JP5458415B2 - Flattened hole-filled printed wiring board and method for manufacturing the same - Google Patents

Description

  The present invention relates to a method for manufacturing a printed wiring board and a printed wiring board manufactured thereby. In particular, the present invention relates to a novel surface flattening method for a hole-filled printed wiring board and a flattened hole-filled printed wiring board manufactured thereby.

Conventionally, the surface flattening of the hole-filled printed wiring board has been performed by removing the hole-filling resin that has eroded from the substrate surface by polishing the substrate surface with a buff or belt sander (Patent Document 1, Example 1).
However, when the substrate is thin, the substrate is damaged and bent during polishing, or the substrate is deformed (e.g., stretched) to cause a dimensional change.
Therefore, for printed wiring boards (especially those with a thickness of about 0.1 mm) that have been thinned in recent years due to the total thickness regulation and the trend toward lighter and shorter, for conventional PKG boards that are extremely vulnerable to dimensional changes, etc. The physical polishing method could not cope.

JP-A-10-126054.

  In view of the above circumstances, the present invention can flatten the surface of the printed wiring board without polishing, and as a result, there is no breakage, bending, deformation of the board, dimensional change, etc. An object of the present invention is to provide a novel method for flattening the surface of a substrate, which is suitable for a printed wiring board that is vulnerable to damage.

  In order to solve the above-mentioned problems, the inventors of the present application diligently studied and as a result, the following inventions of the present application were achieved.

  That is, the first invention of this application places a non-transparent printed wiring board having a through hole on the translucent flat member B such that one opening end surface A of the through hole faces the translucent flat member B. The photocurable resin composition is applied and filled in the through hole, and another flat material B ′ is placed on the surface of the printed wiring board including the other opening end face A ′ of the through hole, and a hard roll is placed on the flat material B ′. , The resin is exposed through the light transmissive flat material B, the light transmissive flat material B is removed at any step after the exposure, the flat material B ′ is removed, and the unexposed resin is removed by development. A printed wiring board manufacturing method characterized by the above.

In the second invention of the present application, I) a non-transparent printed wiring board in which a pad is provided on at least a part of the periphery of one opening end surface A of the through hole, and the other opening end surface A ′ of the through hole is translucent. It is placed on the translucent flat material B so as to face the flat material B, and a photocurable resin composition is applied and filled in the through hole so that the resin is filled at least the height of the pad end surface, and includes the pad end surface. Another flat material B ′ is placed on the surface of the printed wiring board, or II) a non-transparent printed wiring board in which a pad is provided on at least a part of the peripheral edge of one opening end surface A of the through hole. The surface of the printed wiring board that is placed on the light transmissive flat material B so as to face the light transmissive flat material B, is coated and filled with a photocurable resin composition in the through hole, and includes the other opening end surface A ′ of the through hole Put another flat material B 'on top,
The hard roll is moved on the flat material B ′, the resin is exposed through the light transmissive flat material B, the light transmissive flat material B is removed at any step after the exposure, and the flat material B ′ is removed. And a method for producing a printed wiring board, wherein unexposed resin is removed by development.

  In the third invention of the present application, a non-translucent printed wiring board in which pads are provided on at least a part of the periphery of both opening end faces of the through-holes, and one pad end face C faces the translucent flat member B. The photocurable resin composition is placed on the translucent flat member B, and is coated and filled in the through-hole so that the resin is filled at least the height of the other pad end surface C ′. The other flat material B ′ is placed on the surface of the wiring board, the hard roll is moved on the flat material B ′, the resin is exposed through the translucent flat material B, and the transparent material is transmitted in an arbitrary process step after the exposure. There is provided a method for manufacturing a printed wiring board, characterized in that the optical flat material B is removed, the flat material B ′ is removed, and unexposed resin is removed by development.

  A fourth invention of the present application provides the method for manufacturing a printed wiring board according to any one of the first to third inventions of the present invention, wherein the printed wiring board is a board having a thickness of 0.2 mm or less or a PKG board. To do.

The present fifth invention, the photocurable resin composition is a solventless, a manufacturing method, any of the printed wiring board of the first invention to fourth invention, characterized in that the alkali developability To do.

  In the sixth invention of the present application, the photocurable resin composition has an [I] unsaturated group and an alkali-soluble resin, [II] (meth) acrylic monomers, [III] a photoreaction initiator, [IV] Provided is a method for producing a printed wiring board according to the fifth aspect of the present invention, which is a photo / thermosetting resin composition containing an epoxy compound and a [V] thermosetting agent.

  A seventh invention of the present application provides the method for producing a printed wiring board according to any one of the first to sixth inventions, wherein the hard roll is made of metal.

  The eighth invention of the present application uses the surface including the opening end face or the pad end face of the through hole on which the flat material B ′ is placed as a reference surface so that the resin layer thickness above the reference surface is 5 μm or less. A method for producing a printed wiring board according to any one of the first to seventh inventions of the present application, wherein a hard roll is moved upward.

