JP5446543B2 - Wiring board manufacturing method - Google Patents

Description

  The present invention relates to a method of manufacturing a wiring board that can be processed while maintaining dimensional stability up to the formation of wiring on surfaces laminated by back-to-back, and that can ensure high working efficiency.

Conventionally, in the method of manufacturing a wiring board, for example, in a single-sided wiring board, the wiring density is asymmetric on both sides of the substrate, and in some cases, a large warp may occur during the manufacturing process.
In order to improve this, measures such as providing a reinforcing plate on the back side of the substrate were taken. However, thin flexible substrates with a base material thickness of 25 μm or less had problems such as wrinkles being easily generated when the reinforcing plate was installed. It was.
Also, a back-to-back method in which two substrates are bonded together as a useful method for ensuring warp suppression, dimensional stability of the substrates, and high work efficiency, and wiring is formed as one apparently thick substrate (Patent Document) 1 and 2) are useful. For example, as described in Patent Document 1, a method of sandwiching two copper foils with a prepreg or a dry film, or as described in Patent Document 2, a method using a release layer on both sides of an adhesive layer. is there.
However, in the back-to-back method described above, it is necessary to form the wiring after separating the substrates on the stacked surfaces, and the stress accumulated in the substrate during the separation is released, so that when the wiring of the back-to-back separation surface is formed In addition, there is a problem that the alignment accuracy with the previously formed wiring is lowered. Furthermore, if wiring (such as an optical waveguide) having a high thermal contraction rate is formed on the separation surface after back-to-back separation, warping occurs, making it difficult to flow through the production line.

JP-A-6-209150 JP 2006-49660 A

  An object of this invention is to provide the manufacturing method of the wiring board which can be processed, maintaining dimensional stability until wiring formation of a back-to-back separation surface, and can ensure high working efficiency.

  As a result of intensive studies, the inventors of the present invention have a process of making two substrates back to back to form a single substrate, a step of forming wiring on both surfaces of the single substrate, and two on the wiring surface. A step of laminating each support, a step of separating two substrates while being fixed to the support, a step of forming wiring on a separation surface of the two substrates, and after forming a wiring on the separation surface, The inventors have found that the above object can be achieved by performing a step of separating the support, and have completed the present invention.

That is, the present invention
(1) Step A in which two substrates are back to back to form a single substrate, Step B in which wiring is formed on both surfaces of the one substrate, and Step C in which two supports are laminated on the wiring surface. And a method of manufacturing a wiring board, comprising a step D of separating two substrates while being fixed to the support,
(2) The method for manufacturing a wiring board according to (1), further comprising a step E of forming a wiring on a separation surface of the two substrates after the step A.
(3) The method for manufacturing a wiring board according to (2), further comprising a step F of separating the support after the step E.
(4) After the step B, after the step E, before the step F, or at least after the step F, the step G in which a coating for protecting the wiring is applied to the wiring. A method of manufacturing a wiring board according to any one of (1) to (3),
(5) The method for manufacturing a wiring board according to any one of (1) to (4), wherein in step A, only the frame portion of the substrate is back-to-back with each other using an adhesive to form one substrate.
(6) The wiring board manufacturing method according to any one of (1) to (5), wherein the wiring includes an optical waveguide and an electrical wiring.
(7) The wiring is a single-layer electrical wiring or a multilayer electrical wiring in which a step of forming an electrical wiring on the substrate is repeated one or more times after a substrate is laminated on the surface on which the electrical wiring is formed. A method for manufacturing a wiring board according to any one of (1) to (5),
(8) The method for manufacturing a wiring board according to any one of (1) to (5), wherein the wiring is one or more optical waveguides,
(9) The method for manufacturing a wiring board according to (6) or (7), wherein the electrical wiring is formed using at least one of a subtractive method, an additive method, and a semi-additive method,
(10) The method for manufacturing a wiring board according to (6) or (8), wherein the optical waveguide is an optical waveguide with a mirror.

  According to the method for manufacturing a wiring board of the present invention, the wiring board can be processed while maintaining dimensional stability until wiring formation of the surfaces laminated by back-to-back, and high work efficiency can be ensured until product completion. Can be manufactured.

It is a figure explaining one embodiment of the manufacturing method of the wiring board of this invention. It is a figure explaining another embodiment of the manufacturing method of the wiring board of this invention. It is a figure explaining another embodiment of the manufacturing method of the wiring board of this invention. It is a figure explaining another embodiment of the manufacturing method of the wiring board of this invention.

  As shown in FIG. 1 (l), for example, the wiring board manufactured according to the present invention has an optical structure in which a lower clad layer 6, a core pattern 7 and an upper clad layer 8 are sequentially laminated on an electric wiring board 7. These are a laminate in which the waveguide 10 is laminated, a multilayer board thereof (see FIG. 2), a substrate in which electrical wiring is formed on both sides as shown in FIG. 4D, and the multilayer board.

(Back-to-back method of two substrates)
As a back-to-back method for two substrates, the back-to-back method is not particularly limited as long as one substrate 2 can be formed by back-to-back. For example, a substrate using a removable adhesive 3 is used. The cores may be formed by sticking one to the other, or as shown in FIG. 4 (a), by placing the release sheet 14 on the inner side of the product workpiece on both sides of the adhesive 3 or the support 4 coated with adhesive. Adhesive 2 and two substrates 1 are laminated on the frame portion via adhesive 3 to form substrate 2, or varnish or film adhesive 3 as shown in FIG. This is a method in which only the frame portion of the substrate 1 is applied, the two substrates 1 are back to back, and the product central portion is the non-bonded portion. For back-to-back, hand bonding, press, vacuum press, roll laminator, vacuum laminator and the like are preferable, and when there is a heating step in the subsequent step, it is more preferable to use a vacuum press or a vacuum laminator. Moreover, when performing wiring formation with the back-to-back substrates 2 in a roll, it is preferable to use a roll laminator.

