JP2013004913A - Manufacturing method of laminated plate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To stably manufacture laminated plates with excellent surface smoothness and credibility.SOLUTION: A manufacturing method of a laminated plate 100 continuously performs the following steps: a laminating step of obtaining a laminate by laminating a prepreg 200 for buildup formed of a thermosetting resin on a circuit formation surface 103 of a core layer 102 having the circuit formation surface 103 on one side or both sides under heating and pressuring conditions and a smoothing step of smoothing a surface of the laminated prepreg 200 for buildup. This manufacturing method then performs a curing step of further advancing curing of the thermosetting resin by heating a laminate. The curing step gradually raises a temperature of the laminate from an initial temperature to a maximum reaching temperature.

Description

  The present invention relates to a method for manufacturing a laminated board.

  As a manufacturing method of a laminated board for a multilayer printed wiring board, a manufacturing method by a built-up method in which insulating layers and conductor layers are alternately stacked on a circuit board as a core layer is known. According to this method, an adhesive film in which a thermosetting resin layer is formed on a plastic film is mainly used for forming an insulating layer. This adhesive film is laminated (laminated) on the core layer, the plastic film is peeled off, and then the thermosetting resin is thermoset to form an insulating layer.

  On the other hand, due to recent needs for downsizing electronic devices and electronic components, multilayer printed wiring boards tend to be made thinner and thinner, for example, requiring a thinner or omitted core layer. In order to maintain the mechanical strength of the multilayer printed wiring board as the thickness of the multilayer printed wiring board progresses in this way, as a material for forming the insulating layer, a sheet-like fiber substrate and a heat are used instead of the above adhesive film. It is effective to apply a prepreg provided with a curable resin.

  For example, in Patent Document 1 (Japanese Patent Laid-Open No. 2009-231240), a cured prepreg layer obtained by compressing and thermosetting a prepreg impregnated with a thermosetting resin composition on a sheet-like fiber substrate, and a cured prepreg layer are formed on both surfaces. Further, it is described that an insulating resin sheet having a thermosetting resin layer is used for manufacturing a multilayer printed wiring board. It has been shown that the use of such an insulating resin sheet can suppress the exposure of the sheet-like fiber base material even when the surface of the formed insulating layer is roughened.

  In Patent Document 2 (International Publication No. 2009/035014), an adhesive sheet in which a prepreg is formed on a support film is laminated on a circuit board, and then the prepreg is thermally cured without peeling off the support film. The formation of a layer is described. When such an adhesive sheet is used, even when a thermosetting resin composition having fluidity enough to embed circuit irregularities is used in the prepreg, the resin does not ooze out from the prepreg in the thermosetting process. It has been shown that layers can be formed.

JP 2009-231240 A International Publication No. 2009/035014 Pamphlet

  When a prepreg is used as the insulating layer, since the prepreg includes a fiber base material having a high elastic modulus such as glass cloth, the elastic modulus of the laminate surface is large. Therefore, there are cases where smoothing cannot be performed sufficiently in the step of smoothing the surface of the laminate. Therefore, it was necessary to smooth the laminate while ensuring the fluidity of the prepreg by keeping the viscosity of the prepreg dynamic viscoelasticity test low.

  When the viscosity of the prepreg in the dynamic viscoelasticity test is kept low, the curing conditions such as the heating temperature and the heating time are set in order to complete the curing of the thermosetting resin in the prepreg in the subsequent curing process. It was necessary to use strict conditions. For example, Patent Documents 1 and 2 describe that a prepreg is thermally cured at 180 ° C. for 30 minutes using a hot air circulating furnace.

  However, if the thermosetting process is performed under such severe conditions, the rapid curing of the thermosetting resin in the prepreg may occur locally, resulting in locally different cured product characteristics or resulting laminates. In some cases, a large amount of residual stress was generated on the plate. Depending on the degree of non-uniform hardening and residual stress, stress strain with plated copper may occur, and heat resistance and moisture resistance reliability may deteriorate. When heat resistance and moisture resistance reliability deteriorate, peeling occurs during reflow during mounting, and the mounting yield decreases.

  Furthermore, when the viscosity of the prepreg for buildup is kept low by the dynamic viscoelasticity test, a large amount of unreacted components and solvents remain, so the surface of the laminate swells due to their volatilization during the curing process. There was a case. In this case, unevenness due to this blistering is generated on the surface of the laminate, and the thickness of the resulting laminated plate varies.

  This invention is made | formed in view of the said situation, and provides the manufacturing method of a laminated board which can produce stably the laminated board excellent in surface smoothness and excellent in reliability. .

According to the present invention,
A laminating step of laminating a build-up prepreg formed of a thermosetting resin under heat and pressure on the circuit forming surface of the core layer having a circuit forming surface on one or both sides; and
A smoothing step of smoothing the surface of the laminated prepreg for buildup is continuously performed, and then
A method of manufacturing a laminated board that heats the laminated body and performs a curing step of further proceeding with curing of the thermosetting resin,
In the curing step, there is provided a method for manufacturing a laminate, wherein the temperature of the laminate is gradually raised from an initial temperature to a maximum temperature.

According to the present invention, by gradually raising the temperature of the laminate from the initial temperature to the highest temperature in the curing step, while suppressing the occurrence of swelling and residual stress in the laminate, The thermosetting resin in the prepreg can be cured.
By suppressing the swelling generated on the surface of the laminate, a laminate having excellent surface smoothness can be obtained. Further, by suppressing the occurrence of residual stress, a laminated board having excellent reliability can be obtained.

  ADVANTAGE OF THE INVENTION According to this invention, the manufacturing method of a laminated board which can produce stably the laminated board excellent in surface smoothness and excellent in reliability is provided.

It is sectional drawing which shows the manufacturing process of the laminated board in this embodiment. It is sectional drawing which shows the structure of the prepreg for buildup in this embodiment.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In all the drawings, the same reference numerals are given to the same components, and the description will be omitted as appropriate.

(Laminate production method)
An outline of a method for manufacturing a laminated board in the present embodiment will be described. FIG. 1 is a cross-sectional view showing a manufacturing process of the laminated plate 100 in the present embodiment.
First, a prepreg for buildup comprising a thermosetting resin layer 201, a fiber substrate 202, and a thermosetting resin layer 203 on a circuit forming surface 103 of a core layer 102 having a circuit 101 formed on one side or both sides under heat and pressure. 200 is laminated to obtain a laminate (lamination process). Subsequently, the surface of the laminated buildup prepreg 200 is smoothed by hot pressing through a pair of opposing metal members (smoothing step). Thereafter, the laminate is heated to further advance the curing of the thermosetting resin (curing step), and the laminate 100 in the present embodiment can be obtained.

