Photoelectric composite substrate, optical component, substrate, and method for manufacturing photoelectric composite substrate

Abstract

To provide a photoelectric composite substrate and a substrate that can reduce end face sagging on a cut surface.SOLUTION: A photoelectric composite substrate 100 comprises an optical waveguide layer 20 on a substrate 10. The substrate 10 includes an insulating layer. In the photoelectric composite substrate 100, a value (μm / GPa) obtained by dividing the thickness (μm) of the insulating layer by the storage elastic modulus E' (GPa) at 30°C of the insulating layer obtained by the following method 1, is 4.5 or less. [Method 1] The temperature of the insulating layer is increased from 25°C to 350°C under the air atmosphere by using a dynamic viscoelasticity measuring device in conditions of a frequency of 1 Hz, in a pulling mode, an inter-sample distance of 2 cm, a sample width of 0.8 cm, and a rate of temperature increase of 5°C / min, the storage elastic modulus E' to the temperature is measured, and the storage elastic modulus E' at 30°C is calculated.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to an optical / electrical composite substrate, an optical component, a substrate, and a method for manufacturing an optical / electrical composite substrate. [Background technology]

[0002] In recent years, there has been a demand for components in information and communication devices that can realize more advanced information communication, such as larger information capacity and faster information communication speeds, and as such components, optical and electrical composite substrates and optical components equipped with optical and electrical composite substrates have been considered. Examples of techniques relating to optical and electrical composite substrates include those described in Patent Documents 1 and 2.

[0003] Patent Document 1 describes an optical fiber connector having a substrate, an optical fiber guide section having an optical fiber mounting groove for fixing the optical fiber, and an optical waveguide consisting of a cladding layer and a core pattern for transmitting an optical signal, in which the optical fiber guide section and the optical waveguide are arranged side by side on a part of the substrate, and the substrate has a space portion where the surface of the substrate is exposed other than the portion where the optical fiber guide section and the optical waveguide are arranged side by side, and the optical fiber guide section and the optical waveguide are arranged side by side so that the optical fiber to be mounted is joined at a position where an optical signal can be transmitted to the core pattern for transmitting an optical signal of the optical waveguide. The optical fiber connector in Patent Document 1 is described as being able to easily align the optical fiber with the optical waveguide core, and as having an optical waveguide and optical fiber guide section only in a part of the substrate and having space on the substrate, it is possible to reduce warping of the substrate.

[0004] Patent Document 2 describes an opto-electrical hybrid board having a first printed circuit board having a circuit through which an electric signal flows, an optical waveguide layer laminated on the first printed circuit board, an optical waveguide section penetrating the first printed circuit board and the optical waveguide layer in the thickness direction, and a recess formed on the opposite side of the first printed circuit board at the intersection of the optical waveguide layer and the optical waveguide section, with an inclined surface at the tip end being a reflection surface for light between the optical waveguide layer and the optical waveguide section. According to the opto-electric hybrid board of Patent Document 2, it is described that the reflective surface that reflects light between the optical waveguide layer and the optical waveguide section can be accurately aligned with the optical waveguide section. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2012-168207 [Patent Document 2] Japanese Patent Application Laid-Open No. 2016-33587 Summary of the Invention [Problem to be solved by the invention]

[0006] The present invention provides an optical / electrical composite substrate and a substrate that can reduce sagging of the cut edges. [Means for solving the problem]

[0007] According to the present invention, there are provided the following optical / electrical composite substrate, optical component, substrate, and method for manufacturing the optical / electrical composite substrate.

[0008] [1] An optical / electrical composite substrate having an optical waveguide layer on a substrate, the substrate includes an insulating layer; An optical / electrical composite substrate, wherein the value [μm / GPa] obtained by dividing the thickness [μm] of the insulating layer by the storage modulus E' [GPa] at 30°C of the insulating layer obtained by the following method 1 is 4.5 or less. [Method 1] The insulating layer is heated from 25°C to 350°C using a dynamic viscoelasticity measuring device under the conditions of an air atmosphere, a frequency of 1 Hz, a tensile mode, a sample distance of 2 cm, a sample width of 0.8 cm, and a heating rate of 5°C / min, and the storage modulus E' versus temperature is measured, and the storage modulus E' at 30°C is calculated. [2] The electrical and optical composite substrate according to [1] above, wherein the insulating layer obtained by the method 1 above has a storage modulus E' at 30° C. of 6 GPa or more. [3] The optical / electrical composite substrate according to [1] or [2] above, wherein the insulating layer has a thickness of 70 μm or less. [4] The optical / electrical composite substrate according to any one of [1] to [3] above, wherein the insulating layer has an average linear expansion coefficient of 15 ppm / °C or less at 50°C or more and 150°C or less. [5] The optical / electrical composite substrate according to any one of [1] to [4] above, wherein the insulating layer has a glass transition temperature of 170°C or higher and 300°C or lower. [6] The optical / electrical composite substrate according to any one of [1] to [5] above, wherein the insulating layer contains a fiber base material and a thermosetting resin composition. [7] The optical / electrical composite substrate according to [6] above, wherein the thermosetting resin composition contains an inorganic filler. [8] The optical / electrical composite substrate according to [7] above, wherein the inorganic filler contains silica. [9] The optical / electrical composite substrate according to any one of [1] to [8], wherein the optical waveguide layer comprises, in order from the substrate side, a first clad layer, a core layer, a second clad layer, and a base material.

[10] The optical and electrical composite substrate according to any one of [1] to [9], wherein an end face of the optical and electrical composite substrate includes a surface for connecting an optical fiber.

[11] The optical and electrical composite substrate according to any one of [1] to

[10] above, wherein an end face of the optical and electrical composite substrate includes a cut surface.

[12] A method for producing an optical / electrical composite substrate according to

[11] , A preparation step of preparing a laminate including an optoelectronic composite substrate (1) having an optical waveguide layer on a substrate and a dicing film; a dicing step of cutting the optoelectronic composite substrate (1) in the laminate with a dicing blade.

[13] The structure includes an end face of an optical / electrical composite substrate (a) and an end face of an optical / electrical composite substrate (b) different from the optical / electrical composite substrate (a) connected via an optical fiber, An optical component, wherein at least one selected from the group consisting of the optoelectronic composite substrate (a) and the optoelectronic composite substrate (b) is the optoelectronic composite substrate according to any one of [1] to

[11] above.

[14] A substrate for carrying an optical waveguide layer, the substrate includes an insulating layer; A substrate in which the value [μm / GPa] obtained by dividing the thickness [μm] of the insulating layer by the storage modulus E' [GPa] at 30°C of the insulating layer obtained by the following method 1 is 4.5 or less. [Method 1] The insulating layer is heated from 25°C to 350°C using a dynamic viscoelasticity measuring device under the conditions of an air atmosphere, a frequency of 1 Hz, a tensile mode, a sample distance of 2 cm, a sample width of 0.8 cm, and a heating rate of 5°C / min, and the storage modulus E' versus temperature is measured, and the storage modulus E' at 30°C is calculated.

[15] The substrate according to

[14] above, wherein the insulating layer obtained by the method 1 has a storage modulus E' at 30°C of 6 GPa or more.

[16] The substrate according to

[14] or

[15] above, wherein the insulating layer has a thickness of 70 μm or less.

[17] A method for producing an optical / electrical composite substrate, comprising the step of forming the optical waveguide layer on the substrate according to any one of

[14] to

[16] above. [Effects of the Invention]

[0009] According to the present invention, it is possible to provide an optical / electrical composite substrate and a substrate that can reduce sagging of the cut edges. [Brief explanation of the drawings]

[0010] [Figure 1]1 is a cross-sectional view schematically illustrating an example of the structure of an optical component according to an embodiment of the present invention. [Figure 2] 1 is a cross-sectional view schematically showing an example of the structure of an optoelectronic composite substrate according to an embodiment of the present invention. [Figure 3] FIG. 1 is a cross-sectional view schematically showing an example of the structure of a substrate according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the drawings are simplified and do not correspond to actual dimensional proportions. The numerical range "A to B" indicates A or more and B or less unless otherwise specified. In this specification, when simply referring to a "clad layer," it means that both the first clad layer and the second clad layer are included. The term "(meth)acrylic resin" is a concept that includes both acrylic resin and methacrylic resin.

