JP2009137658A - Method for continuously manufacturing laminated sheet - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for continuously manufacturing laminated sheets, capable of manufacturing multilayer printed-wiring boards with a high yield without generating large warpage in use of the laminated sheets even when the laminated sheets are continuously manufactured. <P>SOLUTION: In the method for continuously manufacturing laminated sheets, the diameter of a core of a take-up roll for winding up the laminated sheets is set to be ≥150 mm and ≤400 mm. In particular, suitably, the continuously manufacturing method has a process of laminating resin sheets with metal foil obtained by forming an electrical insulating resin layer comprising a resin composition on metal foil on both faces of a base material. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a method for continuously producing laminated sheets.

In recent years, the demand for miniaturization and high functionality has been increasing for multilayer printed wiring boards, but price competition has been intense, and in particular, multilayer laminated boards used for multilayer printed wiring boards, epoxy resin laminated boards with glass cloth substrates, or glass For all the laminates using nonwoven fabric as the intermediate layer base material and glass woven fabric as the surface layer base material, cost reduction is a major issue. In recent years, electrical devices, electronic devices, communication devices, etc. have been digitized, and stable impedance in multilayer printed wiring boards has been required. With this, in laminated boards that are raw materials for multilayer printed wiring boards, Thickness accuracy has been required. In the case of laminating a multilayer laminate used for a multilayer printed wiring board or an epoxy resin laminate containing a glass cloth substrate, or a laminate having a glass nonwoven fabric as a surface layer substrate and a glass nonwoven fabric as an intermediate layer substrate, A multi-stage batch press is generally used in which a number of copper foils, laminated plates, mirror plates, and the like are stacked between heating plates and are heated and pressed. However, in such a multi-stage batch press, the heat history applied to each laminated plate during lamination molding differs depending on the position of each laminated plate in the hot platen. Therefore, it was difficult to supply a product with less quality variation. Furthermore, there is a problem that the plate thickness accuracy cannot be obtained by the resin flow because the laminated plate is formed at a high pressure of ^{20 to} 100 kg / cm ² . In order to solve the above problem, a process for continuously producing a laminated board has been proposed in recent years (see, for example, Patent Documents 1 to 4).
However, in the case of continuous production, in the process of winding the molded laminate, when stress is accumulated in the wound laminate, and when this laminate is used, it is cut according to the intended use. There was a problem of warping. For this reason, there was a problem that the yield was lowered during the subsequent production of the multilayer printed wiring board.

JP 2001-260241 A JP 2004-223864 A JP 2004-291580 A JP 2005-271349 A

  It is an object of the present invention to provide a method for continuously producing a laminated board capable of producing a multilayer printed wiring board having a high yield without causing a large warp when the laminated board is used.

Such an object is achieved by the present invention described in the following [1] to [8].
[1] A continuous production method of a laminate, wherein the winding core has a winding core diameter of 150 mm or more and 400 mm or less in the step of winding the laminate with a take-up roll. Method.
[2] The method for continuously producing a laminated board according to [1], wherein the thickness of the laminated board is 15 μm or more and 100 μm or less.
[3] The laminate is a laminate obtained by laminating a resin sheet with a metal foil formed by forming an insulating resin layer made of a resin composition on a metal foil on both surfaces of the substrate [1] or [ 2] The continuous manufacturing method of the laminated board as described in 2].
[4] The method for continuously producing a laminated board according to any one of [1] to [3], wherein the resin composition is an epoxy resin composition.
[5] The method for continuously producing a laminated board according to [4], wherein the resin composition further contains a phenol resin.
[6] The method for continuously producing a laminated board according to [4] or [5], wherein the resin composition further contains a phenoxy resin.
[7] The method for continuously producing a laminated board according to any one of [4] to [6], wherein the resin composition further contains a cyanate resin.
[8] The method for continuously producing a laminated board according to any one of [4] to [7], wherein the resin composition further contains an inorganic filler.