  Here, in the curing step, the temperature of the laminate is gradually raised from the initial temperature to the maximum temperature. By doing so, the thermosetting resin in the prepreg can be cured while suppressing the occurrence of swelling and residual stress of the laminate on the surface of the laminate. By suppressing the swelling generated on the surface of the laminate, the laminate 100 having excellent surface smoothness can be obtained. Moreover, the laminated board 100 excellent in reliability is obtained by suppressing generation | occurrence | production of a residual stress.

  Further, depending on the amount of residual stress generated, the laminated plate may be warped. In particular, this warp may be noticeably generated after the laser via forming step. When warpage occurs in the laminate, the warpage of the semiconductor package increases and the mounting yield decreases. Since the residual stress which generate | occur | produces in a laminated board can be suppressed when the manufacturing method of the laminated board in this embodiment is used, the laminated board by which curvature was suppressed can be obtained.

  It continues and demonstrates each material which comprises the laminated board 100 in this embodiment.

(Core layer)
The core layer 102 is a sheet having a circuit forming surface 103 in which one or both surfaces of a glass epoxy substrate, a metal substrate, a polyester substrate, a polyimide substrate, a BT resin substrate, a thermosetting polyphenylene ether substrate or the like are patterned. Say. The core layer 102 further includes an inner layer circuit board of an intermediate product on which the buildup layer 300 and the circuit 101 are to be formed.

  Although the manufacturing method of the core layer 102 is not specifically limited, For example, the core layer which has metal foil on both surfaces is used, A predetermined place is opened with a drill machine, and conduction | electrical_connection of both surfaces of a core layer is aimed at by electroless plating. Then, the circuit 101 is formed by etching the metal foil. Note that the inner layer circuit portion can be suitably used after being subjected to a roughening process such as a blackening process. The opening can be appropriately filled with a conductor paste or a resin paste.

(Build-up prepreg)
FIG. 2 is a cross-sectional view showing the configuration of the buildup prepreg 200 in the present embodiment. The prepreg 200 includes a fiber base material 202, a thermosetting resin layer 201 and a thermosetting resin layer 203 provided on both surfaces of the fiber base material 202. The prepreg 200 can be formed by impregnating the fiber base material 202 with the resin composition P.
Hereinafter, the resin composition P used for the prepreg 200 will be described. However, the thermosetting resin layer 201 and the thermosetting resin layer 203 provided on both surfaces of the fiber base 202 may be the same as each other, Each may be different.

  The resin composition P used for the prepreg 200 contains (A) an epoxy resin. (A) As an epoxy resin, for example, bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, bisphenol E type epoxy resin, bisphenol M type epoxy resin, bisphenol P type epoxy resin, bisphenol Z type epoxy Bisphenol type epoxy resin such as resin, phenol novolak type epoxy resin, novolak type epoxy resin such as cresol novolak type epoxy resin, arylalkylene type epoxy resin such as biphenyl type epoxy resin and biphenyl aralkyl type epoxy resin, naphthalene type epoxy resin, anthracene Type epoxy resin, phenoxy type epoxy resin, dicyclopentadiene type epoxy resin, norbornene type epoxy resin, adamantane type epoxy resin Such as epoxy resins and fluorene type epoxy resins. One of these can be used alone, or two or more can be used in combination.

  (A) Although content of an epoxy resin is not specifically limited, It is preferable that it is 15 to 80 weight% of the resin composition P whole. More preferably, it is 25 to 50 weight%. In addition, it is preferable to use a liquid epoxy resin such as a liquid bisphenol A type epoxy resin or a bisphenol F type epoxy resin because impregnation into the fiber base material 202 can be improved. The content of the liquid epoxy resin is more preferably 3% by weight or more and 14% by weight or less of the entire resin composition P. Moreover, when solid bisphenol A type epoxy resin and bisphenol F type epoxy resin are used in combination, adhesion to the conductor can be improved.

  The resin composition P may contain a thermosetting resin other than an epoxy resin such as a melamine resin, a urea resin, or a cyanate ester resin, and it is preferable to use a cyanate ester resin in combination. Although it does not specifically limit as a kind of cyanate resin, For example, bisphenol-type cyanate resin, such as a novolak-type cyanate resin, a bisphenol A-type cyanate resin, a bisphenol E-type cyanate resin, a tetramethylbisphenol F-type cyanate resin, etc. can be mentioned. Among these, phenol novolac type cyanate resin is preferable from the viewpoint of low thermal expansion. Further, other cyanate resins may be used alone or in combination of two or more, and are not particularly limited. The cyanate resin is preferably 8% by weight or more and 20% by weight or less of the entire resin composition P.

  The resin composition P preferably contains (B) an inorganic filler. (B) Examples of inorganic fillers include silicates such as talc, fired clay, unfired clay, mica, and glass, oxides such as titanium oxide, alumina, silica, and fused silica, calcium carbonate, magnesium carbonate, and hydrotalc. Carbonate such as site, hydroxide such as aluminum hydroxide, magnesium hydroxide, calcium hydroxide, sulfate or sulfite such as barium sulfate, calcium sulfate, calcium sulfite, zinc borate, barium metaborate, aluminum borate And borate salts such as calcium borate and sodium borate, nitrides such as aluminum nitride, boron nitride, silicon nitride and carbon nitride, titanates such as strontium titanate and barium titanate. One of these can be used alone, or two or more can be used in combination.

  Among these, silica is particularly preferable, and fused silica (especially spherical fused silica) is preferable in terms of excellent low thermal expansion. Its shape is crushed and spherical, but in order to reduce the melt viscosity of the resin composition P in order to ensure the impregnation of the fiber substrate, a method of use that suits the purpose, such as using spherical silica, is adopted. The

  (B) Although the average particle diameter of an inorganic filler is not specifically limited, 0.01 micrometer or more and 3 micrometers or less are preferable, and 0.02 micrometer or more and 1 micrometer or less are especially preferable. (B) By making the particle size of an inorganic filler 0.01 micrometer or more, a varnish can be made low viscosity and the fiber base material can be made to impregnate the resin composition P favorably. Moreover, by setting it as 3 micrometers or less, sedimentation etc. of (B) inorganic filler can be suppressed in a varnish. This average particle diameter can be measured by, for example, a particle size distribution meter (manufactured by Shimadzu Corporation, product name: laser diffraction particle size distribution measuring device SALD series).

  In addition, the inorganic filler (B) is not particularly limited, but an inorganic filler having a monodispersed average particle diameter can also be used, and an inorganic filler having a polydispersed average particle diameter can also be used. Furthermore, one or two or more inorganic fillers having an average particle size of monodisperse and / or polydisperse can be used in combination.

  Furthermore, spherical silica (especially spherical fused silica) having an average particle size of 3 μm or less is preferable, and spherical fused silica having an average particle size of 0.02 μm or more and 1 μm or less is particularly preferable. Thereby, the filling property of (B) inorganic filler can be improved.