[0012] FIG. 1 is a cross-sectional view showing a schematic example of the structure of the optical component of this embodiment. As an optical component including an opto-electrical composite substrate, for example, an optical component including a structure 300 in which an end face of an opto-electrical composite substrate 100a and an end face of an opto-electrical composite substrate 100b are connected via an optical fiber 200 as shown in FIG. 1 is an example of the end face of the opto-electrical composite substrate 100a. The cut surface of the opto-electrical composite substrate when cut with a dicing blade is required to have reduced end face sagging in order to further improve the optical properties of the optical component. The present invention provides an optoelectronic composite substrate and a substrate that can reduce edge sagging on the cut surface of the optoelectronic composite substrate. Furthermore, the optical / electrical composite substrate and substrate of this embodiment can reduce optical attenuation in the optical / electrical composite substrate and optical components.

[0013] Fig. 2 is a cross-sectional view schematically showing an example of the structure of an optoelectronic composite substrate of this embodiment, and Fig. 3 is a cross-sectional view schematically showing an example of the structure of a substrate of this embodiment.

[0014] [Optical / electrical composite substrate] The optical-electrical composite substrate 100 is an optical-electrical composite substrate having an optical waveguide layer 20 on a substrate 10, and the substrate 10 includes an insulating layer 11, and the value [μm / GPa] obtained by dividing the thickness [μm] of the insulating layer by the storage modulus E' [GPa] of the insulating layer at 30°C is 4.5 or less.

[0015] When cutting the optoelectronic composite substrate with a dicing blade, a method can be used in which a laminate including the optoelectronic composite substrate and a dicing film is used as a workpiece, and the optoelectronic composite substrate in the workpiece is cut with the dicing blade. The workpiece may be, for example, a laminate in which the substrate in an optoelectronic composite substrate and a dicing film are in direct contact with each other. The dicing film has an adhesive layer. The adhesive layer may be made of a soft adhesive resin. Therefore, depending on the type of substrate, which is the layer adjacent to the adhesive layer, when the optoelectronic composite substrate in the workpiece is cut with a dicing blade, the substrate may be pressed in by the dicing blade, which may easily cause sagging of the edge of the cut surface of the optoelectronic composite substrate. The inventors believed that by increasing the storage modulus E' at 30°C of the insulating layer in the substrate, the pressing of the substrate by the dicing blade would be suppressed, thereby reducing the edge sagging of the cut surface of the photoelectric composite substrate. Therefore, the present inventors conducted extensive research focusing on the storage modulus E' at 30°C of the insulating layer in the substrate and the thickness of the insulating layer in the substrate, and as a result, the present inventors discovered for the first time that edge sagging of the cut surface of the optoelectronic composite substrate can be reduced by setting the value obtained by dividing the thickness of the insulating layer in the substrate by the storage modulus E' at 30°C of the insulating layer within a specific range.

[0016] Each component of the optical / electrical composite substrate 100 will be described below.

[0017] <Substrate> The configuration of the substrate 10 included in the optical / electrical composite substrate 100 is the same as the configuration of the substrate of this embodiment, which will be described later.

[0018] <Optical waveguide layer> The optical / electrical composite substrate 100 includes an optical waveguide layer 20 on a substrate 10 . The optical waveguide layer 20 is not particularly limited as long as it is a layer that can be used as an optical waveguide, and may include any layer other than a cladding layer and a core layer.

[0019] The optical waveguide layer 20 preferably comprises, in order from the substrate 10 side, a first clad layer 21, a core layer 22, and a second clad layer 23, and more preferably comprises, in order from the substrate 10 side, the first clad layer 21, the core layer 22, the second clad layer 23, and a base material 24.

[0020] The cladding layer is formed, for example, from a cured product of a resin composition. The resin forming the cladding layer is not particularly limited, but may include, for example, at least one selected from the group consisting of polyimide resins, compounds having a cyclic ether structure, rubber-based elastomers, resins having a norbornene structure, silicone resins, and (meth)acrylic resins, and is preferably at least one selected from the group consisting of polyimide resins, compounds having a cyclic ether structure, rubber-based elastomers, and resins having a norbornene structure, and is more preferably at least one selected from the group consisting of polyimide resins, compounds having a cyclic ether structure, and rubber-based elastomers. Here, the compound having a cyclic ether structure of this embodiment can be a monomer, oligomer, or polymer in general, and its molecular weight and molecular structure are not particularly limited.

[0021] From the viewpoint of further improving the light propagation efficiency of the optical-electrical composite substrate, the thickness of the first clad layer 21 is preferably 1 μm or more and 150 μm or less, more preferably 5 μm or more and 100 μm or less, even more preferably 10 μm or more and 50 μm or less, and even more preferably 15 μm or more and 40 μm or less. The thickness of the second cladding layer 23 is preferably 1 μm or more and 150 μm or less, more preferably 3 μm or more and 100 μm or less, even more preferably 5 μm or more and 50 μm or less, and even more preferably 8 μm or more and 20 μm or less.

[0022] The core layer 22 is formed, for example, from a cured product made of a resin composition. The resin forming the core layer 22 is not particularly limited, but may include, for example, at least one selected from the group consisting of a resin having a norbornene structure, a compound having a cyclic ether structure, a (meth)acrylic resin, etc., and preferably includes a resin having a norbornene structure.

[0023] The thickness of the core layer 22 is preferably 1 μm or more and 100 μm or less, more preferably 5 μm or more and 80 μm or less, even more preferably 10 μm or more and 60 μm or less, and even more preferably 30 μm or more and 50 μm or less.

[0024] The substrate 24 is not particularly limited, but is preferably a polyimide substrate. The polyimide substrate is, for example, a polyimide film. The thickness of the substrate 24 is preferably 1 μm or more and 150 μm or less, more preferably 5 μm or more and 100 μm or less, even more preferably 8 μm or more and 50 μm or less, and even more preferably 10 μm or more and 40 μm or less.

[0025] The end face of the optical / electrical composite substrate 100 preferably includes a surface for connecting an optical fiber.

[0026] The end surface of the optical / electrical composite substrate 100 preferably includes a cut surface. The cut surface is preferably a cut surface cut by a dicing blade.

[0027] [Method of manufacturing an optical / electrical composite substrate] There are no particular limitations on the method for producing the optical / electrical composite substrate 100, but a preferred embodiment will be described below.

[0028] The method for manufacturing the optical and electrical composite substrate 100 preferably includes the step of forming an optical waveguide layer 20 on the substrate 10 . Methods for forming the optical waveguide layer 20 on the substrate 10 include, for example, a method in which films for forming each layer of the optical waveguide layer 20 are sequentially laminated onto the substrate 10 to form each layer of the optical waveguide layer 20 (sequential lamination method); a method in which varnishes for forming each layer of the optical waveguide layer 20 are sequentially applied to the substrate 10 to form each layer of the optical waveguide layer 20; and among these, the sequential lamination method is preferred.

[0029] The method for manufacturing the optoelectronic composite substrate 100 preferably includes a preparation step of preparing a laminate comprising an optoelectronic composite substrate (1) having an optical waveguide layer 20 on a substrate 10 and a dicing film, and a dicing step of cutting the optoelectronic composite substrate (1) in the laminate with a dicing blade. If the manufacturing method of the optoelectronic composite substrate 100 includes a dicing step, an optoelectronic composite substrate can be obtained in which the end faces of the optoelectronic composite substrate include cut surfaces. The photoelectric composite substrate (1) means the photoelectric composite substrate before cutting by dicing.

[0030] The dicing film in the laminate in the preparation step is not particularly limited, and for example, a commercially available dicing film such as ELEGRIP TAPE UDT-1005M3-27B (manufactured by Denka Co., Ltd.) can be used. In the preparation step, the method for preparing the laminate is not particularly limited, and for example, a method of attaching a dicing film to the photoelectric composite substrate (1) using a cleaning roller to obtain the laminate can be mentioned.

[0031] In the dicing process, the dicing speed is preferably 0.1 mm / sec or more and 5.0 mm / sec or less, more preferably 0.3 mm / sec or more and 4.0 mm / sec or less, and even more preferably 0.4 mm / sec or more and 3.0 mm / sec or less, from the viewpoint of further reducing the edge sagging of the cut surface of the optoelectronic composite substrate and further improving production efficiency.

[0032] The dicing device used in the dicing step is not particularly limited, and a known dicing device can be used, for example, DAD3240 (manufactured by Disco Corporation).

[0033] [substrate] The substrate 10 is a substrate for mounting the optical waveguide layer 20, and includes an insulating layer 11, and the value [μm / GPa] obtained by dividing the thickness [μm] of the insulating layer by the storage modulus E' [GPa] of the insulating layer at 30°C is 4.5 or less.