  The ninth invention of the present application is the production of a printed wiring board according to any one of the first to eighth inventions of the present invention, wherein the resin is heated and degassed or vacuum degassed after the photocurable resin composition is applied and filled. Method.

  The tenth invention of the present application provides the method for producing a printed wiring board according to any one of the first to ninth inventions of the present invention, wherein after the unexposed resin is removed by development, the exposed resin is further heat-cured. .

  The eleventh aspect of the present invention provides a printed wiring board manufactured by the method for manufacturing a printed wiring board according to any one of the first to tenth aspects of the present invention.

  According to the present invention, the surface of the printed wiring board can be flattened without polishing, and as a result, there is no breakage, bending, deformation of the board, dimensional change, etc., and therefore a very thin printed wiring board or a printed wiring board that is vulnerable to dimensional changes. It is possible to provide a novel method for planarizing the surface of a substrate, which is also suitable for the above.

Sectional drawing of a manufacturing process in the case of applying the manufacturing method of the printed wiring board which concerns on this invention with respect to the printed wiring board which does not have a pad is represented.

The manufacturing process sectional drawing in the case of applying the manufacturing method of the printed wiring board which concerns on this invention with respect to the printed wiring board which has a pad on one side is represented.

The manufacturing process sectional drawing in the case of applying the manufacturing method of the printed wiring board of another aspect which concerns on this invention with respect to the printed wiring board which has a pad on one side is represented.

The manufacturing process sectional drawing in the case of applying the manufacturing method of the printed wiring board which concerns on this invention with respect to the printed wiring board which has a pad on both surfaces is represented.

It is a partial expanded sectional view for demonstrating "a level | step difference" between a hole-filling hardening resin surface and a printed wiring board surface.

It is a partial expanded sectional view for demonstrating "a level | step difference" between a hole-filling hardening resin surface and a pad surface.

Hereinafter, the present invention will be described in detail with reference to the drawings.
In a first aspect of the method for manufacturing a printed wiring board according to the present invention, a non-transparent printed wiring board having a through hole is made transparent so that one open end surface A of the through hole faces the translucent flat member B. Place on the optical flat material B, apply and fill the photocurable resin composition into the through hole, and place another flat material B ′ on the surface of the printed wiring board including the other opening end face A ′ of the through hole, The hard roll is moved on the material B ′, the resin is exposed through the light transmissive flat material B, the light transmissive flat material B is removed at any step after the exposure, the flat material B ′ is removed, The unexposed resin is removed by development.

  In the first aspect of the manufacturing method of the present application, a printed wiring board 1 (FIG. 1a) serving as a base material has a through hole 2 (FIG. 1a). On both sides of the through hole 2 (FIG. 1a), there are open end faces A (FIG. 1a) and A ′ (FIG. 1a), respectively. Examples of the through hole include a through hole, a via hole, and a component hole. The hole diameter is, for example, 50 to 500 μm.

  As the printed wiring board, a substrate that does not transmit exposure light described later (that is, a non-translucent substrate) is used. Specifically, the printed wiring board is surface-coated with a non-translucent material, a light-shielding agent, and a light-shielding material (film, sheet, plate, etc.). And the like.

  In the manufacturing method according to the present application, it has been difficult or unsuitable to polish, and an extremely thin printed wiring board (thickness of 0.2 mm or less (especially 0.1 mm or less)) or a dimensional change is extremely difficult. A weak printed wiring board (for example, a circuit width of 10 μm or less, a PKG board, or the like) can be preferably used.

  In the first aspect of the manufacturing method of the present application, first, the printed wiring board 1 (FIG. 1b) is placed on the translucent flat member B (FIG. 1b). The translucent flat material B transmits exposure light described later (that is, has translucency), and has at least one surface (preferably both surfaces) having a flat surface and can be easily removed in a subsequent process. Those are preferred. Specifically, the translucent flat material B includes a film (PET film or the like), a sheet, a plate, or the like, and is preferably a film. As for the film thickness of a film, 10-200 micrometers is preferable, for example.

  When the printed wiring board is placed on the translucent flat member B, one opening end surface A of the through hole is opposed to the translucent flat member B. Thereby, the opening end surface A is closed by the translucent flat material B. Specifically, the entire surface of the printed wiring board on the side having the opening end surface A or only the opening end surface A and the vicinity thereof may be placed on the translucent flat member B.

Thereafter, the photocurable resin composition 3 (FIG. 1c) is applied and filled into the through holes. The photocurable resin composition is solvent-free. In the case of the solvent type, when the solvent is removed by drying, the volume change of the coating resin layer is large, and as a result, a dent may be formed on the coating surface. In the case of the solvent type, after the solvent is removed by drying, the resin viscosity of the coated resin layer becomes high, and it may be difficult to make a thin layer using a hard roll described later. As the photocurable resin composition, those having alkali developability, that is, developable with an aqueous alkali solution are preferable from the viewpoint of the environment.

