JP4590982B2 - Metal foil with resin - Google Patents

Description

  The present invention relates to a resin-coated metal foil.

  The laminate for a printed wiring board is obtained by stacking a predetermined number of prepregs and metal foils, or prepregs and metal foils with a resin, and integrating them by heating and pressing. When a printed circuit is formed by a subtractive method, a metal-clad laminate is used. This metal-clad laminate is manufactured by stacking a metal foil such as a copper foil on the surface (one side or both sides) of the prepreg, or by heating and pressing a prepreg and a metal foil with resin. In addition, in a multilayer wiring board having a plurality of circuit layers, an insulating resin layer or a method of manufacturing by laminating a resin and metal foil for forming a second circuit on the upper part of the inner layer circuit and performing circuit processing by providing interlayer connection And forming the upper circuit layer by electroless plating and electroplating. As a method of laminating the resin and metal foil for forming the second circuit, a method of laminating and pressing a prepreg and a copper foil at the same time, or providing an electrically insulating resin layer having adhesiveness on the copper foil in advance, so-called with resin A method of laminating metal foils has been performed. As the electrically insulating resin, a thermosetting resin such as a phenol resin, an epoxy resin, a polyimide resin, or a bismaleimide-triazine resin is widely used, and a thermoplastic resin such as a fluorine resin or a polyphenylene ether resin is used. There is also.

  On the other hand, with the spread of information terminal devices such as personal computers and mobile phones, printed circuit boards mounted on them are becoming smaller and higher in density. The mounting form has progressed from a pin insertion type to a surface mounting type and further to an area array type represented by BGA (ball grid array) using a plastic substrate. In a substrate on which a bare chip such as a BGA is directly mounted, the connection between the chip and the substrate is generally performed by wire bonding by thermosonic bonding. For this reason, the substrate on which the bare chip is mounted is exposed to a high temperature of 150 ° C. or higher, and the electrically insulating resin needs a certain degree of heat resistance.

  In addition, there is a case where so-called repairability is required to remove the chip once mounted, but since this is subject to the same level of heat as chip mounting, the substrate is then chip mounted again. In addition, heat treatment will be added. Along with this, a substrate requiring repairability is also required to have a cyclic thermal shock resistance at a high temperature, and in a conventional insulating resin system, peeling may occur between the fiber base material and the resin.

  A prepreg in which a fiber base material is impregnated with a resin composition containing polyamideimide as an essential component has been proposed in order to have excellent thermal shock resistance, reflow resistance, and crack resistance and to improve fine wiring formation (for example, Patent Document 1). See). In addition, a heat-resistant base material in which a fiber base material is impregnated with a resin composition composed of a silicone-modified polyimide resin and a thermosetting resin has been proposed (see, for example, Patent Document 2).

  Furthermore, with the miniaturization and high performance of electronic devices, it has become necessary to accommodate printed circuit boards with component mounting in a limited space. In this method, a plurality of printed circuit boards are arranged in multiple stages and connected to each other by a wire harness or a flexible wiring board. In addition, a rigid-flex substrate in which a flexible substrate based on polyimide and a conventional rigid substrate are multilayered is used.

JP 2003-55486 A JP-A-8-193139

  The present invention solves the above-mentioned problems of the prior art, and provides a resin-coated metal foil that is excellent in dimensional stability, heat resistance, dust generation resistance, and impact resistance and can be bent arbitrarily.

The present invention relates to the following.
1. A metal foil with a resin obtained by laminating a fiber base material impregnated with a resin composition and a metal foil, and an elastic modulus of a cured resin obtained by curing the resin composition is 0.1 GPa or more at 25 ° C., Metal foil with resin which is 2.0 GPa or less.
2. Item 2. The metal foil with resin according to Item 1, wherein the fiber substrate is a fiber substrate having a thickness of 50 μm or less.
3. Item 3. The metal foil with resin according to Item 1 or 2, wherein the resin composition contains a thermosetting resin.
4). Item 4. The resin-attached metal foil according to Item 3, wherein the thermosetting resin is a thermosetting resin containing a resin having a glycidyl group.
5). Item 5. The metal foil with resin according to any one of Items 1 to 4, wherein the resin composition is a resin composition containing a resin having an amide group.
6). Item 6. The resin-attached metal foil according to any one of Items 1 to 5, wherein the resin composition is a resin composition containing an acrylic resin.
7). Item 7. The metal foil with resin according to any one of Items 1 to 6, wherein the resin composition is a resin composition containing polyamic acid.
8). Item 8. The resin-attached metal foil according to any one of Items 1 to 7, wherein the fiber base material is impregnated with the resin composition from the fiber base side in a state where the metal foil and the fiber base material are stacked, and then dried. Obtained metal foil with resin.
9. Item 8. A metal foil with a resin according to any one of items 1 to 7, wherein the resin composition is obtained by applying a resin composition on the metal foil, then impregnating the resin composition with a fiber base material, and drying the resin base material. Foil.