[0034] As shown in FIG. 3, the substrate 10 includes, in this order, a metal foil 14a, an insulating resin layer 13a made of a thermosetting resin composition, a fiber base material 12, an insulating resin layer 13b made of a thermosetting resin composition, and a metal foil 14b. Hereinafter, the term "insulating resin layer made of a thermosetting resin composition" may be abbreviated to "insulating resin layer". In FIG. 3, the insulating layer 11 includes an insulating resin layer 13a, a fiber base material 12, and an insulating resin layer 13b.

[0035] The thickness of the substrate 10 is preferably 20 μm or more and 95 μm or less, more preferably 30 μm or more and 75 μm or less, even more preferably 40 μm or more and 65 μm or less, and even more preferably 45 μm or more and 55 μm or less.

[0036] Each component of the substrate 10 will be described below.

[0037] <Insulating layer> The substrate 10 includes an insulating layer 11 . Insulating layer 11 has a value [μm / GPa] obtained by dividing the thickness [μm] of the insulating layer by the storage modulus E′ [GPa] of the insulating layer at 30° C. of 4.5 or less.

[0038] The value [μm / GPa] obtained by dividing the thickness [μm] of the insulating layer by the storage modulus E ' [GPa] of the insulating layer at 30 ° C. is preferably 4.3 or less, more preferably 4.0 or less, even more preferably 3.8 or less, and even more preferably 3.5 or less, from the viewpoint of further reducing the end sagging of the cut surface of the photoelectric composite substrate. The lower limit is not particularly limited, but may be, for example, 0.2 or more, 0.5 or more, 0.8 or more, or 1.0 or more. Furthermore, the value [μm / GPa] obtained by dividing the thickness [μm] of the insulating layer by the storage modulus E ' [GPa] of the insulating layer at 30 ° C. is preferably 0.2 or more and 4.3 or less, more preferably 0.5 or more and 4.0 or less, even more preferably 0.8 or more and 3.8 or less, and even more preferably 1.0 or more and 3.5 or less, from the viewpoint of further reducing the end sagging of the cut surface of the photoelectric composite substrate.

[0039] The storage modulus E' of the insulating layer 11 at 30°C is preferably 6 GPa or more, more preferably 7 GPa or more, even more preferably 8 GPa or more, and even more preferably 9 GPa or more, from the viewpoint of further reducing the edge sagging of the cut surface of the opto-electrical composite substrate, and the upper limit is not particularly limited, but may be, for example, 50 GPa or less, 40 GPa or less, 35 GPa or less, or 30 GPa or less. Furthermore, the storage modulus E' of the insulating layer 11 at 30°C is preferably 6 GPa or more and 50 GPa or less, more preferably 7 GPa or more and 40 GPa or less, even more preferably 8 GPa or more and 35 GPa or less, and even more preferably 9 GPa or more and 30 GPa or less, from the viewpoint of further reducing the edge sagging of the cut surface of the opto-electrical composite substrate.

[0040] In this specification, the storage modulus E' of the insulating layer at 30° C. means the value obtained by Method 1.

[0041] [Method 1] The insulating layer is heated from 25°C to 350°C using a dynamic viscoelasticity measuring device under the conditions of air atmosphere, frequency: 1 Hz, tensile mode, sample distance: 2 cm, sample width: 0.8 cm, and heating rate: 5°C / min, and the storage modulus E' versus temperature is measured, and the storage modulus E' at 30°C is calculated.

[0042] The storage modulus E' at 30°C of the insulating layer can be adjusted to a desired value by appropriately selecting the material constituting the insulating layer, and specifically, for example, by using an insulating layer containing a fiber substrate and a thermosetting resin composition as the insulating layer; by using an epoxy resin and at least one selected from the group consisting of a cyanate resin, a resin having a benzoxazine ring, and a maleimide resin as the thermosetting resin contained in the insulating layer and adjusting the resin content; by incorporating an inorganic filler into the insulating layer and adjusting the inorganic filler content; etc.

[0043] The thickness of insulating layer 11 is preferably 70 μm or less, more preferably 50 μm or less, even more preferably 40 μm or less, and even more preferably 30 μm or less, and the lower limit is not particularly limited, but may be, for example, 10 μm or more, 15 μm or more, 20 μm or more, or 23 μm or more. The thickness of insulating layer 11 is preferably 10 μm or more and 70 μm or less, more preferably 15 μm or more and 50 μm or less, even more preferably 20 μm or more and 40 μm or less, and even more preferably 23 μm or more and 30 μm or less. When the thickness of the insulating layer 11 is equal to or less than the above upper limit, the optical attenuation of the optoelectronic composite substrate and the optical component can be further reduced.

[0044] The average linear expansion coefficient of the insulating layer 11 at 50°C or higher and 150°C or lower is preferably 15 ppm / °C or lower, more preferably 13 ppm / °C or lower, and even more preferably 11 ppm / °C or lower, from the viewpoint of further reducing edge sagging of the cut surface of the optoelectronic composite substrate, and the lower limit is not particularly limited, but may be, for example, 3 ppm / °C or higher, 5 ppm / °C or higher, or 7 ppm / °C or higher. Furthermore, the average linear expansion coefficient of the insulating layer 11 at 50°C or higher and 15 ppm / °C or lower, more preferably 5 ppm / °C or higher and 13 ppm / °C or lower, and even more preferably 7 ppm / °C or higher and 11 ppm / °C or lower, from the viewpoint of further reducing edge sagging of the cut surface of the optoelectronic composite substrate. Here, the average linear expansion coefficient of insulating layer 11 at 50° C. or higher and 150° C. or lower means a value obtained by the following measurement method.

[0045] [Method for measuring the average linear expansion coefficient] Using a thermomechanical analyzer, the insulating layer is heated from 0°C to 350°C in a nitrogen atmosphere under the conditions of tensile mode, load: 0.05N, sample distance: 8mm, sample width: 4mm, and heating rate: 10°C / min (heating cycle 1), and then cooled from 350°C to 0°C by flowing cooled nitrogen. The layer is then heated under the same conditions as the first cycle (heating cycle 2), and the average linear expansion coefficient is calculated from the elongation from 50°C to 150°C during the heating cycle 2.

[0046] The glass transition temperature of the insulating layer 11 is preferably 170°C or higher and 300°C or lower, more preferably 200°C or higher and 280°C or lower, and even more preferably 230°C or higher and 270°C or lower. Here, the glass transition temperature of the insulating layer 11 means a value obtained by the following measurement method.

[0047] [Method for measuring glass transition temperature] The insulating layer is heated from 25°C to 350°C using a dynamic viscoelasticity measuring device under the conditions of an air atmosphere, a frequency of 1 Hz, a tensile mode, a sample distance of 2 cm, a sample width of 0.8 cm, and a heating rate of 5°C / min, and tan δ is measured against the temperature. The value of the top peak of tan δ is taken as the glass transition temperature.

[0048] The material constituting the insulating layer 11 is not particularly limited, but a preferred embodiment will be described below.

[0049] The insulating layer 11 preferably contains a fiber base material and a thermosetting resin composition. The thermosetting resin composition contained in the insulating layer 11 preferably includes a cured product of the thermosetting resin composition. An example of an insulating layer 11 containing a fiber substrate and a thermosetting resin composition is a structure containing an insulating resin layer 13a, a fiber substrate 12, and an insulating resin layer 13b, as shown in Figure 3. In this case, the fiber substrate 12 may be a fiber substrate at least partially impregnated with the thermosetting resin composition. The insulating resin layer 13 is preferably a layer formed from a cured product of the thermosetting resin composition. Another example of the insulating layer 11 containing a fiber base material and a thermosetting resin composition is a fiber base material impregnated with a thermosetting resin composition.

[0050] The fiber substrate of the present embodiment is not particularly limited, and may be a woven fiber fabric or a nonwoven fiber fabric. The fibers constituting the fiber substrate of this embodiment include at least one selected from the group consisting of, for example, glass fibers; inorganic fibers other than glass fibers; and organic fibers such as aromatic polyamide fibers, polyamide fibers, aromatic polyester fibers, polyester fibers, polyimide fibers, and fluorine fibers, and preferably include glass fibers.

[0051] The fiber base material of this embodiment is preferably a glass woven fabric from the viewpoint of further improving the mechanical strength, heat resistance, etc. of the substrate. The glass woven fabric has, for example, a thickness of 5 μm or more and 150 μm or less and a basis weight of 5 g / cm 2More than 200g / cm 2 The following is the result.