  As such a photocurable resin composition, a light / thermosetting (light / thermal two-stage curable) resin composition is preferable. The photo / thermosetting resin composition includes [I] unsaturated group, alkali-soluble resin, [II] (meth) acrylic monomers, [III] photoreaction initiator, [IV] epoxy compound, And [V] those containing a thermosetting agent.

  In the photo / thermosetting resin composition, the resin [I] is, for example, a resin [I-1] having two or more ethylenically unsaturated groups and a carboxyl group and having a solid content acid value of 50 to 150 mgKOH / g. ].

  As the resin [I-1], for example, a polyfunctional epoxy resin (a) having two or more epoxy groups and an unsaturated monocarboxylic acid (b) are esterified and saturated with the hydroxyl group of the obtained esterified product. And / or resin [I-1-i] obtained by reacting unsaturated polybasic acid anhydride (c).

  In the resin [I-1-i], as the polyfunctional epoxy resin (a), specifically, bisphenol A type epoxy resin, hydrogenated bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, Examples thereof include phenol novolac type epoxy resins, cresol novolac type epoxy resins, bisphenol A novolak type epoxy resins, biphenol type epoxy resins, bixylenol type epoxy resins, trisphenol methane type epoxy resins, N-glycidyl type epoxy resins and the like.

  In the resin [I-1-i], the unsaturated monocarboxylic acid (b) includes acrylic acid, methacrylic acid, cinnamic acid, a saturated or unsaturated dibasic acid anhydride, and one hydroxyl group in one molecule. Reaction products with (meth) acrylates having

  In the resin [I-1-i], examples of the saturated and / or unsaturated polybasic acid anhydride (c) include phthalic acid, tetrahydrophthalic acid, hexahydrophthalic acid, succinic acid, trimellitic acid, pyromellitic acid, and the like. The anhydride of these is mentioned.

  As other resin [I-1], for example, a glycidyl acrylate and / or a copolymer of acrylic acid and / or methacrylic acid and another copolymerizable monomer (d) having an ethylenically unsaturated bond may be used. Alternatively, resin [I-1-ii] having a weight average molecular weight of 5,000 to 20,000 obtained by reacting glycidyl methacrylate can be mentioned.

  In the resin [I-1-ii], specific examples of the copolymerizable monomer (d) include styrene, chlorostyrene, α-methylstyrene; substituents [methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl. , T-butyl, amyl, 2-ethylhexyl, octyl, capryl, nonyl, dodecyl, hexadecyl, octadecyl, cyclohexyl, isobornyl, methoxyethyl, butoxyethyl, 2-hydroxyethyl, 2-hydroxypropyl, 3-chloro-2-hydroxy Acrylate or methacrylate having propyl etc .; morpholine acrylate or methacrylate, polyethylene glycol monoacrylate or monomethacrylate, polypropylene glycol monoacrylate or monomethacrylate G: vinyl acetate, vinyl butyrate, vinyl benzoate; acrylamide, methacrylamide, N-hydroxymethyl acrylamide, N-hydroxymethyl methacrylamide, N-methoxymethyl acrylamide, N-ethoxymethyl acrylamide, N-butoxymethyl acrylamide; acrylonitrile or And maleic anhydride.

  As another resin [I-1], for example, a reaction product obtained by reacting an unsaturated monocarboxylic acid (b) with a copolymer of glycidyl acrylate and / or glycidyl methacrylate and a copolymerizable monomer (d). A resin [I-1-iii] having a weight average molecular weight of 5,000 to 20,000 obtained by reacting a hydroxyl group of the product with a saturated and / or unsaturated polybasic acid anhydride (c) can be mentioned.

  In resin [I-1-iii], as copolymerizable monomer (d), unsaturated monocarboxylic acid (b), and saturated and / or unsaturated polybasic acid anhydride (c), resin [I-1 -I] and resin [I-1-ii] are exemplified.

  In the photo / thermosetting resin composition, specific examples of [II] (meth) acrylic monomers include isobornyl acrylate, dicyclopentanyl methacrylate, hydroxypentylglycol diacrylate, tricyclode Examples include candimethanol acrylate, trimethylolpropane triacrylate, dipentaerythritol hexaacrylate, and isobornyl crotonic acid.

  In the photo / thermosetting resin composition, specific examples of [III] photoreaction initiator include benzyl dimethyl ketal, 1-hydroxy-cyclohexyl-phenyl ketone, 2-hydroxy-2-methyl-1-phenylpropane- Hydroxy ketones such as 1-one, 2-methyl-1 [(4-methylthio) phenyl] -2-morpholinopropan-1-one, 2-benzyl-2-dimethylamino-1- (4-morpholino Amino ketones such as phenyl) butanone-1, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, phosphine oxides such as bis (2,4,6-trimethylbenzoyl) phenylphosphine oxide, benzoin methyl ether, benzoin Benzoin ethers such as isobutyl ether, isopropyl Thioxanthones such as thioxanthone and 2-chlorothioxanthone, benzophenone, 2-benzoylnaphthalene, 4-benzoylbiphenyl, 4-benzoyldiphenyl ether, benzophenones such as [4- (methylphenylthio) phenyl] phenylmethane, 2-ethylanthraquinone and the like Anthraquinones, biimidazoles such as 2,2′-bis (o-chlorophenyl) 4,5,4 ′, 5 ′,-tetraphenyl-1,2′biimidazole, 10-butyl-2-chloroacridone And titanocene compounds marketed as Irgacure 784, triallylsulfonium-6-fluoride (or 6-antimony fluoride), and the like.

