JP2010111115A - Metal foil-clad laminate, double-sided metal foil-clad laminate, method of manufacturing the same, and printed wiring board - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a metal foil-clad laminate having excellent dimensional stability, capable of being bent along an arbitrarily given bending line, and showing excellent tear resistance, and to provide a printed wiring board using the metal foil-clad laminate. <P>SOLUTION: The metal foil-clad laminate includes at least a metal foil, a 50 μm or less thick composite resin layer in which a fiber base material is embedded, and a resin film arranged in this order. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a metal foil-clad laminate, a double-sided metal foil-clad laminate, a manufacturing method thereof, and a printed wiring board.

  Conventionally, printed wiring boards that can be bent arbitrarily have played an important role in miniaturization and high performance of electronic devices. As a metal foil-clad laminate constituting such a printed wiring board, a copper foil is usually formed directly on a three-layer substrate or a polyimide film obtained by bonding a copper foil and a polyimide film via an adhesive. A layer base material etc. are used (for example, refer nonpatent literature 1 and 2). Patent Document 1 below discloses a wiring board obtained by wiring a composite copper foil composed of a base film in which a glass cloth is impregnated with a polyimide resin and a copper foil.

JP-A-11-330651

Electronic Materials, October 2004, p. 15-19 Electronic Materials, October 2004, p. 20-24

  The wiring boards described in Non-Patent Document 1 and Non-Patent Document 2 are obtained by wiring a composite metal foil composed of a polyimide film and a metal foil, and can be bent, but dimensional stability is not always satisfactory. It wasn't going to be good.

  In recent years, electronic devices have been further reduced in size and performance. In order to cope with this, a printed wiring board that can be arbitrarily bent is required to be more compactly accommodated. As a method for storing the wiring board in a compact manner, for example, a method in which a crease is once made and folded so as to wind a housing inside the electronic device is conceivable. However, the present situation is that the wiring board which can be used for such a method has not been proposed yet.

  For example, although the wiring board described in Patent Document 1 can be bent and has improved dimensional stability, there has been a new problem that the fold portion of the wiring board is damaged by repeated bending. . In addition, there is a problem that damage due to tearing (breaking) induced by twisting of the wiring board occurs.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a metal foil-clad laminate, excellent in dimensional stability, capable of being bent with a crease, and excellent in tear resistance, a manufacturing method thereof, and a printed wiring board. And

  Conventionally, in the field of metal foil-clad laminates, there is no idea of overlapping another insulating layer on the insulating layer, and there is no particular purpose to do so. Overlapping insulation layers have not been performed.

  Under such circumstances, the present inventors have intensively studied a metal foil-clad laminate having both dimensional stability, foldability with a crease, and tear resistance. This finding was found for the first time that the composite resin layer (insulating layer) with a thickness of 50 μm or less formed by embedding the material in the resin and the resin film (insulating layer) in this order can combine the above three characteristics. Based on this, the present invention has been completed.

  The present invention relates to a metal foil-clad laminate in which at least a metal foil and a composite resin layer having a thickness of 50 μm or less and a resin film in which a fiber base material is embedded in a resin are arranged in this order.

  Such a metal foil-clad laminate is excellent in dimensional stability and can be arbitrarily folded and folded. Moreover, such a metal foil-clad laminate is excellent in tear resistance. Moreover, such a metal foil-clad laminate can be repeatedly bent at the crease portion.

  The present invention also relates to the metal foil-clad laminate, wherein the fiber base material is a glass cloth having a thickness of 8 to 30 μm.

  The present invention also relates to the metal foil-clad laminate, wherein the resin film is flexible and self-supporting. Here, in this specification, having flexibility means having a property of being easily bent when an external force is applied.

  Moreover, this invention relates to the said metal foil clad laminated board whose thickness of the said resin film is 1-80 micrometers.

  Moreover, this invention relates to the said metal foil tension laminated board whose thickness of the said resin film is 5-50 micrometers.

  The present invention also relates to the metal foil-clad laminate, wherein the resin film is selected from the group consisting of polyimide resin, polyethylene terephthalate resin, polyether resin, polyethylene naphthalate resin, and polybenzoxazole resin.

  The present invention also relates to the metal foil-clad laminate, wherein the composite resin layer includes a cured product of a resin selected from the group consisting of a resin having a glycidyl group, a resin having an amide group, and an acrylic resin.

  In the present invention, the first metal foil, the first composite resin layer having a thickness of 50 μm or less, the resin film, and the second fiber base material embedded in the resin are embedded in the resin. The second composite resin layer having a thickness of 50 μm or less and the second metal foil are positioned in this order, the distance between the first fiber base and the second fiber base is 10 to 170 μm, and the total thickness is The present invention relates to the double-sided metal foil-clad laminate having a thickness of 300 μm or less.

  Such a double-sided metal foil-clad laminate is excellent in dimensional stability, and can be arbitrarily bent and folded. Moreover, such a double-sided metal foil-clad laminate is excellent in tear resistance and can be repeatedly bent at the crease portion. Furthermore, such a double-sided metal foil-clad laminate has suppressed warpage.

  Moreover, this invention relates to the said double-sided metal foil tension laminated board whose said fiber base material is a glass cloth with a thickness of 8-30 micrometers.

  The present invention also relates to the double-sided metal foil-clad laminate in which the resin film is flexible and self-supporting.

  Moreover, this invention relates to the said double-sided metal foil tension laminated board whose thickness of the said resin film is 1-80 micrometers.

  Moreover, this invention relates to the said double-sided metal foil clad laminated board whose thickness of the said resin film is 5-50 micrometers.

  The present invention also relates to a method for producing a metal foil-clad laminate, in which a metal foil, a prepreg having a thickness of 60 μm or less formed by impregnating a fiber base material with a resin, and a resin film are laminated so as to be positioned in this order and thermocompression-bonded.

  The present invention also provides a thermocompression bonded product obtained by thermocompression bonding of a metal foil and a prepreg having a thickness of 60 μm or less formed by impregnating a fiber base material with a resin, and then a resin film is formed on the metal foil side of the thermocompressed product. Relates to a method for producing a metal foil-clad laminate that is thermocompression bonded to the opposite surface.

  In the present invention, a metal foil, a prepreg having a thickness of 60 μm or less formed by impregnating a fiber base material with a resin, a resin film, a prepreg having a thickness of 60 μm or less formed by impregnating the fiber base material and a metal foil are positioned in this order. It is related with the manufacturing method of a double-sided metal foil clad laminated board which laminates | stacks and thermocompression-bonds.

  In the present invention, two sets of thermocompression-bonded products obtained by thermocompression bonding of a metal foil and a prepreg having a thickness of 60 μm or less formed by impregnating a fiber base material with a resin are made to face opposite surfaces of the metal foil. In addition, the present invention relates to a method for producing a double-sided metal foil-clad laminate, in which a resin film is interposed between two sets of the thermocompression-bonded products and these are thermocompression bonded.

  Moreover, this invention relates to the printed wiring board by which wiring formation processing is given to the said metal foil of the said metal foil tension laminated board or the metal foil tension laminated board obtained by the said manufacturing method.

  In the present invention, the first metal foil and the second metal foil of the double-sided metal foil-clad laminate or the double-sided metal foil-clad laminate obtained by the production method are subjected to wiring formation processing, The present invention relates to a printed wiring board.

  Since such a printed wiring board is provided with the metal foil-clad laminate or the double-sided metal foil-clad laminate as described above, it has good bendability, excellent dimensional stability, and excellent tear resistance.

  According to the present invention, it is possible to provide a metal foil-clad laminate or a double-sided metal foil-clad laminate that can be bent with an arbitrary crease, is excellent in dimensional stability, and is excellent in tear resistance, and a method for producing the same. be able to. According to the present invention, it is also possible to provide a printed wiring board using the metal foil-clad laminate or the double-sided metal foil-clad laminate.

It is a schematic cross section which shows one Embodiment of the metal foil clad laminated board of this invention. It is a schematic cross section which shows one Embodiment of the double-sided metal foil clad laminated board of this invention. It is a schematic diagram which shows the evaluation method of tear resistance in this invention.

  Hereinafter, preferred embodiments of the present invention will be described in more detail with reference to the drawings. However, the present invention is not limited to the following embodiments. In the description of the drawings, the same or equivalent elements are denoted by the same reference numerals, and redundant description is omitted.

[Metal foil-clad laminate (single-sided metal foil-clad laminate)]
FIG. 1 is a schematic cross-sectional view showing an embodiment (an example of a single-sided metal foil-clad laminate) of the metal foil-clad laminate of the present invention. A metal foil-clad laminate 100 shown in FIG. 1 has a composite resin layer 20 and a resin film 40 obtained by curing the metal foil 1 and the prepreg. The thickness of the prepreg is preferably 60 μm or less, and more preferably 15 to 45 μm.