  (B) Although content of an inorganic filler is not specifically limited, 2 to 70 weight% of the whole resin composition P is preferable, and 5 to 60 weight% is especially preferable. When the content is within the above range, particularly low thermal expansion and low water absorption can be achieved. Further, if necessary, the thermosetting resin layer 201 and the thermosetting resin layer 203 can change the content of the inorganic filler (B) to achieve both adhesion to the conductor and low thermal expansion.

  The resin composition P used for the prepreg 200 is not particularly limited, but (C) a coupling agent is preferably used. (C) Coupling agent improves (A) epoxy resin and (B) inorganic filling with respect to fiber base material by improving the wettability of the interface between (A) epoxy resin and (B) inorganic filler. The material can be fixed uniformly, and the heat resistance, particularly the solder heat resistance after moisture absorption can be improved.

  (C) Any coupling agent can be used as long as it is usually used. Specifically, an epoxy silane coupling agent, a cationic silane coupling agent, an amino silane coupling agent, a titanate coupling agent, and a silicone oil type. It is preferable to use one or more coupling agents selected from coupling agents. Thereby, the wettability with the interface of (B) inorganic filler can be made high, and thereby heat resistance can be improved more.

  (C) The amount of coupling agent added depends on the specific surface area of (B) inorganic filler, and is not particularly limited. However, (B) 0.05% by weight or more and 3% by weight based on 100 parts by weight of inorganic filler. The following is preferable, and 0.1 to 2% by weight is particularly preferable. By setting the content to 0.05% by weight or more, (B) the inorganic filler can be sufficiently covered, and the heat resistance can be improved. By setting the content to 3% by weight or less, the reaction proceeds satisfactorily and a decrease in bending strength or the like can be prevented.

  The resin composition P can further use (D) a phenolic curing agent. As the phenolic curing agent, known or commonly used phenolic novolac resins, alkylphenol novolac resins, bisphenol A novolac resins, dicyclopentadiene type phenol resins, zyloc type phenol resins, terpene modified phenol resins, polyvinylphenols, etc. Can be used in combination.

  (D) As for the compounding quantity of a phenol hardening | curing agent, it is preferable in (A) the equivalent ratio (phenolic hydroxyl group equivalent / epoxy group equivalent) with an epoxy resin being 0.1-1.0. As a result, there remains no unreacted phenol curing agent, and the moisture absorption heat resistance is improved. When the resin composition P uses an epoxy resin and a cyanate resin in combination, the range of 0.2 to 0.5 is particularly preferable. This is because the phenol resin not only acts as a curing agent but also promotes curing of the cyanate group and the epoxy group.

  In the resin composition P, (E) a curing catalyst may be used as necessary. (E) A well-known thing can be used as a curing catalyst. For example, organic metal salts such as zinc naphthenate, cobalt naphthenate, tin octylate, cobalt octylate, bisacetylacetonate cobalt (II), trisacetylacetonate cobalt (III), triethylamine, tributylamine, diazabicyclo [2,2 , 2] tertiary amines such as octane, 2-phenyl-4-methylimidazole, 2-ethyl-4-methylimidazole, 2-ethyl-4-ethylimidazole, 2-phenyl-4-methylimidazole, 2-phenyl Imidazoles such as -4-methyl-5-hydroxyimidazole and 2-phenyl-4,5-dihydroxyimidazole, phenol compounds such as phenol, bisphenol A and nonylphenol, acetic acid, benzoic acid, salicylic acid, paratoluenesulfonic acid, etc. Such as organic acids, or mixtures thereof. As the curing catalyst, one kind including these derivatives can be used alone, or two or more kinds including these derivatives can be used in combination.

(E) Although content of a curing catalyst is not specifically limited, 0.05 weight% or more of the whole resin composition P is preferable, and 0.08 weight% or more is especially preferable. By setting the content of the curing catalyst to the lower limit value or more, a build-up prepreg having a complex dynamic viscosity η1 by a dynamic viscoelasticity test of 20 Pa · s or more can be obtained more efficiently. Furthermore, curing can be sufficiently promoted.
The content of the curing catalyst is not particularly limited, but is preferably 5% by weight or less, particularly preferably 2% by weight or less, based on the entire resin composition P. By setting it to the upper limit value or less, a prepreg for buildup having a complex dynamic viscosity η1 by a dynamic viscoelasticity test of 300 Pa · s or less can be obtained more efficiently. Further, it is possible to prevent the storage stability of the prepreg 200 from being lowered.

  Resin composition P is composed of a thermoplastic resin such as phenoxy resin, polyimide resin, polyamideimide resin, polyamide resin, polyphenylene oxide resin, polyethersulfone resin, polyester resin, polyethylene resin, polystyrene resin, styrene-butadiene copolymer, styrene. -Polystyrene thermoplastic elastomers such as isoprene copolymers, thermoplastic elastomers such as polyolefin thermoplastic elastomers, polyamide elastomers and polyester elastomers, dienes such as polybutadiene, epoxy-modified polybutadiene, acrylic-modified polybutadiene, and methacryl-modified polybutadiene An elastomer may be used in combination. Among these, heat-resistant polymer resins such as phenoxy resin, polyimide resin, polyamideimide resin, polyamide resin, polyphenylene oxide resin, and polyethersulfone resin are preferable. Thereby, the thickness uniformity of the prepreg is excellent, and as a wiring board, the heat resistance and the insulating property of the fine wiring are excellent. In addition, the resin composition P may contain additives other than the above components such as pigments, dyes, antifoaming agents, leveling agents, ultraviolet absorbers, foaming agents, antioxidants, flame retardants, and ion scavengers as necessary. Things may be added.

  The fiber base material 202 impregnated with the resin composition P is not particularly limited, but glass fiber base materials (glass cloth) such as glass woven fabric and glass nonwoven fabric, polyamide resin fibers, aromatic polyamide resin fibers, wholly aromatic polyamide resins. Consists of woven or non-woven fabrics mainly composed of polyamide resin fibers such as fibers, polyester resin fibers, aromatic polyester resin fibers, polyester resin fibers such as wholly aromatic polyester resin fibers, polyimide resin fibers, and fluororesin fibers. And organic fiber base materials such as paper base materials mainly composed of synthetic fiber base materials, kraft paper, cotton linter paper, mixed paper of linter and kraft pulp, and the like. Among these, glass cloth is preferable. Thereby, a prepreg having low water absorption, high strength, and low thermal expansion can be obtained.

  Examples of the glass constituting the glass cloth include E glass, C glass, A glass, S glass, D glass, NE glass, T glass, and H glass. Among these, E glass or T glass is preferable. Thereby, the high elasticity of a prepreg can be achieved and the thermal expansion coefficient of a prepreg can be reduced.

  The method of impregnating the fiber base material 202 with the resin composition P includes, for example, a method of preparing the resin varnish V using the resin composition P, immersing the fiber base material 202 in the resin varnish V, and a method of applying with various coaters And a method of spraying with a spray. Among these, the method of immersing the fiber base material 202 in the resin varnish V is preferable. Thereby, the impregnation property of the resin composition P with respect to the fiber base material 202 can be improved. In addition, when the fiber base material 202 is immersed in the resin varnish V, a normal impregnation coating equipment can be used.

