JP5685925B2 - Photoelectric composite substrate manufacturing method and photoelectric composite substrate obtained thereby - Google Patents

Description

  The present invention relates to a method for manufacturing a photoelectric composite substrate and a photoelectric composite substrate obtained thereby.

  With the increase in information capacity, development of an optical interconnection technology that uses optical signals not only for communication fields such as trunk lines and access systems but also for information processing in routers and servers is underway. Specifically, in order to use light for short-distance signal transmission between boards in a router or a server device or in a board, an opto-electric composite board in which an optical transmission path is combined with an electric wiring board has been developed. As the optical transmission line, it is desirable to use an optical waveguide that has a higher degree of freedom of wiring and can be densified than an optical fiber, and among them, an optical waveguide that uses a polymer material that is excellent in processability and economy. Promising.

As a method of manufacturing the optical waveguide and the optical / electrical composite substrate in which the optical waveguide and the electric wiring board are integrally combined, for example, after the lower cladding layer is cured and formed on the carrier film, the core layer is formed on the lower cladding layer. However, a build-up method in which a patterned core layer is formed by performing exposure and development, and an upper clad layer is laminated has been used.
However, the photoelectric composite substrate obtained in this way is formed by laminating at least an electric wiring pattern, a lower clad layer, a core layer, and an upper clad layer. The thickness of the entire optoelectric composite substrate increases, and the distance from the reflection mirror provided on the optical waveguide to the optical element increases, so that there is a problem in photoelectric conversion efficiency.
As a method for solving these problems, Patent Document 1 discloses a thin structure in which a wiring pattern is formed on a support, a lower clad layer is laminated on the wiring pattern, and the wiring pattern is embedded to save the base material. A method for manufacturing an optoelectric composite substrate is disclosed.

JP 2010-170150 A

However, since the present inventors have laminated the lower cladding layer on the wiring pattern in the manufacturing method disclosed in Patent Document 1, the unevenness of the wiring pattern affects the surface of the lower cladding layer, and the core pattern formed thereon It has been found that the flatness of the layer is impaired, the light propagation loss is insufficient in terms of reduction and variation, and a resist for electrical wiring must be used, which incurs material costs.
The present invention has been made to solve the above-mentioned problems, and is excellent in the flatness of the core pattern layer, reduces the light propagation loss, reduces the variation in the light propagation loss, and provides a resist for forming an electrical wiring. An object of the present invention is to provide a photoelectric composite substrate having an optical waveguide without using it and a method for manufacturing the same.

As a result of intensive studies, the inventors have embedded the wiring pattern in the opening of the patterned lower clad layer, and the upper surface of the lower clad layer becomes smooth, and the core pattern is formed on the upper surface. The present inventors have found that the problems can be solved and have completed the present invention.
That is, the present invention
1. A method of manufacturing an optoelectric composite substrate having a first lower cladding layer, a wiring pattern embedded therein, a core pattern, and an upper cladding layer, wherein (A) a first lower cladding layer is formed on a support and patterned (B) a step of forming a wiring pattern in the pattern-shaped opening of the first lower cladding layer, (C) a step of forming a core pattern on the first lower cladding layer, and (D) a core pattern A method of manufacturing a photoelectric composite substrate, comprising: a step of forming an upper cladding layer so as to cover the substrate; and (E) a step of removing the support to expose the wiring pattern,
2. The support has a first metal foil on a substrate, and in the step (B), a pattern is formed on the first metal foil using the pattern shape of the first lower cladding layer as a resist to form a wiring pattern. The manufacturing method of the photoelectric composite substrate according to 1 above,
3. The support further has a second metal foil between the substrate and the first metal foil, and the step (E) is (E-1) at the interface between the first metal foil and the second metal foil. The method for producing an optoelectric composite substrate according to 2 above, comprising a step of peeling and removing the second metal foil and the base material; and (E-2) a step of removing the first metal foil.
4). Between the said process (B) and a process (C), (B ') The manufacturing method of the photoelectric composite board | substrate in any one of said 1-3 which has the process of forming a 2nd lower clad layer, and 5. The photoelectric composite substrate manufactured by the manufacturing method according to any one of 1 to 4,
Is to provide.

  According to the method for producing an optoelectric composite substrate of the present invention, an optoelectric composite substrate having an optical waveguide with excellent flatness of the core pattern layer, low optical propagation loss, and less variation in optical propagation loss is obtained. Can do.

It is sectional drawing which shows each process of the manufacturing method of the photoelectric composite board | substrate of this invention. It is sectional drawing which shows each process of the manufacturing method of the photoelectric composite board | substrate of this invention which forms a 2nd lower clad layer.

