Method for manufacturing optical component

Abstract

To provide a method for manufacturing an optical component capable of reducing edge rounding at a cut end surface of a photoelectric composite substrate.SOLUTION: The method for manufacturing an optical component includes the steps of: preparing a laminate 500 including a photoelectric composite substrate 100 having an optical waveguide layer 20 on a substrate 10 and a dicing film 400 (step A); and cutting the photoelectric composite substrate 100 in the laminate 500 with a dicing blade to obtain a photoelectric composite substrate after cutting (step B), step (B) satisfying at least one condition selected from the group consisting of conditions (1) to (3).SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a method for manufacturing an optical component. [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. As a technology relating to an optical / electrical composite substrate, for example, the technology described in Patent Document 1 can be mentioned.

[0003] Patent Document 1 describes an opto-electrical hybrid board that includes an electric circuit board having electrical wiring formed on the surface of an insulating layer and an optical waveguide provided on the back side of the electric circuit board, and that is given a predetermined shape by contour processing, and that has an alignment mark for contour processing that is positioned using the same reference as the electrical wiring on the surface of the insulating layer near the contour processing portion of the surface of the insulating layer, and that is given the predetermined shape by contour processing based on the alignment mark for contour processing. According to the optical / electrical hybrid board of Patent Document 1, it is described that alignment marks for external processing can be formed accurately and in an easily visible arrangement. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-85315 Summary of the Invention [Problem to be solved by the invention]

[0005] The present invention provides a method for manufacturing an optical component that can reduce sagging of the edge of the cut surface of an optoelectronic composite substrate. [Means for solving the problem]

[0006] According to the present invention, there is provided a method for manufacturing an optical component as follows.

[0007] [1] A step (A) of preparing a laminate including an optical / electrical composite substrate having an optical waveguide layer on a substrate and a dicing film; and (B) cutting the optoelectronic composite substrate in the laminate with a dicing blade to obtain a cut optoelectronic composite substrate, The method for producing an optical component, wherein the step (B) satisfies at least one condition selected from the group consisting of the following conditions (1) to (3): Condition (1) The method includes a first cutting step of cutting the optoelectronic composite substrate in the laminate with the dicing blade, and a second cutting step of cutting the cut surface of the optoelectronic composite substrate in the laminate with the dicing blade after the first cutting step. Condition (2): The dicing blade is ultrasonically vibrated to cut the photoelectric composite substrate in the laminate. Condition (3) The dicing speed is 0.4 mm / sec or less. [2] The method for producing an optical component according to [1] above, wherein the step (B) satisfies at least one condition selected from the group consisting of the conditions (1) and (2). [3] The method for manufacturing an optical component according to [1] or [2], wherein the optical waveguide layer and the dicing film are in direct contact with each other in the laminate. [4] the optical waveguide layer comprises a polyimide substrate; The method for producing an optical component according to any one of [1] to [3] above, wherein the polyimide base material and the dicing film are in direct contact with each other in the laminate. [5] The method for producing an optical component according to any one of [1] to [4] above, wherein the substrate is a flexible printed circuit board. [6] The method for manufacturing an optical component according to any one of [1] to [5] above, wherein the grit size of the abrasive grains of the dicing blade is #2000 to #8000. [7] The method for producing an optical component according to any one of [1] to [6] above, wherein the cut surface of the optoelectronic composite substrate after cutting is a surface for connecting an optical fiber. [8] The method for producing an optical component according to any one of [1] to [7], wherein when the cut optoelectric composite substrate is designated as optoelectric composite substrate (a), the optical component includes a structure in which a cut surface of the optoelectric composite substrate (a) is connected to an end face of an optoelectric composite substrate (b) different from the optoelectric composite substrate (a) via an optical fiber. [Effects of the Invention]

[0008] According to the present invention, it is possible to provide a method for manufacturing an optical component that can reduce sagging of the end faces of the cut surface of an optoelectronic composite substrate. [Brief explanation of the drawings]

[0009] [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] FIG. 2 is a cross-sectional view schematically showing an example of the structure of the laminate in step (A). [Figure 3] FIG. 10 is a diagram illustrating the condition (1) in the step (B). DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, embodiments of the present invention will be described with reference to the drawings. The drawings are simplified and do not correspond to actual dimensional proportions. The numerical range "A to B" represents A or more and B or less unless otherwise specified. In this specification, when simply referring to a "clad layer," it means that it includes both the first clad layer and the second clad layer. Unless otherwise specified, the "optoelectronic composite substrate after cutting" means the optoelectronic composite substrate obtained after step (B). The term "(meth)acrylic resin" is a concept that includes both acrylic resin and methacrylic resin.