[0052] The thermosetting resin composition of the present embodiment contains a thermosetting resin. The thermosetting resin includes, for example, at least one selected from the group consisting of epoxy resins, cyanate resins, phenolic resins, resins having a benzoxazine ring, (meth)acrylic resins, melamine resins, unsaturated polyester resins, maleimide resins, polyurethane resins, diallyl phthalate resins, and silicone resins, and preferably includes at least one selected from the group consisting of epoxy resins, cyanate resins, resins having a benzoxazine ring, and maleimide resins, more preferably includes at least one selected from the group consisting of epoxy resins and cyanate resins, and even more preferably includes an epoxy resin and a cyanate resin.

[0053] The thermosetting resin preferably comprises an epoxy resin. The epoxy resin includes at least one selected from the group consisting of, for example, epoxy resins having a naphthalene skeleton, such as naphthylene ether-type epoxy resins, naphthol-type epoxy resins, naphthalenediol-type epoxy resins, binaphthyl-type epoxy resins, naphthalene aralkyl-type epoxy resins, and naphthalene-modified cresol novolac epoxy resins; bisphenol-type epoxy resins, such as bisphenol A-type epoxy resins, bisphenol F-type epoxy resins, and bisphenol E-type epoxy resins; novolac-type epoxy resins; and biphenyl-type epoxy resins. From the viewpoints of further improving the storage modulus E' and further reducing the average linear expansion coefficient of the insulating layer, the epoxy resin preferably includes an epoxy resin having a naphthalene skeleton.

[0054] When the total content of non-volatile components in the thermosetting resin composition is taken as 100% by mass, the content of the epoxy resin in the thermosetting resin composition of the present embodiment is preferably 5% by mass or more and 40% by mass or less, more preferably 8% by mass or more and 35% by mass or less, and even more preferably 10% by mass or more and 30% by mass or less, from the viewpoint of further improving the performance balance of the insulating layer, such as heat resistance and moisture resistance.

[0055] From the viewpoint of further improving the storage modulus E' of the insulating layer and further reducing the average linear expansion coefficient, the thermosetting resin preferably contains at least one selected from the group consisting of a cyanate resin, a resin having a benzoxazine ring, and a maleimide resin, and more preferably contains a cyanate resin. The cyanate resin is a resin containing a cyanate group (—O—CN) in the molecule, and preferably a resin containing two or more cyanate groups in the molecule. The cyanate resin includes at least one selected from the group consisting of, for example, phenol novolac cyanate ester resins; dicyclopentadiene cyanate ester resins; naphthol aralkyl cyanate resins; novolac cyanate resins; and bisphenol cyanate resins such as bisphenol A cyanate resins, bisphenol E cyanate resins, and tetramethylbisphenol F cyanate resins. From the viewpoint of further improving the storage modulus E' of the insulating layer and further reducing the average linear expansion coefficient, the cyanate resin preferably includes at least one selected from the group consisting of phenol novolac cyanate resins, dicyclopentadiene cyanate ester resins, and naphthol aralkyl cyanate resins, and more preferably includes a phenol novolac cyanate resin.

[0056] The content of one or more resins selected from the group consisting of cyanate resins, resins having a benzoxazine ring, and maleimide resins in the thermosetting resin composition of this embodiment is preferably 5% by mass or more and 40% by mass or less, more preferably 8% by mass or more and 35% by mass or less, and even more preferably 10% by mass or more and 30% by mass or less, from the viewpoint of further improving the storage modulus E' of the insulating layer and further reducing the average linear expansion coefficient, when the total content of non-volatile components in the thermosetting resin composition is 100% by mass.

[0057] The thermosetting resin composition of the present embodiment preferably contains a filler, and more preferably contains an inorganic filler. The inorganic filler includes at least one selected from the group consisting of, for example, silica, talc, alumina, glass, mica, aluminum hydroxide, magnesium hydroxide, and the like, and preferably includes silica.

[0058] The silica includes, for example, at least one selected from the group consisting of spherical silica and crushed silica, and preferably includes spherical silica. The silica may also be fused spherical silica.

[0059] Average particle size of filler D 50 is preferably 0.01 μm or more and 10 μm or less, more preferably 0.05 μm or more and 5 μm or less, and even more preferably 0.1 μm or more and 3 μm or less. Average particle size of filler D 50 means a value measured using, for example, a laser diffraction particle size distribution analyzer.

[0060] The content of the filler in the thermosetting resin composition of the present embodiment is preferably 45% by mass or more and 85% by mass or less, more preferably 50% by mass or more and 80% by mass or less, and even more preferably 55% by mass or more and 75% by mass or less, when the total content of non-volatile components in the thermosetting resin composition is 100% by mass. When the content of the filler in the thermosetting resin composition of the present embodiment is equal to or greater than the above lower limit, the storage modulus E' of the insulating layer can be further improved and the average linear expansion coefficient can be further reduced.

[0061] The thermosetting resin composition of the present embodiment may contain other components. The other components include, for example, at least one selected from the group consisting of a thermoplastic resin, a curing accelerator, a coupling agent, a leveling agent, an antioxidant, a flame retardant, etc. The content of the other components is an appropriate amount.

[0062] <Other layers> The substrate 10 may include other layers in addition to the insulating layer 11. The substrate 10 includes, for example, a metal foil 14. The metal foil 14 is preferably a copper foil. Preferably, at least one outermost layer of the substrate 10 is a metal foil 14, and more preferably, both outermost layers are metal foils 14.

[0063] The thickness of the metal foil 14 is preferably 1 μm or more and 50 μm or less, more preferably 5 μm or more and 30 μm or less, and even more preferably 10 μm or more and 20 μm or less.

[0064] [Substrate manufacturing method] The method for producing the substrate of this embodiment is not particularly limited, and examples thereof include the methods described in the Examples. Specifically, examples of the method for producing the substrate of this embodiment include a method in which the insulating resin layer sides of the first and second metal foils with insulating resin layers are superimposed on both sides of a fiber base material to form a laminate, and these are bonded under reduced pressure conditions, and after bonding, are heated at a temperature equal to or higher than the melting temperature of the insulating resin.

[0065] [Optical components] The optical component of this embodiment is an optical component including the optoelectronic composite substrate of this embodiment. The optical component of this embodiment may be a final product or an intermediate product.

[0066] A preferred embodiment of the optical component of this embodiment will be described with reference to FIG. The optical component of this embodiment preferably includes a structure 300 in which an end face of an opto-electrical composite substrate (a) 100a is connected to an end face of an opto-electrical composite substrate (b) 100b that is different from the opto-electrical composite substrate (a) 100a via an optical fiber 200, and at least one selected from the group consisting of the opto-electrical composite substrate (a) 100a and the opto-electrical composite substrate (b) 100b is the opto-electrical composite substrate of this embodiment. Preferably, at least one of the end faces of the optical-electrical composite substrate (a) 100a and the end face of the optical-electrical composite substrate (b) 100b of the structure 300 is a cut surface, and both the end faces of the optical-electrical composite substrate (a) 100a and the end faces of the optical-electrical composite substrate (b) 100b are cut surfaces.

[0067] 1, the optical / electrical composite substrate (a) 100a includes an optical waveguide layer 20 on a substrate 10. The optical waveguide layer 20 includes, in order from the substrate 10 side, a first clad layer 21, a core layer 22, a second clad layer 23, and a polyimide base material 24. The optical / electrical composite substrate (b) 100b has a similar layer configuration. In the structure 300, the core layer 22 at the end face of the optical / electrical composite substrate (a) 100a and the core layer 22 at the end face of the optical / electrical composite substrate (b) 100b are preferably connected via the optical fiber 200.

[0068] An example of a propagation path of light in the structure 300 of FIG. 1 will be described. 1 includes a light-emitting element 41, a light-receiving element 42, a mirror 51 on the light-emitting element side, and a mirror 52 on the light-receiving element side. A through-hole is formed in the substrate 10, and the through-hole is filled with a resin composition for a first cladding layer. Light emitted from the light-emitting portion of the light-emitting element 41 passes through a through-hole formed in the substrate 10 and is incident on the mirror 51 on the light-emitting element side, whereby it is transmitted sequentially through the core layer 22 of the opto-electrical composite substrate 100a, the optical fiber 200, and the core layer 22 of the opto-electrical composite substrate 100b. The light then enters the mirror 52 on the light-receiving element side, passes through a through-hole formed in the substrate 10, and is incident on the light-receiving element 42. The arrows in FIG. 1 are a schematic representation of the propagation of light.

