WO2018180785A1

WO2018180785A1 - Photoelectric wiring substrate

Info

Publication number: WO2018180785A1
Application number: PCT/JP2018/011065
Authority: WO
Inventors: 覚詞淺井; 松原　孝宏
Original assignee: 京セラ株式会社
Priority date: 2017-03-30
Filing date: 2018-03-20
Publication date: 2018-10-04
Also published as: JP2018169552A

Abstract

This photoelectric wiring substrate comprises: an insulating substrate having a first surface including a mounting area for semiconductor elements; a connection terminal arranged inside a first surface mounting area and to which semiconductor elements are connectable; optical wiring arranged upon the first surface and having an optical modulator including a first electrode arranged on the first surface, a core section comprising an electro-optical polymer material and arranged upon the first electrode, and a second electrode arranged upon part of the core section and being electrically connected to the connection terminal; and a first conductor arranged inside the insulating substrate and overlapping the optical modulator in the planar view. As a result, connection loss between an optical waveguide path and the optical modulator in the optical wiring can be reduced.

Description

Opto-electric wiring board

The present invention relates to an opto-electric wiring board, and more particularly to an opto-electric wiring board having an optical modulator.

Conventionally, an optoelectric wiring board on which an electric wiring and an optical wiring including an optical modulator are formed is known. For example, Patent Document 1 includes an opto-electric wiring board having an optical wiring including an electric wiring and an optical modulator, an integrated circuit device mounted on the opto-electric wiring board, and a laser light source. Discloses an optical system electrically driven by the integrated circuit device.

JP 2006-262476 A

An optoelectric wiring board of the present disclosure includes an insulating substrate having a first surface including a mounting region of a semiconductor element;
At least one connection terminal disposed in the mounting region of the first surface to which a semiconductor element can be connected;
An optical wiring disposed on the first surface, the first electrode disposed on the first surface; and a core portion made of an electro-optic polymer material disposed on the first electrode; An optical wiring having an optical modulator that is disposed on a part of the core portion and includes a second electrode electrically connected to the connection terminal;
And at least one first conductor disposed in the insulating substrate and overlapping the optical modulator in plan view.

Objects, features and advantages of the present disclosure will become more apparent from the following detailed description and drawings.
It is sectional drawing which shows typically the optoelectric wiring board which concerns on embodiment of this indication. It is a sectional view showing typically an example which extracted a part of optoelectric wiring board concerning an embodiment of this indication. It is sectional drawing which shows typically another example which extracted a part of optoelectric wiring board which concerns on embodiment of this indication. It is sectional drawing which shows typically another example which extracted a part of optoelectric wiring board which concerns on embodiment of this indication. It is a top view showing typically an optoelectric wiring board concerning an embodiment of this indication.

Hereinafter, embodiments of the optoelectric wiring board of the present disclosure will be described with reference to the drawings. Note that the optoelectric wiring board may be used with any direction set upward or downward, but in this specification, an orthogonal coordinate system (X, Y, Z) is defined for convenience. In addition, the term “upper surface” or “lower surface” is used with the positive side in the Z-axis direction as the upper side.

1 to 5 show an optoelectric wiring board 1 according to an embodiment of the present disclosure. FIG. 1 is a cross-sectional view schematically showing an optoelectric wiring board 1. FIG. 2 is a cross-sectional view schematically showing an example of a part of the photoelectric wiring board 1 extracted. FIG. 3 is a cross-sectional view schematically showing another example in which a part of the photoelectric wiring board 1 is extracted. FIG. 4 is a cross-sectional view schematically showing still another example in which a part of the photoelectric wiring board 1 is extracted. FIG. 5 is a plan view schematically showing the opto-electric wiring board 1. 2 to 4 are cross sections taken along a plane parallel to the first surface of the insulating substrate, and a portion of the clad portion 38 located above the EO polymer core portion 36 is not shown. ing. The second electrode 37 is indicated by a two-dot chain line. In the plan view of FIG. 5, the resin layer 50, the EO polymer core portion 36 of the optical modulator 32, and the cladding portion 38 are omitted.