[0011] 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 a method for manufacturing an optical component that can reduce sagging of the edge of the cut surface of an optoelectronic composite substrate. Furthermore, the optical component of this embodiment can reduce optical attenuation of the optical component.

[0012] [Manufacturing methods for optical components] The method for manufacturing an optical component of this embodiment includes step (A) of preparing a laminate including an optoelectronic composite substrate having an optical waveguide layer on a substrate and a dicing film, and step (B) of cutting the optoelectronic composite substrate in the laminate with a dicing blade to obtain the cut optoelectronic composite substrate, wherein step (B) satisfies at least one condition selected from the group consisting of conditions (1) to (3). Condition (1) The method includes a first cutting step of cutting the optoelectronic composite substrate in the laminate with a dicing blade, and a second cutting step of cutting the cut surface of the optoelectronic composite substrate in the laminate with the dicing blade after the first cutting step. Condition (2): The dicing blade is ultrasonically vibrated to cut the photoelectric composite substrate in the laminate. Condition (3) The dicing speed is 0.4 mm / sec or less.

[0013] Each step of the method for manufacturing an optical component according to this embodiment will now be described.

[0014] <Process (A)> The method for producing an optical component of this embodiment includes a step (A) of preparing a laminate including an optoelectronic composite substrate having an optical waveguide layer on a substrate, and a dicing film.

[0015] 2 is a cross-sectional view schematically showing an example of the structure of the laminate in step (A). The laminate 500 includes an optoelectronic composite substrate 100 having an optical waveguide layer 20 on a substrate 10, and a dicing film 400. In FIG. 2, the optical waveguide layer 20 includes, in order from the substrate 10 side, a first cladding layer 21, a core layer 22, a second cladding layer 23, and a polyimide base material 24.

[0016] In order to further reduce the sagging of the end faces of the cut surface of the optical-electrical composite substrate, the laminate 500 preferably has the optical waveguide layer 20 and the dicing film 400 in direct contact with each other, and more preferably, the optical waveguide layer 20 comprises a polyimide substrate 24, and the polyimide substrate 24 and the dicing film 400 are in direct contact with each other.

[0017] As a result of investigations, the present inventors have found that sagging of the edge of the cut surface of the optoelectronic composite substrate can be further reduced by making the layer in direct contact with the dicing film 400 in the laminate 500 the optical waveguide layer 20 instead of the substrate 10. The present inventors speculate that the reason for this is as follows. The dicing film 400 includes an adhesive layer. The adhesive layer may be made of a soft adhesive resin, and depending on the type of layer adjacent to the adhesive layer, the layer adjacent to the adhesive layer may be pressed in by the dicing blade in step (B) described below, which may cause sagging of the edges of the cut surface of the optoelectronic composite substrate. The substrate 10 has, for example, a copper foil as its outermost layer. In the laminate 500, if the adhesive layer of the dicing film 400 and the copper foil of the substrate 10 are in direct contact with each other, the copper foil may be pressed into the dicing blade in step (B) described below, which may result in sagging of the edges of the cut surface of the opto-electrical composite substrate. On the other hand, in the laminate 500, if the adhesive layer of the dicing film 400 and the optical waveguide layer 20 are in direct contact with each other, the optical waveguide layer 20 is prevented from being pressed into the dicing blade in step (B) described below, which may further reduce sagging of the edges of the cut surface of the opto-electrical composite substrate.

[0018] A preferred embodiment of the optoelectronic composite substrate in the laminate of this embodiment will be described below with reference to FIG.