(Lamination method of support)
In the step C of laminating the support 4 on the front and back of the back-to-back substrates, there is no particular limitation on the laminating method unless peeling occurs between the two substrates 1 that separate back-to-back and the support 4. However, for example, the substrate and the support 4 are affixed to the entire surface by using the releasable adhesive 3, or the substrate and the support 4 are partially attached inside the product workpiece as shown in FIG. At least one of the substrate 2 and the support 4 with the adhesive 3 in the form of the varnish or film shown in the column of (Method of Backing Two Substrates) The substrate 2 and the support 4 can be laminated by applying only to the frame portion of the plate. As the laminating method, hand bonding, press, vacuum press, roll laminator, vacuum laminator and the like are preferable, and when there is a heating step in the subsequent step, it is more preferable to use a vacuum press or a vacuum laminator.

(Separation between two substrates and between support and substrate)
Among the methods mentioned in the back-to-back method for the two substrates 1, the two substrates 1 are back-to-back using the re-peelable adhesive 3, and the re-peelable adhesive is also laminated on the support 4. 3 is used, the adhesive strength of the adhesive 3 used for laminating the support 4 is stronger than the adhesive strength of the adhesive 3 used in the back-to-back method of the two substrates 1. It becomes easy to sequentially perform the separation between the substrates 1 and the substrate 1 and the support 4.
Further, among the methods mentioned in the back-to-back method of the substrate 1, only the frame portion is back-to-back using the adhesive 3, and the support 4 is laminated using only the frame portion adhesive. In the case of performing the above, it is preferable that the size of the non-adhesive portion of the two substrates 1 is larger than the size of the non-adhesive portion when the support 4 is laminated. This is because when the back-to-back substrates 2 are separated, the non-bonded portion is cut between the substrates 1 and the bonded portion is cut between the substrate 2 and the support 4 so that the support 4 and the substrate 1 are stacked. This is because it is possible to easily separate the two.

Hereinafter, each component of the wiring board will be described.
〔substrate〕
Although it does not restrict | limit especially as a kind of board | substrate 1, For example, FR-4 board | substrate, a buildup board | substrate, a polyimide board | substrate, a semiconductor substrate, a silicon substrate, a glass substrate etc. can be used, and those single side | surface or both surfaces It may be a laminated board in which a metal foil is installed. Further, it may be a flexible flexible material or a non-flexible hard material.
Further, by using a film as the substrate 1, flexibility and toughness can be imparted to the substrate 1 and the optical waveguide 10. The material of the film is not particularly limited, but from the viewpoint of flexibility and toughness, polyesters such as polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polyethylene, polypropylene, polyamide, polycarbonate, polyphenylene ether, polyether Preferable examples include films of sulfide, polyarylate, liquid crystal polymer, polysulfone, polyethersulfone, polyetheretherketone, polyetherimide, polyamideimide, and polyimide.
The thickness of the 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 can be easily obtained, and if it is 250 μm or less, sufficient flexibility can be obtained.

[Support to be laminated with substrate 1]
Although it does not restrict | limit especially as a kind of support body 4, For example, a metal plate, FR-4 board | substrate, a polyimide board | substrate, a semiconductor substrate, a silicon substrate, a glass substrate etc. can be used, Those single side | surface or both surfaces Or a laminated plate of the support listed above. Further, it may be a flexible flexible material or a non-flexible hard material.
Further, when a rigid and thick non-flexible support is used as the support 4, a substrate with good dimensional stability and less warping and distortion can be formed. The thickness of the support 4 may be appropriately changed depending on the intended amount of warpage and the product thickness that can be produced, but is preferably 5 μm to 1 cm, and sufficient handling properties are obtained when the thickness is 50 μm to 1 mm. It is further preferable.

[Support as core of back-to-back substrates]
When the support 4 is used between the substrates 1 in the back-to-back method of the two substrates 1, the type of the support 4 is not particularly limited. For example, a metal plate, an FR-4 substrate, a polyimide substrate, A semiconductor substrate, a silicon substrate, a glass substrate, or the like can be used, and may be a laminated plate in which a metal layer is provided on one side or both sides thereof, or a laminated plate of the substrates listed above. Further, an adhesive that becomes a rigid substance by curing may be used. Preferable examples of adhesives that exhibit rigidity upon curing include prepregs, build-up materials, and thermosetting adhesives. The thickness of the support may be appropriately changed depending on the thickness of the release material to be used and the required dimensional stability, but it is preferably 5 μm to 1 cm, and sufficient handling properties can be obtained when the thickness is 50 μm to 1 mm. To more preferable.

〔adhesive〕
Although it does not specifically limit for the adhesive agent 3, A double-sided tape, a hot-melt-adhesive agent, UV curable adhesive agent, a thermosetting adhesive agent, a prepreg, a buildup material, a heat resistant adhesive agent etc. are mentioned suitably. When a rigid and non-flexible adhesive 3 is required, the adhesive 3 is bonded to the front and back of the substrate listed in the column of the material of the support 4, and the support 4 as a core is held at the center. The adhesive 3 may be used.
Moreover, when it has the process of using a vacuum press or a vacuum lamination, it is preferable that it is the heat resistant adhesive agent 3, and a prepreg, a buildup material, a heat resistant adhesive agent etc. are mentioned suitably. In the optical waveguide 10, an adhesive 3 having a high transmittance is required for adhesion of a portion through which an optical signal is transmitted. The material of the adhesive 3 is not particularly limited, but is described in (PCT / JP2008 / 05465). More preferably, an adhesive is used. The thickness of the adhesive 3 should just be the thickness of the range which does not affect the process after bonding, and it is more preferable that it is 25 micrometers or less.
Moreover, when performing wiring formation with the board | substrate 2 being a roll, it is preferable to use the adhesive agent 3 which has sufficient softness | flexibility after hardening.