  In the photo / thermosetting resin composition, the [IV] epoxy compound preferably has two or more epoxy groups, and examples thereof include those soluble in (meth) acrylic monomers and those hardly soluble. Specifically, the epoxy compound component [IV] includes soluble epoxy compounds [bisphenol A type epoxy resin, bisphenol F type epoxy resin, N, N, O-tris (glycidyl) -p-aminophenol, bisphenol AD type. Liquid epoxy resins such as epoxy resins and novolac type epoxy resins, etc., and poorly soluble epoxy compounds [triglycidyl isocyanurate type, biphenyl type (tetramethylbiphenyl type, etc.), diphenyl type [di- (p-glycidylphenyl) ether Etc.], crystalline epoxy resins such as hydroquinone type (hydroquinone diglycidyl ether, etc.), biphenyl novolac type, fluorin type, etc.].

  In the photo / thermosetting resin composition, specific examples of the [V] thermosetting agent include dicyandiamides (DICY), melamine, imidazoles, BF3-amine complexes, amine adduct type curing agents, and amine-acid anhydrides. (Polyamide) Adduct type curing agents, hydrazide type curing agents, amine type curing agent carboxylates, onium salts and the like.

  In the photo / thermosetting resin composition, for example, an antihalation agent, an antifoaming agent, a filler, a leveling agent, a thixotropy imparting agent, an organic / inorganic colorant, a flame retardant, and the like may be contained as additives.

  In the composition of the photo / thermosetting resin composition, when the component [I] is 100 parts by weight, the component [II] is 50 to 400 (particularly 100 to 300) part by weight, and the component [III] is 1 to 20 (particularly 5). To 15) parts by weight, component [IV] 10 to 100 (particularly 50 to 80) parts by weight, and component [V] 1 to 20 (particularly 5 to 10) parts by weight are preferred.

  In the first aspect of the production method of the present application, the application and filling of the photocurable resin composition into the through holes can be performed by, for example, screen printing or roll coating under vacuum or in the air. When coating and filling in the atmosphere, it is preferable to further defoam the resin (heat defoaming, vacuum defoaming, etc.). The filling amount of the resin into the through hole is an amount that is at least the height of the opening end surface A ′. Usually, the surface including the opening end surface A ′ is used as a reference surface, and is higher than the reference surface 4 (FIG. 1c). The amount of the resin layer is 50 to 500 μm.

  Thereafter, a flat material B '(FIG. 1d) is placed on the surface of the printed wiring board on the side where the opening end surface A' of the through hole is located. In this case, the flat material B ′ is placed on at least the opening end surface A ′. Preferably, the flat material B 'is placed so that the exposed surface of the coating filling resin 3 (FIG. 1d) is covered. Specifically, the flat material B ′ may be placed on the entire surface of the printed wiring board on the side where the opening end surface A ′ is present or on the opening end surface A ′ and the vicinity thereof.

  It is preferable that the flat material B ′ has at least one surface (preferably both surfaces) has a flat surface and can be easily removed in a subsequent process. Specifically, examples of the flat material B ′ include a film (PET film and the like), a sheet, a plate, and the like, and a film is preferable. As for the film thickness of a film, 10-100 micrometers is preferable, for example. The flat material B 'includes the translucent flat material B.

  Thereafter, the hard roll 5 (FIG. 1d) is moved on the flat member B ′ (FIG. 1d). Specifically, the hard roll 5 (FIG. 1d) is moved at a speed of 0.1 to 2 m / min while being rotated while being pressed against the flat material B ′ (FIG. 1d) at a pressure of 0.1 to 1 MPa. The hard roll preferably has a Vickers hardness equal to or higher than the circuit material. Specifically, the material of the hard roll includes metal (stainless steel, iron, aluminum, copper, etc.), and preferably stainless steel. The roll diameter is preferably 5 to 250 mm, for example.

  By the roll movement, the coating resin on the opening end surface A ′ is handled (ladder) and thinned to a desired layer thickness. Specifically, with the surface including the opening end surface A ′ as a reference surface, the resin layer thickness above the reference surface 4 (FIG. 1e) is preferably 5 μm or less (more preferably 3 μm or less, most preferably 1 μm or less). The hard roll is moved on the flat material B ′.