[0019] The optical / electrical composite substrate 100 includes a substrate 10 . The substrate 10 is not particularly limited as long as it can be used in an optoelectronic composite substrate, and may be a flexible printed circuit board or a rigid board, but is preferably a flexible printed circuit board. The flexible printed circuit board is, for example, a board selected from the group consisting of an LCP board, a polyimide board, and the like.

[0020] Additionally, the substrate 10 is preferably a double-sided copper-clad laminate.

[0021] The thickness of the substrate 10 is, for example, 5 μm or more and 1000 μm or less, preferably 10 μm or more and 500 μm or less, and more preferably 20 μm or more and 100 μm or less. The thickness of the insulating layer in the substrate 10 is, for example, 1 μm or more and 800 μm or less, preferably 3 μm or more and 300 μm or less, and more preferably 5 μm or more and 50 μm or less. When the substrate 10 is a flexible printed circuit board, the insulating layer in the substrate 10 is, for example, a base film layer such as an LCP film or a polyimide film. When the substrate 10 is a rigid substrate, the insulating layer in the substrate 10 is, for example, a glass epoxy layer.

[0022] 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.

[0023] 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 polyimide base material 24.

[0024] 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.

[0025] 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.

[0026] 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.

[0027] 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.

[0028] The polyimide substrate 24 is, for example, a polyimide film. The thickness of the polyimide 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.

[0029] The method for manufacturing the optical-electrical composite substrate 100 is not particularly limited, and an example thereof includes 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, thereby obtaining the optical-electrical composite substrate 100.

[0030] The dicing film 400 is not particularly limited, and for example, a commercially available dicing film can be used. The dicing film 400 is preferably a UV peelable dicing film whose adhesive strength decreases when exposed to ultraviolet light.

[0031] The dicing film 400 has an adhesive layer. Therefore, in the laminate 500, the optoelectronic composite substrate 100 and the adhesive layer of the dicing film 400 are in direct contact with each other.

[0032] As a commercially available dicing film, for example, ELEGRIP TAPE UDT-1005M3-27B (manufactured by Denka Co., Ltd.) can be used.

[0033] In step (A), the method for preparing the laminate 500 is not particularly limited, and an example thereof includes a method in which the laminate 500 is obtained by attaching the dicing film 400 to the photoelectric composite substrate 100 using a cleaning roller.

[0034] <Process (B)> The method for manufacturing an optical component of this embodiment includes step (B) of cutting the optoelectronic composite substrate in the laminate with a dicing blade to obtain the cut optoelectronic composite substrate, and step (B) satisfies at least one condition selected from the group consisting of conditions (1) to (3). Condition (1) The method includes a first cutting step of cutting the optoelectronic composite substrate in the laminate with a dicing blade, and a second cutting step of cutting the cut surface of the optoelectronic composite substrate in the laminate with the dicing blade after the first cutting step. Condition (2): The dicing blade is ultrasonically vibrated to cut the photoelectric composite substrate in the laminate. Condition (3) The dicing speed is 0.4 mm / sec or less.

[0035] From the viewpoint of further improving production efficiency, step (B) preferably satisfies at least one condition selected from the group consisting of conditions (1) and (2).

[0036] The condition (1) in the step (B) will be specifically explained. FIG. 3 is a diagram illustrating the condition (1) in the step (B).

[0037] Condition (1) includes a first cutting step of cutting the optoelectronic composite substrate in the laminate with a dicing blade, and a second cutting step, subsequent to the first cutting step, of cutting the cut surface of the optoelectronic composite substrate in the laminate with a dicing blade. That is, the second cutting step is a step of cutting again the cut surface of the optoelectronic composite substrate obtained after the first cutting step with a dicing blade.

[0038] FIG. 3(a) is a cross-sectional view that schematically shows an example of the laminate 500 after the first cutting step. In the first cutting step, the optoelectronic composite substrate is cut to obtain a cut optoelectronic composite substrate 100c and a cut optoelectronic composite substrate 100d. The distance S between the cut surface of the optoelectronic composite substrate 100c and the cut surface of the optoelectronic composite substrate 100d corresponds to the blade thickness of the dicing blade used in the first cutting step.