  The method for producing an optoelectric composite substrate of the present invention is a method for producing an optoelectric composite substrate having a first lower cladding layer, a wiring pattern embedded therein, a core pattern, and an upper clad layer, and (A) a support. Forming and patterning a first lower cladding layer thereon; (B) forming a wiring pattern in a pattern-shaped opening of the first lower cladding layer; and (C) a core on the first lower cladding layer. A step of forming a pattern, (D) a step of forming an upper clad layer so as to cover the core pattern, and (E) a step of removing the support to expose the wiring pattern.

  As shown in FIG. 1, the photoelectric composite substrate 10 manufactured according to the present invention has a core pattern 4 on one surface of the first lower cladding layer 2 in which the wiring pattern 3 is embedded. An upper cladding layer 5 is provided so as to cover the surface.

  As shown in FIG. 2, the photoelectric composite substrate 10 manufactured according to the present invention has a second lower cladding layer 6 between the first lower cladding layer 2 and the wiring pattern 3 and the core pattern 4. Also good. When the second lower cladding layer 6 is not provided, the optoelectric composite substrate 10 is thinned, so that it is easy to bend and warp, and the distance between the core pattern 4 and the optical element mounted on the wiring pattern 3 is reduced. In addition to reducing the optical propagation loss, variations in the optical propagation loss are reduced, contributing to an increase in transfer speed. On the other hand, when the second lower clad layer 6 is provided, the lower clad is ubiquitous on the lower surface of the core pattern 4, so that the light propagation loss is particularly reduced at the portion where the wiring pattern 3 and the core pattern 4 intersect. preferable.

<Process (A)>
In the step (A), the first lower cladding layer 2 is formed on the support 1 and patterned.
(Support)
The support 1 is preferably one that can be easily removed in the step (E). Further, when the support 1 having the first metal foil 1a on the substrate 1c is used, by performing pattern plating using the pattern shape of the first lower clad layer 2 as a resist in the step (B), the wiring pattern 3 is obtained. Is preferably embedded in the first lower cladding layer 2. Further, when a material having the second metal foil 1b is used between the base material 1c and the first metal foil 1a, peeling is performed at the interface between the first metal foil 1a and the second metal foil 1b in the step (E). And since the 2nd metal foil 1b and the base material 1c can be removed easily, it is still more preferable.

(First metal foil)
The first metal foil 1a only needs to function as a seed layer for supplying current when pattern plating is performed using the pattern shape of the first lower cladding layer 2 as a resist in the step (B). Although it does not ask | require, from the point of versatility and a handleability, as a material, copper foil and aluminum foil are preferable, and 1-18 micrometers is preferable as thickness. Furthermore, when the wiring pattern 3 is exposed in the step (E), it is removed by etching or the like, and therefore an ultrathin metal foil of 1 to 5 μm is preferable.
Moreover, it is preferable to provide a release layer for stabilizing the peel strength at the interface at the interface with the substrate 1c or the interface with the second metal foil 1b provided as necessary. Is preferable to have a stable peel strength even when the heating and pressurization are repeated a plurality of times when laminated with an insulating resin. As such a release layer, a metal oxide layer or an organic agent layer disclosed in Japanese Patent Application Laid-Open No. 2003-181970, or a Cu—Ni—Mo alloy disclosed in Japanese Patent Application Laid-Open No. 2003-094553 is used. The thing consisting of is mentioned.

  As for the 1st metal foil 1a, what provided the unevenness | corrugation whose average roughness (Ra) is 0.08-0.6 micrometer in advance on the surface is desirable. Thereby, the adhesiveness with the first lower cladding layer 2 and the resolution of the pattern shape can be improved, which is advantageous for forming a high-density circuit. When Ra is 0.08 μm or more, the adhesion with the first lower cladding layer 2 used as a resist is improved, and when Ra is 0.6 μm or less, the first lower cladding layer 2 is easy to follow and the adhesion is still good. improves. Here, the average roughness (Ra) is an average roughness (Ra) defined by JIS B 0601 (2001), and can be measured using a stylus type surface roughness meter or the like.

(Base material)
The substrate 1c is not particularly limited as long as it has sufficient strength to withstand the lamination of each layer in the steps (A) to (D). For example, a glass epoxy resin substrate, a ceramic substrate, a glass substrate, silicon Examples include a substrate, a plastic substrate, a metal substrate, a substrate with a resin layer, a substrate with a metal layer, a plastic film, a plastic film with a resin layer, and a plastic film with a metal layer.
As the substrate 1c, a substrate having flexibility and toughness, for example, a clad layer forming resin film and a core layer forming resin film, which will be described later, may be used as the substrate.

(Second metal foil)
The second metal foil 1b is not particularly limited in material and thickness as long as it is physically peelable at the interface with the first metal foil 1a. However, in terms of versatility and handleability, the material is copper foil. And aluminum foil are preferable, and the thickness is preferably 1 to 35 μm.

(First lower cladding layer)
The method for forming the first lower clad layer 2 is not particularly limited, and may be a known method. For example, a clad layer forming resin is applied on the support 1 or a clad layer forming resin film is laminated. Can be formed. In the case of application, the method is not limited, and the clad layer forming resin may be applied by a conventional method such as spin coating. Moreover, the resin film for clad layer formation used for a lamination can be easily manufactured, for example by melt | dissolving the said resin in a solvent, apply | coating to a carrier film, and removing a solvent.