The optoelectric wiring board 1 includes an insulating substrate 10, a connection terminal 20, an optical wiring 30, and a first conductor 40.

The insulating substrate 10 has a first surface (upper surface) 11. The first surface 11 of the insulating substrate 10 has a mounting area A for the semiconductor element 90. The mounting area A is an area immediately below the semiconductor element 90 on the first surface 11 of the insulating substrate 10 when the semiconductor element 90 is mounted on the optoelectric wiring board 1 and overlaps the semiconductor element 90 in plan view. Point to.

The insulating substrate 10 may be made of, for example, a resin material such as an epoxy resin, or a ceramic material such as silica (SiO ₂ ), alumina (Al ₂ O ₃ ), or zirconia (ZrO ₂ ).

The first surface 11 of the insulating substrate 10 further has a light emitting element mounting region B. The light emitting element mounting region B is a region immediately below the light emitting element 100 on the first surface 11 of the insulating substrate 10 when the light emitting element 100 is mounted on the photoelectric wiring substrate 1. Refers to the overlapping area.

The light emitting element 100 may be, for example, a vertical cavity surface emitting laser (VCSEL) that is flip-chip mounted on the first surface 11. The optoelectric wiring board 1 has a connection member (not shown) disposed in the light emitting element mounting region B in order to optically connect to the light emitting element 100. The connecting member is, for example, an inclined surface that reflects light emitted downward from the light emitting element 100 (the negative direction of the Z axis) in the plane direction (XY plane direction) and guides the light to the optical wiring 30. . For example, the inclined surface may be formed by cutting out a part of the optical wiring 30 using dicing, laser processing, or the like.

The optoelectric wiring board 1 has a laminated body 13 that is disposed on the second surface 12 of the insulating substrate 10 and is formed by alternately laminating at least one metal layer 14 and at least one insulating layer 15. . At least one metal layer 14 can function as wiring of the optoelectric wiring board 1. At least one metal layer 14 includes a ground layer 16 to which a ground potential is applied. The at least one metal layer 14 may be formed of a metal material such as copper or aluminum, for example. The insulating layer 15 may be formed of, for example, a resin material such as an epoxy resin, or a ceramic material such as silica (SiO ₂ ), alumina (Al ₂ O ₃ ), or zirconia (ZrO ₂ ).

The laminated body 13 may have, for example, a laminated structure composed of a plurality of insulating layers and metal layers disposed on the upper and lower surfaces of the laminated structure. The laminated body 13 may be, for example, a mixture of a single insulating layer, a laminated structure including a plurality of insulating layers, and a plurality of metal layers.

The semiconductor element 90 is flip-chip mounted on the mounting area A via a connection conductor 91 that is, for example, a solder ball. The optoelectric wiring board 1 has at least one connection terminal 20 disposed in the mounting area A of the first surface 11 for electrical connection to the semiconductor element 90. The connection terminal 20 may be formed of a metal material such as copper or aluminum, for example.

The optical wiring 30 is disposed on the first surface 11 of the insulating substrate 10. The optical wiring 30 includes an optical waveguide 31 and an optical modulator 32.

The optical waveguide 31 can transmit an optical signal. The optical waveguide 31 has an end portion 31 a located in the light emitting element mounting region B in order to be optically connected to the light emitting element 100.

The optical waveguide 31 includes a waveguide core portion 33 through which light passes, and a waveguide cladding portion 34 surrounding the waveguide core portion 33.

The waveguide core portion 33 may be formed of, for example, an epoxy resin. The waveguide clad portion 34 may be formed of, for example, an epoxy resin, a polyimide resin, a phenol resin, an acrylic resin, or the like.