[0039] FIG. 3(b) is a diagram for explaining the second cutting step. In FIG. 3(b), a dicing blade 700 is used to cut the cut surface of the optical / electrical composite substrate 100c.

[0040] In the second cutting step, preferably, from the viewpoint of further reducing the edge sagging of the cut surface of the opto-electrical composite substrate, the cut surface of the opto-electrical composite substrate 100c is cut while the dicing blade 700 is pressed against the opto-electrical composite substrate 100c in the blade thickness direction of the dicing blade 700 (X direction in FIG. 3(b)), as shown in FIG. 3(b). When cutting the cut surface of the opto-electrical composite substrate 100c by pressing the dicing blade 700 against the opto-electrical composite substrate 100c in the blade thickness direction of the dicing blade 700, preferably, 30% to 70% of the blade thickness is pressed into the opto-electrical composite substrate 100c, and more preferably, 40% to 60% of the blade thickness is pressed into the opto-electrical composite substrate 100c.

[0041] In the second cutting step, the cut surface of the optoelectric composite substrate 100c is cut while the dicing blade 700 is pressed against the optoelectric composite substrate 100c in the blade thickness direction of the dicing blade 700, so that the dicing blade 700 does not come into contact with the optoelectric composite substrate 100c, and only one side of the dicing blade 700 comes into contact with the optoelectric composite substrate 100c. This reduces the load when the dicing blade 700 cuts the cut surface of the optoelectric composite substrate 100c, thereby further reducing edge sagging of the cut surface of the optoelectric composite substrate.

[0042] The dicing device and the type of dicing blade used in the second cutting step may be the same as or different from those used in the first cutting step. The dicing speed in the second cutting step may be the same as or different from that in the first cutting step.

[0043] The condition (2) in the step (B) will be specifically explained. Condition (2) is that the optoelectronic composite substrate in the laminate is cut while the dicing blade is ultrasonically vibrated. Condition (2) can be achieved, for example, by using a dicing device capable of performing ultrasonic dicing.

[0044] By cutting the optoelectronic composite substrate in the laminate while ultrasonically vibrating the dicing blade, the load caused by friction between the side of the dicing blade and the cut surface of the optoelectronic composite substrate can be reduced, and edge sagging of the cut surface of the optoelectronic composite substrate can be further reduced.

[0045] In condition (2), the dicing blade is preferably subjected to ultrasonic vibration in the radial direction of the dicing blade.

[0046] In step (B), the dicing speed is preferably 1.0 mm / sec or less, more preferably 0.6 mm / sec or less, and even more preferably 0.4 mm / sec or less, from the viewpoint of further reducing sagging of the edge of the cut surface of the optoelectronic composite substrate, and is preferably 0.1 mm / sec or more, more preferably 0.2 mm / sec or more, from the viewpoint of further improving production efficiency. In step (B), the dicing speed is preferably 0.1 mm / sec or more and 1.0 mm / sec or less, more preferably 0.2 mm / sec or more and 0.6 mm / sec or less, and even more preferably 0.2 mm / sec or more and 0.4 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.

[0047] The dicing device used in step (B) is not particularly limited, and for example, a known dicing device can be used. Examples of dicing devices include DAD3240 (manufactured by Disco Corporation), CSX-100Lab (manufactured by Takada Kogyosho Co., Ltd., a dicing device capable of ultrasonic dicing), and CSX501 (manufactured by Takada Kogyosho Co., Ltd., a dicing device capable of ultrasonic dicing).

[0048] The grain size of the abrasive grains of the dicing blade is preferably #2000 to #8000, and more preferably #2500 to #6000, from the viewpoint of further reducing sagging of the edges of the cut surface of the optoelectronic composite substrate. Here, the grain size of the abrasive grains of the dicing blade refers to a value measured by an electrical resistance test method conforming to, for example, JIS R 6001-2: 2017. When the grain size is a value measured by an electrical resistance test method conforming to JIS R 6001-2: 2017, a grain size of #2000 to #8000 means any grain size selected from the group consisting of #2000, #2500, #3000, #4000, #6000, and #8000.