According to the continuous manufacturing method of the laminated board of this invention, a laminated board with small curvature can be provided. Moreover, when a multilayer printed wiring board is manufactured using the laminated board obtained by the continuous manufacturing method of the laminated board of this invention, a multilayer printed wiring board can be manufactured with a sufficient yield.

Below, the continuous manufacturing method of the laminated board of this invention is demonstrated in detail.

  The present invention is a continuous production method of a laminated board in which the laminated board is wound up by a take-up roll, and the diameter of the winding core when the laminated board is taken up by the take-up roll is from 150 mm to 400 mm. It is the continuous manufacturing method of the laminated board characterized.

The diameter of the winding core when winding the laminate is preferably 200 mm or more, more preferably 300 mm or more.
When it is less than the lower limit, warpage is increased when a laminated board is used, and the yield when a multilayer printed wiring board is manufactured decreases. When the value is larger than the upper limit value, the warp is small when the laminate is used, but it is inconvenient to handle and the amount of the laminate that can be wound is reduced. In the step of winding the laminated plate around the winding core, an internal / external difference occurs between the outside and inside of the winding of the laminated plate. The cause of warping is that internal stress is generated in the resin layer, resulting in distortion and warping. In order to suppress this internal stress, the diameter of the winding core is the most important factor.

  Although the material of the said winding core is not specifically limited, For example, a metal, a plastics, vinyl chloride, paper, resin, glass fiber etc. are mentioned.

The surface of the winding core is preferably one with less unevenness. This is because the irregularities are transferred to the laminate when the laminate is wound up. Smoothing the irregularities on the surface of the core can be performed according to the material of the core used.
Moreover, the inside of the winding core is not particularly limited to a hollow state or a filled state.

The winding tension at the time of winding the laminate on the winding core increases the internal stress due to the difference between inside and outside as the tension increases. Therefore, it is preferable that the winding tension is small.
When the length of the laminate in the direction perpendicular to the transport direction of the laminate is X and “winding tension” / “X” (unit: N / mm), it is preferably 0.5 N / mm or less. Preferably it is 0.3 N / mm or less.

  The laminate is formed using a resin composition, a base material, and a metal foil. Although the said metal foil is not specifically limited, For example, copper, nickel, aluminum, stainless steel etc. can be used. Among these, copper or aluminum is preferable from the viewpoint of workability. More preferred are rolled copper and electrolytic copper, and particularly preferred is electrolytic copper. Electrolytic copper is less susceptible to defects during the production of multilayer printed wiring boards because of its low elastic modulus.

  The metal foil may be a two-layer metal foil having a peelable metal foil layer. A laminate having a thin metal foil can be produced by peeling a peelable metal foil layer after laminating a metal foil having a two-layer structure. On the other hand, it is a metal foil having a two-layer structure provided with a peelable metal foil layer at the time of handling, and since it has a thickness that is easy to handle, it is possible to easily manufacture a laminate having a thin metal foil. it can.

  The thickness of the laminate is preferably 15 μm or more and 100 μm or less. If the thickness of the laminate is less than the lower limit value, sufficient strength may not be obtained, and if it is thicker than the upper limit value, the distortion increases due to the effect of internal and external differences when wound, May cause warping.

In the continuous manufacturing method of the laminate, the step of forming the laminate is not particularly limited. For example, a step of laminating metal foil on both surfaces of a prepreg obtained by impregnating a resin composition on a base material, resin in advance A step of preparing a resin sheet with a metal foil formed by forming an insulating resin layer made of a composition on a metal foil, and laminating the resin sheet with the metal foil on both surfaces of a substrate using a laminator device, etc. And a step of laminating a resin sheet with metal foil on both surfaces of the substrate is preferable. If it is this process, it is possible to set arbitrarily the thickness of each resin layer of a base material both surfaces.
Moreover, since the reaction rate of an insulating resin layer can be changed by heating etc. at the time of preparation of the resin sheet with metal foil, the laminated board from which the reaction rate differed in the front and back of a laminated board can be manufactured. Here, the reaction rate refers to a value obtained as described later using a DSC (differential scanning calorimeter).