The thickness of the waveguide core portion 33 is, for example, not less than 1 μm and not more than 5 μm. The thickness of the waveguide cladding 34 from the lower surface of the waveguide cladding 34 to the lower surface of the waveguide core 33 is, for example, not less than 5 μm and not more than 50 μm. The thickness up to the upper surface is, for example, 5 μm or more and 50 μm or less.

The refractive index of the waveguide core portion 33 may be, for example, 1.5 or more and 1.85 or less. The refractive index of the waveguide clad part 34 should just be 1.45 or more and 1.8 or less, for example. Moreover, the refractive index of the waveguide core part 33 should just be large in the range of 1% or more and 3% or less with respect to the refractive index of the waveguide clad part 34, for example.

The optical modulator 32 is inserted into the optical waveguide 31 and optically connected to the optical waveguide 31.

The optical modulator 32 is a Mach-Zehnder optical modulator. The optical modulator 32 includes a first electrode 35, a core portion (hereinafter also referred to as an EO polymer core portion) 36 made of an electro-optic polymer material, a second electrode 37, and a cladding portion 38.

The first electrode 35 is disposed on the first surface 11 of the insulating substrate 10. A ground potential is applied to the first electrode 35.

The first electrode 35 may be made of a metal material mainly composed of gold, silver, copper, aluminum, platinum, titanium, palladium, zinc, chromium, or the like. The thickness of the first electrode 35 is, for example, not less than 0.1 μm and not more than 5 μm.

For example, as shown in FIG. 2, the EO polymer core unit 36 includes a branch unit 36a that branches an input optical signal into two, a first arm unit 36b and a second arm unit 36c through which the branched optical signal propagates. And a combining unit 36d that combines and outputs two optical signals respectively propagated through the first arm unit 36b and the second arm unit 36c. The EO polymer core portion 36 is optically connected to the waveguide core portion 33. In the present embodiment, for example, end faces 36e and 36f of the EO polymer core portion 36 are in contact with end faces 33a and 33b of the waveguide core portion 33, respectively.

The EO polymer core part 36 is formed of a material whose refractive index changes according to the applied voltage. As a material constituting the EO polymer core portion 36, a conventionally known electro-optic polymer material may be used.

The thickness of the EO polymer core portion 36 is, for example, 1 μm or more and 5 μm or less. The width of the EO polymer core 36 is, for example, not less than 1 μm and not more than 5 μm. The thickness of the EO polymer core 36 refers to the dimension in the vertical direction (Z-axis direction) of the cross section perpendicular to the light propagation direction in the EO polymer core 36. The width of the EO polymer core 36 refers to the dimension in the plane direction (Y-axis direction) of the cross section perpendicular to the light propagation direction in the EO polymer core 36.

Note that the thickness and width of the EO polymer core portion 36 do not have to be constant, and the optical waveguide 31 and the optical waveguide 31 can be coupled with the optical substrate 31 in consideration of warpage, deformation, and the like of the insulating substrate 10 and the optical wiring 30 due to heat generated from the semiconductor element 90. It can be set as appropriate so as to suppress the optical axis deviation from the modulator 32. In other words, the EO polymer core portion 36 may have at least two portions that differ in at least one of the thickness and the width of the cross section perpendicular to the direction in which the optical wiring 30 extends. For example, at least one of the thickness and width of the EO polymer core portion 36 may be different between the incident side and the emission side of the optical modulator 32. At this time, the incident-side EO polymer core portion 36 has a thickness and / or width larger than that of the waveguide core portion 33, and the emission-side EO polymer core portion 36 has a thickness and width larger than that of the waveguide core portion 33. At least one of these may be small.

The second electrode 37 is disposed on a part of the EO polymer core portion 36. The second electrode 37 is electrically connected to at least one connection terminal 20 via an electrical wiring. An electrical signal for driving the optical modulator 32 is supplied from the semiconductor element 90 to the second electrode 37. The first electrode 35 and the second electrode 37 apply a voltage to a part of the EO polymer core portion 36 in accordance with an electric signal supplied to the second electrode 37.