[0069] Although the embodiments of the present invention have been described above, these are merely examples of the present invention, and various other configurations can also be adopted. Furthermore, the present invention is not limited to the above-described embodiment, and modifications and improvements within the scope of achieving the object of the present invention are included in the present invention. [Example]

[0070] The present embodiment will be described in detail below based on examples and comparative examples, but the present embodiment is not limited to the descriptions of these examples.

[0071] First, the method for producing the films used in each of the examples and comparative examples will be described.

[0072] <Preparation of the first clad layer film> (Synthesis of polyimide resin) A 3-liter separable glass flask equipped with a stirrer and a stirring blade was charged with 67.3 g (0.210 mol) of 2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl, 97.7 g (0.220 mol) of 4,4'-(hexafluoroisopropylidene)diphthalic dianhydride, and 495 g of dimethylacetamide, and the mixture was stirred to dissolve. The mixture was further stirred at room temperature under a nitrogen stream for 12 hours to carry out the polymerization reaction, yielding a polyamic acid solution.

[0073] After adding 16 g of pyridine to the obtained polyamic acid solution, 82 g of acetic anhydride was added dropwise at room temperature, and then the liquid temperature was kept at 20 to 100°C and stirring was continued for 24 hours to carry out the imidization reaction, thereby obtaining a polyimide solution.

[0074] The resulting polyimide solution was poured into 1,000 g of methanol in a 5 L container while stirring to precipitate the polyimide resin. The solid polyimide resin was then filtered using a suction filter and washed with 1,000 g of methanol. The solid was then dried in a vacuum dryer at 100°C for 24 hours and then at 200°C for 3 hours to obtain a powdered polyimide resin. The weight average molecular weight (Mw) of the polyimide resin measured by GPC was 51,000. 1 H-NMR measurement was performed, and the imidization rate was calculated from the quantitative value of the amide peak relative to the peak of the aromatic ring of the polyimide, and the imidization rate was found to be 99% or more. A polyimide resin was dissolved in propylene glycol monomethyl ether acetate to a solids concentration of 25%, and then coated using an applicator to a film thickness of 30 μm. The film was then dried in an oven at 100°C for 10 minutes to obtain a polyimide coating. The refractive index of the resulting coating was measured using an Abbe refractometer (manufactured by Atago Co., Ltd., product name: NAR-1T SOLID) under conditions of 23°C and 589 nm, and the refractive index of the polyimide was found to be 1.54.

[0075] (Preparation of Resin Composition for First Clad Layer) 50 parts by weight of the polyimide resin synthesized above, 50 parts by weight of Celloxide 2021P (Daicel Corporation, epoxy compound), 0.08 parts by weight of CPI-310B (San-Apro Co., Ltd., photocationic polymerization initiator), 0.1 parts by weight of BYK-333 (BYK Japan K.K., silicone surfactant), 187 parts by weight of propylene glycol monomethyl ether acetate, and 47 parts by weight of propylene glycol monomethyl ether were stirred at room temperature until the raw materials were completely dissolved, yielding a solution. The resulting solution was filtered through a PTFE filter with a pore size of 0.2 μm to obtain a varnish-like resin composition for the first cladding layer.

[0076] (Preparation of film for first clad layer) The resin composition for the first clad layer was applied using an applicator to a 38 μm thick antistatic treated polyethylene terephthalate (PET) substrate (manufactured by Nippa Corporation, product name: PET38×1-TR1-ASQ) so that the thickness after drying would be 25 μm. The coating was then dried at 100°C for 10 minutes, and an OPP cover film (manufactured by Oji F-Tex Corporation, product name: E201F-50 μm) was attached to the surface of the layer made of the resin composition for the first clad layer, thereby obtaining a film for the first clad layer.

[0077] <Preparation of Core Layer Film> (Synthesis of polymer for core layer) In a glove box filled with dry nitrogen and with moisture and oxygen concentrations both controlled to 1 ppm or less, 7.2 g (40.1 mmol) of hexylnorbornene (HxNB) and 12.9 g (40.1 mmol) of diphenylmethylnorbornene methoxysilane were weighed into a 500 mL vial, to which 60 g of dehydrated toluene and 11 g of ethyl acetate were added, and the vial was then sealed with a silicone sealer. Next, 1.56 g (3.2 mmol) of Ni catalyst and 10 mL of dehydrated toluene were weighed into a 100 mL vial, the vial was sealed with a stirrer tip, and the Ni catalyst was thoroughly stirred to completely dissolve, yielding a Ni catalyst solution. 1 mL of the Ni catalyst solution was accurately measured with a syringe and quantitatively injected into the vial containing the two norbornenes dissolved above. The mixture was stirred at room temperature for 1 hour, resulting in a significant increase in viscosity. At this point, the stopper was removed, and 60 g of tetrahydrofuran (THF) was added and stirred to obtain a reaction solution. A 100 mL beaker was charged with 9.5 g of acetic anhydride, 18 g of hydrogen peroxide (30% concentration), and 30 g of ion-exchanged water, and the resulting mixture was stirred to prepare an aqueous solution of peracetic acid. The entire amount of the aqueous solution of peracetic acid was then added to the reaction solution and stirred for 12 hours to reduce Ni. Next, the reaction solution after the treatment was transferred to a separatory funnel, and after removing the lower aqueous layer, 100 mL of a 30% aqueous solution of isopropyl alcohol was added and vigorously stirred. After allowing to stand and allowing the two layers to separate completely, the aqueous layer was removed. This water washing process was repeated a total of three times, and the oil layer was then dropped into a large excess of acetone to reprecipitate the resulting polymer. The filtrate was separated by filtration and then heated and dried for 12 hours in a vacuum dryer set at 60°C to obtain the core layer polymer. The molecular weight of the core layer polymer was measured by GPC and found to be Mw = 100,000 and Mn = 40,000. The molar ratio of each structural unit in the core layer polymer was identified by NMR measurement and found to be 50 mol % of hexylnorbornene structural units and 50 mol % of diphenylmethylnorbornenemethoxysilane structural units.

[0078] (Preparation of Core Layer Resin Composition) 10 g of the purified core layer polymer was weighed into a 100 mL glass container, and 3 g of methylcyclohexane, 27 g of toluene, 2.4 g of OXT-213 (manufactured by Toagosei Co., Ltd., an oxetane compound), 0.8 g of Celloxide 2021P (manufactured by Daicel Corporation, an epoxy compound), 0.4 g of Celloxide 2000 (manufactured by Daicel Corporation, an epoxy resin), and 0.4 g of CPI-310B (manufactured by San-Apro Co., Ltd., a photocation 0.06 g of a polymerization initiator, 0.003 g of Curesol C11z (manufactured by Shikoku Chemical Industries, Ltd., an imidazole-based compound), 0.1 g of Irgafox168 (manufactured by BASF, a phosphorus-based antioxidant), and 0.025 g of Irganox1076 (manufactured by BASF, a hindered phenol-based antioxidant) were added and dissolved uniformly, and then filtered through a 0.2 μm PTFE filter to obtain a varnish-like resin composition for the core layer.

[0079] (Preparation of Core Layer Film) The core layer resin composition was applied to a release-treated PET substrate using an applicator so that the thickness after drying would be 40 μm, and then the substrate was placed in a 45°C dryer for 5 minutes to completely remove the solvent.After that, an OPP cover film (manufactured by Oji F-Tex Co., Ltd., product name: E201F-50 μm) was attached to the surface of the layer consisting of the core layer resin composition, thereby obtaining a core layer film.

[0080] <Preparation of film for second clad layer> (Preparation of Resin Composition for Second Clad Layer) 300.6 parts by mass of toluene, 91.7 parts by mass of Septon Q1250 (Kuraray Co., Ltd., rubber-based elastomer), 2.8 parts by mass of BYK-361N (BYK Japan K.K., acrylic polymer-based surfactant), 2.8 parts by mass of X-12-1281C (Shin-Etsu Chemical Co., Ltd., silane coupling agent), and 2.8 parts by mass of Curesol C11z (Shikoku Kasei Co., Ltd., imidazole-based compound) were stirred at room temperature until the raw materials were completely dissolved to obtain a solution. The solution was then filtered through a PTFE filter with a pore size of 0.2 μm to obtain a varnish-like resin composition for the second clad layer.