  The solvent used in the resin varnish V desirably has good solubility in the resin component in the resin composition P, but a poor solvent may be used within a range that does not adversely affect the resin varnish V. Examples of the solvent exhibiting good solubility include acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, cyclopentanone, tetrahydrofuran, dimethylformamide, dimethylacetamide, dimethyl sulfoxide, ethylene glycol, cellosolve, and carbitol.

  The solid content of the resin varnish V is not particularly limited, but the solid content of the resin composition P is preferably 20% by weight to 80% by weight, and particularly preferably 50% by weight to 65% by weight. Thereby, the impregnation property to the fiber base material 202 of the resin varnish V can further be improved. Although the predetermined temperature which impregnates the fiber base material 202 with the resin composition P is not specifically limited, For example, the prepreg 200 can be obtained by drying at 90 degreeC or more and 220 degrees C or less. The thickness of the prepreg 200 is preferably 20 μm or more and 100 μm or less.

  In the prepreg 200, the thickness of the thermosetting resin layer 201 and the thermosetting resin layer 203 may be substantially the same with the fiber base 202 as the center, and the fiber base 202 may be different. May be. In other words, in the prepreg 200, the center of the fiber base in the thickness direction may be shifted from the center of the prepreg in the thickness direction.

  The prepreg 200 may be a laminate of a plurality of sheets via metal foil or film. Metal foils include, for example, copper and copper alloys, aluminum and aluminum alloys, silver and silver alloys, gold and gold alloys, zinc and zinc alloys, nickel and nickel alloys, tin and tin alloys, iron and iron Metal foils such as alloy alloys can be mentioned. Among these, copper foil is particularly preferable.

  After laminating a plurality of sheets via a metal foil or film, heating and pressurization may be performed. Although the temperature to heat is not specifically limited, 120 to 230 degreeC is preferable and especially 150 to 210 degreeC is preferable. Moreover, the pressure to pressurize is not particularly limited, but is preferably 1 MPa or more and 5 MPa or less, and particularly preferably 2 MPa or more and 4 MPa or less. By using such a prepreg 200, it is possible to obtain a laminate having excellent dielectric properties, mechanical and electrical connection reliability at high temperature and high humidity.

  The prepreg 200 may be wound and laminated in a roll shape. At this time, a support base material may be provided on one side or both sides, and the support base material may be wound and laminated. Examples of a method for winding and laminating the prepreg 200 in a roll shape include the following.

After impregnating the fiber base material 202 with the resin composition P, the fiber base material 202 is conveyed to a roll type laminator together with the support base material, and the support base material is continuously pressed and heated on the prepreg 200 with a metal roll or an elastic material roll. Laminate by. Then, the prepreg 200 can be wound and laminated | stacked in roll shape by winding up in roll shape.
In addition, the sheet-like fiber base material 202 wound up in a roll shape is continuously conveyed by a roll, and impregnated and dried in the resin varnish V to produce a prepreg 200 wound and laminated in a roll shape. Also good.

  As the support substrate, a plastic film can be used. For example, polyesters such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), polycarbonate (PC), acrylic resin (PMMA), cyclic polyolefin, triacetyl cellulose ( TAC), polyether sulfide (PES), polyether ketone, polyimide and the like. Among these, a PET film and a PEN film are preferable, and a PET film is particularly preferable. The support substrate may be subjected to mat treatment or corona treatment on the laminated surface of the thermosetting resin layers 201 and 203. In order to peel off the supporting substrate after the prepreg 200 is thermally cured, a release layer may be provided on the surface in contact with the prepreg 200.

  Moreover, when providing a support base material in one side, you may provide a protective material in the other surface. In this case, it is conveyed to the roll type laminating apparatus so that the supporting surface is in contact with the second surface S2 and the protective material is in contact with the first surface S1, and a metal roll or an elastic material roll is formed from both the supporting substrate and the protective material. It can be laminated by pressurizing and heating. As the protective material, for example, polyolefins such as polyethylene, polypropylene and polyvinyl chloride, polyesters such as PET and PEN, plastic films such as PC and polyimide can be used. The thickness of the protective material is preferably in the range of 5 μm to 30 μm.

Then, each process of the manufacturing method of a laminated board is each demonstrated in detail.
(Lamination process)
First, a prepreg 200 wound in a roll shape is prepared and conveyed to a laminator together with a sheet-like core layer 102. The laminator includes a pair of opposing elastic members, and is laminated by heating and pressing through the elastic member in a state where the core layer 102 and the prepreg 200 are sandwiched between the elastic members.
Since the elastic member is flexible and follows the uneven shape of the circuit 101 formed on the core layer, the core layer 102 and the prepreg 200 can be further adhered to each other.

Here, the build-up prepreg 200 at the stage of completing the laminating process is a complex dynamic viscosity minimum value η1 (hereinafter, referred to as “dynamic complex elasticity test”) in a measurement range of 50 to 200 ° C. and a frequency of 62.83 rad / sec. (Sometimes simply referred to as complex dynamic viscosity η1) is preferably 20 Pa · s or more, more preferably 30 Pa · s or more, and particularly preferably 40 Pa · s or more. By setting the complex dynamic viscosity η1 to be equal to or greater than the above lower limit value, the fluidity of the thermosetting resin in the prepreg does not become too large. The laminate can be smoothed.
Further, the build-up prepreg 200 at the stage of completing the laminating process preferably has a minimum value η1 of complex dynamic viscosity in a measurement range of 50 to 200 ° C. and a frequency of 62.83 rad / sec by a dynamic viscoelasticity test. It is 300 Pa · s or less, more preferably 200 Pa · s or less, and particularly preferably 100 Pa · s or less. By setting the complex dynamic viscosity η1 to be equal to or less than the above upper limit value, the fluidity of the thermosetting resin in the prepreg can be secured, and the unevenness derived from the fiber base material 202 does not remain on the surface of the laminate, and the laminate can be stably formed. Can be smoothed.

  In addition, the reaction of the prepreg for buildup 200 may proceed due to the heat remaining in the laminated body even after the lamination process is completed and before the smoothing process is performed. Therefore, the stage where the above-described laminating process is completed represents a state immediately before entering the smoothing process. Therefore, the build-up prepreg 200 does not need to satisfy the complex dynamic viscosity η1 immediately after the laminating process, and may satisfy the complex dynamic viscosity η1 immediately before the smoothing process.