  The clad layer-forming resin used in the present invention is not particularly limited as long as it is a resin composition that has a lower refractive index than the core pattern 4 and is cured by light or heat. A thermosetting resin composition or a photosensitive resin composition is used. Can be preferably used. More preferably, the clad layer forming resin is preferably composed of a resin composition containing (A) a base polymer, (B) a photopolymerizable compound, and (C) a photopolymerization initiator. The resin composition used for the resin for forming the cladding layer is different in the first lower cladding layer 2, the second lower cladding layer 6, and the upper cladding layer 5 even if the components contained in the resin composition are the same. The refractive index of the resin composition may be the same or different.

  The (A) base polymer used here is for forming a clad and ensuring the strength of the clad, and is not particularly limited as long as the object can be achieved. Phenoxy resin, epoxy resin, (meta ) Acrylic resin, polycarbonate resin, polyarylate resin, polyether amide, polyether imide, polyether sulfone, etc., or derivatives thereof. These base polymers may be used alone or in combination of two or more. Of the base polymers exemplified above, from the viewpoint of high heat resistance, the main chain preferably has an aromatic skeleton, and particularly preferably a phenoxy resin. From the viewpoint of three-dimensional crosslinking and improving heat resistance, an epoxy resin, particularly an epoxy resin that is solid at room temperature is preferable. Further, compatibility with the photopolymerizable compound (B) described in detail later is important for ensuring the transparency of the resin for forming the cladding layer. From this point, the phenoxy resin and the (meth) acrylic resin are used. Is preferred. Here, (meth) acrylic resin means acrylic resin and methacrylic resin.

  Among phenoxy resins, those containing bisphenol A, bisphenol A type epoxy compounds or derivatives thereof, and bisphenol F, bisphenol F type epoxy compounds or derivatives thereof as a constituent unit of the copolymer component are heat resistant, adhesive and soluble. It is preferable because of its excellent properties. Preferred examples of the bisphenol A or bisphenol A type epoxy compound include tetrabromobisphenol A and tetrabromobisphenol A type epoxy compounds. Moreover, as a derivative of bisphenol F or a bisphenol F-type epoxy compound, tetrabromobisphenol F, a tetrabromobisphenol F-type epoxy compound, etc. are mentioned suitably. Specific examples of the bisphenol A / bisphenol F copolymer type phenoxy resin include “Phenotote YP-70” (trade name) manufactured by Toto Kasei Co., Ltd.

  Examples of the epoxy resin that is solid at room temperature include, for example, “Epototo YD-7020, Epototo YD-7019, Epototo YD-7007” (all trade names) manufactured by Toto Chemical Co., Ltd., and “Epicoat 1010” manufactured by Japan Epoxy Resins Co., Ltd. Bisphenol A type epoxy resin such as “Epicoat 1009, Epicoat 1008” (both trade names).

Next, (B) the photopolymerizable compound is not particularly limited as long as it is polymerized by irradiation with light such as ultraviolet rays, and the compound having an ethylenically unsaturated group in the molecule or two or more in the molecule. Examples thereof include compounds having an epoxy group.
Examples of the compound having an ethylenically unsaturated group in the molecule include (meth) acrylate, vinylidene halide, vinyl ether, vinyl pyridine, vinyl phenol, etc., among these, from the viewpoint of transparency and heat resistance, (Meth) acrylate is preferred.
As the (meth) acrylate, any of monofunctional, bifunctional, trifunctional or higher polyfunctional ones can be used. Here, (meth) acrylate means acrylate and methacrylate.
Examples of the compound having two or more epoxy groups in the molecule include bifunctional or polyfunctional aromatic glycidyl ethers such as bisphenol A type epoxy resins, bifunctional or polyfunctional aliphatic glycidyl ethers such as polyethylene glycol type epoxy resins, and water. Bifunctional alicyclic glycidyl ether such as bisphenol A type epoxy resin, bifunctional aromatic glycidyl ester such as diglycidyl phthalate, bifunctional alicyclic glycidyl ester such as tetrahydrophthalic acid diglycidyl ester, N, N- Bifunctional or polyfunctional aromatic glycidylamine such as diglycidylaniline, bifunctional alicyclic epoxy resin such as alicyclic diepoxycarboxylate, bifunctional heterocyclic epoxy resin, polyfunctional heterocyclic epoxy resin, bifunctional Or polyfunctional silicon-containing epoxy resin It is. These (B) photopolymerizable compounds can be used alone or in combination of two or more.