The second electrode 37 may be formed of, for example, a metal material whose main component is gold, silver, copper, aluminum, platinum, titanium, palladium, zinc, chromium, or the like. The thickness of the second electrode 37 is, for example, not less than 0.1 μm and not more than 5 μm.

The second electrode 37 is disposed so as to overlap the first arm portion 36b and not the second arm portion 36c in plan view. That is, the optical modulator 32 applies a voltage to the first arm unit 36b, changes the refractive index of the first arm unit 36b, phase-modulates the light propagating through the first arm unit 36b, and then performs the first arm unit 36b. The light propagating through 36b and the light propagating through the second arm portion 36c are caused to interfere with each other to modulate the intensity of the light.

The clad portion 38 surrounds the EO polymer core portion 36. The clad portion 38 may be formed of, for example, an epoxy resin, an acrylic resin, a polyimide resin, a silicon resin, or the like. The cladding portion 38 has a thickness from the first surface 11 of the insulating substrate 10 to the lower surface of the EO polymer core portion 36, for example, 5 μm or more and 50 μm or less, and a thickness from the upper surface of the EO polymer core portion 36 to the lower surface of the second electrode 37. Is, for example, 5 μm or more and 50 μm or less.

In the photoelectric wiring board 1 of the present embodiment, the optical modulator 32 is configured to apply a voltage only to the first arm portion 36b, but the optical modulator 32 includes the first arm portion 36b and the first arm portion 36b. The configuration may be such that a reverse voltage is applied to each of the second arm portions 36c.

The optoelectric wiring board 1 of the present embodiment includes a first conductor 40. At least one first conductor 40 is disposed inside the insulating substrate 10. The first conductor 40 overlaps the first electrode 35 of the light modulator 32 when viewed in plan.

The first conductor 40 may be formed of, for example, a metal material mainly composed of silver, copper, tungsten, or the like.

Since the first conductor 40 overlaps the first electrode 35 of the light modulator 32 in plan view, the heat generated from the semiconductor element 90 and conducted to the vicinity of the light modulator 32 is transmitted to the first conductor 40. Can diffuse. As a result, the temperature rise in the vicinity of the optical modulator 32 can be suppressed, and the optical axis shift between the optical waveguide 31 and the optical modulator 32 due to the difference in thermal expansion coefficient between the waveguide core portion 33 and the EO polymer core portion 36 can be prevented. Can be suppressed. Therefore, the connection loss between the optical waveguide 31 and the optical modulator 32 can be reduced.

By the way, in the conventional optoelectric wiring board, when the heat generated from the integrated circuit device is conducted in the vicinity of the optical modulator, the difference in thermal expansion coefficient between the core portion of the optical waveguide and the core portion of the optical modulator is caused. There is a possibility that the optical axis shift between the optical waveguide and the optical modulator occurs, and the connection loss between the optical waveguide and the optical modulator increases. In addition, in the conventional optoelectric wiring board, an optical axis shift between the optical waveguide and the optical modulator occurs due to warpage or deformation of the optoelectronic wiring board due to heat generated from the integrated circuit device. The connection loss between the two may increase.

On the other hand, the optoelectric wiring board 1 having the above-described configuration can reduce the optical loss between the waveguide core portion 33 and the EO polymer core portion 36, which are slightly misaligned. That is, according to the optoelectric wiring board 1 of the present embodiment, the heat generated from the semiconductor element such as the light emitting element 100 and conducted to the vicinity of the optical modulator can be diffused to the first conductor 40. As a result, the optical axis deviation between the optical waveguide (core portion 33) and the optical modulator 32 can be suppressed, and the connection loss between the optical waveguide and the optical modulator can be reduced.

According to the optoelectric wiring board 1 of the present embodiment, high-speed modulation can be performed using an inexpensive light emitting element and an external modulation type modulator inserted in the optical wiring, and the optical waveguide And the connection loss between the optical modulators can be reduced.