As a laminator, it is preferable to use a laminator (vacuum laminator) that is heated and pressurized under vacuum. As the elastic member, for example, a plate-shaped or roll-shaped rubber can be used.
Although heating temperature is not specifically limited, 80 degreeC or more is preferable and 90 degreeC or more is more preferable. By setting it to the above lower limit value or more, a build-up prepreg having a complex dynamic viscosity minimum value η1 by a dynamic viscoelasticity test of 20 Pa · s or more can be obtained more efficiently. The heating temperature is preferably 150 ° C. or lower, and more preferably 140 ° C. or lower. By setting it to the upper limit value or less, a prepreg for buildup having a complex dynamic viscosity η1 by a dynamic viscoelasticity test of 300 Pa · s or less can be obtained more efficiently.
The heating time is not particularly limited, but is preferably 10 seconds or longer, and more preferably 30 seconds or longer. By setting it as the said lower limit or more, the prepreg for buildups whose complex dynamic viscosity (eta) 1 by a dynamic viscoelasticity test is 30 Pa.s or more can be obtained still more efficiently. The heating time is not particularly limited, but is preferably 500 seconds or shorter, and more preferably 300 seconds or shorter. By setting it to the upper limit value or less, a prepreg for buildup having a complex dynamic viscosity η1 by a dynamic viscoelasticity test of 300 Pa · s or less can be obtained more efficiently.
The pressure is preferably in the range of 0.4 MPa to 1.5 MPa.

  Said laminator process can be performed using the commercially available vacuum laminator. For example, a vacuum pressurizing laminator provided in Nichigo-Morton CPV300 or an equivalent thereof can be used.

(Smoothing process)
After the laminator process, the thermosetting resin layer 201 and the thermosetting resin layer 203 that form the prepreg 200 are softened and deformed into irregularities following the circuit 101 formed on the core layer 102. Therefore, the laminated body is smoothed by hot pressing the laminated buildup layer 300 and the core layer 102 via a pair of opposing metal members.
A smoothing process is performed by heating and pressurizing a laminated body through a metal member under atmospheric pressure.

  Here, the build-up prepreg 200 at the stage where the smoothing process is completed is a minimum value of complex dynamic viscosity η2 (hereinafter referred to as “dynamic complex elasticity test”) in a measurement range of 50 to 200 ° C. and a frequency of 62.83 rad / sec. (Sometimes simply referred to as complex dynamic viscosity η2) preferably satisfies η2 ≧ η1 × 1.1. By satisfy | filling the said relationship, the swelling of a laminated body etc. cannot occur easily in a subsequent hardening process, and the laminated board which was further excellent in surface smoothness can be obtained. Moreover, a hardening process can be performed still more efficiently by satisfy | filling the said relationship.

In addition, the build-up prepreg 200 at the stage of completing the smoothing process preferably has a complex dynamic viscosity minimum value η2 by a dynamic viscoelasticity test of 350 Pa · s or more, preferably 400 Pa · s or more. Is more preferable, and is particularly preferably 500 Pa · s or more. By setting the complex dynamic viscosity η2 to be equal to or higher than the above lower limit value, it is possible to obtain a laminated sheet that is less prone to swelling of the laminated body in the subsequent curing step and has a further excellent surface smoothness. Moreover, a hardening process can be performed still more efficiently by satisfy | filling the said relationship.
In addition, the build-up prepreg 200 at the stage where the smoothing process is completed preferably has a complex dynamic viscosity minimum value η2 by a dynamic viscoelasticity test of 50,000 Pa · s or less, and 10,000 Pa · s. More preferably, it is as follows. By setting the complex dynamic viscosity η2 to be equal to or lower than the above upper limit value, the curing process is performed in a state where the stress strain is small, so that a laminated board that is unlikely to swell can be obtained.

  Such a smoothing step can be performed using a commercially available hot press apparatus. For example, a hot press apparatus included in a CPV300 manufactured by Nichigo-Morton or an equivalent thereof can be used.

Although heating temperature is not specifically limited, 80 degreeC or more is preferable and 90 degreeC or more is more preferable. By setting it to the above lower limit value or more, a build-up prepreg having a complex dynamic viscosity η2 by a dynamic viscoelasticity test at the stage of completing the smoothing step of 350 Pa · s or more can be obtained more efficiently. Further, the heating temperature is preferably 180 ° C. or lower, and more preferably 170 ° C. or lower. By setting it to the upper limit value or less, a buildup prepreg having a complex dynamic viscosity η2 by a dynamic viscoelasticity test of 50,000 Pa · s or less can be obtained more efficiently.
The heating time is not particularly limited, but is preferably 10 seconds or longer, and more preferably 30 seconds or longer. By setting it to the above lower limit value or more, a build-up prepreg having a complex dynamic viscosity η2 by a dynamic viscoelasticity test at the stage of completing the smoothing step of 350 Pa · s or more can be obtained more efficiently. The heating time is not particularly limited, but is preferably 500 seconds or shorter, and more preferably 300 seconds or shorter. By setting it to the upper limit or less, a build-up prepreg having a complex dynamic viscosity η2 by a dynamic viscoelasticity test at the stage of completing the smoothing step of 50,000 Pa · s or less can be obtained more efficiently.
The pressure is preferably in the range of 0.4 MPa to 1.5 MPa.

  Moreover, it is preferable that the time of the lamination process which combined vacuum drawing and pressurization time, and the time of the smoothing process are equal. By carrying out like this, since the line speed which conveys a laminated body can be made constant, a lamination process and a smoothing process can be performed efficiently efficiently continuously.

(Curing process)
After the smoothing step, the thermosetting resin layer 201 and the thermosetting resin layer 203 forming the build-up prepreg 200 are further heated to be cured. A hardening process is performed by heating a laminated body under atmospheric pressure.

  In the curing step in the present embodiment, the temperature of the laminate is gradually raised from the initial temperature to the highest temperature. By doing so, as described above, the thermosetting resin layer 201 and the thermosetting resin layer 203 that form the build-up prepreg 200 while suppressing the occurrence of swelling and residual stress in the laminate as described above. Can be cured.

  The initial temperature is not particularly limited as long as it does not cause a rapid curing reaction. In the case where the curing step is performed after the temperature of the laminate is cooled to around room temperature after the smoothing step, the initial temperature is preferably around room temperature. For example, it is 0 degreeC or more and 40 degrees C or less.

When the curing process is performed after the smoothing process, the curing process does not have to be performed after the temperature of the laminated body has cooled to near room temperature. In that case, 40 degreeC or more is preferable and 60 degreeC or more is more preferable. By setting it to the above lower limit value or more, the thermosetting resin layer can be cured more efficiently while suppressing the occurrence of swelling and residual stress of the laminate on the surface of the laminate.
The initial temperature is not particularly limited, but is preferably 90 ° C. or less, and more preferably 80 ° C. or less. By setting it to the upper limit value or less, rapid temperature rise of the laminate is unlikely to occur, and curing of the thermosetting resin layer is advanced while further suppressing the occurrence of swelling and residual stress of the laminate. be able to.

The maximum temperature reached is not particularly limited, but is preferably 90 ° C or higher, more preferably 120 ° C or higher. By setting it to the above lower limit value or more, curing can be sufficiently promoted.
Moreover, although the maximum attainment temperature is not specifically limited, 230 degrees C or less is preferable and 200 degrees C or less is more preferable. By setting it to the upper limit value or less, curing of the thermosetting resin layer can be promoted more efficiently while suppressing the occurrence of swelling and residual stress in the laminate.