  Next, the photopolymerization initiator of component (C) is not particularly limited. For example, as an initiator when an epoxy compound is used as component (B), aryldiazonium salt, diaryliodonium salt, triarylsulfonium salt, triallyl Examples include selenonium salts, dialkylphenazylsulfonium salts, dialkyl-4-hydroxyphenylsulfonium salts, and sulfonate esters. When a luminescent photopolymerization initiator is used, a luminescent cladding layer can be obtained.

Moreover, as an initiator in the case of using a compound having an ethylenically unsaturated group in the molecule as the component (B), aromatic ketones such as benzophenone, quinones such as 2-ethylanthraquinone, benzoin ethers such as benzoin methyl ether Compounds, benzoin compounds such as benzoin, benzyl derivatives such as benzyldimethyl ketal, 2,4,5-triarylimidazole dimers such as 2- (o-chlorophenyl) -4,5-diphenylimidazole dimer, 2- Benzimidazoles such as mercaptobenzimidazole, phosphine oxides such as bis (2,4,6-trimethylbenzoyl) phenylphosphine oxide, acridine derivatives such as 9-phenylacridine, N-phenylglycine, N-phenylglycine derivatives , Coumarin compound And the like. Moreover, you may combine a thioxanthone type compound and a tertiary amine compound like the combination of diethyl thioxanthone and dimethylaminobenzoic acid. Of the above compounds, aromatic ketones and phosphine oxides are preferable from the viewpoint of improving the transparency of the cladding layer.
These (C) photopolymerization initiators can be used alone or in combination of two or more.

(A) It is preferable that the compounding quantity of a base polymer shall be 5-80 mass% with respect to the total amount of (A) component and (B) component. Moreover, it is preferable that the compounding quantity of (B) photopolymerizable compound shall be 95-20 mass% with respect to the total amount of (A) and (B) component.
As a blending amount of the component (A) and the component (B), when the component (A) is 5% by mass or more and the component (B) is 95% by mass or less, the resin composition is easily formed into a film. Can do. On the other hand, when the component (A) is 80% by mass or less and the component (B) is 20% by mass or more, the (A) base polymer can be easily entangled and cured, and the pattern formability is improved. And the photocuring reaction proceeds sufficiently. From the above viewpoint, the blending amount of the component (A) and the component (B) is more preferably 10 to 85% by mass of the component (A) and 90 to 15% by mass of the component (B), and 20 to 70 of the component (A). More preferably, the content is 80% by mass and the component (B) is 80 to 30% by mass.
(C) It is preferable that the compounding quantity of a photoinitiator shall be 0.1-10 mass parts with respect to 100 mass parts of total amounts of (A) component and (B) component. When the blending amount is 0.1 parts by mass or more, the photosensitivity is sufficient, while when it is 10 parts by mass or less, the absorption in the surface layer of the photosensitive resin composition does not increase during exposure, and the internal Is sufficiently cured. Furthermore, when used as a core layer to be described later, it is preferable that the light propagation loss does not increase due to the light absorption effect of the polymerization initiator itself. From the above viewpoint, the blending amount of the (C) photopolymerization initiator is more preferably 0.2 to 5 parts by mass.
In addition, if necessary, in the cladding layer forming resin, an antioxidant, an anti-yellowing agent, an ultraviolet absorber, a visible light absorber, a colorant, a plasticizer, a stabilizer, a filler, etc. You may add what is called an additive in the ratio which does not have a bad influence on the effect of this invention. Further, if the additive has luminescent properties, a luminescent cladding layer can also be obtained.

The carrier film used in the production process of the resin film for forming the clad layer is not particularly limited in terms of material, but for example, an FR-4 substrate, a polyimide substrate, a semiconductor substrate, a silicon substrate, a glass substrate, or the like is used. It may be a flexible material with flexibility or a non-flexible hard material.
The material of the material having flexibility is not particularly limited, but from the viewpoint of having flexibility and toughness, polyesters such as polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polyethylene, polypropylene, polyamide, polycarbonate, Preferable examples include polyphenylene ether, polyether sulfide, polyarylate, liquid crystal polymer, polysulfone, polyether sulfone, polyether ether ketone, polyether imide, polyamide imide, and polyimide.
The thickness of the carrier film may be appropriately changed depending on the intended flexibility, but is preferably 5 to 250 μm. If it is 5 μm or more, there is an advantage that toughness is easily obtained, and if it is 250 μm or less, sufficient flexibility can be obtained.
The solvent used here is not particularly limited as long as it can dissolve the resin. For example, acetone, methyl ethyl ketone, methyl cellosolve, ethyl cellosolve, toluene, N, N-dimethylacetamide, propylene glycol monomethyl ether, propylene glycol A solvent such as monomethyl ether acetate, cyclohexanone, N-methyl-2-pyrrolidone, or a mixed solvent thereof can be used. The solid content concentration in the resin solution is preferably about 30 to 80% by mass.

  Regarding the thickness of the cladding layer, the thickness after drying is preferably in the range of 5 to 500 μm. When the thickness is 5 μm or more, a thickness necessary for light confinement can be secured, and when the thickness is 500 μm or less, the film thickness can be easily controlled uniformly. From the above viewpoint, the thickness of the cladding layer is more preferably in the range of 10 to 100 μm.