[Release sheet]
The type of the release sheet 14 is not particularly limited. For example, a release sheet for press, a releasable resin or adhesive, a UV or heat releasable resin, and the like can be used. .
Further, the film-like material for the release sheet 14 is not particularly limited, but is not limited to copper foil, silver foil, gold foil, polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, or other polyester, polyethylene, polypropylene, polyamide, polycarbonate, polyphenylene ether. Preferable examples include polyether sulfide, polyarylate, liquid crystal polymer, polysulfone, polyether sulfone, polyether ether ketone, polyether imide, polyamide imide, and polyimide. From the viewpoint of heat resistance and releasability from the substrate, copper foil, polyimide film, and aramid film are more preferable.
The thickness of the film may be appropriately changed depending on the intended flatness and embedding property of the electric wiring 5, but is preferably 5 to 250 μm.

〔wiring〕
The wiring refers to an electric wiring 5 patterned with a conductor such as a metal layer, an optical wiring such as an optical waveguide 10, each multilayer board, and a multilayer board in which each is combined.
Specifically, (i) a wiring composed of an optical waveguide and electrical wiring, (ii) a single layer of electrical wiring, or a process of forming an electrical wiring on the substrate after laminating a substrate on the surface on which the electrical wiring is formed There are multilayer electrical wirings in which the above is repeated once or more, and (iii) wirings that are one or more optical waveguides.

[Method of forming electrical wiring]
As a method for forming the electric wiring 5, a metal layer is formed on the surface on which the electric wiring 5 is formed, an etching resist is further formed, and unnecessary portions of the metal layer are removed by etching (subtract method), and a plating resist is formed. A method of forming the electric wiring 5 by plating only on a necessary portion of the surface on which the electric wiring 5 is to be formed (additive method), forming a thin metal layer (seed layer) on the surface on which the electric wiring 5 is to be formed, There is a method (semi-additive method) in which a plating resist is formed, and then an electric wiring 5 necessary for electroplating is formed, and then a thin metal layer is removed by etching.
Any method may be used as the method for forming the electrical wiring 5, but the semi-additive method is more preferable in order to form fine wiring with (electric wiring width) ≦ 20 μm.
The etching resist or plating resist used for forming the electric wiring can be either a positive type or a negative type. However, the positive type resist is more preferable because fine wiring can be easily formed.

[Formation of seed layer in semi-additive process]
In the case of forming the electric wiring by the semi-additive method, there are a method for forming the seed layer on the surface on which the electric wiring 5 is formed, a method by vapor deposition or plating, and a method of bonding a metal layer.

[Formation of seed layer by vapor deposition or plating]
A seed layer can be formed on the surface on which the electrical wiring 5 is to be formed by vapor deposition or plating.
For example, when a base metal and a thin film copper layer are formed by sputtering as a seed layer, the sputtering apparatus used to form the thin film copper layer is a bipolar sputtering, a three-pole sputtering, a four-pole sputtering, a magnetron sputtering, a mirror. Tron sputtering or the like can be used.
A target used for sputtering is sputtered 5 to 50 nm using, for example, a metal such as Cr, Ni, Co, Pd, Zr, Ni / Cr, or Ni / Cu as a base metal in order to ensure adhesion.
Thereafter, a seed layer can be formed by sputtering 200 to 500 nm using copper as a target.
Moreover, it is also possible to form plated copper on the surface on which the electric wiring 5 is formed by performing electroless copper plating of 0.5 to 3 μm.

[Method of bonding metal foil]
When the surface on which the electric wiring 5 is formed has an adhesive function, the seed layer can be formed by bonding the metal layer by pressing or laminating.
However, since it is very difficult to directly bond a thin metal layer, there are a method of thinning a thick metal layer after etching, a method of thinning by etching, a method of removing a carrier layer after bonding a metal layer with a carrier, etc. is there.
For example, the former has a three-layer copper foil of carrier copper / nickel / thin film copper, the carrier copper is removed with an alkaline etching solution, nickel is removed with a nickel etching solution, and the latter is made of aluminum, copper, insulating resin or the like as a carrier. A peelable copper foil or the like can be used, and a seed layer of 5 μm or less can be formed.
Alternatively, a metal layer (for example, a metal foil such as a copper foil) having a thickness of 9 to 18 μm may be attached, and the seed layer may be formed by etching to a thickness of 5 μm or less.
Although what is generally used should just be used about the kind of electroplating, in order to form the electrical wiring 5, it is preferable to use copper as a plating metal.

[Electric wiring formation by additive method]
In the case of forming the electrical wiring by the additive method, as in the semi-additive method, it is formed by plating only on a necessary portion of the surface on which the electrical wiring 5 is formed. However, the plating used in the additive method is usually not used. Electroplating is used.
For example, after depositing an electroless plating catalyst on the surface on which the electrical wiring 5 is to be formed, a plating resist is formed on a surface portion where plating is not performed, and the substrate is immersed in an electroless plating solution and covered with the plating resist. Electroless plating is performed only at the locations where there is no electrical wiring 5.

[Formation of coating for wiring protection]
An insulating coating can be formed on the outermost surface (wiring surface located in the outermost layer) of the wiring board obtained as the final product. In the case of electrical wiring, the pattern formation of the insulation coating can be performed by printing if it is a varnish-like material, but in order to ensure more accuracy, a photosensitive solder resist, a coverlay film, It is preferable to use a film resist. Moreover, when there is an optical waveguide with a mirror in the product (in the case of an optical wiring), it is preferable to protect the mirror portion using a protective film with an adhesive.
As a material, an epoxy-based material, a polyimide-based material, an epoxy acrylate-based material, or a fluorene-based material can be used.