The fiber base material 2 is embedded in the composite resin layer 20, and the thickness (d ₂ ) of the composite resin layer 20 is 50 μm or less. Here, the thickness (d ₁ ) of the fiber base material 2 is preferably 8 to 30 μm, and the thickness of the composite resin layer 20 is 1.2 to 2.5 times the thickness of the fiber base material 2. Is preferred. In other words, the composite resin layer 20 and the metal foil 1 or the composite resin layer 20 and the resin film 40 are favorably adhered by having the resin layer 20 a having a predetermined thickness on the front and back of the fiber base 2. The thickness (d ₄ , d ₅ ) of the resin layer 20a is preferably 0.8 to 22.5 μm, more preferably 3 to 15 μm, and still more preferably 5 to 10 μm. If the thickness of the resin layer 20a exceeds 22.5 μm, the dimensional change accompanying heating and moisture absorption tends to increase, and if it is less than 0.8 μm, the resin existing between the fiber substrate 2 and the resin film 40 Tends to decrease and the adhesive strength tends to decrease. When the thickness of the resin layer 20a is within this range, the adhesiveness between the composite resin layer 20, the resin film 40 and the metal foil 1 is excellent, and the bendability is improved. The total thickness of the metal foil-clad laminate 100 is 200 μm or less. When the thickness of the metal foil-clad laminate 100 is within this range, the folding property with a crease is excellent.

  The thickness of the composite resin layer 20 obtained by curing the metal foil 1 and the prepreg can be measured, for example, by observing the cross section of the metal foil-clad laminate 100 with an electron microscope or a metal microscope. If it is before producing a metal foil-clad laminate, the thickness of the composite resin layer 20 can also be confirmed with a micrometer. The total thickness of the metal foil-clad laminate 100 can be measured and confirmed with a micrometer.

  Moreover, as thickness of the fiber base material 2, the cross-sectional photograph of the metal foil clad laminated board 100 is image | photographed, for example with an electron microscope, In the photograph, the convex part which goes to the resin film 40 side of the fiber base material 2 and it adjoins it. From the straight line connecting the convex part toward the resin film 40 side, the perpendicular line is lowered toward the metal foil 1 side, and the perpendicular line reaches the convex part toward the metal foil 1 side of the fiber substrate 2 as the perpendicular line. Measure the length of the perpendicular. This is measured at five locations, and the average value is defined as the thickness of the fiber substrate 2 in the present invention.

  The metal foil 1 is not particularly limited as long as it is used when producing a metal foil-clad laminate or a multilayer printed wiring board, but usually a copper foil, an aluminum foil, or the like is used. The thickness of the metal foil 1 is usually about 1 to 35 μm.

  Specific examples of the copper foil include F3-WS-12 (manufactured by Furukawa Circuit Foil Co., Ltd., trade name).

  As the fiber base material 2, what is conventionally used when manufacturing a metal foil clad laminated board or a multilayer printed wiring board, etc. can be used. Such fiber base materials include glass, alumina, boron, silica alumina glass, silica glass, tyrano, silicon carbide, silicon nitride, zirconia, and other inorganic materials, aramid, polyether ether ketone, polyether imide, poly Organic substances such as ether sulfone, carbon, and cellulose are listed. Moreover, you may use these individually by 1 type or in combination of multiple types (mixed paper type). There is no restriction | limiting in particular as a form of a fiber base material, Although a woven fabric or a nonwoven fabric may be sufficient, a woven fabric is preferable and a glass cloth (glass fiber woven fabric) is more preferable. Specific examples of the glass cloth include WEX-1017, WEX-1027, WEX-1037 (manufactured by Asahi Sebel Co., Ltd., trade name) and the like.

  It is preferable to use a glass cloth having a thickness of 8 to 30 μm for the fiber base 2. By using such a material as a fiber base material, both bendability and dimensional stability can be achieved at a higher level.

  The resin film 40 is preferably flexible and self-supporting. Moreover, it is preferable that there is no spontaneous adhesiveness. Here, being flexible means having a property of easily bending when an external force is applied. Self-supporting is a film that is self-supporting without a support film, and self-adhesive adhesiveness is that the resin itself does not have tackiness or adhesiveness.

  Such a resin can be used without particular limitation as long as it can be used for a metal foil-clad laminate constituting a flexible substrate. For example, polyimide resin, polyethylene terephthalate resin, polyether resin, polyethylene A phthalate resin, a polybenzoxazole resin, etc. are mentioned, It is preferable that it is resin insoluble in a solvent. A commercially available resin film may be used. Examples of commercially available resin films include Upilex S (trade name, manufactured by Ube Industries, Ltd.), Kapton H, Kapton E, Kapton EN (trade name, manufactured by Toray DuPont Co., Ltd.), Apical AV, and Apical NP. , Polyethylene terephthalate films such as polyimide film such as Apical HP (above, manufactured by Kaneka Co., Ltd., trade name) and Teijin Tetron Film G2 (trade name, manufactured by Teijin DuPont Films Ltd.), Teonex Q51 (Polyethylene naphthalate film such as trade name) and polyether ether ketone films such as Sumilite FS-1100C (trade name, manufactured by Sumitomo Bakelite Co., Ltd.). Moreover, the resin film after removing the copper foil of the flexible copper foil clad laminated board marketed by an etching etc. can also be used. Examples of commercially available flexible copper foil-clad laminates include Neofrex (trade name, manufactured by Mitsui Chemicals) and Espanex (trade name, manufactured by Nippon Steel Chemical Co., Ltd.).

  The thickness of the resin film 40 is preferably 1 to 80 μm, more preferably 5 to 50 μm, and particularly preferably 8 to 25 μm. If it exceeds 80 μm, the bendability tends to decrease, and if it is less than 1 μm, the strength of the film tends to decrease.

  The composite resin layer 20 is obtained by curing a prepreg in which the fiber base material 2 is embedded. In addition, in this specification, a prepreg means the thing of the B stage state (uncured state) which has a fixed thickness formed by impregnating a fiber base material with resin.

  The composite resin layer 20 preferably contains a thermosetting resin composition from the viewpoints of heat resistance, electrical insulation, and chemical resistance. Moreover, it is preferable that the said thermosetting resin composition contains resin which has a glycidyl group from a viewpoint that it can shape | mold at a low shaping | molding temperature.

  From the viewpoint of further improving the bendability (flexibility) and heat resistance of the metal foil-clad laminate 100, the thermosetting resin composition preferably contains a resin having an amide group. It is preferable to use a polyamideimide resin having a siloxane bond as the resin having an amide group because the effect of improving the bendability and heat resistance is more excellent.

  Moreover, from the viewpoint of further improving the bendability and heat resistance of the metal foil-clad laminate 100, the thermosetting resin composition preferably includes an acrylic resin.

  The resin portion in the composite resin layer 20 of the metal foil-clad laminate 100 is preferably a cured product of a resin selected from the group consisting of a resin having a glycidyl group, a resin having an amide group, and an acrylic resin. When the resin portion is such, the bendability and heat resistance of the metal foil-clad laminate 100 can be further improved. In addition, in this specification, the hardened | cured material means the thing of the state hardened | cured to the C stage state generally, and the unreacted functional group may remain in resin. The C stage state refers to a state in which the resin is cured to a degree insoluble and infusible with respect to the solvent.

  The prepreg can be produced, for example, by impregnating the fiber base 2 into a prepreg-forming resin composition and drying it as necessary. The production conditions of the prepreg are not particularly limited, but in order to obtain the composite resin layer 20 having a thickness within a preferable range of the present embodiment, the solvent used in the prepreg-forming resin composition should be volatilized by 80% by mass or more. Is preferred. From such a viewpoint, it is preferable that the temperature at the time of drying shall be 80 to 180 degreeC. Moreover, what is necessary is just to adjust drying time according to the gelatinization time of the resin composition for prepreg formation. The amount of the prepreg-forming resin composition impregnated into the fiber substrate 2 is 30 to 80 masses of the prepreg-forming resin composition with respect to the solid content in the prepreg-forming resin composition and the total mass of the fiber substrate 2. % Is preferred.

  As the resin to be contained in the prepreg-forming resin composition, for example, an insulating resin generally used in the wiring board field can be used. In the present invention, the prepreg-forming resin composition is preferably a thermosetting resin composition containing a thermosetting resin.

  Examples of the thermosetting resin include epoxy resins, polyimide resins, unsaturated polyester resins, polyurethane resins, bismaleimide resins, triazine-bismaleimide resins, and phenol resins.

  The thermosetting resin is preferably a resin having a glycidyl group, and more preferably includes an epoxy resin. By using an epoxy resin, the thermosetting resin composition can be cured at a temperature of 180 ° C. or lower, and the thermal characteristics, mechanical characteristics, and electrical characteristics of the composite resin can be improved.