  The thickness of the clad layer may be the same or different in the first lower clad layer 2, the second lower clad layer 6, and the upper clad layer 5. The thickness of the layer 5 is preferably larger than the thickness of the core pattern 4.

(Patterning method)
The patterning method for the first lower cladding layer 2 is usually performed by pattern-exposing the first lower cladding layer 2 and then developing and removing the uncured portion.
The exposure method is not particularly limited, and may be either a negative type in which an exposed portion remains as a pattern or a positive type in which an unexposed portion remains as a pattern, and may be determined depending on the properties of the clad layer forming resin to be used.

<Process (B)>
In the step (B), the wiring pattern 3 is formed in the pattern-shaped opening of the first lower cladding layer 2.
As a method for forming the wiring pattern 3, as described above, the support 1 having the first metal foil 1a on the substrate 1c is used, and pattern plating is performed using the pattern shape of the first lower cladding layer 2 as a resist. The method used is preferably used. As the pattern plating, electroplating using copper sulfate is preferably used.
Through the step (A) and the step (B), as shown in FIG. 1 and FIG. 2, the wiring pattern 3 is embedded in the opening of the first lower cladding layer 2, and the first lower cladding layer in which the wiring pattern 3 is embedded. Since the surface of 2 is smooth, the core pattern 4 formed in the step (C) described later is excellent in flatness.

<Process (B ')>
The manufacturing method of the present invention further includes a step (B ′) of forming the second lower cladding layer 6 between the step (B) and the step (C), and on the formed second lower cladding layer 6. You may implement a process (C)-a process (E).
The method for forming the second lower cladding layer 6 is the same as the method for forming the first lower cladding layer 2 described above. When the second lower cladding layer 6 is provided, the lower cladding layer 6 is ubiquitous on the lower surface of the core pattern 4 as described above, which is preferable from the viewpoint of reducing optical propagation loss.

<Process (C)>
In the step (C), the core pattern 4 is formed on the first lower cladding layer 2.
The method for forming the core pattern 4 is not particularly limited, and may be a known method. For example, a core layer having a higher refractive index than these layers is formed on the first lower cladding layer 2 or the second lower cladding layer 6. After the formation, it can be formed in the same manner as the above-described patterning method.
The first lower clad layer 2 or the second lower clad layer 6 in contact with the core pattern 4 is preferably flat without a step on the surface on the core pattern 4 stacking side, from the viewpoint of adhesion to the core pattern 4. Moreover, the surface flatness of the 1st lower clad layer 2 or the 2nd lower clad layer 6 is securable by using the resin film for clad layer formation.

The method of forming the core layer laminated on the first lower clad layer 2 or the second lower clad layer 6 is not particularly limited. For example, the core layer is formed by applying a core layer forming resin or laminating a core layer forming resin film. Just do it.
As the resin for forming the core layer, a resin composition that is designed so that the core layer has a higher refractive index than that of the clad layer and can form the core layer with actinic rays can be used, and depending on the emission wavelength from the lower clad A photosensitive resin composition to be cured or a core layer forming resin containing a photopolymerization initiator that initiates polymerization by the emission wavelength from the lower clad is suitable. Specifically, it is preferable to use the same resin as that used for the cladding layer forming resin.
In the case of application, the method is not limited, and the resin may be applied by a conventional method as described above.

Hereinafter, the resin film for core layer formation used for lamination is explained in full detail.
The resin film for forming a core layer can be easily produced by dissolving the resin composition in a solvent, applying the resin composition on a carrier film, and removing the solvent. The solvent used here is not particularly limited as long as it can dissolve the resin composition. For example, acetone, methyl ethyl ketone, methyl cellosolve, ethyl cellosolve, toluene, N, N-dimethylformamide, N, N-dimethyl A solvent such as acetamide, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, cyclohexanone, N-methyl-2-pyrrolidone, or a mixed solvent thereof can be used. It is preferable that the solid content concentration in the resin solution is usually 30 to 80% by mass.

  The thickness of the resin film for forming the core layer is not particularly limited, and the thickness of the core layer after drying is usually adjusted to be 10 to 100 μm. If the thickness of the film is 10 μm or more, there is an advantage that the alignment tolerance can be increased in the coupling with the light emitting / receiving element or the optical fiber after the optical waveguide is formed. In coupling with an element or an optical fiber, there is an advantage that coupling efficiency is improved. From the above viewpoint, the thickness of the film is preferably in the range of 30 to 70 μm.