[Method of forming optical waveguide]
Hereinafter, the manufacturing method of the wiring board of the present invention in which the optical waveguide 10 is formed on both surfaces of the substrate 2 will be described in detail (see FIG. 1).
First, as shown in FIGS. 1D and 1E, the lower clad layer 6 is provided on the polyimide surface of the substrate 2, and the core pattern 7 is formed thereon. Further, the upper clad layer 8 is laminated to form a mirror part (see FIGS. 1 (f) and 1 (g)). When there is no adhesive force between the substrate 2 and the lower clad layer 6, they may be attached via the adhesive layer 3. Further, a method of directly sticking the optical waveguide substrate having the lower clad layer 6, the core pattern 7, and the upper clad layer 8 as described above onto the electric wiring 5 through the adhesive 3 can be used.
The formation of the lower clad layer 6 on the substrate 2 is not particularly limited and may be performed by a known method. For example, a material for forming the lower clad layer 6 is applied on the lower support film by spin coating or the like, and prebaked. Thereafter, the thin film can be formed by irradiating ultraviolet rays. Also, the formation of the core pattern 7 is not particularly limited. For example, a core layer having a refractive index higher than that of the lower cladding layer 6 may be formed on the lower cladding layer 6 and the core pattern 7 may be formed by etching. The formation method of the upper cladding layer 8 is not particularly limited, and may be formed by, for example, the same method as that for the lower cladding layer 6.

[Lower cladding layer and upper cladding layer]
Hereinafter, the lower clad layer 6 and the upper clad layer 8 used in the present invention will be described. As the lower clad layer 6 and the upper clad layer 8, a clad layer forming resin or a clad layer forming resin film can be used.

  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 layer and is cured by light or heat. A thermosetting resin composition or a photosensitive resin composition It 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 clad layer forming resin may be the same or different in the components contained in the resin composition in the upper clad layer 8 and the lower clad layer 6. The refractive indexes may be the same or different.

  The (A) base polymer used here is for forming a clad layer and ensuring the strength of the clad layer, and is not particularly limited as long as the object can be achieved, phenoxy resin, epoxy resin, (Meth) 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, phenoxy resin using at least one selected from bisphenol A, bisphenol A type epoxy compound bisphenol F, bisphenol F type epoxy compound and derivatives thereof as a copolymerization component has excellent heat resistance, adhesion and solubility. It is preferable because it is excellent. 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.

  As the bisphenol A type epoxy resin, as an epoxy resin solid at room temperature, for example, “Epototo YD-7020, Epototo YD-7919, Epototo YD-7007” (all trade names) manufactured by Toto Chemical Co., Ltd., Japan Epoxy Resin Co., Ltd. "Epicoat 1010, Epicoat 1009, Epicoat 1008" (all are brand names) etc. are mentioned.

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 indicates acrylate and methacrylate. An acrylate means a compound having an acryloyl group, and a methacrylate means a compound having a methacryloyl group. Moreover, monofunctional here means having any one of an acryloyl group and a methacryloyl group.
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.

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 these compounds, aromatic ketones and phosphine oxides are preferred from the viewpoint of improving the transparency of the core layer and 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 an optical waveguide is formed. The pattern forming property 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 80% by mass of the component (B).
(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 an optical waveguide, it is preferable that the 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.

In the present invention, the method for forming the clad layer is not particularly limited. For example, the clad layer may be formed by applying a clad layer forming resin or laminating a clad layer forming resin film.
In the case of application, the method is not limited. For example, the resin composition containing the components (A) to (C) may be applied by a conventional method.
Moreover, the resin film for clad layer formation used for a lamination can be easily manufactured, for example by melt | dissolving the said resin composition in a solvent, apply | coating to a support film, and removing a solvent.

The material of the support film used in the production process of the resin film for forming a clad layer is not particularly limited, and various types can be used. From the viewpoints of flexibility and toughness as a support film, those exemplified above as the film material of the substrate can be similarly mentioned.
The thickness of the support 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 can be 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 composition. For example, acetone, methyl ethyl ketone, methyl cellosolve, ethyl cellosolve, toluene, N, N-dimethylacetamide, propylene glycol monomethyl ether, propylene A solvent such as glycol 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 lower clad layer 6 and the upper clad layer 8 (hereinafter abbreviated as clad layers 6 and 8), the thickness after drying is preferably in the range of 5 to 500 μm. When the thickness is 5 μm or more, a clad thickness necessary for light confinement can be secured, and when the thickness is 500 μm or less, it is easy to control the film thickness uniformly. From the above viewpoint, the thickness of the cladding layers 6 and 8 is more preferably in the range of 10 to 100 μm.

  The thicknesses of the clad layers 6 and 8 may be the same or different in the lower clad layer 6 formed first and the upper clad layer 8 for embedding the core pattern 7. For embedding, it is preferable that the thickness of the upper cladding layer 8 is larger than the thickness of the core layer.

[Core layer forming resin and core layer forming resin film]
In the present invention, the method for forming the core layer laminated on the lower clad layer 6 in order to form the core pattern 7 is not particularly limited. For example, the coating of the core layer forming resin or the lamination of the core layer forming resin film is performed. It may be formed by.
As the resin for forming the core layer, a resin composition that is designed so that the core pattern 7 has a higher refractive index than the cladding layers 6 and 8 and can form the core pattern 7 with actinic rays can be used. Compositions are preferred. Specifically, it is preferable to use the same resin composition as that used in the clad layer forming resin.
In the case of application, the method is not limited, and the resin composition may be applied by a conventional method.

