with the remaining layer in the thickness direction.

5. 5. The optical / electrical hybrid board according to claim 1, wherein the remaining layers include power supply wiring and signal wiring.

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