[0081] (Preparation of film for second clad layer) The resin composition for the second cladding layer was applied using an applicator to a 25 μm thick polyimide substrate (manufactured by UBE Corporation, product name: Upilex 25S) so that the thickness after drying would be 10 μm, and then dried at 160°C for 10 minutes. An OPP cover film (manufactured by Oji F-Tex Corporation, product name: E201F-50 μm) was attached to the surface of the layer made of the resin composition for the second cladding layer, thereby obtaining a film for the second cladding layer.

[0082] [Example 1] <Preparation of substrate> (Preparation of Thermosetting Resin Composition) 14.5% by mass of naphthalene-modified cresol novolac epoxy resin (manufactured by DIC Corporation, product name: HP-5000) as the epoxy resin, 14.5% by mass of phenol novolac cyanate ester resin (manufactured by LONZA Corporation, product name: PT-30) as the cyanate resin, 70% by mass of spherical silica particles (manufactured by Admatechs Corporation, product name: SO-C4, average particle size 1.0 μm, phenylaminosilane-treated) as the filler, 0.5% by mass of tetraphenylphosphonium tetrakis(4-methylphenyl)borate (manufactured by Hokko Chemical Industry Co., Ltd., product name: TPP-MK) as the curing accelerator, and 0.5% by mass of epoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd., product name: KBM-403) as the coupling agent were dissolved and dispersed in methyl ethyl ketone and stirred for 1 hour using a high-speed stirrer. This produced a varnish-like thermosetting resin composition.

[0083] (Preparation of copper foil with insulating resin layer) The copper foil used was a copper foil (manufactured by Mitsui Mining & Smelting Co., Ltd., product name: 3EC-M3-VLP) with a thickness of 12 μm and a width of 580 mm. The varnish-like thermosetting resin composition prepared above was applied to the copper foil using a comma coater and dried at 120°C for 5 minutes using a dryer, forming an insulating resin layer made of the thermosetting resin composition with a thickness of 30 μm and a width of 555 mm, positioned at the center of the copper foil in the width direction. The obtained insulating resin layer was in the form of a film. A protective film (polyethylene film) was laminated on the insulating resin layer side to obtain a copper foil with an insulating resin layer. Two copper foils with an insulating resin layer were prepared, and designated as first and second copper foils with an insulating resin layer.

[0084] (Preparation of substrate) As the fiber substrate, glass woven fabric (manufactured by Unitika Glass Fiber Co., Ltd., product name: E10T, IPC product number: #2116, basis weight: 106 g / cm 2 , thickness: 90 μm, width: 540 mm) was used. While peeling off the protective films from the first and second copper foils with insulating resin layers prepared above, the fiber base material and the first and second copper foils with insulating resin layers were each stacked to form a laminate so that the insulating resin layer side of the copper foil with insulating resin layer was in contact with both sides of the fiber base material and the fiber base material was positioned at the center of the copper foil in the width direction, and the laminate was then pressed and bonded from both sides using a laminating roll at 150°C under reduced pressure conditions of 20 Torr. Here, in the inner region of the width direction of the fiber substrate, the first and second copper foils with insulating resin layers were bonded to the fiber substrate, respectively, and in the outer region of the width direction of the fiber substrate, the insulating resin layers of the first and second copper foils with insulating resin layers were bonded to each other. Next, the laminate bonded as described above was passed through a horizontally conveying hot air dryer for 2 minutes at 130°C, 150°C, and 180°C, respectively. Next, the laminate bonded as described above was passed through a horizontally conveying hot air dryer for 30 minutes at 200°C, whereby the laminate was heat-cured without applying pressure, to obtain the substrate of Example 1.

[0085] <Fabrication of optoelectronic composite substrate> (Formation of the first cladding layer) The substrate of Example 1 was placed on a stainless steel plate. The OPP cover film of the first clad layer film was peeled off, and the substrate and the first clad layer film were superimposed such that the surface of the substrate opposite the stainless steel plate was in contact with the layer of the first clad layer resin composition in the first clad layer film. Next, the substrate and the first clad layer film were laminated using a vacuum laminator (manufactured by Nikko Materials Co., Ltd., product name: CVP-300) at a temperature of 140°C, a pressure of 0.5 MPa, and a time of 120 seconds to obtain Laminate 1 having a layer structure of "substrate / layer of first clad layer resin composition / PET substrate." Next, the PET substrate surface of the laminate 1 was irradiated with light using a direct imaging exposure machine (manufactured by SCREEN Co., Ltd., product name: LI-9000). After the light irradiation, the laminate 1 was placed in an oven at 160°C for 30 minutes to cure the layer made of the resin composition for the first cladding layer. Hereinafter, the layer made of the resin composition for the first cladding layer after curing will be referred to as the first cladding layer.

[0086] (Core layer formation) The PET substrate was peeled off from Laminate 1, and Laminate 1 and the core layer film were overlapped so that the first clad layer in Laminate 1 came into contact with the layer of the core layer resin composition in the core layer film. At this time, the OPP cover film in the core layer film was peeled off. Next, Laminate 1 and the core layer film were laminated using a vacuum laminator (manufactured by Nikko Materials Co., Ltd., product name: CVP-300) at a temperature of 60°C, a pressure of 0.5 MPa, and a time of 30 seconds to obtain Laminate 2 having a layer structure of "substrate / first clad layer / layer of core layer resin composition / PET substrate." Next, 20 lines were exposed onto the layer made of the core layer resin composition using a direct imaging exposure machine (manufactured by SCREEN Co., Ltd., product name: LI-9000) with an exposure width of 50 μm and a pitch of 100 μm. Next, the PET substrate was peeled off from the laminate 2, and the laminate was placed in an oven at 150°C for 30 minutes. When it was removed from the oven, it was confirmed that a clear waveguide pattern (multiple core portions) with a rectangular cross section had appeared on the coating. Hereinafter, the layer made of the core layer resin composition after the waveguide pattern had been formed will be referred to as the core layer.

[0087] (Formation of the second cladding layer) The OPP cover film of the second cladding layer film was peeled off, and the laminate 2 and the second cladding layer film were overlapped so that the core layer in the laminate 2 and the layer of the second cladding layer resin composition in the second cladding layer film were in contact. Next, using a vacuum laminator (Nikko Materials Co., Ltd., product name: CVP-300), laminate 2 and the second cladding layer film were laminated at a temperature of 140°C, a pressure of 0.5 MPa, and a time of 210 seconds to obtain laminate 3, which had a layer structure of "substrate / first cladding layer / core layer / layer of the second cladding layer resin composition / polyimide substrate." Laminate 3 was then heat-treated in an oven at 160°C for 2 hours to obtain the optoelectronic composite substrate of Example 1, which consisted of "substrate / first cladding layer / core layer / second cladding layer / polyimide substrate."

[0088] <Preparation of photoelectric composite substrate after cutting> A laminate was obtained by attaching the dicing film (manufactured by Denka Co., Ltd., product name: ELEGRIP TAPE UDT-1005M3-27B) to the optoelectronic composite substrate while applying pressure at room temperature using a cleaning roller (manufactured by Teknek) so that the substrate in the optoelectronic composite substrate of Example 1 came into contact with the adhesive layer of the dicing film. That is, the layer structure of the obtained laminate was "dicing film / substrate / first clad layer / core layer / second clad layer / polyimide base material."

[0089] Using a dicing machine (manufactured by Disco Corporation, product name: DAD3240), the optoelectronic composite substrate was cut with a dicing blade at a dicing speed of 0.5 mm / sec to obtain a cut optoelectronic composite substrate with one end face as the cut surface. Next, the cut optoelectronic composite substrate with one end face as the cut surface was cut under the same conditions to obtain a cut optoelectronic composite substrate with both end faces as the cut surfaces. At this time, the cut portion was set so that the length of the waveguide pattern portion was 7 cm. The dicing blade is manufactured by Tokyo Seimitsu Co., Ltd., product name: CRM4660130, type of abrasive: diamond abrasive, grinding stone grain size: #3000, abrasive grain diameter: 4 to 6 μm, blade thickness: 0.06 to 0.07 mm, blade tip exposure: 1.3 to 1.43 mm, blade diameter: 55.5 mm.

[0090] Next, the dicing film was irradiated with ultraviolet light to reduce the adhesive strength of the dicing film, and the dicing film was peeled off from the laminate, thereby obtaining the optoelectronic composite substrate after cutting of Example 1.

[0091] [Example 2] <Preparation of substrate> (Preparation of Thermosetting Resin Composition) In the same manner as in Example 1, a varnish-like thermosetting resin composition was obtained.

[0092] (Preparation of copper foil with insulating resin layer) A copper foil with an insulating resin layer was obtained in the same manner as in Example 1, except that the thickness of the insulating resin layer made of a thermosetting resin composition was set to 19 μm.