In addition, as a metal material which comprises the 1st conductor 40, it has high thermal conductivity by using, for example, copper which has high thermal conductivity, and tungsten having a relatively small thermal expansion coefficient as a metal. And the 1st conductor 40 by which thermal expansion was suppressed can be formed. Thereby, the 1st conductor 40 which has high thermal conductivity and the thermal expansion coefficient difference with the insulating substrate 10 was reduced can be formed. As a result, warpage, deformation, and the like of the insulating substrate 10 due to the thermal expansion of the first conductor 40 can be suppressed, and as a result, connection loss between the optical waveguide 31 and the optical modulator 32 can be reduced. Moreover, the difference in thermal expansion coefficient between the first conductor 40 and the insulating substrate 10 can also be reduced by forming the first conductor 40 from a composite of a metal material and a ceramic material.

The first conductor 40 of the present embodiment is a columnar conductor extending in the thickness direction (Z-axis direction) of the insulating substrate 10. The first conductor 40 may have a circular shape, an elliptical shape, or a polygonal shape when viewed in a cross section parallel to the first surface 11 of the insulating substrate 10. Other shapes may also be used. When the cross-sectional shape of the first conductor 40 is circular, the diameter is, for example, 20 μm to 100 μm. When the cross-sectional shape of the first conductor 40 is different from the circular shape, the equivalent circle diameter may be a value within the above range.

Since the first conductor 40 is columnar, the heat conducted in the vicinity of the optical modulator 32 can be diffused over a wide range in the thickness direction of the insulating substrate 10. Thereby, the optical axis shift between the optical waveguide 31 and the optical modulator 32 can be effectively suppressed, and the connection loss between the optical waveguide 31 and the optical modulator 32 can be effectively reduced.

Further, the first conductor 40 of the present embodiment extends to the ground layer 16 of the multilayer body 13 and is connected to the ground layer 16 as shown in FIG. As a result, the heat dissipated in the first conductor 40 can be radiated to the outside through the ground layer 16. Thereby, the optical axis shift between the optical waveguide 31 and the optical modulator 32 can be effectively suppressed, and the connection loss between the optical waveguide 31 and the optical modulator 32 can be effectively reduced.

A plurality of first conductors 40 may be provided. As a result, it is possible to effectively diffuse the heat in the vicinity of the optical modulator 32 as compared with the case where one first conductor 40 is provided.

FIG. 2 is a cross-sectional view schematically showing an example of a part of the photoelectric wiring board 1 including the optical modulator 32 extracted. In FIG. 2, a portion of the clad portion 38 located above the EO polymer core portion 36 is not shown. The second electrode 37 is indicated by a two-dot chain line. In FIG. 2, the outer shape of the first electrode 35 is substantially equal to the outer shape of the cladding portion 38.

For example, as shown in FIG. 2, the plurality of first conductors 40 may be arranged at equal intervals in a line in the direction in which the optical wiring 30 extends (X-axis direction) in a plan view. As a result, warping, deformation, and the like of the insulating substrate 10 in the vicinity of the optical modulator 32 can be suppressed over a wide range in the X-axis direction. Thereby, the optical axis shift of the optical waveguide 31 and the optical modulator 32 can be suppressed, and the connection loss between the optical waveguide 31 and the optical modulator 32 can be reduced.

The intervals between the adjacent first conductors 40 are not necessarily the same in the plurality of first conductors 40. 3 and 4 are cross-sectional views showing modifications of the arrangement pattern of the plurality of first conductors 40. 3 and FIG. 4 differs from the example shown in FIG. 2 in the arrangement pattern of the plurality of first conductors 40, and the other configurations are the same, so the configurations are the same. Are denoted by the same reference numerals and description thereof is omitted.

For example, as shown in FIG. 3, the plurality of first conductors 40 are arranged such that the distance between adjacent first conductors 40 is wide at the center of the optical modulator 32 in the X-axis direction and narrows at both ends. May be. As a result, the heat conducted to the vicinity of the connection portion between the optical waveguide 31 and the optical modulator 32 can be effectively diffused to the plurality of first conductors 40, so that the optical axis between the optical waveguide 31 and the optical modulator 32 The shift can be suppressed, and the connection loss between the optical waveguide 31 and the optical modulator 32 can be reduced.