The carrier film used in the production process of the core layer forming resin is a carrier film that supports the core layer forming resin, and the material thereof is not particularly limited, but the film material described above in the item of (carrier film) is preferable. It is mentioned in. Moreover, polyesters, such as a polyethylene terephthalate, a polypropylene, polyethylene, etc. are mentioned suitably from the viewpoint that it is easy to peel resin for core layer formation, and has heat resistance and solvent resistance.
The thickness of the carrier film is preferably 5 to 50 μm. When it is 5 μm or more, there is an advantage that the strength as a carrier film is easily obtained, and when it is 50 μm or less, there is an advantage that a gap with the mask at the time of pattern formation becomes small and a finer pattern can be formed. From the above viewpoint, the thickness of the carrier film is more preferably in the range of 10 to 40 μm, and particularly preferably 15 to 30 μm.

  In the manufacturing method of the present invention, a photoelectric composite substrate having a multilayer structure may be manufactured by laminating a plurality of core layers and cladding layers.

<Process (D)>
In the step (D), the upper clad layer 5 is formed so as to cover the core pattern 4.
The method for forming the upper clad layer 5 is not particularly limited, and for example, it may be formed by the same method as that for the first lower clad layer 2 before patterning.

<Process (E)>
In the step (E), the support 1 is removed and the wiring pattern 3 is exposed.
When the support body 1 has the 1st metal foil 1a, the 2nd metal foil 1b, and the base material 1c in this order, and a process (E) has the following process (E-1) and a process (E-2), This is preferable because the wiring pattern 3 can be efficiently exposed and problems such as the wiring pattern 3 falling off hardly occur.

<Process (E-1)>
At a process (E-1), it peels in the interface of the 1st metal foil 1a and the 2nd metal foil 1b, and removes the 2nd metal foil 1b and the base material 1c.
By adjusting the peel strength at the interface between the first metal foil 1a and the second metal foil 1b and physically peeling at the interface, the peeling work can be easily performed.

<Process (E-2)>
In the step (E-2), the first metal foil 1a is removed.
Etching is preferably used as a method for removing the first metal foil 1a. By removing the first metal foil 1a, the wiring pattern 3 is exposed, and various components can be mounted thereon.

EXAMPLES The present invention will be described more specifically with reference to examples. However, the present invention is not limited to these examples.
Example 1
[Production of support]
First copper foil (thickness: 3 μm), second copper foil (thickness: 9 μm) and base material (FR-4, manufactured by Hitachi Chemical Co., Ltd., trade name: MCL-E-679F (b), thickness : 0.6 mm) was prepared in this order. On the surface of the first copper foil, irregularities having an average roughness (Ra) of 0.08 to 0.6 [mu] m are provided in advance, and Cu-Ni-Mo can be physically separated from the second copper foil. A release layer made of an alloy was formed.
The base material, the first copper foil, and the second copper foil were obtained by superimposing two metal foils on the base material, and heating and pressurizing them by hot pressing to laminate and integrate them to obtain a support 1.

[Preparation of resin film for forming clad layer]
(A) As a base polymer, 48 parts by mass of a phenoxy resin (trade name: Phenototo YP-70, manufactured by Toto Kasei Co., Ltd.), (b) As a photopolymerizable compound, an alicyclic diepoxycarboxylate (trade name: KRM) -2110, molecular weight: 252, manufactured by Asahi Denka Kogyo Co., Ltd.) 50 parts by mass, (c) As a photopolymerization initiator, triphenylsulfonium hexafluoroantimonate salt (trade name: SP-170, manufactured by Asahi Denka Kogyo Co., Ltd.) 2 parts by mass, 40 parts by mass of propylene glycol monomethyl ether acetate as an organic solvent are weighed in a wide-mouthed plastic bottle, and stirred for 6 hours under the conditions of a temperature of 25 ° C. and a rotation speed of 400 rpm using a mechanical stirrer, shaft and propeller. A clad layer forming resin varnish A was prepared. After that, using a polyflon filter (trade name: PF020, manufactured by Advantech Toyo Co., Ltd.) with a pore diameter of 2 μm, the mixture is filtered under pressure at a temperature of 25 ° C. and a pressure of 0.4 MPa, and further the degree of vacuum using a vacuum pump and a bell jar Degassed under reduced pressure for 15 minutes under the condition of 50 mmHg.
The coating varnish A for clad layer formation obtained above was applied to a corona-treated surface of a polyamide film (trade name “Mictron”, thickness 12 μm, manufactured by Toray Industries, Inc.) (Multicoater TM-MC, Inc. The resin film for clad layer formation was obtained by carrying out solvent drying at 80 ° C. for 10 minutes and then at 100 ° C. for 10 minutes. At this time, the thickness of the resin layer can be arbitrarily adjusted by adjusting the gap of the coating machine, and here, the thickness after curing was adjusted to be 70 μm. This obtained the resin film for upper clad layer 5 formation.
Coating the resin varnish A for forming a clad layer obtained above on a release polyethylene terephthalate (hereinafter referred to as “PET”) film (trade name: Purex A31, Teijin DuPont Films, Inc., thickness: 25 μm) The resin film for forming the first lower clad layer 2 and the second lower clad are applied by using a coating machine (Multicoater TM-MC, manufactured by Hirano Techseed Co., Ltd.), dried at 80 ° C. for 10 minutes and then at 100 ° C. for 10 minutes. A resin film for forming layer 6 was obtained. At this time, the thickness of the resin layer can be arbitrarily adjusted by adjusting the gap of the coating machine. Here, the thickness after curing was adjusted to 15 μm. Thus, a resin film for forming the first lower cladding layer 2 and a resin film for forming the second lower cladding layer 6 were obtained.