Thereafter, the resin is exposed through the translucent flat member B (FIG. 1e). Specifically, light irradiation is performed from the translucent flat member B side toward the resin. The light irradiation conditions are, for example, an irradiation light wavelength of 300 to 450 nm and an irradiation amount of 10 to 2000 mJ / cm ² .

  After the exposure, the translucent flat material B is removed from the printed wiring board (specifically, peeled off). The timing for removing the translucent flat member B is not particularly limited as long as it is after the exposure, and may be performed at any step. Specifically, it may be before, after, or simultaneously with the step of removing the following flat material B 'or the step of developing and removing the unexposed resin.

  The flat material B 'is removed from the printed wiring board (specifically, it is peeled off). As a result, the resin covered with the flat material B ′ is exposed.

  Of the exposed resin, the unexposed resin is removed by development, and the printed wiring board surface is washed (washed with water, etc.) as necessary. The developer is preferably an aqueous alkaline developer (such as an aqueous sodium carbonate solution). As a result, the coating resin shielded by the non-transparent printed wiring board, specifically, the coating resin on the printed wiring board surface excluding the opening end face A ′ is removed (FIG. 1f).

Thereafter, when, for example, a photo / thermosetting resin composition or the like is used as the photocurable resin composition, the exposure resin is further heat-cured (for example, 100 to 200 ° C., 10 to 180 minutes) as necessary.
As described above, the printed wiring board is manufactured from the first aspect of the manufacturing method of the present application.

  In the second aspect of the method for manufacturing a printed wiring board according to the present invention, after performing the following step I), the hard roll is moved on the flat material B ′, and the resin is exposed through the translucent flat material B. The light-transmitting flat material B is removed at any process stage after exposure, the flat material B ′ is removed, and the unexposed resin is removed by development.

  In the step I), a non-translucent printed wiring board in which a pad is provided on at least a part of the periphery of one opening end surface A of the through hole is used, and the other opening end surface A ′ of the through hole is a translucent flat material B. A printed wiring board including the pad end surface, which is placed on the translucent flat member B so as to face the substrate, and is coated and filled with a photocurable resin composition so that the resin is filled at least at the height of the pad end surface. Placing another flat material B ′ on the surface.

  In step I), as the printed wiring board 1 (FIG. 2a) serving as a base material, a printed wiring board exemplified in the first embodiment provided with a pad can be used. The pad 7 (FIG. 2a) is provided over at least a part of the peripheral edge of one open end surface A (FIG. 2a) of the through hole 2 (FIG. 2a), typically over the entire periphery. The pad thickness is preferably 10 to 100 (particularly 20 to 50) μm, for example.

  In step I), the printed wiring board 1 (FIG. 2b) is placed on the translucent flat material B (FIG. 2b). As translucent flat material B, what was illustrated in the 1st aspect is mentioned.

  When the printed wiring board is placed on the translucent flat member B, the other opening end surface A ′ (FIG. 2 a) of the through hole is opposed to the translucent flat member B in the same manner as in the first embodiment.

  Thereafter, the photocurable resin composition 3 (FIG. 2c) is applied and filled into the through holes. As a photocurable resin composition, what was illustrated in the 1st aspect is mentioned.

  The application and filling of the photocurable resin composition into the through holes can be performed in the same manner as in the first embodiment. The filling amount of the resin into the through hole is an amount that is at least the height of the pad end surface. Usually, the resin layer thickness above the reference surface 4 (FIG. 2c) is a surface including the pad end surface. Is an amount of 50 to 500 μm.

Thereafter, a flat material B ′ (FIG. 2d) is placed on the surface of the printed wiring board on the side having the pad end face. In that case, the flat material B ′ is placed on at least the pad end face. Preferably, the flat material B ′ is placed so that the exposed surface of the coating filling resin 3 (FIG. 2d) is covered. Specifically, the flat material B ′ may be placed on the entire surface of the printed wiring board on the side having the pad end face, or on the pad end face and the vicinity thereof.
Examples of the flat material B ′ include those exemplified in the first embodiment.

  After performing step I), the hard roll 5 (FIG. 2d) is moved on the flat material B ′ (FIG. 2d) in the same manner as in the first embodiment.

  By the roll movement, the coating resin on the pad end surface is handled and thinned to a desired layer thickness. Specifically, with the surface including the pad end surface as the reference surface, the resin layer thickness above the reference surface 4 (FIG. 2e) is preferably 5 μm or less (more preferably 3 μm or less, most preferably 1 μm or less). As described above, the hard roll is moved on the flat member B ′.

  Thereafter, in the same manner as in the first aspect, the resin 3 (FIG. 2e) is exposed through the light-transmitting flat material B (FIG. 2e), and the light-transmitting flat material B is removed in an arbitrary process step after the exposure. The flat material B ′ is removed, and the unexposed resin is removed by development.

As a result, the coating resin shielded by the non-transparent printed wiring board, specifically, the coating resin on the surface of the printed wiring board excluding the pad end face is removed (FIG. 2f).
Thereafter, as in the first embodiment, the exposed resin may be further heat-cured.
As described above, a printed wiring board is manufactured from the second aspect of the manufacturing method of the present application.