In addition, as shown in FIG. 4, for example, the plurality of first conductors 40 are such that the distance between the adjacent first conductors 40 is narrow at the center of the optical modulator 32 in the direction (X-axis direction) in which the optical wiring 30 extends. You may arrange | position so that it may become wide at both ends. As a result, the heat conducted to the vicinity of the first arm portion 36b and the second arm portion 36c for phase-modulating the light can be effectively diffused to the plurality of first conductors 40, so that the performance of the optical modulator 32 is deteriorated. Can be suppressed and reliability can be improved.

The arrangement pattern of the first conductor 40 is not limited to the examples shown in FIGS. In the first conductor 40, the interval between the adjacent first conductors 40 may be narrow on the incident side of the optical modulator 32 and wide on the outgoing side, wide on the incident side of the optical modulator 32, and on the outgoing side. It may be narrower. Moreover, the 1st conductor 40 may be arrange | positioned along with multiple rows, for example. The arrangement pattern of the plurality of rows may be a combination of the arrangement patterns shown in FIGS.

The first conductor 40 and the first electrode 35 may be electrically connected. As a result, the heat conduction from the first electrode 35 to the first conductor 40 is improved as compared with the case where the first conductor 40 and the first electrode 35 are separated via a part of the insulating substrate 10. Can do. Thereby, the heat generated from the semiconductor element 90 and conducted to the vicinity of the optical modulator 32 can be diffused to the first conductor 40. As a result, the optical axis shift between the optical waveguide 31 and the optical modulator 32 can be suppressed, and the connection loss between the optical waveguide 31 and the optical modulator 32 can be reduced.

In the present embodiment, since the first conductor 40 is connected to the ground layer 16, when the first conductor 40 and the first electrode 35 are electrically connected, the heat stored in the first conductor 40 is stored. Then, heat can be radiated to the outside through the ground layer 16, and the connection loss between the optical waveguide 31 and the optical modulator 32 can be further effectively reduced. In addition, since the ground potential of the first electrode 35 can be stabilized, the reliability of the optical modulator 32 can be improved.

For example, as shown in FIG. 1, the first conductor 40 and the first electrode 35 are such that the end surface 41 of the first conductor 40 is exposed to the first surface 11 and the end surface 41 is in direct contact with the first electrode 35. May be electrically connected.

The opto-electric wiring board 1 according to the present embodiment is configured such that when the connection terminal 20 to which the second electrode 37 is electrically connected is the first connection terminal 21, the second electrode 37 is not electrically connected. 2 connection terminal 22, and the wiring conductor 60 which electrically connects the 1st electrode 35 and the 2nd connection terminal 22 are provided. A ground potential is applied to the second connection terminal 22, and a ground electrode of the semiconductor element 90 may be connected thereto. The wiring conductor 60 is disposed on the first surface 11 of the insulating substrate 10. The wiring conductor 60 may be formed of, for example, a metal material whose main component is gold, silver, copper, aluminum, platinum, titanium, palladium, zinc, chromium, or the like.

Since the first electrode 35 is connected to the ground layer 16 via the first conductor 40, the ground potential of the first electrode 35 can be stabilized according to the wiring conductor 60 having the above configuration. The reliability of the optical modulator 32 can be improved. In addition, since the ground potential of the semiconductor element 90 can be stabilized, the reliability of the optoelectric wiring board 1 can be improved.