[Preparation of resin film for core layer formation]
(A) As a base polymer, 26 parts by mass of phenoxy resin (trade name: Phenototo YP-70, manufactured by Toto Kasei Co., Ltd.), (b) 9,9-bis [4- (2-acryloyl) as a photopolymerizable compound Oxyethoxy) phenyl] fluorene (trade name: A-BPEF, Shin-Nakamura Chemical Co., Ltd.) 36 parts by mass, and bisphenol A type epoxy acrylate (trade name: EA-1020, Shin-Nakamura Chemical Co., Ltd.) 36 mass Parts, (c) 1 part by weight of bis (2,4,6-trimethylbenzoyl) phenylphosphine oxide (trade name: Irgacure 819, manufactured by Ciba Specialty Chemicals) as a photopolymerization initiator, and 1- [4 -(2-Hydroxyethoxy) phenyl] -2-hydroxy-2-methyl-1-propan-1-one (trade name: yl Cure 2959, manufactured by Ciba Specialty Chemicals Co., Ltd.) A resin varnish B for forming a core layer was prepared by the same method and conditions as described above except that 1 part by mass and 40 parts by mass of propylene glycol monomethyl ether acetate as an organic solvent were used. . Thereafter, pressure filtration and degassing under reduced pressure were performed in the same manner and conditions as described above.
The core layer-forming resin varnish B obtained above is applied and dried in the same manner as described above on the non-treated surface of a PET film (trade name: Cosmo Shine A1517, manufactured by Toyobo Co., Ltd., thickness: 16 μm). Next, a release PET film (trade name: PUREX A31, Teijin DuPont Film Co., Ltd., thickness: 25 μm) is attached as a protective film so that the release surface is on the resin side, and a resin film for forming a core layer is attached. Obtained. Here, the gap of the coating machine was adjusted so that the film thickness after curing was 50 μm.

[Step (A)]
A roll laminator (HLM-1500, manufactured by Hitachi Chemical Technoplant Co., Ltd.) is used for the resin surface of the resin film for forming the first lower cladding layer 2 obtained above on the first copper foil of the support 1 obtained above. Lamination was performed under the conditions of a pressure of 0.4 MPa, a temperature of 50 ° C., and a laminating speed of 0.2 m / min. Next, through a negative photomask with a width of 50 μm, ultraviolet rays (wavelength 365 nm) were applied to 0.8 J from the resin film side for forming the first lower cladding layer 2 using an ultraviolet exposure machine (EXM-1172, manufactured by Oak Manufacturing Co., Ltd.). / Cm ² and then post-exposure heating at 80 ° C. for 12 minutes. Thereafter, the PET film which is the carrier film of the resin film for forming the first lower cladding layer 2 was peeled off, and the pattern shape of the first lower cladding layer 2 was developed using a developer (cyclohexanone). Then, it wash | cleaned using the washing | cleaning liquid (isopropanol), and heat-dried at 100 degreeC for 10 minute (s).

[Step (B)]
The pattern shape of the first lower cladding layer 2 remaining on the first copper foil is used as a resist, and a copper pattern is used to form a wiring pattern 3 having a thickness of 15 μm in the pattern-shaped opening, and the first lower cladding layer 2 and the wiring pattern 3 were smoothed.

[Step (C)]
Using a roll laminator (HLM-1500, manufactured by Hitachi Chemical Technoplant Co., Ltd.), the resin surface of the core layer forming resin film is placed on the first lower clad layer 2 in which the wiring pattern 3 is embedded, pressure 0.4 MPa, temperature 50 ° C. Lamination was performed at a lamination speed of 0.2 m / min. Next, through a negative photomask with a width of 50 μm, ultraviolet rays (wavelength 365 nm) are irradiated with 0.8 J / cm ² from the core layer forming resin film side by an ultraviolet exposure machine (EXM-1172, manufactured by Oak Manufacturing Co., Ltd.). Subsequently, post-exposure heating was performed at 80 ° C. for 12 minutes. Thereafter, the PET film which is the carrier film of the resin film for forming the core layer is peeled off, and the core pattern 4 is formed using a developer (propylene glycol monomethyl ether acetate / N, N-dimethylacetamide = 7/3, mass ratio). Developed. Then, it wash | cleaned using the washing | cleaning liquid (isopropanol), and heat-dried at 100 degreeC for 10 minute (s).