[0049] The material that constitutes the abrasive grains of the dicing blade may be, for example, diamond. The thickness of the dicing blade is not particularly limited, but may be, for example, 0.01 mm to 0.2 mm, 0.1 mm to 5 mm protrusion, and 30 mm to 150 mm diameter.

[0050] In the cut optoelectronic composite substrate obtained after step (B), at least one end surface is a cut surface. Furthermore, the cut optoelectric composite substrate obtained after step (B) may have both end faces that are cut surfaces. That is, step (B) may include a step of obtaining a cut optoelectric composite substrate having one end face that is a cut surface, and then further cutting the cut optoelectric composite substrate having one end face that is a cut surface, to obtain a cut optoelectric composite substrate having both end faces that are cut surfaces.

[0051] <Other processes> The method for manufacturing an optical component of this embodiment may include steps other than steps (A) and (B).

[0052] The method for producing an optical component of this embodiment may include a step of peeling the dicing film from the laminate after step (B). The method for peeling the dicing film from the laminate is not particularly limited, but examples include a method in which the dicing film is irradiated with ultraviolet light to reduce the adhesive strength of the dicing film, thereby peeling the dicing film from the laminate.

[0053] The method for producing an optical component of the present embodiment preferably further includes a step (C) of connecting, when the cut optoelectric composite substrate is designated as optoelectric composite substrate (a), a cut surface of the optoelectric composite substrate (a) to an end face of an optoelectric composite substrate (b) different from the optoelectric composite substrate (a) via an optical fiber. By including step (C) in the method for producing an optical component of this embodiment, an optical component including the structure shown in FIG. 1 can be obtained.

[0054] The optoelectric composite substrate (b) may or may not be an optoelectric composite substrate after cutting, but is preferably an optoelectric composite substrate after cutting. In step (C), when the optoelectronic composite substrate (b) is a cut optoelectronic composite substrate, the cut surface of the optoelectronic composite substrate (a) and the cut surface of the optoelectronic composite substrate (b) are preferably connected via an optical fiber.

[0055] Examples of methods for connecting the cut surface of the opto-electrical composite substrate (a) and the end face of the opto-electrical composite substrate (b) via an optical fiber include a method in which the cut surface of the opto-electrical composite substrate (a) and one end of an optical fiber are connected with an adhesive, and then the other end of the optical fiber is connected with the end face of the opto-electrical composite substrate (b) with an adhesive, thereby connecting the cut surface of the opto-electrical composite substrate (a) and the end face of the opto-electrical composite substrate (b) via an optical fiber.

[0056] The method for manufacturing the optical component of this embodiment may include a reflow process, a wire bonding process, and the like.

[0057] [Optical components] The optical component obtained by the method for producing an optical component of this embodiment is an optical component including the optoelectronic composite substrate after cutting obtained after step (B). Note that the optical component of this embodiment conceptually includes only the optoelectronic composite substrate after cutting obtained after step (B). The optical component of this embodiment may be a final product or an intermediate product.

[0058] In the optical / electrical composite substrate of this embodiment after cutting, the cut surface is preferably a surface for connecting optical fibers.

[0059] A preferred embodiment of an optical component obtained by the method for producing an 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, when the cut opto-electrical composite substrate is opto-electrical composite substrate (a) 100a, a cut surface of the 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. The opto-electrical composite substrate (b) 100b may or may not be an opto-electrical composite substrate after cutting, but is preferably an opto-electrical composite substrate after cutting. When the optical-electrical composite substrate (b) 100b is an optical-electrical composite substrate after cutting, the structure 300 preferably has the cut surface of the optical-electrical composite substrate (a) 100a and the cut surface of the optical-electrical composite substrate (b) 100b connected via an optical fiber 200.

[0060] 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 on the cut surface of the optical / electrical composite substrate (a) 100a is preferably connected to the core layer 22 on the cut surface of the optical / electrical composite substrate (b) 100b via the optical fiber 200.