  In the third aspect of the method for producing a printed wiring board according to the present invention, after performing the following step II), the hard roll is moved on the flat material B ′, and the resin is exposed through the translucent flat material B. The light-transmitting flat material B is removed at any process stage after exposure, the flat material B ′ is removed, and the unexposed resin is removed by development.

  In step II), a non-translucent printed wiring board in which a pad is provided on at least a part of the periphery of one opening end surface A of the through hole is translucent so that the pad end surface faces the translucent flat material B. A step of placing on the flat surface material B, coating and filling the photocurable resin composition in the through hole, and placing another flat material B ′ on the surface of the printed wiring board including the other open end surface A ′ of the through hole. Including.

  In the step II), as the printed wiring board 1 (FIG. 3a) serving as a base material, those exemplified in the step I) can be used.

  In step II), the printed wiring board 1 (FIG. 3b) is placed on the translucent flat material B (FIG. 3b). As translucent flat material B, what was illustrated in the 1st aspect is mentioned.

  When the printed wiring board is placed on the translucent flat member B, the end surface of the pad 7 (FIG. 3b) is opposed to the translucent flat member B. As a result, the pad end face is closed by the translucent flat material B. Specifically, the entire surface of the printed wiring board on the side having the pad end face or only the pad end face and the vicinity thereof may be placed on the translucent flat member B.

Thereafter, the photocurable resin composition 3 (FIG. 3c) is applied and filled into the through holes. As a photocurable resin composition, what was illustrated in the 1st aspect is mentioned.
The application and filling of the photocurable resin composition into the through holes can be performed in the same manner as in the first embodiment.
Thereafter, in the same manner as in the first embodiment, a flat material B ′ (FIG. 3d) is placed on the surface of the printed wiring board on the side where the opening end surface A ′ (FIG. 3a) of the through hole is located.
Examples of the flat material B ′ include those exemplified in the first embodiment.

After performing Step II), the hard roll 5 (FIG. 3d) is moved on the flat material B ′ (FIG. 3d) in the same manner as in the first embodiment, and the transparent flat material B (FIG. 3e) is interposed. Then, the resin 3 (FIG. 3e) is exposed, the translucent flat material B is removed at any step after the exposure, the flat material B ′ is removed, and the unexposed resin is removed by development (FIG. 3f).
Thereafter, as in the first embodiment, the exposed resin may be further heat-cured.
As described above, the printed wiring board is manufactured from the third aspect of the manufacturing method of the present application.

  According to a fourth aspect of the method for manufacturing a printed wiring board according to the present invention, a non-transparent printed wiring board in which pads are provided on at least a part of the periphery of both opening end faces of the through-holes, The photocurable resin composition is placed on the translucent flat member B so as to face the translucent flat member B, and the photocurable resin composition is applied to the through hole so that the resin is filled at least the height of the other pad end surface C ′. Fill and place another flat material B ′ on the surface of the printed wiring board including the pad end face C ′, move the hard roll on the flat material B ′, and expose the resin through the translucent flat material B. The light-transmitting flat material B is removed at any step after the exposure, the flat material B ′ is removed, and the unexposed resin is removed by development.

  In the fourth aspect of the manufacturing method of the present application, as the printed wiring board 1 (FIG. 4a) serving as a base material, a printed wiring board exemplified in the first aspect provided with pads on both sides can be used. The pad 7 (FIG. 4a) is provided over at least a part of the periphery of the opening end surface on both sides of the through hole 2 (FIG. 4a), typically over the entire periphery, and the pad end surface C (see FIG. 4a). 4a) and C ′ (FIG. 4a) are formed. The pad thickness is preferably 10 to 100 (particularly 20 to 50) μm, for example.

In the fourth aspect of the present application manufacturing method, the printed wiring board 1 (FIG. 4b) is placed on the translucent flat member B (FIG. 4b). As translucent flat material B, what was illustrated in the 1st aspect is mentioned.
When the printed wiring board is placed on the translucent flat member B, one pad end surface C is opposed to the translucent flat member B in the same manner as in the step II).

  Thereafter, the photocurable resin composition 3 (FIG. 4c) is applied and filled into the through holes. As a photocurable resin composition, what was illustrated in the 1st aspect is mentioned.

  Application and filling of the photocurable resin composition into the through holes can be performed in the same manner as in step I). The filling amount of the resin into the through-hole is an amount that is at least the height of the other pad end surface C ′. Usually, the reference surface 4 (FIG. 4c) is defined with the surface including the pad end surface C ′ as the reference surface. The amount of the upper resin layer is 50 to 500 μm.

Thereafter, in the same manner as in step I), a flat material B ′ (FIG. 4d) is placed on the surface of the printed wiring board on the side having the pad end surface C ′.
Examples of the flat material B ′ include those exemplified in the first embodiment.
Thereafter, similarly to the first embodiment, the hard roll 5 (FIG. 4d) is moved on the flat material B ′ (FIG. 4d).