The average rate of temperature increase from the initial temperature to the highest temperature is not particularly limited as long as it does not cause a rapid curing reaction, but is preferably 1 ° C./min or more, and more preferably 3 ° C./min or more. By setting it to the above lower limit value or more, the curing reaction can be advanced more efficiently.
Moreover, the average rate of temperature increase from the initial temperature to the highest temperature is not particularly limited, but is preferably 15 ° C./min or less, and more preferably 12 ° C./min or less. By setting it to the upper limit value or less, curing of the thermosetting resin layer can be promoted more efficiently while suppressing the occurrence of swelling and residual stress in the laminate.
The average rate of temperature increase from the initial temperature to the maximum temperature can be calculated from the time until the surface temperature of the laminate reaches the maximum temperature and the difference between the maximum temperature and the initial temperature. it can. Here, the surface temperature of the laminate can be measured, for example, by embedding a thermocouple in the laminate.

  Note that the rate of temperature increase from the initial temperature to the highest temperature may be constant, or may be changed in at least two stages. In order to advance the curing process more efficiently while suppressing the occurrence of blisters on the surface of the laminate and the residual stress of the laminate, the initial temperature increase rate in the curing process is set to be slow and gradually increases as the curing progresses. It is preferable to set the temperature rate to be high.

Although the heating apparatus of the laminated body in a hardening process is not specifically limited, A well-known heating method is used. For example, a heat drying apparatus such as hot air drying, far infrared heating, high frequency induction heating, or the like can be used.
The method for heating the laminated body is not particularly limited, but the laminated body may be continuously heated by passing it through a horizontal conveyance type heating and drying apparatus, or the laminated body may be left in the heating and drying apparatus and batch-type. You may heat by.

  The method of gradually raising the temperature of the laminated body from the initial temperature to the highest temperature is not particularly limited, and examples thereof include the following methods. For example, when the laminated body is continuously heated by passing it through a horizontal conveyance type heating and drying apparatus, it can be performed using a heating and drying apparatus having two or more units. By increasing the temperature sequentially from the first unit through which the laminate passes, the temperature at which the laminate is heated changes stepwise. Therefore, the temperature of the laminate can be changed stepwise from the initial temperature to the maximum temperature.

  In addition, when the laminated body is left in the heating / drying apparatus and heated in a batch system, for example, by setting a temperature rising profile of the heating / drying apparatus, the temperature of the laminated body is gradually increased from the initial temperature to the highest temperature. The temperature can be increased. It is also possible to reach the maximum temperature of the laminate from the initial temperature by placing the laminate in the initial temperature state in a heating and drying device that has been set to the highest temperature in advance so that the entire laminate is heated evenly. The temperature can be gradually raised to the temperature.

Although hardening time is not specifically limited, 30 minutes or more are preferable and 45 minutes or more are more preferable. By setting it to the above lower limit value or more, curing can be sufficiently promoted.
Moreover, although hardening time is not specifically limited, 75 minutes or less are preferable and 60 minutes or less are more preferable. By setting it to the upper limit value or less, curing of the thermosetting resin layer can be promoted more efficiently while suppressing the occurrence of swelling and residual stress in the laminate.

  Also, in the step of lowering the temperature of the laminated body, it is preferable that the temperature of the laminated body is gradually lowered from the highest temperature. By doing so, the temperature of the laminate can be returned to room temperature while suppressing the occurrence of residual stress in the laminate.

(Laser via formation process)
Next, the hardened buildup layer 300 is irradiated with a laser such as a carbon dioxide laser or a YAG laser to form via holes. Resin residues after laser irradiation are preferably removed with an oxidizing agent such as permanganate or dichromate. Further, the surface of the smooth build-up layer 300 can be simultaneously roughened, and the adhesion of the circuit formed by subsequent metal plating can be improved. The build-up layer 300 can uniformly apply a fine uneven shape in the roughening treatment. In addition, since the surface of the buildup layer 300 has high smoothness, a fine wiring circuit can be formed with high accuracy. Thereafter, a solder resist is formed on the outermost layer, the connection electrode part is exposed so that a semiconductor element can be mounted by exposure and development, nickel gold plating is performed, and the laminate is cut to a predetermined size. .
Since the residual stress which generate | occur | produces in a laminated board will be suppressed if the manufacturing method of the laminated board in this embodiment is used, even if it performs a laser via formation process, it will be hard to generate | occur | produce the laminated board obtained. Therefore, it is possible to obtain a laminated board in which warpage is suppressed.

(Semiconductor package)
Next, the semiconductor package will be described.
This semiconductor package can be manufactured by mounting a semiconductor element on the above laminate. The mounting method and the sealing method of the semiconductor element are not particularly limited. For example, it can be manufactured by the following method.

  First, using a flip chip bonder or the like, the connection electrode portion on the laminated wiring board and the solder bump of the semiconductor element are aligned. Next, the solder bump is heated to the melting point or higher by using an IR reflow device, a hot plate, or other heating device, and the multilayer printed wiring board and the solder bump are connected by fusion bonding. Finally, a liquid sealing resin is filled between the laminated wiring board and the semiconductor element and cured to obtain a semiconductor package.

As mentioned above, although embodiment of this invention was described with reference to drawings, these are the illustrations of this invention, Various structures other than the above are also employable.
For example, FIG. 1 shows the case where the build-up layer is one layer, but a configuration in which two or more build-up layers are laminated on one side or both sides of the core layer may be adopted. 1 and 2 show the case where one layer of the sheet-like fiber base material is included in the prepreg for buildup, but a configuration in which two or more layers of the fiber base material are included in the prepreg may be adopted. Further, FIGS. 1 and 2 show the case where the thermosetting resin layer 201 and the thermosetting resin layer 203 have the same thickness, but the thermosetting resin layer 201 and the thermosetting resin layer 203 have different thicknesses. A configuration may be adopted.