(Calculation of reaction rate)
First, in the production of a resin sheet with a metal foil, a part of the insulating resin layer immediately after being formed on the metal foil is taken, and the heat generation peak area when the heat generation amount is measured by DSC is determined. This exothermic peak area (= A) is the total curing reaction heat. When the resin sheet with metal foil is heated and the curing reaction proceeds and is completely cured, the exothermic peak disappears. The point at which the exothermic peak disappeared was defined as a reaction rate of 100%.
Next, the curing is arbitrarily progressed by heating or the like, and at that time, a part of the insulating resin layer is taken and the calorific value is measured by DSC to obtain the exothermic peak area (= B). The reaction rate at that time was a value obtained from (1−B / A) × 100 (%).

  In the production of the laminate, conditions for laminating with a laminator apparatus are not particularly limited, but it is preferably performed under vacuum, more preferably under vacuum heating.

  The thickness of the metal foil is preferably 0.1 μm or more and 18 μm or less. Furthermore, it is preferably 0.5 μm or more and 12 μm or less, and more preferably 1 μm or more and 10 μm or less. If the thickness of the metal foil is less than the lower limit, pinholes are likely to occur in the metal foil, and defects may occur in the multilayer printed wiring board manufacturing process. If the upper limit is exceeded, the internal stress increases. For this reason, the warp of the laminated plate is increased.

  The base material is not particularly limited. For example, glass fiber base materials such as glass woven fabric and glass nonwoven fabric, polyamide resin fibers, aromatic polyamide resin fibers, polyamide resin fibers such as wholly aromatic polyamide resin fibers, and polyester resins. Synthetic fiber substrate, kraft paper, composed of woven fabric or nonwoven fabric mainly composed of fibers, aromatic polyester resin fibers, polyester resin fibers such as wholly aromatic polyester resin fibers, polyimide resin fibers, fluororesin fibers, etc. Examples thereof include organic fiber base materials such as paper base materials mainly composed of cotton linter paper, mixed paper of linter and kraft pulp, and the like. Among these, a glass fiber base material is preferable. Thereby, the intensity | strength of a laminated board rises and it can make a low water absorption. Moreover, the linear expansion coefficient of a laminated board can be made small.

  The resin composition is not particularly limited, but is preferably an epoxy resin composition.

The epoxy resin constituting the epoxy resin composition is not particularly limited. For example, bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, phenol novolac type epoxy resin, cresol novolac type epoxy resin, Biphenyl type epoxy resin, aryl alkylene type epoxy resin, naphthalene type epoxy resin, triphenolmethane type epoxy resin, alicyclic epoxy resin, and copolymers thereof may be mentioned. One of these can be used alone, or two or more having different weight average molecular weights can be used in combination, or one or two or more of these prepolymers can be used in combination.

  The epoxy resin composition preferably further contains a phenol resin. The phenol resin is not particularly limited, but, for example, a novolak phenol resin such as a phenol novolak resin, a cresol novolak resin, a bisphenol A novolak resin, an arylalkylene type novolak resin, an unmodified resole phenol resin, tung oil, linseed oil, walnut oil And resol type phenolic resins such as oil-modified resol phenolic resins modified with the above. One of these can be used alone, or two or more having different weight average molecular weights can be used in combination, or one or two or more of these prepolymers can be used in combination. Among these, arylalkylene type phenol resins are particularly preferable. Thereby, moisture absorption solder heat resistance can be improved further.

The epoxy resin composition preferably further contains a phenoxy resin. The phenoxy resin is not particularly limited, and examples thereof include a phenoxy resin having a bisphenol skeleton, a phenoxy resin having a novolak skeleton, a phenoxy resin having a naphthalene skeleton, a phenoxy resin having a biphenyl skeleton, and the like. It is also possible to use a phenoxy resin having the structure. These may be used alone or in combination.