  Epoxy resins include polyglycidyl ethers and phthalic acids obtained by reacting polychlorophenols such as bisphenol A, novolac phenolic resins, orthocresol novolac phenolic resins, polyhydric alcohols such as 1,4-butanediol and epichlorohydrin. And polyglycidyl ester obtained by reacting a polybasic acid such as hexahydrophthalic acid with epichlorohydrin, an N-glycidyl derivative of a compound having an amine, an amide or a heterocyclic nitrogen base, an alicyclic epoxy resin, and the like.

  The epoxy resin preferably has two or more glycidyl groups. The more the number of glycidyl groups, the better.

  Specific examples include YD128, YD8125, YD907, YDCN-704, YDCN-700-10 (trade name, manufactured by Tohto Kasei Co., Ltd.), Ep815, Ep828 (trade name, manufactured by Yuka Shell Epoxy Co., Ltd.), DER 337 (Dow). Chemical Japan, product name), EPICLON153, N-673-80M, N-680-75M, N-690-75M, HP4032D (manufactured by DIC, product name), EX-212L, EX-214L (Nagase) Chemtex Co., Ltd., trade name), Celoxide 2021P (Daicel Chemical Industries, trade name), EPPN502H, NC3000 (Nippon Kayaku Co., Ltd., trade name) and the like.

  When using an epoxy resin, it is preferable to use the curing agent together. Moreover, you may use a hardening accelerator. The greater the number of glycidyl groups that the epoxy resin has, the smaller the blending amount of the curing agent and curing accelerator.

  The curing agent for the epoxy resin can be used without limitation as long as it reacts with the epoxy resin. For example, amines, imidazoles, polyfunctional phenols, and acid anhydrides can be used. Examples of amines include dicyandiamide, diaminodiphenylmethane, and guanylurea. Examples of the polyfunctional phenols include hydroquinone, resorcinol, bisphenol A and their halogen compounds, and also novolak-type phenol resins and resol-type phenol resins that are condensates with formaldehyde. Examples of acid anhydrides include phthalic anhydride, benzophenone tetracarboxylic dianhydride, methyl hymic acid, and the like. Examples of imidazoles include alkyl group-substituted imidazoles and benzimidazoles. These can be used individually by 1 type or in combination of 2 or more types.

  Specific examples include FG-2000 (manufactured by Teijin Chemicals Ltd., trade name).

  The compounding amount of the curing agent in the thermosetting resin composition is such that when the resin is an epoxy resin and the curing agent is an amine, the equivalent of the active hydrogen of the amine and the epoxy equivalent of the epoxy resin are approximately equal. Is preferred. When the resin is an epoxy resin and imidazole is employed as the curing agent, it is not simply an equivalent ratio with active hydrogen, and is empirically preferably 0.001 to 10 parts by mass with respect to 100 parts by mass of the epoxy resin. In the case of polyfunctional phenols and acid anhydrides, phenolic hydroxyl groups and carboxyl groups of 0.6 to 1.2 equivalents are preferred with respect to 1 equivalent of epoxy resin. If there is little compounding quantity of a hardening | curing agent, uncured epoxy resin will remain and Tg (glass transition temperature) tends to become low. If the amount is too large, unreacted curing agent remains, and the insulation tends to decrease.

  The epoxy resin curing accelerator can be used without limitation as long as it reacts with the epoxy resin. For example, amines, imidazoles, polyfunctional phenols, and acid anhydrides can be used. Examples of amines include diaminodiphenylmethane and guanylurea. Examples of the polyfunctional phenols include hydroquinone, resorcinol, bisphenol A and their halogen compounds, and also novolak-type phenol resins and resol-type phenol resins that are condensates with formaldehyde. Examples of acid anhydrides include phthalic anhydride, benzophenone tetracarboxylic dianhydride, methyl hymic acid, and the like. Examples of imidazoles include alkyl group-substituted imidazoles and benzimidazoles. These can be used individually by 1 type or in combination of 2 or more types.

  Specific examples include 1-cyanoethyl-2-ethyl-1-methylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-cyanoethyl 2-ethyl-1-methylimidazole, and the like.

  The compounding amount of the curing accelerator in the thermosetting resin composition is such that when the resin is an epoxy resin and the curing accelerator is an amine, the equivalent of the active hydrogen of the amine and the epoxy equivalent of the epoxy resin are approximately equal. Preferably there is. When the resin is an epoxy resin and imidazole is employed as a curing accelerator, it is not simply an equivalent ratio with active hydrogen, and is empirically preferably 0.001 to 10 parts by mass with respect to 100 parts by mass of the epoxy resin. . In the case of polyfunctional phenols and acid anhydrides, phenolic hydroxyl groups and carboxyl groups of 0.6 to 1.2 equivalents are preferred with respect to 1 equivalent of epoxy resin. If the blending amount of the curing accelerator is small, an uncured epoxy resin remains and Tg (glass transition temperature) tends to be low. When the amount is too large, unreacted curing accelerator remains, and the insulating property tends to decrease.

  The thermosetting resin composition can contain a high molecular weight resin component for the purpose of improving the flexibility and heat resistance of the metal foil-clad laminate 100. Resins for this purpose include resins having amide groups and acrylic resins. Examples of the resin having an amide group include a polyamideimide resin.

  The polyamideimide resin is a resin containing an imide group and an amide group as a repeating unit, and preferably contains 70 mol% or more of polyamideimide molecules containing 10 or more amide groups in one molecule.

  The content ratio of the polyamideimide molecule containing 10 or more amide groups in one molecule in the polyamideimide resin is calculated as follows.

  First, the mass (A) [g] of the polyamideimide resin and the number of moles (B) of the amide group in the polyamideimide resin (A) g are measured. The number of moles (B) of the amide group in the polyamideimide resin (A) g can be measured by NMR, IR, hydroxamic acid-iron color reaction method, N-bromoamide method, or the like.

Then, using the measured (A) and (B), the average molecular weight (D) of the polyamideimide containing 10 amide groups in one molecule is calculated by the following formula (I).
(D) = (A) / ((B) / 10) (I)

  Next, the chromatogram (C) of the molecular weight distribution of the polyamideimide resin is measured by GPC (gel permeation chromatography) (standard polystyrene conversion at 25 ° C.). As an eluent for GPC, a solution in which 0.06 mol / L of phosphoric acid and 0.03 mol / L of lithium bromide monohydrate are dissolved in a mixed solution of tetrahydrofuran / dimethylformamide = 50/50 (volume ratio) is used. As the column, a column in which two GL-S300MDT-5 (manufactured by Hitachi High-Technologies Corporation, product name) are directly connected is used.

  And in the chromatogram (C) of the molecular weight distribution of the obtained polyamideimide resin, by calculating the area of the region where the molecular weight is equal to or higher than the molecular weight (D) of the polyamideimide containing 10 amide groups in one molecule The content ratio of the polyamideimide molecule containing 10 or more amide groups in one molecule in the polyamideimide resin can be determined.

  As the polyamideimide resin, a siloxane-modified polyamideimide having a siloxane structure in the resin is preferable. The siloxane-modified polyamideimide is obtained by, for example, reacting a mixture containing an aromatic diamine having two or more aromatic rings and a siloxane diamine with diimide dicarboxylic acid obtained by reacting trimellitic anhydride and a diisocyanate. Obtainable. In this case, the mixing ratio (molar ratio) of the aromatic diamine a having two or more aromatic rings and the siloxane diamine b is in the range of a / b = 99.9 / 0.1 to 0/100. Preferably, a / b = 95/5 to 30/70 is more preferable, and a / b = 90/10 to 40/60 is even more preferable. When the mixing ratio of siloxane diamine b increases, Tg tends to decrease. Moreover, when the mixing ratio of the siloxane diamine b is low, a large amount of the solvent used for the varnish tends to remain in the resins 20a and 30a of the metal foil-clad laminate.

  Examples of the aromatic diamine include 2,2-bis [4- (4-aminophenoxy) phenyl] propane (BAPP), bis [4- (3-aminophenoxy) phenyl] sulfone, and bis [4- (4- Aminophenoxy) phenyl] sulfone, 2,2-bis [4- (4-aminophenoxy) phenyl] hexafluoropropane, bis [4- (4-aminophenoxy) phenyl] methane, 4,4′-bis (4- Aminophenoxy) biphenyl, bis [4- (4-aminophenoxy) phenyl] ether, bis [4- (4-aminophenoxy) phenyl] ketone, 1,3-bis (4-aminophenoxy) benzene, 1,4- Bis (4-aminophenoxy) benzene, 2,2′-dimethylbiphenyl-4,4′-diamine, 2,2′-bis (trifluoro) Methyl) biphenyl-4,4′-diamine, 2,6,2 ′, 6′-tetramethyl-4,4′-diamine, 5,5′-dimethyl-2,2′-sulfonylbiphenyl-4,4 ′ -Diamine, 3,3'-dihydroxybiphenyl-4,4'-diamine, (4,4'-diamino) diphenyl ether, (4,4'-diamino) diphenylsulfone, (4,4'-diamino) benzophenone, 3,3′-diamino) benzophenone, (4,4′-diamino) diphenylmethane, (4,4′-diamino) diphenyl ether, (3,3′-diamino) diphenyl ether, and the like.