The optoelectric wiring board 1 of the present embodiment has at least one second conductor 70 that is disposed inside the insulating substrate 10 and overlaps the wiring conductor 60 in plan view, for example, as shown in FIGS. is doing. Thereby, the heat generated from the semiconductor element 90 and conducted to the wiring conductor 60 can be diffused to the second conductor 70. As a result, heat generated from the semiconductor element 90 and conducted to the wiring conductor 60 can be prevented from being conducted to the optical modulator 32. As a result, even when the wiring conductor 60 is provided, the optical axis shift between the optical waveguide 31 and the optical modulator 32 can be suppressed, and the connection loss between the optical waveguide 31 and the optical modulator 32 can be reduced. Can be reduced. For example, as shown in FIG. 1, the second conductor 70 may be connected to the wiring conductor 60 and the ground layer 16. As a result, the ground potential of the first electrode 35 and the semiconductor element 90 can be stabilized. In addition, the heat diffused in the second conductor 70 can be radiated to the outside through the ground layer 16, thereby effectively suppressing the optical axis shift between the optical waveguide 31 and the optical modulator 32. The connection loss between the optical waveguide 31 and the optical modulator 32 can be effectively reduced.

The second conductor 70 may be, for example, a columnar conductor extending in the thickness direction (Z-axis direction) of the insulating substrate 10. In this case, the second conductor 70 may have a circular cross section, an elliptical shape, or a polygonal shape when viewed in a cross section parallel to the first surface 11 of the insulating substrate 10. It may be any other shape. When the cross-sectional shape of the second conductor 70 is circular, the diameter is, for example, 50 μm to 200 μm. When the cross-sectional shape of the second conductor 70 is different from the circular shape, the equivalent circle diameter may be a value within the above range.

A plurality of second conductors 70 may be provided. As a result, heat generated from the semiconductor element 90 and conducted to the wiring conductor 60 can be effectively suppressed from being conducted to the optical modulator 32. The interval between the adjacent second conductors 70 does not need to be constant, and is set as appropriate so as to suppress warping, deformation, and the like of the insulating substrate 10 and the optical wiring 30 due to heat generated from the semiconductor element 90. be able to.

The second conductor 70 may be formed of, for example, a metal material whose main component is silver, copper, tungsten, or the like.

The upper surface of the second electrode 37 of the light modulator 32 may be covered with the resin layer 50. The resin layer 50 is, for example, a solder resist layer deposited on the first surface 11 of the insulating substrate 10 and is formed from an electrically insulating material containing a photosensitive thermosetting resin such as an epoxy resin or a polyimide resin. Just do it. By covering the second electrode 37 with the resin layer 50, the second electrode 37 can be protected from dirt, damage, static electricity, and the like. As a result, the reliability of the optical modulator 32 can be improved. Note that the resin layer 50 may cover, for example, all areas of the optoelectric wiring board 1 except the mounting area A and the light emitting element mounting area B.

The optoelectric wiring board 1 of the present embodiment has a conductor pattern 80 extending from the mounting area A to the outside of the mounting area A, for example, as shown in FIG. The conductor pattern 80 is disposed on the upper surface of the photoelectric wiring substrate 1 above the first surface 11 of the insulating substrate 10.

The conductor pattern 80 is disposed on the first surface 11 of the insulating substrate 10 and may be covered with the resin layer 50 or embedded in the resin layer 50. The conductor pattern 80 may be formed of a metal material whose main component is, for example, silver, copper, or tungsten.

By providing the conductor pattern 80, it is possible to suppress the heat generated from the semiconductor element 90 from being transmitted to the optical modulator 32 side in the thickness direction (Z-axis direction) of the insulating substrate 10, and therefore the optical waveguide 31 and the optical modulator The optical axis deviation with respect to 32 can be suppressed, and the connection loss between the optical waveguide 31 and the optical modulator 32 can be reduced.

For example, as shown in FIG. 5, the conductor pattern 80 may extend from the mounting area A toward the area outside the mounting area A where the optical wiring 30 is not disposed, as viewed in a plan view. Good. As a result, since heat generated from the semiconductor element can be prevented from being transmitted to the optical modulator 32 side in the planar direction (XY direction), the optical axis deviation between the optical waveguide 31 and the optical modulator 32 is suppressed. The connection loss between the optical waveguide 31 and the optical modulator 32 can be reduced.