[0061] The structure 300 may also include other components (not shown) as appropriate. Other components include, for example, a light receiving element, a light emitting element, a stiffener (for example, SUS, etc.), and the like.

[0062] 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]

[0063] 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.

[0064] First, a method for producing the photoelectric composite substrate used in each of the examples and comparative examples will be described.

[0065] <Preparation of film for first clad layer> (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.

[0066] 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.

[0067] 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.

[0068] (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.

[0069] (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.

[0070] <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.

[0071] (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.

[0072] (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.

[0073] <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.

[0074] (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.

[0075] <Fabrication of optoelectronic composite substrate> (Formation of the first cladding layer) A flexible printed circuit board (Panasonic Corporation, product name: FELIOS R-F705S, double-sided copper-clad laminate, three-layer structure: 12 μm copper foil / 25 μm LCP / 12 μm copper foil; hereafter sometimes referred to as "substrate") 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 (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, which had 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.

[0076] (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.

[0077] (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 an optoelectronic composite substrate consisting of "substrate / first cladding layer / core layer / second cladding layer / polyimide substrate."

[0078] [Example 1] <Process (A)> 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 polyimide substrate (hereinafter also referred to as "PI substrate") in the optoelectronic composite substrate came into contact with the adhesive layer of the dicing film. That is, the layer structure of the obtained laminate was "substrate / first clad layer / core layer / second clad layer / PI substrate / dicing film."

[0079] <Process (B)> 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 0.3 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.

[0080] After step (B), 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 of Example 1 after cutting.

[0081] [Example 2] Step (A) was carried out in the same manner as in Example 1, to obtain a laminate including an optoelectronic composite substrate and a dicing film. Using a dicing device, the optoelectronic composite substrate in the laminate was cut with a dicing blade at a dicing speed of 0.3 mm / sec (first cutting step). Next, using a dicing device, the cut surface of the optoelectronic composite substrate obtained after the first cutting step was cut with a dicing blade at a dicing speed of 0.3 mm / sec to obtain a cut optoelectronic composite substrate with one end surface as the cut surface (second cutting step). In the second cutting step, the dicing blade was pressed into the cut surface of the optoelectronic composite substrate by about half the blade thickness in the blade thickness direction of the dicing blade, thereby cutting the optoelectronic composite substrate. The dicing device and dicing blade used in the first cutting step and the second cutting step were the same as those in Example 1. Next, the cut optoelectronic composite substrate with one end surface being the cut surface was cut under the same conditions to obtain a cut optoelectronic composite substrate with both end surfaces being cut surfaces, with the cut portion being such that the length of the waveguide pattern portion was 7 cm. Next, the dicing film was peeled off from the laminate in the same manner as in Example 1, and the optical / electrical composite substrate after cutting of Example 2 was obtained.

[0082] [Example 3] The cut photoelectric composite substrate of Example 3 was obtained in the same manner as in Example 2, except that the dicing speed in the first cutting step and the second cutting step was set to 0.1 mm / sec.

[0083] [Example 4] Step (A) was carried out in the same manner as in Example 1, to obtain a laminate including an optoelectronic composite substrate and a dicing film. Using a dicing machine (manufactured by Takada Kogyosho Co., Ltd., product name: CSX-100Lab), the optoelectronic composite substrate in the laminate 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 surface as the cut surface. At this time, the optoelectronic composite substrate was cut while ultrasonically vibrating the dicing blade. Next, the cut optoelectronic composite substrate with one end surface being the cut surface was cut under the same conditions to obtain a cut optoelectronic composite substrate with both end surfaces being cut surfaces, with the cut portion being such that the length of the waveguide pattern portion was 7 cm. Next, the dicing film was peeled off from the laminate in the same manner as in Example 1, and the optical / electrical composite substrate after cutting of Example 4 was obtained.

[0084] [Comparative Example 1] The substrate in the photoelectric composite substrate was brought into contact with the dicing film, and a laminate was obtained in the same manner as in Example 1. That is, the layer structure of the obtained laminate was "dicing film / substrate / first clad layer / core layer / second clad layer / PI base material." Using the obtained laminate, a cut photoelectric composite substrate of Comparative Example 1 was obtained in the same manner as in Example 1, except that the dicing speed in step (B) was set to 0.5 mm / sec.