  Examples of the siloxane diamine include the following. In addition, in following formula (3), (4), (5), (6), n shows the integer of 1-50 and m shows the integer of 1-10. However, m and n in Formula (6) satisfy 1 <m + n <50.

  In addition, as siloxane diamine represented by the said General formula (3), X-22-161AS (amine equivalent 450), X-22-161A (amine equivalent 840), X-22-161B (amine equivalent 1500) ( As mentioned above, Shin-Etsu Chemical Co., Ltd., product name), BY16-853 (amine equivalent 650), BY16-853B (amine equivalent 2200), (manufactured by Toray Dow Corning Silicone Co., Ltd., product name) can be exemplified. Examples of the siloxane diamine represented by the general formula (6) include X-22-9409 (amine equivalent 700), X-22-1660B-3 (amine equivalent 2200) (manufactured by Shin-Etsu Chemical Co., Ltd., trade name). And the like.

  The diamine to be reacted with trimellitic anhydride may contain an aliphatic diamine. Examples of the aliphatic diamine include a compound represented by the following general formula (7).

In formula (7), X represents a methylene group, a sulfonyl group, an ether group, a carbonyl group or a single bond, and R ¹ and R ² each independently have a hydrogen atom, an alkyl group, a phenyl group or a substituent. May be a phenyl group (substituted phenyl group), and p represents an integer of 1 to 50.

R ¹ and R ² are preferably a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, a phenyl group, or a substituted phenyl group. The substituent that may be bonded to the phenyl group is an alkyl having 1 to 3 carbon atoms. Examples thereof include a group and a halogen atom.

  From the viewpoint of achieving both low elastic modulus and high Tg, X in the general formula (7) is preferably an ether group. Examples of such aliphatic diamines include Jeffamine D-400 (amine equivalent 400) and Jeffamine D-2000 (amine equivalent 1000).

  The diisocyanate to be reacted with diimide dicarboxylic acid is represented by the following general formula (8), for example.

In formula (8), D represents a divalent organic group having at least one aromatic ring or a divalent aliphatic hydrocarbon group. As the divalent organic group having an aromatic ring, a group represented by —C ₆ H ₄ —CH ₂ —C ₆ H ₄ —, a tolylene group, and a naphthylene group are preferable, and as the divalent aliphatic hydrocarbon group, , Hexamethylene group, 2,2,4-trimethylhexamethylene group and isophorone group are preferable.

  As the diisocyanate, an aromatic diisocyanate is preferably used, and an aromatic diisocyanate and an aliphatic diisocyanate are more preferably used in combination.

  Examples of aromatic diisocyanates include 4,4′-diphenylmethane diisocyanate (MDI), 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, naphthalene-1,5-diisocyanate, and 2,4-tolylene dimer. It can be illustrated. Among these, it is particularly preferable to use MDI. By using MDI, the flexibility of the polyamideimide obtained can be improved.

  Specific examples include 4,4'-diphenylmethane diisocyanate (trade name, manufactured by Nippon Polyurethane Co., Ltd.).

  Examples of the aliphatic diisocyanate include hexamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, and isophorone diisocyanate.

  When the aromatic diisocyanate and the aliphatic diisocyanate are used in combination, it is preferable to add the aliphatic diisocyanate to about 5 to 10 mol% with respect to the aromatic diisocyanate. Thereby, the heat resistance of the polyamideimide obtained can be further improved.

  Examples of the polyamideimide resin having a siloxane bond obtained by the above synthesis method include KS6600, KS6600F, KS9500, KS9900F, and KS9900B (trade name, manufactured by Hitachi Chemical Co., Ltd.).

  As the acrylic resin, for example, an acrylic acid monomer, a methacrylic acid monomer, acrylonitrile, an acrylic monomer having a glycidyl group, or a polymer obtained by polymerizing them alone or a copolymer obtained by copolymerizing a plurality thereof can be used. Although there is no restriction | limiting in particular in the molecular weight of an acrylic resin, Preferably it is 300,000-1 million by the weight average molecular weight of standard polystyrene conversion in GPC measurement, More preferably, the thing of 400,000-800,000 is used. These acrylic resins are preferably used in combination with an epoxy resin, a curing agent, and a curing accelerator.

  Specific examples include HTR-860-P3 (trade name, manufactured by Nagase ChemteX Corporation).

  Further, the resin for forming the composite resin layer 20 may contain an additive type flame retardant for the purpose of improving the flame retardancy. Among these, fillers containing aluminum hydroxide (manufactured by Showa Denko KK, trade name HP360), silica (manufactured by Admatechs KK, trade name SO-E5) and phosphorus are preferable. As fillers containing phosphorus, OP930 (manufactured by Clariant, trade name, phosphorus content 23.5 wt%), HCA-HQ (manufactured by Sanko Co., Ltd., trade name, phosphorus content 9.6 wt%), melamine polyphosphate PMP -100 (phosphorus content: 13.8 wt%), PMP-200 (phosphorus content: 9.3 wt%), PMP-300 (phosphorus content: 9.8 wt%) (trade name, manufactured by Nissan Chemical Co., Ltd.) Can be mentioned.

  The metal foil-clad laminate 100 is formed by, for example, laminating a prepreg having a thickness of 60 μm or less and a resin film 40 obtained by impregnating a resin to the metal foil 1 and the fiber base 2 so as to be positioned in this order, and heating and pressurizing (thermocompression bonding). ) Can be obtained. According to this method, only one thermocompression bonding is required from each member to the metal foil-clad laminate 100, and it can be easily and efficiently manufactured with good workability. Note that in this specification, the term “stack” means to overlap.

  Further, the metal foil-clad laminate 100 is obtained by thermocompression bonding a metal foil 1 and a prepreg having a thickness of 60 μm or less formed by impregnating a fiber base material 2 with a resin, and then thermocompression bonding the resin film 40 to the prepreg. Can also be obtained. This method is effective when the metal foil 1 and the composite resin layer 20 need to be thermocompression bonded in advance. For example, when an extremely thin metal foil is used, it is difficult to carry the metal foil alone. Therefore, after thermocompression bonding with a prepreg obtained by impregnating a fiber base with a resin in advance, the resin film 40 is placed on the composite resin side of the thermocompression bonding material. By thermocompression bonding, a desired metal foil-clad laminate can be obtained efficiently.

  As an example, an ultrathin metal foil and a prepreg having a thickness of 10 to 60 μm formed by impregnating a glass cloth with a resin are subjected to thermocompression bonding at a temperature (for example, about 80 to 120 ° C.) at which the prepreg curing reaction does not proceed excessively. (First thermocompression bonding) to temporarily fix to a temporary fixing body, and then place a resin film on the prepreg side of the temporary fixing body to sufficiently accelerate the curing reaction of the prepreg (for example, 170 to 230 ° C. And the like (second thermocompression bonding). Here, the pressure at the time of thermocompression bonding is usually about 0.2 to 10 MPa. Another example is a method in which another adhesive layer is provided between the prepreg and the resin film during the second thermocompression bonding, and thermocompression bonding is performed through the layer. The thermocompression bonding temperature may be such that the curing reaction of the prepreg does not proceed excessively or is sufficiently accelerated. By the method as described above, a desired metal foil-clad laminate can be obtained efficiently.

  Here, the ultrathin metal foil usually refers to a metal foil having a thickness of 1 to 5 μm.

[Double-sided metal foil-clad laminate]
FIG. 2 is a schematic cross-sectional view showing an embodiment of a double-sided metal foil-clad laminate of the present invention. A double-sided metal foil-clad laminate 200 shown in FIG. 2 includes a first composite resin layer 20 obtained by curing a first metal foil 1, a first prepreg in which a fiber substrate 2 is embedded, and a resin. The film 40, the 2nd composite resin layer 30 obtained by hardening | curing the 2nd prepreg by which the fiber base material 3 is embed | buried, and the 2nd metal foil 4 are provided in this order.

Here, each of the composite resin layers 20 and 30 has a thickness (d ₂ ) of 50 μm or less. When this thickness exceeds 50 μm, the bendability is inferior. On the other hand, if the thickness is too thin, the dimensional stability and tear resistance tend to be inferior, so the lower limit of the thickness is preferably 10 μm. Moreover, from a viewpoint of the availability of a fiber base material, it is preferable that it is 16 micrometers or more. In addition, the thickness of the composite resin layers 20 and 30 can be measured by observing the cross section of the double-sided metal foil-clad laminate 200 with an electron microscope or a metal microscope, for example. If it is before producing a double-sided metal foil clad laminated board, thickness can also be confirmed with a micrometer.