The epoxy resin composition preferably further contains a cyanate resin. Although it does not restrict | limit especially as said cyanate resin, For example, it can obtain by making a halogenated cyanide compound and phenols react and prepolymerizing by methods, such as a heating, as needed. Specifically, bisphenol type cyanate resins such as novolac type cyanate resin, bisphenol A type cyanate resin, bisphenol E type cyanate resin, tetramethylbisphenol F type cyanate resin, etc. can be mentioned, and these can be used alone or in combination. May be.

The epoxy resin composition can further use a curing agent as appropriate. As the curing agent, known ones can be used. For example, tertiary amines such as triethylamine, tributylamine, diazabicyclo [2,2,2] octane, 2-ethyl-4-ethylimidazole, 2-phenyl-4-methylimidazole, 2-phenyl-4-methyl-5- Hydroxymethylimidazole, 2-phenyl-4,5-dihydroxymethylimidazole, 2,4-diamino-6- [2'-methylimidazolyl- (1 ')]-ethyl-s-triazine, 2,4-diamino -6- (2'-undecylimidazolyl) -ethyl-s-triazine, 2,4-diamino-6- [2'-ethyl-4-methylimidazolyl- (1 ')]-ethyl-s-triazine, 1 -Imidazole compounds such as benzyl-2-phenylimidazole, phosphine compounds such as triphenylphosphine, etc. That.

  The epoxy resin composition may further contain an inorganic filler. The inorganic filler is not particularly limited, and examples thereof include talc, alumina, glass, silica, mica, aluminum hydroxide, and magnesium hydroxide. Among these, silica is preferable, and fused silica (particularly spherical fused silica) is preferable in that it is excellent in high elasticity and low thermal expansion. There are crushed and spherical shapes, but a method of use that suits the purpose, such as using spherical silica, is employed to lower the melt viscosity of the resin composition.

  When the said epoxy resin composition contains an inorganic filler, it is preferable that a coupling agent is further included. The coupling agent is not particularly limited, and examples thereof include an epoxy silane coupling agent, an amino silane coupling agent, a titanate coupling agent, and a silicone oil type coupling agent, and these may be used alone or in combination. Good. The coupling agent can improve the wettability of the interface between the epoxy resin and the inorganic filler, and can improve the interface strength and melt viscosity.

  The epoxy resin composition may further contain additives such as an antifoaming agent, a leveling agent, a pigment, an antioxidant, and an ultraviolet absorber as necessary.

Hereinafter, the present invention will be described in detail with reference to examples.

(Example 1)
Methoxynaphthalene dimethylene type epoxy resin (Dainippon Ink Chemical Co., Ltd., EXA-7320) 3.0 parts by weight as an epoxy resin, biphenyldimethylene type epoxy resin (Nippon Kayaku Co., Ltd., NC-3000) 22. 0 part by weight, 0.2 part by weight of 1-benzyl-2-phenylimidazole (manufactured by Shikoku Kasei Kogyo Co., Ltd., Curazole 1B2PZ), 10.0 parts by weight of phenoxy resin (manufactured by Japan Epoxy Resin Co., Ltd., jER4275), novolac cyanate 25 parts by weight of a resin (Lonza Japan Co., Ltd., Primaset PT-30) was dissolved and dispersed in methyl isobutyl ketone. Furthermore, 39.6 parts by weight of spherical fused silica (manufactured by Admatechs Corporation, “SO-25R”, average particle size 0.5 μm) as an inorganic filler and an epoxy silane coupling agent (GE Toshiba Silicone Co., Ltd., A-187) ) 0.2 part by weight was stirred for 10 minutes using a high-speed stirrer to prepare a resin varnish having a solid content of 50% by weight. The prepared resin varnish is applied by a die coater type casting apparatus so that 50 g / m ² of solid content adheres on the roughened surface of the electrolytic copper foil having a thickness of 12 μm, and then dried at 80 ° C. for 2 minutes to obtain a semi-cured resin. A formed resin sheet with metal foil was obtained. Using a rubber roll laminator, the resin surface side of the resin sheet with metal foil was continuously laminated on both surfaces of a 100 g / m ² glass cloth as a base material to obtain a laminate. The lamination conditions were 80 ° C., 1 MPa, and 2 m / min.
Next, after forming the laminate, the temperature is raised stepwise and dried at 250 ° C. for 30 minutes. In the final winding process, a glass fiber core having a diameter of 150 mm is used, and the winding tension is increased. The laminate was wound up at 0.5 N / mm and a thickness of 100 μm.