Hereinafter, although an example and a comparative example explain the present invention, the present invention is not limited to these.
The raw materials used in the examples and comparative examples are as follows.
Inorganic filler: spherical silica (manufactured by Admatechs, SO-25R, average particle size 0.5 μm)
Epoxy resin: biphenyl aralkyl type novolac epoxy resin (NC-3000 manufactured by Nippon Kayaku Co., Ltd.)
Epoxy resin: dicyclopentadiene type novolac epoxy resin (manufactured by DIC, HP-7200)
Cyanate resin: Novolac type cyanate resin (Primase PT-30 manufactured by LONZA)
Epoxy resin: Bisphenol A type liquid epoxy resin (Mitsubishi Chemical Corporation, jER-828)
Epoxy resin: Bisphenol F type liquid epoxy resin (Mitsubishi Chemical Corporation, jER-807)
Phenol curing agent: novolak type phenol resin (manufactured by DIC, TD-2090-60M, 60% (w / v) methyl ethyl ketone solution)
Phenoxy resin: (Mitsubishi Chemical Corporation, YX6954BH30, 30% (w / v) methyl ethyl ketone / anone solution)
Polyvinyl acetal resin: KS-10 (hydroxyl group 25 mol%) manufactured by Sekisui Chemical Co., Ltd.
Curing catalyst: 2-ethyl-4-methylimidazole (2E4MZ manufactured by Shikoku Chemicals)
Coupling agent: N-phenyl-3-aminopropyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd., KBM-573)

Example 1
(1) Preparation of resin varnish A 30 parts by weight of dicyclopentadiene type epoxy resin (manufactured by DIC, HP-7200), 3 parts by weight of bisphenol F type liquid epoxy resin (manufactured by Mitsubishi Chemical Corporation, jER807) as an epoxy resin, cyanate resin 14 parts by weight of a phenol novolac cyanate resin (manufactured by LONZA, Primaset PT-30), 3 parts by weight of YX6954BH30 manufactured by Mitsubishi Chemical Co. as a phenoxy resin in terms of solid content, and imidazole (manufactured by Shikoku Kasei Co., Ltd., 2E4MZ) 0. 2 parts by weight were stirred for 60 minutes with a mixed solvent of methyl ethyl ketone and cyclohexanone and dissolved. Furthermore, 0.1 part by weight of N-phenyl-3-aminopropyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd., KBM-573) as a coupling agent and spherical silica (SO25R manufactured by Admatechs Co., Ltd., average particle size 0) as an inorganic filler. 0.5 μm) 49.7 parts by weight were added and stirred for 10 minutes with a high-speed stirrer to prepare a resin varnish with a solid content of 65%.

(2) Production of Resin Sheet A The obtained resin varnish was applied to one side of a 36 μm thick PET (polyethylene terephthalate) film using a comma coater device. This was dried with a drying apparatus at 160 ° C. for 3 minutes to prepare a resin sheet A with a substrate having a resin thickness of 17.5 μm.

(3) Preparation of prepreg A A glass woven fabric (manufactured by Unitika Ltd., cross type # 1017, width 530 mm, thickness 15 μm, basis weight 12 g / m ² ) was used as a fiber substrate, and the prepreg was prepared by a vacuum laminator and a hot air dryer Manufactured.
Specifically, two resin sheets A are prepared (referred to as A1 and A2), and the resin sheet A1 and the resin sheet A2 are positioned on the both sides of the glass woven fabric at the center in the width direction of the glass woven fabric, respectively. The sheets were stacked one by one and joined using a laminate roll at 80 ° C. under a reduced pressure of 0.1 MPa (750 Torr).
Here, in the inner region of the width direction dimension of the glass woven fabric, the resin layers of the resin sheet A1 and the resin sheet A2 are respectively bonded to both sides of the fiber cloth, and in the outer region of the width direction dimension of the glass woven fabric. The resin layers of the resin sheet A1 and the resin sheet A2 were joined together.
Next, the bonded material was heat-treated without applying pressure by passing it through a horizontal conveying type hot air drying apparatus set at 120 ° C. for 2 minutes, to obtain a prepreg having a thickness of 40 μm.

(4) Lamination process The laminated body was manufactured from the prepreg with a PET base material using 2 stage buildup laminator CVP300 by Nichigo-Morton Co., Ltd. Specifically, using ELC-4785GS-B (Sumitomo Bakelite Co., Ltd., copper foil 12 μm) with a thickness of 200 μm, a predetermined place is opened with a drill machine, and conduction is achieved by electroless plating. Was etched to prepare a core layer having a circuit formation surface. The prepreg was cut into single sheets, set on the CVP 300, temporarily attached to the core layer, and vacuum lamination was performed in a vacuum laminator at 120 ° C., 0.7 MPa for 60 seconds.

(5) Smoothing process Then, using the hot press apparatus with which CPV300 made from Nichigo-Morton was equipped, it hot-smoothed at 120 degreeC and 0.6 Mpa for 60 second.
(6) Curing Step After that, the obtained laminate is put into a hot air drying apparatus in which the temperature profile is set to an initial temperature of 25 ° C., a maximum temperature of 160 ° C., a heating rate of 3 ° C./min, and a curing time of 60 minutes, The curing reaction of the thermosetting resin of the prepreg for up was performed.
The curing time here refers to the time from placing the laminate in the hot air drying device set to the initial temperature to taking it out. After the inside of the apparatus reached the maximum temperature, curing reaction was performed for the remaining time while maintaining the maximum temperature. Moreover, the temperature of the laminated body was measured by embedding a thermocouple in the laminated body, and it was confirmed that the temperature rising rate of the laminated body and the temperature rising rate of the hot air drying apparatus were almost the same.

(7) Preparation of circuit board Next, via holes were formed in the obtained laminate by a carbonic acid laser. The via and the resin layer surface were immersed in a 60 ° C. swelling solution (Atotech Japan, Swelling Dip Securigant P) for 5 minutes, and then an 80 ° C. potassium permanganate aqueous solution (Atotech Japan, Concentrate). After immersion in compact CP) for 10 minutes, neutralization and roughening treatment were performed.

  After going through the steps of degreasing, applying a catalyst, and activating this, an electroless copper plating film is formed to about 0.5 μm, a plating resist is formed, and a pattern electroplated copper is formed to 10 μm using the electroless copper plating film as a feeding layer. , L / S = 50/50 μm fine circuit processing was performed. Next, after performing an annealing process at 200 ° C. for 60 minutes with a hot air drying apparatus, the power feeding layer was removed by flash etching.

Next, a solder resist layer was formed on the laminate obtained above, and a blind via hole (non-through hole) was formed by a carbonic acid laser so that the semiconductor element mounting pad and the like were exposed.
Finally, an electroless nickel plating layer of 3 μm is formed on the circuit layer exposed from the solder resist layer, and further, an electroless gold plating layer of 0.1 μm is formed thereon. A circuit board for a semiconductor package was obtained by cutting into × 50 mm size.

(8) Production of Semiconductor Package A semiconductor element (TEG chip, size 20 mm × 20 mm, thickness 725 μm) having solder bumps was mounted on a circuit board for a semiconductor package by thermocompression bonding using a flip chip bonder device. Next, after melt-bonding the solder bumps in an IR reflow furnace, a liquid sealing resin (manufactured by Sumitomo Bakelite Co., Ltd., CRP-X4800B) was filled and the liquid sealing resin was cured to obtain a semiconductor package. The liquid sealing resin was cured at a temperature of 150 ° C. for 120 minutes. Moreover, the solder bump of the semiconductor element used what was formed with the lead free solder of Sn / Ag / Cu composition.

(Example 2)
A laminated board, a circuit board, and a semiconductor package were manufactured in the same manner as in Example 1 except that the temperature rising rate was 10 ° C./min.