Although FIG. 5 shows the case where the conductors 80a to 80e constituting the conductor pattern 80 are linear, the conductors 80a to 80e may be bent or curved, or may be connected to each other. The conductors 80a to 80e do not need to have a constant width, thickness, or the like, and can be appropriately adjusted in consideration of warping, deformation, and the like of the insulating substrate 10 due to heat generated from the semiconductor element 90. The conductors 80a to 80e may have, for example, two portions that differ in at least one of width and thickness. For example, the conductor pattern 80 may surround one or a plurality of connection terminals 20.

The present invention can be implemented in various other forms without departing from the spirit or main features thereof. Therefore, the above-described embodiment is merely an example in all points, and the scope of the present invention is shown in the scope of claims, and is not restricted by the text of the specification. Further, all modifications and changes belonging to the claims are within the scope of the present invention.

DESCRIPTION OF SYMBOLS 1 Photoelectric wiring board 10 Insulating board 11 1st surface 12 2nd surface 13 Laminated body 14 Metal layer 15 Insulating layer 16 Ground layer 20 Connection terminal 21 1st connection terminal 22 2nd connection terminal 30 Optical wiring 31 Optical waveguide 31a End part 32 Optical modulator 33

Waveguide core part

33a, 33b End face 34 Waveguide clad part 35 First electrode 36 EO polymer core part 36a Branch part 36b First arm part 36c Second arm part 36d Combined

part

36e, 36f End face 37 Second Electrode 38 Cladding portion 40 First conductor 41 End face 50 Resin layer 60 Wiring conductor 70 Second conductor 80

Conductor pattern

80a, 80b, 80c, 80d, 80e Conductor 90 Semiconductor element 91 Connection conductor 100 Light emitting element A Mounting area B Light emitting element mounting area

Claims

An insulating substrate having a first surface including a semiconductor element mounting region;
At least one connection terminal disposed in the mounting region of the first surface to which a semiconductor element can be connected;
An optical wiring disposed on the first surface, the first electrode disposed on the first surface; and a core portion made of an electro-optic polymer material disposed on the first electrode; An optical wiring having an optical modulator including a second electrode electrically connected to the at least one connection terminal disposed on a part of the core portion;
At least one first conductor disposed in the insulating substrate and overlapping the optical modulator in plan view;
An optoelectric wiring board comprising:
The optoelectric wiring board according to claim 1, wherein the at least one first conductor is a columnar conductor extending in a thickness direction of the insulating substrate.
The photoelectric circuit board according to claim 1 or 2, wherein a plurality of the at least one first conductors are provided, and are arranged along the core portion of the optical modulator in a plan view.
The optoelectric wiring board according to any one of claims 1 to 3, wherein the at least one first conductor and the first electrode are electrically connected.
The light according to any one of claims 1 to 4, wherein the at least one first conductor has an end surface exposed to the first surface, and the end surface is in direct contact with the first electrode. Electrical wiring board.
6. The optoelectric wiring board according to claim 1, wherein the first electrode of the optical modulator is connected to a ground potential.
The optoelectric wiring board according to any one of claims 1 to 6, wherein the second electrode of the optical modulator is covered with a resin layer.
When the at least one connection terminal is a first connection terminal,
A second connection terminal not electrically connected to the second electrode;
A wiring conductor disposed on the first surface for electrically connecting the first electrode and the second connection terminal;
At least one second conductor disposed in the insulating substrate and overlapping the wiring conductor in plan view;
The optoelectric wiring board according to any one of claims 1 to 7, comprising:
The core portion of the optical modulator has at least two portions that differ in at least one of thickness and width of a cross section perpendicular to the light propagation direction in the core portion. The optoelectric wiring board according to item
10. The photoelectric wiring according to claim 1, wherein a conductor pattern extending from the inside of the mounting area to the outside of the mounting area in a plan view is disposed above the first surface. substrate.