[0093] (Preparation of substrate) As the fiber substrate, glass woven fabric (manufactured by Unitika Glass Fiber Co., Ltd., product name: E03C, IPC product number: #1067, basis weight: 30 g / cm 2 The substrate of Example 2 was obtained in the same manner as in Example 1, except that a 1000-kJ / cm2 aluminum foil (thickness: 30 μm, width: 540 mm) was used.

[0094] <Fabrication of optoelectronic composite substrate> An optoelectronic composite substrate of Example 2 was obtained in the same manner as in Example 1, except that the substrate of Example 2 was used.

[0095] <Preparation of photoelectric composite substrate after cutting> The optoelectronic composite substrate of Example 2 was cut in the same manner as in Example 1, to obtain the cut optoelectronic composite substrate of Example 2.

[0096] [Example 3] <Preparation of substrate> (Preparation of Thermosetting Resin Composition) In the same manner as in Example 1, a varnish-like thermosetting resin composition was obtained.

[0097] (Preparation of copper foil with insulating resin layer) A copper foil with an insulating resin layer was obtained in the same manner as in Example 1, except that the thickness of the insulating resin layer made of a thermosetting resin composition was set to 12 μm.

[0098] (Preparation of substrate) As the fiber substrate, glass woven fabric (manufactured by Unitika Glass Fiber Co., Ltd., product name: E01B, IPC product number: #1027, basis weight: 20 g / cm 2 The substrate of Example 3 was obtained in the same manner as in Example 1, except that a 1000-kJ / cm2 aluminum foil (thickness: 20 μm, width: 540 mm) was used.

[0099] <Fabrication of optoelectronic composite substrate> An optoelectronic composite substrate of Example 3 was obtained in the same manner as in Example 1, except that the substrate of Example 3 was used.

[0100] <Preparation of photoelectric composite substrate after cutting> The optoelectronic composite substrate of Example 3 was cut in the same manner as in Example 1, to obtain the cut optoelectronic composite substrate of Example 3.

[0101] [Example 4] <Preparation of substrate> (Preparation of Thermosetting Resin Composition) In the same manner as in Example 1, a varnish-like thermosetting resin composition was obtained.

[0102] (Preparation of copper foil with insulating resin layer) A copper foil with an insulating resin layer was obtained in the same manner as in Example 1, except that the thickness of the insulating resin layer made of a thermosetting resin composition was set to 10 μm.

[0103] (Preparation of substrate) As the fiber substrate, glass woven fabric (manufactured by Unitika Glass Fiber Co., Ltd., product name: E01Z, IPC product number: #1017, basis weight: 13 g / cm 2 The substrate of Example 4 was obtained in the same manner as in Example 1, except that a 1000-kJ / cm2 aluminum foil (thickness: 15 μm, width: 540 mm) was used.

[0104] <Fabrication of optoelectronic composite substrate> An optoelectronic composite substrate of Example 4 was obtained in the same manner as in Example 1, except that the substrate of Example 4 was used.

[0105] <Preparation of photoelectric composite substrate after cutting> The optoelectronic composite substrate of Example 4 was cut in the same manner as in Example 1, to obtain the cut optoelectronic composite substrate of Example 4.

[0106] [Example 5] <Preparation of substrate> The substrate of Example 5 was obtained in the same manner as in the preparation of the substrate of Example 4.

[0107] <Fabrication of optoelectronic composite substrate> An optoelectronic composite substrate of Example 5 was obtained in the same manner as in the optoelectronic composite substrate of Example 4.

[0108] <Preparation of photoelectric composite substrate after cutting> The optoelectronic composite substrate of Example 5 was cut in the same manner as in Example 1, except that the dicing speed was set to 2.0 mm / sec, to obtain the cut optoelectronic composite substrate of Example 5.

[0109] [Example 6] <Preparation of substrate> (Preparation of Thermosetting Resin Composition) The epoxy resin consisted of 19.5% by mass of a naphthalene-modified cresol novolac epoxy resin (manufactured by DIC Corporation, product name: HP-5000), 5% by mass of a modified bisphenol epoxy resin (manufactured by Mitsubishi Chemical Corporation, product name: jER YX6954), 14.5% by mass of a phenol novolac cyanate ester resin (manufactured by LONZA Corporation, product name: PT-30), 60% by mass of spherical silica particles (manufactured by Admatechs Corporation, product name: SO-C4, average particle size 1.0 μm, phenylaminosilane-treated) as a filler, 0.5% by mass of tetraphenylphosphonium tetrakis(4-methylphenyl)borate (manufactured by Hokko Chemical Industry Co., Ltd., product name: TPP-MK) as a curing accelerator, and 0.5% by mass of an epoxy silane (manufactured by Shin-Etsu Chemical Co., Ltd., product name: KBM-403) as a coupling agent. These were dissolved and dispersed in methyl ethyl ketone and then stirred for 1 hour using a high-speed stirrer. As a result, a varnish-like thermosetting resin composition was obtained.

[0110] (Preparation of copper foil with insulating resin layer) A copper foil with an insulating resin layer was obtained in the same manner as in Example 1, except that the varnish-like thermosetting resin composition of Example 6 was used and the thickness of the insulating resin layer made of the thermosetting resin composition was 10 μm.

[0111] As the fiber substrate, glass woven fabric (manufactured by Unitika Glass Fiber Co., Ltd., product name: E01Z, IPC product number: #1017, basis weight: 13 g / cm 2 The substrate of Example 6 was obtained in the same manner as in Example 1, except that a 1000-kJ / cm2 aluminum foil (thickness: 15 μm, width: 540 mm) was used.

[0112] <Fabrication of optoelectronic composite substrate> An optoelectronic composite substrate of Example 6 was obtained in the same manner as in Example 1, except that the substrate of Example 6 was used.

[0113] <Preparation of photoelectric composite substrate after cutting> The optoelectronic composite substrate of Example 6 was cut in the same manner as in Example 1, to obtain the cut optoelectronic composite substrate of Example 6.

[0114] [Comparative Example 1] <Fabrication of optoelectronic composite substrate> As the substrate of Comparative Example 1, R-F705S (manufactured by Panasonic Industries Co., Ltd., liquid crystal polymer substrate, thickness of insulating layer of substrate: 25 μm) was used. An optoelectronic composite substrate of Comparative Example 1 was obtained in the same manner as in Example 1, except that the substrate of Comparative Example 1 was used.

[0115] <Preparation of photoelectric composite substrate after cutting> The optoelectric composite substrate of Comparative Example 1 was cut in the same manner as in Example 1, to obtain the cut optoelectric composite substrate of Comparative Example 1.

[0116] Comparative Example 2 <Fabrication of optoelectronic composite substrate> As the substrate of Comparative Example 2, Apical NPI (manufactured by Kaneka Corporation, polyimide substrate, thickness of insulating layer of substrate: 25 μm) was used. An optoelectronic composite substrate of Comparative Example 2 was obtained in the same manner as in Example 1, except that the substrate of Comparative Example 2 was used.

[0117] <Preparation of photoelectric composite substrate after cutting> The optoelectric composite substrate of Comparative Example 2 was cut in the same manner as in Example 1, to obtain the cut optoelectric composite substrate of Comparative Example 2.

[0118] [Measurement and evaluation] The evaluation methods for each example and comparative example are described below. The results of each measurement and evaluation are shown in Table 1.

[0119] <Thickness of the insulating layer on the board> The thickness of the insulating layer of the substrate in Examples 1 to 6 was measured by peeling the copper foil from the substrate, taking out only the insulating layer of the substrate, and using a thickness measuring device (micrometer, manufactured by Mitutoyo Corporation).

[0120] <Storage modulus E' and glass transition temperature of the insulating layer of the substrate at 30°C> The copper foil was peeled off from the substrate, and only the insulating layer of the substrate was taken out and used as a measurement sample. The measurement sample was heated from 25°C to 350°C using a dynamic viscoelasticity measuring device (manufactured by TA Corporation, product name: Q800) in an air atmosphere under the following conditions: frequency: 1 Hz, tensile mode, sample distance: 2 cm, sample width: 0.8 cm, and heating rate: 5°C / min, and the storage modulus E' and tan δ versus temperature were measured. The storage modulus E' at 30°C was calculated from the storage modulus E' versus temperature. The value of the top peak of tan δ versus temperature was taken as the glass transition temperature.