(Example 2)
The same steps as in Example 1 were used, except that a glass fiber core having a diameter of 300 mm was used in the winding step of the laminated plate, and the winding tension was 0.5 N / mm. A laminated board having a thickness of 100 μm was produced in the same manner as in Example 1.

(Example 3)
The same steps as in Example 1 were used, except that a glass fiber winding core having a diameter of 400 mm was used in the winding step of the laminated plate, and the winding tension was 0.5 N / mm. A laminated board having a thickness of 100 μm was produced in the same manner as in Example 1.

Example 4
A laminated board having a thickness of 60 μm was produced in the same manner as in Example 1 except that a glass cloth of 45 g / m ² was used as a substrate using the same steps as in Example 1.

(Comparative Example 1)
The same steps as in Example 1 were used, except that a glass fiber core having a diameter of 100 mm was used and the winding tension was 0.5 N / mm. A laminated board having a thickness of 100 μm was produced in the same manner as in Example 1.

(Comparative Example 2)
Using the same process as in Example 1, a laminated sheet is formed using a glass cloth of 45 g / m ² as a base material, a glass fiber core having a diameter of 100 mm is used, and a winding tension is 0.5 N. A laminate having a thickness of 60 μm was prepared in the same manner as in Example 1 except that the film was wound as / mm.

(Evaluation)
Using Examples 1 to 4 and Comparative Examples 1 and 2 obtained above, the warpage of the laminate was evaluated by the following evaluation method.

The obtained laminate was cut into a sheet of 200 mm × 200 mm to prepare a test piece. A laminated plate was placed on the flat plate, and the distance between the four corners of the test piece and the flat plate was measured with a caliper. Table 1 shows the results of the average values of the four points. In addition, the upper surface of the installed laminated board was made into the surface close | similar to the center of a winding core at the time of winding up a laminated board.

In Examples 1 to 4, it is possible to manufacture a multilayer printed wiring board with a small yield and a high yield. On the other hand, Comparative Examples 1 and 2 using a winding core having a winding core diameter as small as 100 μm have a large warpage and a low yield during the production of a printed wiring board.

Since the laminate obtained by the continuous production method of the laminate of the present invention has a small warp, a circuit pattern or the like may be drawn by exposure / development using a photosensitive resin when producing a multilayer printed wiring board. In this case, since the resolution is good, it is possible to draw a circuit pattern or the like with high accuracy. Therefore, the circuit pattern can be usefully used for a multilayer printed wiring board that requires a circuit pattern with a particularly narrow line width.

Claims (8)

  A method for continuously producing a laminated board, wherein the winding core has a winding core diameter of 150 mm or more and 400 mm or less in the step of winding the laminated board with a take-up roll.   The method for continuously producing a laminated board according to claim 1, wherein the thickness of the laminated board is 15 µm or more and 100 µm or less.   The said laminated board is a laminated board formed by laminating | stacking the resin sheet with metal foil which forms the insulating resin layer which consists of a resin composition on metal foil on both surfaces of a base material. A continuous manufacturing method for laminated boards.   The said resin composition is an epoxy resin composition, The continuous manufacturing method of the laminated board in any one of Claim 1 thru | or 3.   The method for continuously producing a laminated board according to claim 4, wherein the resin composition further contains a phenol resin.   The method for continuously producing a laminated board according to claim 4 or 5, wherein the resin composition further contains a phenoxy resin.   The method for continuously producing a laminated board according to any one of claims 4 to 6, wherein the resin composition further contains a cyanate resin.   The continuous production method of a laminated board according to any one of claims 4 to 7, wherein the resin composition further contains an inorganic filler.