[0085] Comparative Example 2 The optoelectronic composite substrate after cutting for Comparative Example 2 was obtained in the same manner as in Example 1, except that the dicing speed in step (B) was set to 0.5 mm / sec.

[0086] [evaluation] The evaluation methods for each example and comparative example are described below. The evaluation results are shown in Table 1.

[0087] <Evaluation of edge sagging on cut surfaces> Each example and each comparative example was repeated 10 times, 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%.

[0088] <Light attenuation evaluation> The propagation loss [dB] of the cut optical / electrical composite substrates obtained in each example and comparative example was measured in accordance with the 4.6.2.1 cutback method of the "Test Method for Polymer Optical Waveguides (JPCA-PE02-05-01S-2008)." The measurement was performed using light with a wavelength of 850 nm. The light attenuation was evaluated based on the following evaluation criteria. A: Propagation loss is less than 2.0 dB B: Propagation loss is 2.0 dB or more

[0089] Here, the evaluation of the above <Evaluation of optical attenuation> in Example 1 was carried out on the optoelectronic composite substrates for which the evaluation result of both cut surfaces in the above <Evaluation of edge sagging of cut surfaces> was "good".

[0090] [Table 1]

[0091] 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 method for manufacturing an optical component of this embodiment can reduce the edge sagging of the cut surfaces of the optoelectronic composite substrate. Furthermore, the optical and electrical composite substrates after cutting in the examples all had good results in the evaluation of optical attenuation. That is, it can be seen that the method for manufacturing an optical component according to this embodiment can reduce optical attenuation of the optical component. [Explanation of symbols]

[0092] 10 Substrate 20 Optical waveguide layer 21 First cladding layer 22 Core layer 23 Second cladding layer 24 Polyimide substrate 100 Optical and electrical composite substrate 200 optical fiber 300 structures 400 dicing film 500 laminate 700 dicing blade

Claims

1. A step (A) of preparing a laminate including an optoelectronic composite substrate having an optical waveguide layer on a substrate and a dicing film; and (B) cutting the optoelectronic composite substrate in the laminate with a dicing blade to obtain a cut optoelectronic composite substrate, The method for producing an optical component, wherein the step (B) satisfies at least one condition selected from the group consisting of the following conditions (1) to (3): Condition (1) The method includes a first cutting step of cutting the optoelectronic composite substrate in the laminate with the dicing blade, and a second cutting step of cutting a cut surface of the optoelectronic composite substrate in the laminate with the dicing blade after the first cutting step. Condition (2): The dicing blade is ultrasonically vibrated to cut the photoelectric composite substrate in the laminate. Condition (3) The dicing speed is 0.4 mm / sec or less.

2. The method for manufacturing an optical component according to claim 1 , wherein the step (B) satisfies at least one condition selected from the group consisting of the conditions (1) and (2).

3. 3. The method for manufacturing an optical component according to claim 1, wherein the optical waveguide layer and the dicing film are in direct contact with each other in the laminate.

4. the optical waveguide layer comprises a polyimide substrate; 3. The method for manufacturing an optical component according to claim 1, wherein the polyimide substrate and the dicing film are in direct contact with each other in the laminate.

5. The method for manufacturing an optical component according to claim 1 or 2, wherein the substrate is a flexible printed circuit board.

6. 3. The method for manufacturing an optical component according to claim 1, wherein the grit size of the abrasive grains of the dicing blade is #2000 to #8000.

7. 3. The method for manufacturing an optical component according to claim 1, wherein the cut surface of the optical / electrical composite substrate after cutting is a surface for connecting an optical fiber.

8. 3. The method for manufacturing an optical component according to claim 1 or 2, wherein when the cut optoelectric composite substrate is defined as optoelectric composite substrate (a), the optical component includes a structure in which a cut surface of the optoelectric composite substrate (a) and an end face of an optoelectric composite substrate (b) different from the optoelectric composite substrate (a) are connected via an optical fiber.

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