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 and applying the resin composition to the lower cladding layer 6 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. When 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, and when the thickness is 100 μm or less, the light receiving / emitting 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 support film used in the manufacturing process of the core layer forming resin is a support film that supports the core layer forming resin, and the material thereof is not particularly limited, but it is easy to peel off the core layer forming resin later. From the viewpoint of having heat resistance and solvent resistance, polyesters such as polyethylene terephthalate, polypropylene, polyethylene, and the like are preferable.
The thickness of the support film is preferably 5 to 50 μm. When it is 5 μm or more, there is an advantage that the strength as a support 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 support film is more preferably in the range of 10 to 40 μm, and particularly preferably 15 to 30 μm.

  The optical waveguide 10 used in the present invention may be a multilayer optical waveguide in which a plurality of polymer layers having a core pattern 7 and a cladding layer are stacked.

  EXAMPLES The present invention will be described more specifically with reference to examples. However, the present invention is not limited to these examples.

[Preparation of adhesive]
An adhesive described in PCT / JP2008 / 05465 was prepared. That is, (a) YDCN-703 (trade name, manufactured by Toto Kasei Co., Ltd., cresol novolac type epoxy resin, epoxy equivalent 210) 55 parts by mass as an epoxy resin, (b) Millex XLC-LL (Mitsui Chemicals, Inc.) as a curing agent Product name, phenol resin, hydroxyl group equivalent 175, water absorption rate 1.8% by mass, heating weight reduction rate 4% at 350 ° C. 45% by mass, silane coupling agent NUC A-189 (trade name, manufactured by Nihon Unicar Co., Ltd.) 1.7 parts by weight of γ-mercaptopropyltrimethoxysilane) and 3.2 parts by weight of NUC A-1160 (trade name, γ-ureidopropyltriethoxysilane manufactured by Nihon Unicar Co., Ltd.), (d) Aerosil R972 (silica) as filler The surface is coated with dimethyldichlorosilane and hydrolyzed in a 400 ° C reactor. , A filler having an organic group such as a methyl group on its surface, Nippon Aerosil Co., Ltd., trade name, silica, average particle size 0.016 μm) 32 parts by mass, cyclohexanone is added to the mixture, and the mixture is further stirred. And kneaded for 90 minutes. 280 parts by mass of (c) acrylic rubber HTR-860P-3 (trade name, weight average molecular weight of 800,000 manufactured by Nagase ChemteX Corporation) containing 3% by mass of glycidyl acrylate or glycidyl methacrylate as a polymer compound, and (e ) Curazole 2PZ-CN (trade name, 1-cyanoethyl-2-phenylimidazole manufactured by Shikoku Kasei Kogyo Co., Ltd.) as a curing accelerator was added in an amount of 0.5 parts by mass, stirred and mixed, and vacuum degassed. This adhesive varnish was applied onto a 75 μm thick polyethylene terephthalate (PET) film (Purex A31) subjected to a release treatment, dried by heating at 140 ° C. for 5 minutes, and then a 25 μm release mold as a second protective film. The treated polyethylene terephthalate (PET) film (Purex A31) was attached so that the release surface was on the resin side, whereby an adhesive 3 was obtained.
Hereinafter, the description will be made on the assumption that the adhesive is in a state immediately after the second protective film is peeled off immediately before use.

Example 1
(1) Bonding of two substrates Copper foil of polyimide substrate 1 with a single-sided copper foil (trade name: Upicel N, manufactured by Ube Nitto Kasei Co., Ltd., copper foil thickness: 5 μm, polyimide thickness 12.5 μm) A release sheet 14 (product name: Aflex, manufactured by Asahi Glass Co., Ltd., thickness: 30 μm), which is 10 mm smaller on each side than the product size (150 mm square), is placed on the surface, and the adhesive is prepared from above. The adhesive 3 was evacuated to 500 Pa or less using a vacuum pressure laminator (MVLP-500, manufactured by Meiki Seisakusho Co., Ltd.) as a flat plate laminator, and then pressure 0.4 MPa, temperature 50 ° C., pressure time 30 Thermocompression bonding was performed under the conditions of seconds.
Thereafter, the adhesive 3 is irradiated with 1 J / cm ² of ultraviolet light (wavelength 365 nm) with an ultraviolet exposure machine (EXM-1172, manufactured by Oak Manufacturing Co., Ltd.), and a release PET film (Purex) which is a protective film of the adhesive 3 A31) was peeled off (see FIG. 1A). Thereafter, the adhesive 3 adhered to the release sheet 14 was peeled off together with the release sheet 14 to obtain the substrate 1 with the adhesive 3 attached only to the frame portion (see FIG. 1B).
Next, on the bonding surface of the substrate 1 obtained above, the copper foil surface of the polyimide with a single-sided copper foil (150 mm square) is subjected to thermocompression bonding under the above conditions using the above-described vacuum pressure laminator. And the board | substrate 2 with which the board | substrate 1 was affixed by the product frame part was obtained by heat-hardening at 180 degreeC for 1 hour (refer FIG.1 (c)).

(2) Production of optical waveguide [production of resin film for forming clad layer]
(A) As a base polymer, 48 parts by mass of phenoxy resin (trade name: Phenototo YP-70, manufactured by Toto Kasei Co., Ltd.), (B) As a photopolymerizable compound, alicyclic diepoxycarboxylate (trade name: KRM) -2110, molecular weight: 252, Asahi Denka Kogyo Co., Ltd.) 50 parts by mass, (C) As a photopolymerization initiator, triphenylsulfonium hexafluoroantimonate salt (trade name: SP-170, 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 clad layer forming resin varnish A obtained above is applied to a release PET film (trade name: PUREX A31, Teijin DuPont Films Co., Ltd., thickness: 25 μm) as a coating machine (Multicoater TM-MC, Co., Ltd.). It is applied using Hirano Tech Seed, dried at 80 ° C. for 10 minutes, then at 100 ° C. for 10 minutes, and then as a protective film, a release PET film (trade name: Purex A31, Teijin DuPont Films Co., Ltd., thickness: 25 μm) ) Was attached so that the release surface was on the resin side to obtain a resin film for forming a cladding layer. At this time, the thickness of the resin layer can be arbitrarily adjusted by adjusting the gap of the coating machine. In this embodiment, the cured film thickness is 25 μm for the lower cladding layer and 70 μm for the upper cladding layer. Adjusted.