  In addition, from the viewpoint of suppressing warpage of the double-sided metal foil-clad laminate 200, it is preferable that the first composite resin layer 20 and the second composite resin layer 30 have substantially the same thickness.

  Moreover, the distance between the 1st fiber base material 2 and the 2nd fiber base material 3 is 10-170 micrometers. If this distance is less than 10 μm, the fiber base materials are too close to each other and are difficult to bend. Moreover, when it exceeds 170 micrometers, the thickness of the whole laminated board will become thick and it will become difficult to bend.

  In addition, the distance between the 1st fiber base material 2 and the 2nd fiber base material 3 can be measured from the electron micrograph of the cross section of the double-sided metal foil clad laminated board 200, for example. Hereinafter, the definition of the distance will be specifically described with reference to FIG.

From the straight line connecting the arbitrary convex part 50a toward the resin film side in the first fiber base 2 and the convex part 50b toward the resin film adjacent thereto, the perpendicular line goes to the resin film side in the second fiber base 3 The length d _{6 of the} perpendicular is measured by taking the perpendicular to the point where the perpendicular reaches the convex part. This is photographed at five locations, the length of the perpendicular is measured, and the average value is defined as the distance between the first fiber substrate 2 and the second fiber substrate 3 in the present invention.

  The total thickness of the double-sided metal foil-clad laminate 200 is 300 μm or less. When the thickness of the double-sided metal foil-clad laminate 200 is 300 μm or less, the folding property with a crease is improved. The total thickness of the double-sided metal foil-clad laminate 200 can be measured and confirmed with a micrometer.

  The composite resin layers 20 and 30 obtained by curing the prepreg are respectively composed of the resins 20a and 30a and the fiber bases 2 and 3 embedded in these resins, respectively. For example, for prepreg formation It can be formed by curing a prepreg obtained by impregnating a fiber base material into a resin composition. The thickness of the prepreg is preferably 60 μm or less, more preferably 10 to 50 μm, still more preferably 15 to 45 μm, and particularly preferably 17 to 40 μm. If the thickness of the prepreg exceeds 60 μm, the resin flow increases during press lamination, and the thickness of the composite resin layers 20 and 30 tends to be non-uniform. If it is less than 10 μm, the fiber base materials 2 and 3 and the resin The resin existing between the film 40 and the adhesive force tends to be reduced.

The thickness of the resin layers 20a and 30a is preferably 0.8 to 22.5 μm, more preferably 3 to 15 μm, and still more preferably 5 to 10 μm. When the thickness of the resin layers 20a and 30a exceeds 22.5 μm, there is a tendency that the dimensional change accompanying heating and moisture absorption tends to increase, and when the thickness is less than 0.8 μm, between the fiber base materials 2 and 3 and the resin film 40 There is a tendency that the amount of resin present in the resin decreases and the adhesive strength decreases. The thickness of the resin layer 20a indicates the distance between the surface of the composite resin layer and the fiber base material 2. For example, the thickness of the resin layer 20a, as shown in FIG. 2, the _{d 4} or _{d 5.} When the resin layers 20a and 30a have a sufficient thickness, the adhesion between the composite resin layer and the metal foil or the adhesion between the composite resin layer and the resin film is improved. The thickness of the resin layer 20a is measured, for example, by taking a cross-sectional photograph of the double-sided metal foil-clad laminate of the present invention with an electron microscope, and in the photograph, a convex portion facing the metal foil side of the fiber substrate 2 and a metal adjacent thereto A perpendicular is lowered from the straight line connecting the convex portions toward the foil 1 toward the metal foil 1, and the length of the perpendicular is measured up to the point reaching the interface between the metal foil 1 and the composite resin layer 20 as the perpendicular. . This is obtained by measuring five points and calculating the average value.

  The thickness of the resin layer 30a is also determined in the same manner as the thickness of the resin layer 20a.

  As the metal foils 1 and 4, the same metal foil 1 as that of the metal foil-clad laminate 100 can be used. Moreover, as the fiber base materials 2 and 3, the thing similar to the fiber base material 2 of the metal foil-clad laminate 100 can be used.

  In addition, it is preferable that the 1st fiber base material 2 and the 2nd fiber base material 3 are 8-30 micrometers thick glass cloth. By using such a fiber base material, both bendability and dimensional stability can be achieved at a higher level. Further, from the viewpoint of suppressing the warpage of the double-sided metal foil-clad laminate 200, the first fiber base 2 and the second fiber base 3 are preferably of the same type and having substantially the same thickness.

In addition, the thickness of a fiber base material can be measured from the electron micrograph of the cross section of a double-sided metal foil clad laminated board, for example. Specifically, a perpendicular is directed from the straight line connecting the convex portion 50a toward the resin film side in the first fiber base 2 and the convex portion 50b toward the resin film adjacent thereto toward the first metal foil 1 side. The length d _{1 of the} perpendicular is measured with the perpendicular extending to the point where the perpendicular reaches the convex portion toward the metal foil 1 side in the first fiber base 2. This is measured at five locations, and the average value is taken as the thickness of the first fiber base 2. The second fiber substrate 3 can be measured by the same method.

  As the resin for forming the resins 20a and 30a, the same resin as that for forming the composite resin layer 20 of the metal foil-clad laminate 100 is used. Moreover, as the resin film 40, the thing similar to the resin film 40 of the metal foil clad laminated board 100 is used.

  The double-sided metal foil-clad laminate 200 is, for example, a metal foil 1, a prepreg having a thickness of 60 μm or less formed by impregnating a fiber substrate 2 with a resin, a resin film 40, and a thickness 60 μm or less formed by impregnating a fiber substrate 3 with a resin. The prepreg and the metal foil 4 are sequentially laminated in order, and can be manufactured by heating and pressurizing (thermocompression bonding). According to this method, only one thermocompression bonding is required from each member to the double-sided metal foil-clad laminate 200, and it can be simply and efficiently manufactured with good workability.

  The double-sided metal foil-clad laminate 200 is obtained by thermocompression bonding of a metal foil 1 (first metal foil) and a prepreg having a thickness of 60 μm or less formed by impregnating a fiber base 2 with a resin, and then the composite resin layer. It is obtained by laminating a resin film 40 on the side, a prepreg having a thickness of 60 μm or less formed by impregnating the fiber base material 3 with resin, and a metal foil 4 (second metal foil) so as to be positioned in this order, and thermocompression-bonding. be able to. This method is preferable when an extremely thin metal foil is used for the first metal foil 1.

  Further, the double-sided metal foil-clad laminate 200 is produced by producing two sets of thermocompression bonding products obtained by thermocompression bonding of a metal foil and a prepreg having a thickness of 60 μm or less formed by impregnating a fiber base material with a resin, and is opposite to the metal foil. It can also be obtained by interposing a resin film 40 between two sets of the thermocompression products facing each other and thermocompression bonding them. This method is effective when an extremely thin metal foil is used as the metal foil on both sides.

  As a specific example, thermocompression bonding of a prepreg having a thickness of 60 μm or less formed by impregnating an ultrathin metal foil and a fiber base with a resin at a temperature at which the curing reaction does not proceed excessively (for example, about 80 to 120 ° C.) Prepare two sets of temporary fixing bodies (first thermocompression bonding), face the prepreg sides of both temporary fixing bodies, place a resin film between them, and a temperature that sufficiently accelerates the curing reaction of the prepreg (for example, And a method of thermocompression bonding (second thermocompression bonding) at about 170 to 230 ° C. Here, the pressure at the time of thermocompression bonding is usually about 0.2 to 10 MPa.

  Another example includes a method in which another adhesive layer is provided between the prepreg and the resin film during the second thermocompression bonding, and the thermocompression bonding is performed via the adhesive layer. The temperature of one thermocompression bonding may be such that the curing reaction of the prepreg does not proceed excessively or is sufficiently accelerated. By the above method, a desired double-sided metal foil-clad laminate can be obtained efficiently.

  In the double-sided metal foil-clad laminate 200, the resin of the composite resin layer is cured to the C stage state, but partially unreacted functional groups may remain.

[Printed wiring board]
A printed wiring board can be produced by subjecting a metal foil of a metal foil-clad laminate such as the metal foil-clad laminate 100 or the double-sided metal foil-clad laminate 200 to a wiring formation process such as a circuit. Examples of the wiring forming process include etching of a metal foil. Since such a printed wiring board is provided with the metal foil-clad laminate or the double-sided metal foil-clad laminate as described above, it has good bendability, excellent dimensional stability, and excellent tear resistance.