[Step (D)]
The resin surface of the resin film for forming the upper cladding layer 5 is formed on the core pattern 4 using a roll laminator (HLM-1500, manufactured by Hitachi Chemical Technoplant Co., Ltd.), pressure 0.4 MPa, temperature 50 ° C., laminating speed 0.2 m / Lamination was performed under the condition of min. Next, ultraviolet rays (wavelength 365 nm) are irradiated with 3.0 J / cm ² with the above ultraviolet exposure machine to expose the entire upper cladding layer 5 to photocuring, and then heat-treated at 160 ° C. for 1 hour, The clad layer 5 was cured. Thereafter, the polyamide film which is the carrier film of the resin film for forming the upper clad layer 5 was peeled off.

[Step (E-1)]
The support 1 was physically peeled off at the interface between the first copper foil and the second copper foil, and the second copper foil and the substrate were removed.

[Step (E-2)]
The first copper foil was removed by etching to produce a photoelectric composite substrate.
The in-plane thickness variation of the obtained first lower cladding layer was 0.3 μm.

Example 2
After the step (B), the following step (B ′) is performed, and the steps (C) to (E-2) are performed on the formed second lower cladding layer 6 in the same manner as in the first example. Thus, a photoelectric composite substrate was produced.
[Step (B ′)]
A roll laminator (manufactured by Hitachi Chemical Technoplant Co., Ltd., HLM-1500) is applied to the resin surface of the resin film for forming the second lower cladding layer 6 obtained above on the first lower cladding layer 2 in which the wiring pattern 3 is embedded. Lamination was performed under the conditions of a working pressure of 0.4 MPa, a temperature of 50 ° C., and a laminating speed of 0.2 m / min.
When the optical loss at a wavelength of 850 nm was measured in a core pattern having five portions where the core pattern and the electric wiring pattern of the obtained optical waveguide intersected, it was 0.9 dB / 10 cm.
The difference between the total thickness of the second lower cladding layer formed on the electrode wiring pattern and the electrical wiring pattern and the total thickness of the first lower cladding layer and the second lower cladding layer in a portion where there is no electrical wiring pattern is 0.4 μm. Met.

Comparative Example 1
In Example 1, after forming an electrical wiring having the same pattern as Example 1 using a dry film resist (trade name: Photec, manufactured by Hitachi Chemical Co., Ltd.), the dry film resist was peeled off and obtained above. Using a roll laminator (HLM-1500, manufactured by Hitachi Chemical Technoplant Co., Ltd.) on the wiring pattern, the resin surface of the 30 μm lower clad layer forming film is pressure 0.4 MPa, temperature 50 ° C., laminating speed 0.2 m / min. Lamination was performed under the following conditions. Thereafter, a core pattern and an upper clad layer were formed in the same manner as in Example 1.
Similarly to Example 2, when the optical loss at a wavelength of 850 nm was measured in a core pattern having five portions where the core pattern of the obtained optical waveguide and the electric wiring pattern intersected, it was 1.5 dB / 10 cm.
The difference between the total thickness of the lower clad layer formed on the electrode wiring pattern and the electric wiring pattern and the thickness of the lower clad layer in the portion without the electric wiring pattern was 3.0 μm.

  The optoelectric composite substrate obtained by the production method of the present invention can be applied to various fields such as various optical devices and optical interconnections.

DESCRIPTION OF SYMBOLS 1 Support 1a 1st metal foil 1b 2nd metal foil 1c Base material 2 1st lower clad layer 3 Wiring pattern 4 Core pattern 5 Upper clad layer 6 2nd lower clad layer 10 Photoelectric composite board

Claims (5)

  A method of manufacturing an optoelectric composite substrate having a first lower cladding layer, a wiring pattern embedded therein, a core pattern, and an upper cladding layer, wherein (A) a first lower cladding layer is formed on a support and patterned (B) a step of forming a wiring pattern in the pattern-shaped opening of the first lower cladding layer, (C) a step of forming a core pattern on the first lower cladding layer, and (D) a core pattern A method for manufacturing an optoelectric composite substrate, comprising: forming an upper clad layer so as to cover the substrate; and (E) removing the support to expose the wiring pattern.   The support has a first metal foil on a substrate, and in the step (B), a pattern is formed on the first metal foil using the pattern shape of the first lower cladding layer as a resist to form a wiring pattern. The manufacturing method of the photoelectric composite board | substrate of Claim 1 formed.   The support further has a second metal foil between the substrate and the first metal foil, and the step (E) is (E-1) at the interface between the first metal foil and the second metal foil. The manufacturing method of the photoelectric composite board | substrate of Claim 2 which has the process of peeling and removing a 2nd metal foil and a base material, and the process of (E-2) removing a 1st metal foil.   The method for manufacturing an optoelectric composite substrate according to claim 1, further comprising: (B ′) forming a second lower cladding layer between the step (B) and the step (C).   An optoelectric composite substrate manufactured by the manufacturing method according to claim 1.

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