[Production 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 mass 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) 1 part by weight, and using resin varnish B for forming a core layer under the same method and conditions as in the above production example, except that 40 parts by weight of propylene glycol monomethyl ether acetate was used as the organic solvent Prepared. Thereafter, pressure filtration and degassing under reduced pressure were performed under the same method and conditions as in the above production example.
The core layer-forming resin varnish B obtained above is applied to the non-treated surface of a PET film (trade name: Cosmo Shine A1517, manufactured by Toyobo Co., Ltd., thickness: 16 μm) in the same manner as in the above production example. After coating and drying, a release PET film (trade name: PUREX A31, Teijin DuPont Films Co., Ltd., thickness: 25 μm) is applied as a protective film so that the release surface is on the resin side, and a core layer forming resin A film was obtained. In this example, the gap of the coating machine was adjusted so that the film thickness after curing was 50 μm.

(3) Production of Photoelectric Composite Member (Wiring Board Combined with Optical Waveguide) A method for producing the photoelectric composite member will be described below with reference to FIG.
A pressure laminator (HLM-1500, manufactured by Hitachi Chemical Technoplant Co., Ltd.) is used on both surfaces of the substrate 2 obtained as described above, and a laminate of the adhesive 3 described above is laminated using a roll laminator (HLM-1500, manufactured by Hitachi Chemical Technoplant Co., Ltd.). Lamination was performed at a speed of 0.2 m / min.
Thereafter, the adhesive 3 was irradiated with 1 J / cm ² of ultraviolet light (wavelength 365 nm) with an ultraviolet exposure machine (EXM-1172, manufactured by Oak Manufacturing Co., Ltd.), and release PET as a protective film of the adhesive 3 described above. The film (Purex A31) was peeled off.
Next, the release PET film (Purex A31), which is a protective film for the resin film for forming the lower clad layer obtained above, is peeled off, and the adhesive 3 on both sides of the substrate 2 obtained above is separated from the above. Affixed under the same laminating conditions, irradiated with UV (wavelength 365 nm) 1.5 J / cm ² from the resin side with an UV exposure machine (EXM-1172, manufactured by Oak Manufacturing Co., Ltd.), then heat-treated at 80 ° C. for 10 minutes. Thus, the lower clad layer 6 was formed (see FIG. 1D).
Next, the core layer-forming resin film was laminated on the lower clad layers 6 on both sides under the same lamination conditions as above to form a core layer.

Next, ultraviolet rays (wavelength 365 nm) were irradiated with 0.8 J / cm ² with a UV photomask through a negative photomask having a width of 50 μm, and then after exposure at 80 ° C. for 5 minutes, heating was performed. Thereafter, the PET film as the support film was peeled off, and the core pattern 7 was developed using a developer (propylene glycol monomethyl ether acetate / N, N-dimethylacetamide = 7/3, mass ratio). Then, it wash | cleaned using the washing | cleaning liquid (isopropanol), and heat-dried at 100 degreeC for 10 minute (refer FIG.1 (e)).

Next, a vacuum pressure laminator (MVLP-500, manufactured by Meiki Seisakusho Co., Ltd.) is used as the flat plate laminator, and the resin film for forming the clad layer is evacuated to 500 Pa or less as the upper clad layer 8, and then the pressure is 0.4 MPa. And thermocompression bonding under the conditions of a temperature of 50 ° C. and a pressing time of 30 seconds.
Further, after irradiation with ultraviolet rays (wavelength 365 nm) at 3 J / cm ² , heat treatment was performed at 180 ° C. for 1 hour to cure the upper clad layer 8 and produce the optical waveguide 10 (see FIG. 1F).
A 45 ° mirror portion 12 was formed from the upper clad layer 8 side of the obtained optical waveguide 10 using a dicing saw (DAC552, manufactured by Disco Corporation) (see FIG. 1G).

  As a protective film with the adhesive 3 for mirror protection, what stuck the adhesive 3 as described above on the polyimide film (thickness: 12.5 micrometers) on said conditions was used. Adhesive 3 was prepared by applying a protective film with adhesive 3 to the mirror forming part under the above conditions using a vacuum pressure laminator (manufactured by Meiki Seisakusho Co., Ltd., MVLP-500), and heat-treating at 180 ° C. for 1 hour. Was cured, and a coating 9 for protecting the wiring was provided on the mirror portion 12 (see FIG. 1H).

[Attaching the support]
A 130 mm square release sheet 14 (trade name: Aflex, manufactured by Asahi Glass Co., Ltd., thickness: 30 μm) is installed in the center of the upper clad forming surface, and a build-up material using the above-described vacuum pressure laminator (from above) (Product name: AS-ZII, manufactured by Hitachi Chemical Co., Ltd., thickness: 40 μm) was evacuated to 500 Pa or less, and then thermocompression bonded under conditions of pressure 0.4 MPa, temperature 110 ° C., and pressurization time 30 seconds. Then, 150 mm square FR-4 (trade name: MCL-E-679FB, manufactured by Hitachi Chemical Co., Ltd., thickness: 0.6 mm) from which the copper foil has been removed as the support 4 under the above-mentioned vacuum pressure lamination conditions. Laminated and pasted on the surface of the buildup material, the buildup material was cured by heat treatment at 180 ° C. for 1 hour, and the support 5 was pasted on the optical waveguide 10 (see FIG. 1 (i)).