  From the viewpoint of dimensional stability, it is preferable to use a double-sided metal foil-clad laminate rather than a single-sided metal foil-clad laminate.

  The preferred embodiment of the present invention has been described above, but the present invention is not limited to the above embodiment. For example, the metal foil-clad laminate 100 includes a thermosetting resin between the composite resin layer 20 and the metal foil 1 or between the composite resin layer 20 and the resin film 40 as long as the effects of the present invention are not impaired. An intermediate layer such as an adhesive film may be provided. Moreover, the double-sided metal foil-clad laminate 200 does not impair the effects of the present invention between the composite resin layers 20 and 30 and the metal foils 1 and 4 or between the composite resin layers 20 and 30 and the resin film 40. An intermediate layer such as an adhesive film containing a thermosetting resin may be provided. Here, examples of the thermosetting resin used for the adhesive film include those having the thermosetting property among the resin composition for forming the composite resin layer and the resin used for the resin film. However, it is preferable not to provide a metal wiring layer between the composite resin layer and the resin film in terms of bendability and adhesiveness.

  Examples are described below, but the present invention is not limited to these examples.

[Preparation of resin composition for prepreg formation]
As the prepreg-forming resin composition, varnishes 1 to 4 were prepared as described later.

(Preparation of varnish 1)
Polyamideimide resin having a siloxane bond (trade name KS9900B, manufactured by Hitachi Chemical Co., Ltd.) 22.44 kg (resin solid content: 31.2% by mass), epoxy resin (trade name: EPPN502H manufactured by Nippon Kayaku Co., Ltd.) 2.0 kg (Methyl ethyl ketone solution having a resin solid content of 50% by mass), 3.0 kg of epoxy resin (manufactured by DIC Corporation, trade name HP4032D), 1.0 kg of epoxy resin (trade name NC3000, manufactured by Nippon Kayaku Co., Ltd.) (Methyl ethyl ketone solution in mass%) and 1-cyanoethyl-2-ethyl-1-methylimidazole (8.0 g) as a curing accelerator were mixed and stirred for about 1 hour so that the resin was sufficiently mixed. The varnish 1 was obtained by standing at (25 ° C.) for 24 hours.

(Preparation of varnish 2)
Polyamideimide resin having a siloxane bond (trade name KS9900B, manufactured by Hitachi Chemical Co., Ltd.) 22.44 kg (resin solid content: 31.2% by mass), epoxy resin (trade name: EPPN502H manufactured by Nippon Kayaku Co., Ltd.) 2.0 kg (Methyl ethyl ketone solution having a resin solid content of 50% by mass), 3.0 kg of epoxy resin (manufactured by DIC Corporation, trade name HP4032D), 1.0 kg of epoxy resin (trade name NC3000, manufactured by Nippon Kayaku Co., Ltd.) (Mass% methyl ethyl ketone solution) and 1-cyanoethyl-2-ethyl-1-methylimidazole 8.0 g as a curing accelerator, 1.0 kg of flame retardant (manufactured by Clariant, trade name OP930), aluminum hydroxide ( Showa Denko Co., Ltd., trade name HP360) After stirring for about 3 hours to mix, the 24 hours allowed to stand at room temperature (25 ° C.) for defoaming to obtain a varnish 2.

(Preparation of varnish 3)
Epoxy resin (manufactured by DIC Corporation, trade name EPICLON 153) 3.4 kg, curing agent (manufactured by Teijin Chemicals Ltd., trade name FG-2000) 1.81 kg, 1-cyanoethyl-2-phenylimidazole 10.0 g as a curing accelerator After being dissolved in 6.0 kg of methyl isobutyl ketone, 2.87 kg of acrylic resin (trade name HTR-860-P3, 15% methyl ethyl ketone solution manufactured by Nagase ChemteX Corporation) was added, and the mixture was further stirred for 1 hour to give varnish 3 Obtained.

(Preparation of varnish 4)
First, a polyamideimide resin used for the varnish 4 was synthesized. The synthesis method is shown below.

  2,2-bis [4- (4-aminophenoxy) phenyl as an aromatic diamine was added to a 25-mL separable flask equipped with a faucet connected to a reflux condenser, a thermometer and a stirrer. ] 61.5 g (0.15 mol) of propane, aliphatic diamine (manufactured by Sun Techno Chemical Co., Ltd., trade name Jeffamine D2000, amine equivalent 1000) 180.0 g (0.09 mol), trimellitic anhydride (manufactured by Wako Pure Chemical Industries, Ltd.) Hereinafter, 121.0 g (0.63 mol) of TMA) and 1000 g of N-methyl-2-pyrrolidone (hereinafter abbreviated as NMP) as an aprotic polar solvent were charged and stirred at 80 ° C. for 30 minutes. Then, 150 mL of toluene was added as an aromatic hydrocarbon azeotropic with water, and the temperature was raised and refluxed at about 160 ° C. for 2 hours. While confirming that about 28.6 mL or more of water has accumulated in the moisture determination receiver and that no water has been distilled out, while removing the distillate that has accumulated in the moisture determination receiver, about 190 The temperature was raised to 0 ° C. to remove toluene.

  Thereafter, the solution was returned to room temperature, 82.5 g (0.33 mol) of 4,4′-diphenylmethane diisocyanate (manufactured by Nippon Polyurethane Co., Ltd., hereinafter abbreviated as MDI) was added as an aromatic diisocyanate, and reacted at 190 ° C. for 2 hours. I let you. After completion of the reaction, an NMP solution of polyamideimide resin containing no siloxane bond was obtained (resin solid content: 32.1% by mass).

  And the varnish 4 was prepared using the polyamide-imide resin synthesize | combined as mentioned above. The preparation method is shown below.

  3.12 kg of synthesized polyamideimide resin (resin solid content: 32.1 mass%), epoxy resin (product name: EPPN502H, manufactured by Nippon Kayaku Co., Ltd.) 0.29 kg (methyl ethyl ketone solution having a resin solid content of 50 mass%), epoxy resin (Nippon Kayaku Co., Ltd., trade name NC3000) 0.14 kg (methyl ethyl ketone solution having a resin solid content of 50% by mass) and 1.1 g of 1-cyanoethyl 2-ethyl-1-methylimidazole as a curing accelerator were blended. A flame retardant (manufactured by Clariant, trade name: OP930) 0.14 kg and aluminum hydroxide (product name: HP360, trade name: HP360) 0.21 kg were added and stirred for about 3 hours so that the resin was sufficiently mixed. And after stirring, it left still at room temperature (25 degreeC) for defoaming for 24 hours, and the varnish 4 was obtained.

[Preparation of prepreg]
As prepregs for forming the composite resin layers 20 and 30, prepregs 1 to 10 were prepared as described later.

(Preparation of prepregs 1 to 3)
As a fiber base material, a glass cloth (manufactured by Asahi Schwer, trade name WEX-1017, thickness 13 μm) was prepared. Then, prepregs 1-3 (P1-3) were obtained by apply | coating the prepared varnish 1-3 to a fiber base material with a vertical coating machine, respectively, and making it dry. The amount of varnish applied to the fiber substrate was such that the thickness of the prepreg before curing was 30 μm. Moreover, the drying temperature was adjusted to 120 degreeC for drying, and it dried for 10 minutes.

(Preparation of prepregs 4-6)
As a fiber base material, a glass cloth (manufactured by Asahi Schwer, trade name WEX-1027, thickness 19 μm) was prepared. Then, the prepared varnish 1-3 was apply | coated to the fiber base material with the vertical coating machine, respectively, and the prepreg 4-6 (P4-6) was obtained by making it dry. The amount of varnish applied to the fiber substrate was such that the thickness of the prepreg before curing was 40 μm. Moreover, the drying temperature was adjusted to 120 degreeC for drying, and it dried for 10 minutes.

(Preparation of prepreg 7-9)
As a fiber base material, a glass cloth (manufactured by Asahi Schwer, trade name WEX-1037, thickness 28 μm) was prepared. Then, the prepared varnish 1-3 was apply | coated to the fiber base material with the vertical coating machine, respectively, and the prepregs 7-9 (P7-9) were obtained by making it dry. The amount of varnish applied to the fiber substrate was such that the thickness of the prepreg before curing was 45 μm. Moreover, the drying temperature was adjusted to 120 degreeC for drying, and it dried for 10 minutes.

(Preparation of prepreg 10)
As a fiber base material, a glass cloth (manufactured by Asahi Schwer, trade name WEX-1027, thickness 19 μm) was prepared. Then, the prepared varnish 4 was apply | coated to the fiber base material with the vertical coating machine, and the prepreg 10 (P10) was obtained by making it dry. The amount of varnish applied to the fiber substrate was such that the thickness of the prepreg before curing was 40 μm. Moreover, the drying temperature was adjusted to 120 degreeC for drying, and it dried for 10 minutes.