[0121] <Average linear expansion coefficient of the insulating layer of the substrate> The copper foil was peeled off from the substrate, and only the insulating layer of the substrate was taken out and used as a measurement sample. The measurement sample was heated from 0°C to 350°C (first heating cycle) under the conditions of a nitrogen atmosphere, tension mode, load: 0.05N, sample distance: 8mm, sample width: 4mm, and heating rate: 10°C / min using a thermomechanical analyzer (TA Corporation, product name: Q400). The sample was then cooled from 350°C to 0°C by flowing cooled nitrogen, and a second heating cycle was carried out under the same conditions as the first cycle (second heating cycle). The average linear expansion coefficient was calculated from the elongation from 50°C to 150°C during the second heating cycle.

[0122] <Evaluation of edge sagging on cut surfaces> <Preparation of cut photoelectric composite substrates> was carried out 10 times for each Example and Comparative Example, and 10 cut photoelectric composite substrates were obtained for each Example and Comparative Example. Both end faces (cut surfaces) of 10 cut optoelectronic composite substrates were observed using a microscope for each of the obtained examples and comparative examples. That is, two cut surfaces were observed for each cut optoelectronic composite substrate, so a total of 20 cut surfaces were observed per level. The cut surfaces were checked for edge sagging, scratches, etc. on the optical waveguide layer. Cut surfaces that did not have edge sagging, scratches, etc. on the optical waveguide layer were evaluated as "good." The end sagging of the cut surface was evaluated based on the following evaluation criteria. A: The percentage of photoelectric composite boards for which the cut surface evaluation result was "good" out of the total number of photoelectric composite boards observed is 100%. B: The percentage of the number of photoelectric composite substrates for which the cut surface evaluation result was "good" out of the total number of photoelectric composite substrates observed was 50% or more but less than 100%. C: The percentage of the number of photoelectric composite substrates for which the cut surface evaluation result was "good" out of the total number of photoelectric composite substrates observed was more than 0% but less than 50% D: The percentage of the number of photoelectric composite substrates for which the cut surface evaluation result was "good" out of the number of photoelectric composite substrates observed was 0%.

[0123] <Light attenuation (linear) evaluation> The propagation loss (linear) [dB] of the cut optical / electrical composite substrates obtained in each example and comparative example was measured in accordance with 4.6.2.1 Cutback Method of "Test Methods for Polymer Optical Waveguides (JPCA-PE02-05-01S-2008)." The measurement was performed using light with a wavelength of 850 nm. The light attenuation (linear) was evaluated based on the following evaluation criteria. A: Propagation loss (straight line) is less than 2.0 dB B: Propagation loss (straight line) is 2.0 dB or more

[0124] <Evaluation of optical attenuation (between components)> 1, in consideration of the light propagation path, propagation loss occurs between the light-emitting element 41 and the mirror 51, and between the mirror 52 and the light-receiving element 42. In other words, propagation loss occurs in the thickness direction of the optoelectronic composite substrate. In this specification, "optical attenuation (between components) evaluation" refers to evaluation of optical attenuation by taking into account the propagation loss [dB] in the thickness direction in addition to the propagation loss [dB] obtained in "optical attenuation (linear) evaluation."

[0125] Specifically, the propagation loss (between components) [dB] was calculated using the propagation loss value [dB] obtained in the <Optical attenuation (linear) evaluation> and the propagation loss value [dB] in the thickness direction of each example and each comparative example, which was quantified based on the inventor's knowledge that a 20 μm increase in the thickness direction of the substrate results in a propagation loss of 1 dB. The optical attenuation (between components) was evaluated based on the following criteria: A: Propagation loss (between components) is less than 4.0 dB B: Propagation loss (between components) is 4.0 dB or more

[0126] [Table 1]

[0127] The cut optoelectronic composite substrates of the examples all had good results in the evaluation of the edge sagging of the cut surfaces. That is, it can be seen that the optoelectronic composite substrate and the substrate of this embodiment can reduce the edge sagging of the cut surfaces of the optoelectronic composite substrate.

[0128] Furthermore, the optical and electrical composite substrates after cutting in the examples all had good evaluation results for optical attenuation (linear). That is, it can be seen that the optical and electrical composite substrates and substrates of the present embodiment can reduce the optical attenuation of the optical and electrical composite substrates and optical components. [Explanation of symbols]

[0129] 10 Substrate 11 Insulating layer 12 Fiber substrate 13 Insulating resin layer made of thermosetting resin composition 14 Metal foil 20 Optical waveguide layer 21 First cladding layer 22 Core layer 23 Second cladding layer 24 Base material 41 Light-emitting element 42 Photodetector 51 Mirror on the light-emitting element side 52 Mirror on the light receiving element side 100 Optical and electrical composite substrate 200 optical fiber 300 structures

Claims

1. An optical / electrical composite substrate having an optical waveguide layer on a substrate, the substrate includes an insulating layer; The thickness [μm] of the insulating layer divided by the storage modulus E′ [GPa] at 30° C. of the insulating layer obtained by the following method 1 has a value [μm / GPa] of 4.5 or less. [Method 1] The insulating layer is heated from 25°C to 350°C using a dynamic viscoelasticity measuring device under the conditions of an air atmosphere, a frequency of 1 Hz, a tensile mode, a sample distance of 2 cm, a sample width of 0.8 cm, and a heating rate of 5°C / min, and the storage modulus E' versus temperature is measured, and the storage modulus E' at 30°C is calculated.

2. 2. The optical / electrical composite substrate according to claim 1, wherein the insulating layer obtained by method 1 has a storage modulus E' at 30° C. of 6 GPa or more.

3. 3. The optical / electrical composite substrate according to claim 1, wherein the insulating layer has a thickness of 70 [mu]m or less.

4. 3. The optical / electrical composite substrate according to claim 1, wherein the insulating layer has an average linear expansion coefficient of 15 ppm / [deg.] C. or less at 50[deg.] C. or more and 150[deg.] C. or less.

5. 3. The optical / electrical composite substrate according to claim 1, wherein the insulating layer has a glass transition temperature of 170°C or higher and 300°C or lower.

6. The optical / electrical composite substrate according to claim 1 or 2, wherein the insulating layer comprises a fiber substrate and a thermosetting resin composition.

7. The optical / electrical composite substrate according to claim 6 , wherein the thermosetting resin composition contains an inorganic filler.

8. The optical / electrical composite substrate according to claim 7 , wherein the inorganic filler comprises silica.

9. The optical / electrical composite substrate according to claim 1 , wherein the optical waveguide layer comprises, in order from the substrate side, a first clad layer, a core layer, a second clad layer, and a base material.

10. 3. The optical and electrical composite substrate according to claim 1, wherein an end face of said optical and electrical composite substrate includes a surface for connecting an optical fiber.

11. The optical and electrical composite substrate according to claim 1 , wherein an end surface of the optical and electrical composite substrate includes a cut surface.

12. A method for producing the optical / electrical composite substrate according to claim 11, A preparation step of preparing a laminate including an optoelectronic composite substrate (1) having an optical waveguide layer on a substrate and a dicing film; a dicing step of cutting the optoelectronic composite substrate (1) in the laminate with a dicing blade.

13. The structure includes an end face of an optical / electrical composite substrate (a) and an end face of an optical / electrical composite substrate (b) different from the optical / electrical composite substrate (a) connected via an optical fiber, An optical component, wherein at least one selected from the group consisting of the optoelectronic composite substrate (a) and the optoelectronic composite substrate (b) is the optoelectronic composite substrate according to claim 1 or 2.

14. A substrate for carrying an optical waveguide layer, the substrate includes an insulating layer; A substrate, wherein the value [μm / GPa] obtained by dividing the thickness [μm] of the insulating layer by the storage modulus E′ [GPa] at 30° C. of the insulating layer obtained by the following method 1 is 4.5 or less. [Method 1] The insulating layer is heated from 25°C to 350°C using a dynamic viscoelasticity measuring device under the conditions of an air atmosphere, a frequency of 1 Hz, a tensile mode, a sample distance of 2 cm, a sample width of 0.8 cm, and a heating rate of 5°C / min, and the storage modulus E' versus temperature is measured, and the storage modulus E' at 30°C is calculated.

15. 15. The substrate according to claim 14, wherein the insulating layer obtained by method 1 has a storage modulus E' at 30°C of 6 GPa or more.

16. 16. The substrate according to claim 14 or 15, wherein the insulating layer has a thickness of 70 μm or less.

17. A method for producing an optical / electrical composite substrate, comprising the step of forming the optical waveguide layer on the substrate according to claim 14 or 15.

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