[Separation of back-to-back substrates]
The product was cut at 135 mm smaller by 1.5 cm than the outer periphery of the product workpiece, and the substrate 2 was separated from the back-to-back surface. As a result, a substrate 1 laminated on the two supports 2 was obtained (see FIG. 1 (j)).

[Circuit formation by subtractive method]
Thereafter, a photosensitive dry film resist (trade name: Photec, manufactured by Hitachi Chemical Co., Ltd., thickness: 25 μm) is applied to the copper foil surface of polyimide with a single-sided copper foil, which is the back-to-back separation surface of the substrate 1. TECHNO PLANT Co., Ltd., HLM-1500) was applied under conditions of pressure 0.4 MPa, temperature 110 ° C., laminating speed 0.4 m / min, and then with an ultraviolet exposure machine (EXM-1172, manufactured by Oak Manufacturing Co., Ltd.). The photosensitive dry film resist is irradiated with ultraviolet rays (wavelength 365 nm) of 120 mJ / cm ² through a negative photomask having a width of 50 μm from the photosensitive dry film resist side, and 0.1 to 5% by weight of the photosensitive dry film resist at 35 ° C. is exposed. Removed with dilute solution of sodium carbonate. Then, using a ferric chloride solution, the photosensitive dry film resist was removed, and the exposed copper foil was removed by etching, using a 1-10 wt% sodium hydroxide aqueous solution at 35 ° C., The photosensitive dry film resist in the exposed portion was removed, and the electrical wiring 5 was formed. Next, a coverlay film (trade name: Nikaflex CISG, manufactured by Nikkan Kogyo Co., Ltd., substrate thickness: 12.5 μm, adhesive thickness: 15 μm) was applied to a pressure of 4.0 MPa, a temperature of 160 ° C., and a pressurization time of 90 minutes. The film was vacuum-pressed under the following conditions to provide a coating 9 for protecting the wiring. As a result, a wiring board on which the electrical wiring 5 and the optical waveguide 10 fixed to the support were formed was obtained. (See Fig. 1 (k))

(Separation of support)
The product was cut at 125 mm square, which is 1.0 cm smaller than the outer periphery of the product workpiece, and the support and the substrate were separated. As a result, a wiring board on which two electrical wirings 5 and an optical waveguide 10 were formed was obtained (see FIG. 1 (l)).
About the obtained wiring board, the distortion which arises in an optical waveguide was evaluated by the deviation | shift amount of the core position of the optical waveguide 10 with respect to a design value. The results are shown in Table 1.

(Measurement method of misalignment)
The measurement is performed by measuring the X and Y coordinates of 30 alignment markers placed in 125 mm squares on the front and back wiring, and using the four corner alignment markers, the intersection of the diagonal markers is the scaling factor origin. The average value obtained by dividing the distance between the four alignment markers by the design value was determined as a scaling factor (hereinafter abbreviated as S / F). For example, the alignment markers at the four corners of the design value are A, B, C, and D, the alignment markers at the four corners actually measured are A ′, B ′, C ′, and D ′, and A (or A ′) and C ( Or C ′), when B (or B ′) and D (or D ′) are located on the diagonal line, the intersection of the straight line connecting A and C and the straight line connecting B and D is S of the design value. / F origin, and the intersection of the straight line connecting A ′ and C ′ and the straight line connecting B ′ and D ′ is the S / F origin of the measured value. Also, A′-B ′ distance / AB distance, B′-C ′ distance / BC distance, C′-D ′ distance / CD distance, and D′-A ′. The average value of the inter-distance / D-A distance is S / F. Thereafter, the measured X and Y coordinates are corrected to the position of the S / F origin of the actual measurement S / F origin, and the design value obtained by multiplying the design value by S / F. The amount of deviation from the X and Y coordinates was calculated. With these, the positional deviation between the front and back sides was measured. The measurement results are shown in Table 1.
In Table 1, X represents the amount of displacement in the horizontal direction, Y represents the amount of displacement in the vertical direction, and XY represents the distance of displacement. From the results in Table 1, the maximum deviation was 39.7 μm.

Example 2
In Example 1, when the support 4 was fixed, FR-4 and the upper clad side of the optical waveguide were pasted over the entire surface without using the release sheet 14 and the support 4 was not separated. A wiring board on which the electrical wiring 5 and the optical waveguide 10 were formed was obtained (see FIG. 2).
About the obtained wiring board, the wiring position shift | offset | difference of front and back was measured similarly to Example 1. FIG. The measurement results are shown in Table 2. From the results in Table 2, the maximum deviation was 29.2 μm.

Example 3
In Example 1, instead of forming the optical waveguide 10 by reversing the front and back of the single-sided copper foil polyimide substrate of the substrate 1, the electrical wiring 5 was formed using the subtractive method, and the coverlay film was adhered ( (See FIG. 3 (a)). After that, the substrate that is back-to-back with the lamination of the support 4 is separated in the same manner as in Example 1, and the upper cladding layer 8 is formed on the back-to-back separation surface using the same method for forming the optical waveguide 10 as in Example 1. The exposure was performed (see FIG. 3B). Further, the core pattern 7 and the upper clad layer 8 were formed, the two-layer optical waveguide 10 was formed, and the two mirror layers 12 were formed simultaneously (see FIG. 3C). The mirror part 12 was protected in the same manner as in Example 1 to obtain a wiring board on which the electrical wiring 5 and the two-layer optical waveguide 10 were formed (see FIG. 3D).
About the obtained wiring board, the wiring position shift | offset | difference of front and back was measured similarly to Example 1. FIG. Table 3 shows the measurement results. From the results in Table 3, the maximum deviation was 36.4 μm.