[Preparation of resin film]
As a resin film, Upilex S (polyimide film manufactured by Ube Industries, Ltd., trade name, thickness 25 μm), Kapton EN (polyimide film manufactured by Toray DuPont Co., Ltd., trade name, thickness 25 μm), Espanex MB12-25-12CEG copper Foil etched product (“Espanex MB12-25-12CEG” is a trade name of flexible copper foil-clad laminate manufactured by Nippon Steel Chemical Co., Ltd., thickness 25 μm), Teijin Tetron Film G2 (polyethylene terephthalate film manufactured by Teijin DuPont Films Ltd., Product name, thickness 38 μm), Teonex Q51 (polyethylene naphthalate film manufactured by Teijin DuPont Films, trade name, thickness 25 μm), Sumilite FS-1100C (polyether ether ketone film manufactured by Sumitomo Bakelite Co., Ltd.) Film, product name, thickness 50 μm). These resin films are easily bent with respect to external force and have flexibility.

[Preparation of copper foil]
As copper foil, electrolytic copper foil F3-WS-12 (Furukawa Circuit Foil Co., Ltd., surface roughness Rt = 3.5 μm, thickness 12 μm) was prepared.

[Examples I-1 to I-2]
A single-sided copper foil-clad laminate was produced using the materials prepared as described above in the combinations shown in Table 1. The single-sided copper foil-clad laminate was prepared by laminating and pressing the prepared materials in the order of copper foil / prepreg / resin film. The press conditions were such that the press part of the press machine had a degree of vacuum of 40 hPa, then the material was pressurized and heated at a molding pressure of 4 MPa and a heating rate of 5 ° C./min. When the molding temperature reached 230 ° C., the molding temperature was changed. After maintaining for 30 minutes (molding time), the pressure heating was stopped, and after air cooling, the press part was returned to atmospheric pressure.

[Comparative Examples II-1 to II-2]
A single-sided copper foil-clad laminate was produced using the materials prepared as described above in the combinations shown in Table 1. In Comparative Example II-1, a single-sided copper foil-clad laminate was prepared by stacking and pressing two P7 prepregs in the order of copper foil / prepreg (two sheets) / resin film. Comparative Example II-2 was prepared by laminating and pressing a single-sided copper foil-clad laminate without a resin film in the order of copper foil / prepreg. In either case, the press conditions were such that the pressing part of the press machine had a degree of vacuum of 40 hPa, then the material was pressurized and heated at a molding pressure of 4 MPa and a heating rate of 5 ° C./min. After maintaining for 30 minutes (molding time), the pressure heating was stopped, and after air cooling, the press part was returned to atmospheric pressure.

[Examples II-1 to II-15]
Using the materials prepared as described above in combinations shown in Tables 2 to 5, double-sided copper foil-clad laminates were produced. The double-sided copper foil-clad laminate was prepared by laminating and pressing the prepared materials in the order of copper foil / prepreg / resin film / prepreg / copper foil. The press conditions were those using P1, P2, P4, P5, P7, P8, and P10 prepregs, after the press part of the press machine had a vacuum degree of 40 hPa, a molding pressure of 4 MPa, and a heating rate of 5 ° C./min. Then, the material was pressurized and heated, and when the molding temperature reached 230 ° C., the molding temperature was maintained for 30 minutes (molding time), then the pressure heating was stopped, and after air cooling, the press part was returned to atmospheric pressure. For P3, P6, and P9 prepregs, after pressing the press part of the press machine to a degree of vacuum of 40 hPa, the material was pressurized and heated at a molding pressure of 4 MPa and a heating rate of 5 ° C./min. When the temperature reached, the molding temperature was maintained for 60 minutes (molding time), then the pressure heating was stopped, and after air cooling, the press part was returned to atmospheric pressure.

[Comparative Examples II-1 to II-6]
The characteristics of the resin film used alone in Examples II-1 to II-12 were measured. Tables 2 to 5 show the types and thicknesses of the resin films used.

[Comparative Examples II-7 to II-9]
P7-9 prepregs were used in the order of copper foil / prepreg / prepreg / copper foil and P7 and P8 prepregs were used. The material begins to be heated under pressure at a rate of 5 ° C / min. When the molding temperature reaches 230 ° C, the molding temperature is maintained for 30 minutes (molding time), then the pressure heating is stopped, and after air cooling, the press section is brought to atmospheric pressure. Returned. In the case of using P9 prepreg, after pressing the press part of the press machine to a degree of vacuum of 40 hPa, the material is pressurized and heated at a molding pressure of 4 MPa and a heating rate of 5 ° C./min. When the molding temperature reaches 185 ° C. The temperature was maintained for 60 minutes (molding time), then the pressure heating was stopped, and after air cooling, the press part was returned to atmospheric pressure to produce a double-sided copper foil-clad laminate.

  Tables 2 to 5 show the types and thicknesses of the resin films used.

[Evaluation of double-sided copper foil-clad laminate and resin film]
Double-sided copper foil-clad laminates of Examples II-1 to II-15 and single-sided resin film of Comparative Examples II-1 to II-6 and double-sided copper foil-clad laminates of Comparative Examples II-7 to II-9 (resin film None) was evaluated as follows. The evaluation results are shown in Tables 1-5.

[Evaluation of bendability]
Example I-1, Example I-2, Comparative Example I-1, Single-sided copper foil-clad laminates of Comparative Example I-2 and Examples II-1 to II-15 and Comparative Examples II-7 to II-9 A double-sided copper foil-clad laminate was cut into 100 mm × 20 mm and used as a sample.

  Moreover, the resin base material (henceforth, hereinafter) which etches the copper foil of the single-sided copper foil clad laminated board of Example I-1 and I-2 and the double-sided copper foil clad laminated board of Example II-1 to II-15. A single-sided copper foil-clad laminate or a double-sided copper-clad laminate with the copper foil removed entirely is referred to as a “resin substrate”) and cut into 100 mm × 20 mm as samples. Comparative Examples II-1 to II-6 were evaluated as they were. Each sample was bent 90 degrees in the longitudinal direction, a 5 mm thick aluminum plate was placed on the sample at a right angle to the length direction, bent at 90 degrees, and the bent portion was rubbed against the side of the glass rod from the outside. The presence or absence of cracks in the bent portions (outside and inside) was visually confirmed. It is possible to bend in any cut sample of a resin base material obtained by etching a single-sided copper foil-clad laminate, a double-sided copper foil-clad laminate and a copper foil, and no cracks are seen in the folded part The result was “good”.

[Measurement of thermal expansion coefficient]
Example I-1, Example I-2, Comparative Example I-1, Single-sided copper foil-clad laminates of Comparative Example I-2 and Examples II-1 to II-15 and Comparative Examples II-7 to II-9 The copper foil of the double-sided copper foil-clad laminate obtained in the above was removed by etching. The obtained resin base material was cut into 25 mm × 4 mm and used as a sample. Moreover, about Comparative Examples II-1 to II-6, the resin film simple substance was cut out into 25 mm x 4 mm, and it was set as the sample. Using a thermomechanical analyzer manufactured by Texas Instruments Incorporated, a temperature range of 20 to 300 ° C. was measured in a tensile mode at a temperature rising rate of 10 ° C./min. The coefficient of thermal expansion is measured for evaluation of dimensional stability. The smaller this value, the better the dimensional stability.

[Measurement of humidity expansion coefficient]
Example I-1, Example I-2, Comparative Example I-1, Single-sided copper foil-clad laminates of Comparative Example I-2 and Examples II-1 to II-15 and Comparative Examples II-7 to II-9 The copper foil of the double-sided copper foil-clad laminate obtained in the above was removed by etching. The obtained resin base material was cut into 10 mm × 2 mm and used as a sample. Moreover, about Comparative Examples II-1 to II-6, the resin film simple substance was cut out to 10 mm x 2 mm, and it was set as the sample. Using a humidity control TMA measuring machine manufactured by SII Nano Technology Co., Ltd., the elongation between 30% RH and 60% RH was measured at 30 ° C., and the coefficient of humidity expansion was measured. The load was 5 g. The humidity expansion coefficient is measured for evaluation of dimensional stability, and the smaller this value, the better the dimensional stability.

[Evaluation of heat resistance]
The heat resistance was evaluated based on normal solder heat resistance and hygroscopic solder heat resistance. For normal solder heat resistance, the double-sided copper-clad laminates of Examples II-1 to II-15 and the resin films of Comparative Examples II-1 to II-6 were cut into 50 mm squares and used as samples. The sample was floated in a solder bath at 288 ° C., and the presence or absence of blistering of the sample was visually confirmed. The upper limit of the test time was 300 seconds. The moisture absorption heat resistance is obtained by immersing a sample obtained by etching copper on one side of a laminated board in a saturated PCT apparatus under conditions of 121 ° C. and 2 atm for 2 hours and then immersing the sample in a solder bath heated to 260 ° C. for 20 seconds. The state was visually observed, and the moisture absorption heat resistance was evaluated from abnormalities such as swelling. And the case where abnormality, such as a swelling, was not seen was judged as "good".