  By the roll movement, the coating resin on the pad end surface C ′ is handled and thinned to a desired layer thickness. Specifically, with the surface including the pad end surface C ′ as a reference surface, the resin layer thickness above the reference surface 4 (FIG. 4e) is preferably 5 μm or less (more preferably 3 μm or less, most preferably 1 μm or less). The hard roll is moved on the flat material B ′.

  Thereafter, in the same manner as in the first embodiment, the resin 3 (FIG. 4e) is exposed through the light-transmitting flat material B (FIG. 4e), and the light-transmitting flat material B is removed in an arbitrary process step after the exposure. The flat material B ′ is removed, and the unexposed resin is removed by development.

As a result, the coating resin shielded by the non-transparent printed wiring board, specifically, the coating resin on the printed wiring board surface excluding the pad end face C ′ is removed (FIG. 4f).
Thereafter, as in the first embodiment, the exposed resin may be further heat-cured.
As described above, the printed wiring board is manufactured from the fourth aspect of the manufacturing method of the present application.

  By the method for manufacturing a printed wiring board according to the present invention, the step 8 (FIG. 5) between the surface of the hole-filling cured resin 6 (FIG. 5) and the surface of the printed wiring board 1 (FIG. 5) or the surface of the hole-filling cured resin 6 (FIG. 6). And a pad 7 (FIG. 6) with a step 8 (FIG. 6) of 5 μm or less (more preferably 3 μm or less, most preferably 1 μm or less), and a substantially flat surface-filled printed wiring board is manufactured. be able to.

Hereinafter, the present invention will be specifically described with reference to examples.
Example 1
Printed wiring board: Non-transparent printed wiring board (Mitsubishi Gas Chemical Company, “ CCL-HL802 ", thickness 100 μm, circuit width 20 μm).

  Composition of photo / thermosetting resin composition: unsaturated group-containing alkali-soluble resin (acid value 100 mgKOH / g) obtained by adding tetrahydrophthalic anhydride to 50% acrylic acid adduct of phenol novolac epoxy resin 30 parts by weight), pentaerythritol triacrylate (70 parts by weight), acryloylmorpholine (20 parts by weight), 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1 (photoinitiator) 2 parts by weight), silicone oil (antifoaming agent, 1 part by weight), bisphenol A type epoxy resin (15 parts by weight), triglycidyl isocyanurate type epoxy resin (15 parts by weight), 2-phenyl-4,5- Dihydroxymethylimidazole (thermal initiator, 5 parts by weight), barium sulfate (30 parts by weight), Ca (70 parts) were mixed and composition prepared by dispersing in a roll mill.

  First, the printed wiring board was placed on a PET film (film thickness: 100 μm, also referred to as “film 1”) and hot-pressed (pressure 5 MPa, 120 ° C., 60 minutes). As a result, the lower pad end face was blocked with the PET film 1.

  Next, the through holes were filled with the photo / thermosetting resin composition by vacuum screen printing. The coating filling amount was such that the resin layer thickness above the reference surface was 200 to 300 μm with the surface including the upper pad end surface as the reference surface.

  Next, another PET film (film thickness: 40 μm, also referred to as “film 2”) was placed on the printed wiring board. As a result, the exposed surface of the coating filling resin was covered with the PET film 2.

  Thereafter, a stainless steel roll (roll diameter: 100 mm) was moved at a speed of 1 m / min while rotating while being pressed against the PET film 2 at a pressure of 0.2 MPa. Due to the roll movement, the surface including the upper pad end surface was taken as a reference surface, and the resin layer thickness above this reference surface became 3 μm or less.

Then, light irradiation (irradiation light wavelength 365 nm, irradiation amount 1600 mJ / cm ² ) was performed from the film 1 side toward the resin.
Then, the films 1 and 2 were peeled from the printed wiring board.

Thereafter, the surface of the printed wiring board was developed with an aqueous sodium carbonate solution to remove unexposed resin. As a result, only the coating resin on the upper pad end surface was left, and other coating resins on the surface of the printed wiring board were removed.
Thereafter, the exposed resin was further heat-cured (150 ° C., 60 minutes).

  When the printed wiring board manufactured as described above was observed with an electron microscope (1000 times), the level difference between the hole-filled cured resin surface and the pad surface was 2.6 μm or less, and was further damaged, bent, or deformed. And no dimensional change was observed.

Comparative example 1
The photo / thermosetting resin composition was printed on the printed wiring board using a polyester screen (180 mesh) and filled into the through holes.

Then, light irradiation (irradiation light wavelength 365nm, irradiation amount 1600mJ / cm < ² >) was performed from both surfaces of the printed wiring board, and the photocuring hole-filled printed wiring board was produced.