Example 4
150 mm square prepreg (trade name: GEA-679FG, manufactured by Hitachi Chemical Co., Ltd., thickness: 40 μm) on both sides 140 mm square copper foil (trade name: 3EC-VLP, manufactured by Mitsui Mining & Smelting Co., Ltd., thickness: 18mm) in the center, 150mm square copper foil (trade name: 3EC-VLP, manufactured by Mitsui Mining & Smelting Co., Ltd., thickness: 18μm), 150mm square prepreg (trade name: GEA-679FG, Hitachi) After sequentially forming a copper foil of 150 mm square (trade name: 3EC-VLP, manufactured by Mitsui Mining & Smelting Co., Ltd., thickness: 18 μm) manufactured by Kasei Kogyo Co., Ltd., thickness: 40 μm, and evacuated to 4 kPa or less, Heat lamination was performed under the conditions of a pressure of 2.5 MPa, a temperature of 180 ° C., and a pressurization time of 1 hour to obtain two back-to-back substrates (see FIG. 4A). After that, the electric wiring 5 was formed on both surfaces of the substrate using the subtractive method in the same manner as in Example 1 (see FIG. 4B). Next, 150 mm square prepreg (trade name: GEA-679FG, manufactured by Hitachi Chemical Co., Ltd., thickness: 40 μm), 150 mm square copper foil (trade name: 3EC-VLP, manufactured by Mitsui Mining & Smelting Co., Ltd., thickness: 18 μm) were sequentially formed and heated and laminated under the same conditions as described above (see FIG. 4C). Next, both sides of the substrate were formed on the copper foils on both sides of the substrate by the subtractive method in the same manner as the above-described formation of the electrical wires (see FIG. 4D). The steps after the lamination of the support 4 were performed in the same manner as in Example 1 to obtain a wiring board having three layers of electrical wiring (see FIG. 4E).
About the obtained wiring board, the wiring position shift | offset | difference of front and back was measured similarly to Example 1. FIG. Table 4 shows the measurement results. From the results in Table 4, the maximum deviation was 9.7 μm.

Comparative Example 1
In Example 3, a wiring board in which the electrical wiring 5 and the one-layer optical waveguide 10 were formed was obtained in the same manner except that the support 4 was not used and the optical waveguide 10 was formed in one layer.
About the obtained wiring board, the wiring position shift | offset | difference of front and back was measured similarly to Example 1. FIG. From the results in Table 5, the maximum deviation was 91.5 μm.

  According to the method for manufacturing a wiring board of the present invention, processing can be performed while maintaining dimensional stability up to wiring formation on the surfaces laminated by back-to-back, and high work efficiency can be ensured. In addition, since two substrates can be manufactured by being stacked, it can be handled as an extremely thin wiring board by handling as a substrate having a certain thickness. Moreover, since it can respond to both a copper-clad laminate and a substrate to be built up, it can be applied to a wide range of fields such as a semiconductor package substrate, a flexible substrate, and an optoelectric composite member.

1; Substrate 2; Substrate (after back to back)
3; adhesive 4; support 5; electrical wiring 6; lower clad layer 7; core pattern 8; upper clad layer 9; coating 10 for wiring protection; optical waveguide 11; metal layer 12; ; Release sheet

Claims (10)

Step A in which two substrates are back-to-back to form one substrate, Step B in which wiring is formed on both surfaces of the one substrate, Step C in which two supports are laminated on the wiring surface, and the support step of separating two substrates remains fixed to the body D, the step of forming the wiring on the separation surface of the two substrates E, after step E, have a step F of separating said support,
In step A, the two substrates are back to back using a removable adhesive,
In step C, the support is laminated using a removable adhesive,
1) The adhesive strength of the adhesive used for laminating the support in Step C is stronger than the adhesive strength of the adhesive used for back-to-back of two substrates in Step A, or
2) Adhering the frame portion of the substrate using an adhesive in step A to back-to-back the two substrates, and bonding the frame portion of the support to the wiring surface using an adhesive in step C The support is laminated, and the two substrates are not bonded to each other. The size of the non-bonded portion inside the frame portion is the inner side of the frame portion where the support is not bonded to the wiring surface. A method of manufacturing a wiring board, wherein the size is larger than the size of the non-bonded portion of the wiring board. The manufacturing method of a wiring board according to claim 1, wherein the adhesive force of the adhesive used for laminating the support in step C is stronger than the adhesive force of the adhesive used for back-to-back of two substrates in step A. Method. In step A, the frame portion of the substrate is bonded using an adhesive, and the two substrates are back-to-back, and in step C, the frame portion of the support is bonded to the wiring surface using an adhesive. The size of the non-adhesive part inside the frame part where the two substrates are not bonded is the same as the non-adhesive part inside the frame part where the support is not bonded to the wiring surface. The method for manufacturing a wiring board according to claim 1 , wherein the size is larger than the size of the bonded portion .   After Step B, after Step E, before Step F, or at least after Step F, includes a step G in which a coating for wiring protection is applied to the wiring. The manufacturing method of the wiring board in any one of Claims 1-3 to do.   The process for producing a wiring board according to any one of claims 1 to 4, wherein in step A, the substrates are back-to-back with only the frame portion of the substrate using an adhesive to form one substrate.   The method for manufacturing a wiring board according to claim 1, wherein the wiring includes an optical waveguide and electrical wiring. Wherein the wiring is a layer of electrical wiring or conductive after laminating the substrate to form the surface of the gas line, a multilayer electrical wiring formed by repeating the step of forming the electrical wiring on the base plate at least once The manufacturing method of the wiring board in any one of Claims 1-5.   The method of manufacturing a wiring board according to claim 1, wherein the wiring is one or more optical waveguides.   The method for manufacturing a wiring board according to claim 6 or 7, wherein the electrical wiring is formed using at least one of a subtractive method, an additive method, and a semi-additive method.   9. The method of manufacturing a wiring board according to claim 6, wherein the optical waveguide is an optical waveguide with a mirror.

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