[Evaluation of dust resistance]
The copper foil of the laminate was removed by etching and cut into a width of 100 mm and a length of 250 mm to obtain a sample for evaluating dust generation resistance. The sample was cut 100 times in the width direction with a cutter, and the presence or absence of generation of resin powder was confirmed.

[Evaluation of impact resistance]
Daisy chain having 250 holes for connection with a diameter of 0.25 mm by double-sided metal foil-clad laminates of Examples II-7 to II-15 and Comparative Examples II-7 to II-9 by ordinary drilling, plating and photolithography processes Four rows of patterns were produced. And each start point and end point were connected with the lead wire with the solder, and initial resistance was measured as a conduction pattern of 1000 holes per row. Further, each printed circuit board was then mounted on a predetermined housing and naturally dropped 1000 times from a height of 1.5 m, and the presence or absence of disconnection and the resistance value were measured.

[Evaluation of tear resistance of substrate]
A resin plate obtained by etching copper on a single-sided copper foil-clad laminate or a double-sided copper foil-clad laminate is cut to a width of 10 mm and a length of 100 mm, and a length of 50 mm is 1 mm in the direction perpendicular to the length direction. A notch 71 was formed as a sample 70 (see FIG. 3). While the upper part of the sample was fixed using the clip 60, a twist of 180 degrees to the left and right was applied to the lower part of the sample while applying a load of 300 g with the weight 61, and the number of times until breakage was measured. The upper limit of the number of measurements was 300.

[Evaluation results of each example and comparative example]
In evaluation of bendability, Comparative Example I-1 was not bent even on the resin base material from which the copper foil was removed. In Comparative Examples II-7 to II-9, it was visually determined that cracks were generated on the surface of the bent portion of the resin base material.

  In the evaluation of dust resistance, no dust was seen from any of the samples of Examples II-1 to II-15 and Comparative Examples II-1 to II-6, so all the samples were judged as “good”. did.

  In the impact resistance evaluation, no disconnection was observed in any of the samples of Examples II-7 to II-15 and Comparative Examples II-7 to II-9 tested, and the resistance value increased after the test with respect to the initial resistance value. Since the rate was less than 2%, all samples were judged as “good”.

  The resin base materials of the single-sided copper foil-clad laminates of Examples I-1 and I-2 and the double-sided copper foil-clad laminates of Examples II-1 to II-9, II-13, and II-14 are polyimide films, respectively. The coefficient of thermal expansion is lower than that of a single substance (Comparative Examples II-1 to II-3), and the dimensional change is small with respect to temperature change. In Examples I-1 and II-1 to II-3, compared to Comparative Example II-1 of Upilex S alone, the thermal expansion coefficient can be lowered by 3 ppm / ° C. or more in a low thermal expansion region of 20 ppm / ° C. or less. It was. In Examples I-2 and II-4 to II-6, the thermal expansion coefficient of Kapton EN alone (Comparative Example II-2) is 24 ppm / ° C., and both are suppressed to a low thermal expansion region of 20 ppm / ° C. or lower. I was able to. In Examples II-7 to II-9, Espanex alone (Comparative Example II-3) had a thermal expansion coefficient of 22 ppm / ° C., and all of them were able to be suppressed to a low thermal expansion region of 20 ppm / ° C. or lower. .

  In Comparative Examples II-4 and II-5, the linear expansion coefficient is -1% due to thermal contraction, but in Examples II-10 and II-11, it is suppressed to 18 to 19 ppm. That is, the resin base material of the double-sided copper foil-clad laminates of Examples II-10 and II-11 has a very large dimensional change with respect to temperature change compared to each polyimide film alone (Comparative Examples II-4 and II-5). Very few. Moreover, the resin base material of the double-sided copper foil clad laminated board of Example II-12 and II-15 has few dimensional changes with respect to a temperature change compared with a polyimide film single-piece | unit (Comparative Example II-6). Furthermore, the resin base materials of the double-sided copper foil-clad laminates of Examples II-10 to II-12 and II-15 are more resistant to changes in humidity than the respective polyimide films alone (Comparative Examples II-4 to II-6). Little dimensional change. Comparative Examples I-2 and II-7 to II-9 do not have sufficient tear resistance. That is, sufficient tear resistance could be obtained by providing a resin film having flexibility and self-supporting properties.

DESCRIPTION OF SYMBOLS 1, 4 ... Metal foil, 2, 3 ... Fiber base material, 20a, 30a ... Resin layer, 20, 30 ... Composite resin layer, 40 ... Resin film, 50a, 50b ... On the resin film side of the 1st fiber base material Convex convex part, 50c ... Convex part facing the resin film side of the second fiber substrate, 60 ... Clip, 61 ... Weight, 70 ... Sample, 71 ... Cut, 100 ... Single-sided metal foil-clad laminate, 200 ... Double-sided metal Foil-clad laminate.

Claims (18)

  A metal foil-clad laminate in which at least a composite resin layer having a thickness of 50 μm or less and a resin film in which a metal foil and a fiber base material are embedded in a resin are positioned in this order.   The metal foil-clad laminate according to claim 1, wherein the fiber base material is a glass cloth having a thickness of 8 to 30 μm.   The metal foil-clad laminate according to claim 1 or 2, wherein the resin film is flexible and self-supporting.   The metal foil-clad laminate according to any one of claims 1 to 3, wherein the resin film has a thickness of 1 to 80 µm.   The metal foil-clad laminate according to claim 4, wherein the resin film has a thickness of 5 to 50 µm.   The material of the resin film is selected from the group consisting of a polyimide resin, a polyethylene terephthalate resin, a polyether resin, a polyethylene naphthalate resin, and a polybenzoxazole resin. Metal foil-clad laminate.   The metal foil tension according to any one of claims 1 to 6, wherein the composite resin layer includes a cured product of a resin selected from the group consisting of a resin having a glycidyl group, a resin having an amide group, and an acrylic resin. Laminated board.   The first metal foil, the first composite resin layer having a thickness of 50 μm or less formed by embedding the first fiber base material in the resin, the resin film, and the thickness of 50 μm or less formed by embedding the second fiber base material in the resin The second composite resin layer and the second metal foil are positioned in this order, and the distance between the first fiber substrate and the second fiber substrate is 10 to 170 μm, and the total thickness is 300 μm or less. Metal foil-clad laminate.   The double-sided metal foil-clad laminate according to claim 8, wherein the fiber base material is a glass cloth having a thickness of 8 to 30 µm.   The double-sided metal foil-clad laminate according to claim 8 or 9, wherein the resin film is flexible and self-supporting.   The double-sided metal foil-clad laminate according to any one of claims 8 to 10, wherein the resin film has a thickness of 1 to 80 µm.   The double-sided metal foil-clad laminate according to any one of claims 8 to 11, wherein the resin film has a thickness of 5 to 50 µm.   A method for producing a metal foil-clad laminate, in which a metal foil, a prepreg having a thickness of 60 μm or less formed by impregnating a fiber base material with a resin, and a resin film are laminated so as to be positioned in this order and thermocompression bonded.   A thermocompressed product is produced by thermocompression bonding a metal foil and a prepreg having a thickness of 60 μm or less formed by impregnating a fiber base material with a resin, and then the resin film is opposite to the metal foil side of the thermocompressed product. A method of manufacturing a metal foil-clad laminate that is thermocompression bonded to the substrate.   A metal foil, a prepreg having a thickness of 60 μm or less formed by impregnating a fiber base material with a resin, a resin film, a prepreg having a thickness of 60 μm or less formed by impregnating a fiber base material with a resin and a metal foil are laminated in this order, A method of manufacturing a double-sided metal foil-clad laminate with thermocompression bonding.   Two sets of thermocompression-bonded products obtained by thermocompression bonding of a metal foil and a prepreg having a thickness of 60 μm or less formed by impregnating a fiber base material with a resin, and the two sets of the above-described surfaces opposite to the metal foil are opposed to each other. A method for producing a double-sided metal foil-clad laminate in which a resin film is interposed between thermocompression products and these are thermocompression bonded.   Wiring formation processing is given to the metal foil of the metal foil-clad laminate according to any one of claims 1 to 7, or the metal foil of the metal foil-clad laminate obtained by the manufacturing method according to claim 13 or 14. A printed wiring board. The double-sided metal foil-clad laminate according to any one of claims 8 to 12, or the first metal foil of the double-sided metal foil-clad laminate obtained by the production method according to claim 15 or 16, and the first A printed wiring board in which wiring formation is applied to the second metal foil.

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