(Example 3)
In the curing step, after the temperature of the hot air drying device is set to 100 ° C. in advance, the laminated body is placed on the hot air drying device support so that the entire laminated body is heated uniformly, and the curing step is performed, and the curing time is set to 30. A laminated board, a circuit board, and a semiconductor package were manufactured in the same manner as in Example 1 except that the time was changed to minutes. The surface temperature of the laminate is measured by embedding a thermocouple in the laminate, and the average rate of temperature increase from the time until the laminate reaches a maximum temperature within 5 ° C. before and after 100 ° C., which is the set temperature. Was calculated. The heating rate was 11 ° C./min.

Example 4
A laminate, a circuit board, and a semiconductor package were produced in the same manner as in Example 1 except that the blending amounts of the respective components in the resin varnish were as shown in Table 1 and the rate of temperature increase was 5 ° C./min.

(Comparative Example 1)
In the curing process, after the temperature of the hot air drying device was set to 160 ° C. in advance, the curing process was performed by placing the laminate in the hot air drying device, and the curing time was set to 30 minutes. Laminated plates, circuit boards, and semiconductor packages were manufactured. The average rate of temperature increase calculated by the same method as in Example 3 was 32 ° C./min.

(Comparative Example 2)
A laminated board, a circuit board, and a semiconductor package were produced in the same manner as in Comparative Example 1 except that the amount of each component in the resin varnish was as shown in Table 1. The average rate of temperature increase calculated by the same method as in Example 3 was 30 ° C./min.

(Comparative Example 3)
A laminated board, a circuit board, and a semiconductor package were manufactured in the same manner as in Example 1 except that the temperature rising rate was 20 ° C./min and the curing time was 30 minutes.

[Evaluation]
(1) Measurement of complex dynamic viscosity η1 by dynamic viscoelasticity test After completion of the laminating step, only a thermosetting resin is cut out from the buildup prepreg on the surface of the laminate to obtain a measurement sample. The complex dynamic viscosity η1 was measured under the following conditions using Physica MCR-301 manufactured by Anton Paar.
Frequency: 62.83 rad / sec
Measurement range 50-200 ° C
Geometry: Parallel plate Plate diameter: 10mm
Plate spacing: 0.1mm
Load (normal force): 0N (constant)
Strain: 0.3%
Measurement atmosphere: Nitrogen

(2) Measurement of complex dynamic viscosity η2 by dynamic viscoelasticity test After completion of the smoothing step, only the thermosetting resin is cut out from the prepreg for buildup on the surface of the laminate to obtain a measurement sample. The complex dynamic viscosity η2 was measured under the same conditions as η1.

(3) Thickness variation The cross section of the laminate after the curing step was observed with a scanning electron microscope (SEM), and the difference in thickness between the adjacent portion with and without the copper wiring was measured.
Thickness differences were measured at n = 10, and those with an average of less than 0.8 μm were evaluated as “good”, and those with an average of 0.8 μm or more were evaluated as “failed”. The results are shown in Table 1.

(4) Moisture-resistant and heat-resistant reliability The circuit board after electrolytic plating and annealing treatment was cut into 50 mm squares, treated for 168 hours under 85 ° C. and 85% moisture absorption conditions, and then in an IR reflow furnace (peak temperature 260 ° C.). The treatment was performed 3 times (treatment corresponding to MSL level 1), and the presence or absence of swelling was confirmed.
○: No swelling ×: With swelling

DESCRIPTION OF SYMBOLS 100 Laminated board 101 Circuit 102 Core layer 103 Circuit formation surface 200 Prepreg 201 Thermosetting resin layer 202 Fiber base material 203 Thermosetting resin layer 300 Build-up layer S1 First surface S2 Second surface

Claims (13)

A laminating step of laminating a build-up prepreg formed of a thermosetting resin under heat and pressure on the circuit forming surface of the core layer having a circuit forming surface on one or both sides; and
A smoothing step of smoothing the surface of the laminated prepreg for buildup is continuously performed, and then
A method of manufacturing a laminated board that heats the laminated body and performs a curing step of further proceeding with curing of the thermosetting resin,
The manufacturing method of a laminated board which raises the temperature of the said laminated body gradually from the initial temperature to the highest achieved temperature in the said hardening process.   The manufacturing method of the laminated board of Claim 1 with which the temperature increase rate from the said initial temperature to the said highest ultimate temperature is constant in the said hardening process.   The manufacturing method of the laminated board of Claim 1 which makes the temperature increase rate from the said initial temperature to the said highest ultimate temperature at least 2 steps or more in the said hardening process.   In the said hardening process, manufacture of the laminated board as described in any one of Claims 1 thru | or 3 whose average temperature increase rate from the said initial temperature to the said highest ultimate temperature is 1 degree-C / min or more and 15 degrees C / min or less. Method.   The manufacturing method of the laminated board as described in any one of Claims 1 thru | or 4 whose said highest reached temperature is 90 degreeC or more and 230 degrees C or less in the said hardening process. When the minimum value of the complex dynamic viscosity at a measurement range of 50 to 200 ° C. and a frequency of 62.83 rad / sec is η1 by the dynamic viscoelasticity test of the build-up prepreg at the stage of completing the laminating step,
The manufacturing method of the laminated board as described in any one of Claims 1 thru | or 5 whose (eta) 1 is 20 Pa.s or more and 300 Pa.s or less. When the minimum value of the complex dynamic viscosity in the measurement range of 50 to 200 ° C. and the frequency of 62.83 rad / sec according to the dynamic viscoelasticity test of the build-up prepreg at the stage of completing the smoothing step is η2,
The manufacturing method of the laminated board as described in any one of Claims 1 thru | or 6 which satisfy | fills (eta) 2> = (eta) 1 * 1.1.   The manufacturing method of the laminated board of Claim 7 whose said (eta) 2 is 350 Pa.s or more.   The manufacturing method of the laminated board as described in any one of Claims 1 thru | or 8 which heats and pressurizes in the said lamination process in the state which pinched | interposed the said core layer and the said prepreg for buildup with a pair of elastic member which opposes. The prepreg for buildup is wound and laminated in a roll shape,
10. The buildup prepreg that is wound and laminated is conveyed, the sheet-shaped core layer is conveyed, and the laminating step and the smoothing step are continuously performed. Method for producing a laminated board.   The manufacturing method of the laminated board as described in any one of Claims 1 thru | or 10 which heats and pressurizes in the said smoothing process in the state which pinched | interposed the said core layer and the said prepreg for buildup with a pair of metal member which opposes.   The manufacturing method of the laminated board as described in any one of Claims 1 thru | or 11 which performs a laser via formation process further after the said hardening process.   The manufacturing method of the laminated board as described in any one of Claims 1 thru | or 12 with which the time of the said lamination process which match | combined evacuation and pressurization time, and the time of the said smoothing process are equal.

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