  After that, the unnecessary photo-curing resin portion protruding from the surface of the printed wiring board was tried to be removed by polishing using a polishing machine equipped with a ceramic buff (manufactured by Shoko C & E Co., Ltd., # 600, two each above and below). It was.

  However, the printed wiring board warped when it passed through the first buff, and as a result, the printed wiring board was clogged in the polishing machine and was not discharged (conveyed). When the printed wiring board was taken out from the polishing machine, the printed wiring board was bent and destroyed.

Comparative example 2
In the same manner as in Comparative Example 1, a photocured hole-filled printed wiring board was produced.
This printed wiring board was placed on a jig plate, and unnecessary photocured resin portions protruding from the surface of the printed wiring board were removed by polishing using a belt sander polishing machine (polishing belt # 800).

  When the printed wiring board manufactured as described above was observed with an electron microscope (1000 times), the entire printed wiring board was warped and further polished to a circuit part of 20 μm, and the part where the circuit was lost (worn out). was there.

DESCRIPTION OF SYMBOLS 1 Printed wiring board 2 Through-hole 3 Photocurable resin composition 4 Reference | standard surface containing an opening end surface or a pad end surface 5 Hard roll 6 Filling hardening resin 7 Pad 8 Level difference A, A 'Open end surface B of a through-hole Translucent flat material B 'Flat material C, C' Pad end face

Claims (11)

  A non-transparent printed wiring board having a through hole is placed on the translucent flat member B so that one open end surface A of the through hole faces the translucent flat member B, and a photocurable resin composition is placed on the translucent flat member B. Coating and filling the through hole, placing another flat material B ′ on the surface of the printed wiring board including the other opening end face A ′ of the through hole, moving the hard roll on the flat material B ′, and translucent flat Printed wiring board characterized in that resin is exposed through material B, translucent flat material B is removed at any step after exposure, flat material B ′ is removed, and unexposed resin is removed by development. Manufacturing method. I) A non-transparent printed wiring board in which a pad is provided on at least a part of the peripheral edge of one opening end surface A of the through hole, and the other opening end surface A ′ of the through hole faces the translucent flat member B. As described above, the photocurable resin composition is placed on the translucent flat material B, and is applied and filled in the through-hole so that the resin is filled at least at the height of the pad end surface, and on the printed wiring board surface including the pad end surface. Other flat material B ′ is placed, or II) a non-transparent printed wiring board in which a pad is provided on at least a part of the peripheral edge of one opening end surface A of the through hole, and the pad end surface is translucent flat material B Is placed on the translucent flat material B so as to face the other, and the photocurable resin composition is applied and filled in the through hole, and another flat material is formed on the surface of the printed wiring board including the other opening end surface A ′ of the through hole. Put B ',
The hard roll is moved on the flat material B ′, the resin is exposed through the light transmissive flat material B, the light transmissive flat material B is removed at any step after the exposure, and the flat material B ′ is removed. A method for producing a printed wiring board, wherein unexposed resin is removed by development.   A non-transparent printed wiring board in which pads are provided on at least a part of the peripheral edge of both opening end surfaces of the through hole, and a translucent flat material such that one pad end surface C faces the translucent flat material B A photocurable resin composition is applied to and filled in the through-hole so that the resin is filled at least the height of the other pad end surface C ′, and the other is placed on the surface of the printed wiring board including the pad end surface C ′. The flat material B ′ is placed, the hard roll is moved on the flat material B ′, the resin is exposed through the translucent flat material B, and the translucent flat material B is applied in an arbitrary process step after the exposure. A method for producing a printed wiring board, comprising removing the flat material B ′ and removing unexposed resin by development.   The method for producing a printed wiring board according to any one of claims 1 to 3, wherein the printed wiring board is a board having a thickness of 0.2 mm or less or a PKG board. The photocurable resin composition is a solventless method for producing a printed wiring board according to claim 1, characterized in that the alkali developability.   The photocurable resin composition has an [I] unsaturated group and an alkali-soluble resin, [II] (meth) acrylic monomers, [III] a photoinitiator, [IV] an epoxy compound, and [V The method for producing a printed wiring board according to claim 5, wherein the printed wiring board is a light / thermosetting resin composition containing a thermosetting agent.   The method for manufacturing a printed wiring board according to claim 1, wherein the hard roll is made of metal.   Using the surface including the opening end surface of the through hole or the pad end surface on which the flat material B ′ is placed as a reference surface, a hard roll is placed on the flat material B ′ so that the resin layer thickness above this reference surface is 5 μm or less. The printed wiring board manufacturing method according to claim 1, wherein the printed wiring board is moved.   The method for producing a printed wiring board according to any one of claims 1 to 8, wherein the resin is further subjected to heat defoaming or vacuum defoaming after coating and filling with the photocurable resin composition.   The method for manufacturing a printed wiring board according to claim 1, wherein after the unexposed resin is removed by development, the exposed resin is further heat-cured.   The printed wiring board manufactured with the manufacturing method of the printed wiring board in any one of Claims 1-10.

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