  The metal foil with resin in the present invention includes a fiber base material and is excellent in dimensional stability. The resin composition impregnated into the fiber base is printed with a resin-coated metal foil by setting the resin cured product of the resin composition to have an elastic modulus of 0.1 to 2.0 GPa at room temperature (25 ° C.). Even when an impact is applied to the printed circuit board when it is used as a circuit board, the impact resistance after mounting is improved because the impact is absorbed. In addition, since the resin composition impregnated in the fiber base is impregnated with a flexible resin so that the elastic modulus of the cured product of the resin composition is 0.1 to 2.0 GPa, dust generation during processing is small. . In addition, combined with the use of a fiber substrate of 50 μm or less, the printed circuit board can be bent into an arbitrary state at an arbitrary portion, and can be stored in a high density in a casing on which the printed circuit board is mounted. In general, when a resin-fitted metal foil is produced with a resin having a large drying shrinkage or curing shrinkage, a phenomenon that the resin-fitted metal foil curls inside the resin is seen. Curling is greatly reduced by simultaneously laminating and drying the fiber base material containing the resin composition.

  The metal foil with resin of the present invention is a metal foil with resin obtained by laminating a fiber base material impregnated with a resin composition and a metal foil, and the elastic modulus of the cured resin product obtained by curing the resin composition is , At 25 ° C., 0.1 GPa or more and 2.0 GPa or less. The metal foil with resin of the present invention includes a fiber base material, suppresses dimensional changes due to moisture absorption and temperature, and improves the dimensional stability of the base material. In addition, a base material hardens | cures metal foil with resin. The metal foil with resin of the present invention is preferably in a semi-cured B stage state, but may be in a cured C stage state. By using a resin composition having an elastic modulus of 0.1 to 2.0 GPa at room temperature (25 ° C.) of the cured resin product, the impact resistance when a printed circuit board is obtained by increasing the flexibility of the substrate. It is excellent.

  The elastic modulus of the cured resin obtained by curing the resin composition is 0.1 GPa or more and 2.0 GPa or less at 25 ° C., preferably 0.5 to 2.0 GPa, more preferably 1 to 1.5 GPa. If the elastic modulus is less than 0.1 GPa, there is a problem that handling at the time of manufacturing a printed circuit board becomes difficult, and if it exceeds 2.0 GPa, impact resistance is low and arbitrary bending tends to be difficult. . The elastic modulus in the present invention refers to the elastic modulus at 25 ° C. of the dynamic viscoelastic curve of the resin plate (resin cured product) obtained by curing the resin composition.

  Although it will not restrict | limit especially as a fiber base material used by this invention if it is used when manufacturing a metal foil clad laminated board and a printed circuit board, Usually fiber base materials, such as a woven fabric and a nonwoven fabric, are used. Examples of the fiber base material include glass, alumina, asbestos, boron, silica alumina glass, silica glass, tyrano, silicon carbide, silicon nitride, zirconia, and other inorganic fibers, aramid, polyetheretherketone, polyetherimide, polyether There are organic fibers such as sulfone, carbon, cellulose and the like and mixed papers thereof, and glass fiber woven fabrics are particularly preferably used.

  The fiber base material is preferably a fiber base material of 50 μm or less, more preferably 5 to 50 μm, particularly preferably 10 to 40 μm. A glass cloth is particularly preferably used as the fiber base material. By using a glass cloth having a thickness of 50 μm or less, the resin-attached metal foil of the present invention has flexibility, can be arbitrarily bent, and can further improve impact resistance when used as a printed circuit board. .

  In this invention, it is preferable that the thermosetting resin is included as a component which the elasticity modulus in room temperature (25 degreeC) of a resin cured material comprises 0.1-2.0 GPa. Examples of the thermosetting resin include epoxy resins, polyimide resins, unsaturated polyester resins, polyurethane resins, bismaleimide resins, triazine-bismaleimide resins, phenol resins, and the like.

  In the present invention, the thermosetting resin preferably includes a resin having a glycidyl group, and more preferably includes an epoxy resin. Epoxy resins include polyglycidyl ethers and phthalic acids obtained by reacting polychlorophenols such as bisphenol A, novolak-type phenol resins, ortho-cresol novolac-type phenol resins or polyhydric alcohols such as 1,4-butanediol with 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.

  In the present invention, it is preferable to use an epoxy resin as a thermosetting resin because it can be cured at a temperature of 180 ° C. or less, and is preferable in order to improve thermal, mechanical, and electrical characteristics, and an epoxy having two or more glycidyl groups. It is preferable to use a resin and its curing agent, an epoxy resin having two or more glycidyl groups and its curing accelerator, or an epoxy resin having two or more glycidyl groups, a curing agent, and a curing accelerator. Further, the more glycidyl groups, the better. The blending amount varies depending on the number of glycidyl groups, and the blending amount may be smaller as the glycidyl group is larger.

  The curing agent and curing accelerator of the epoxy resin are not limited as long as they react with the epoxy resin or accelerate curing. For example, amines, imidazoles, polyfunctional phenols, acid anhydrides, etc. Can be used. As the amines, dicyandiamide, diaminodiphenylmethane, guanylurea and the like can be used. As the polyfunctional phenols, hydroquinone, resorcinol, bisphenol A and their halogen compounds, and a novolac type phenol resin which is a condensate with formaldehyde, a resol type A phenol resin or the like can be used. As the acid anhydrides, phthalic anhydride, benzophenone tetracarboxylic dianhydride, methyl hymic acid, or the like can be used. As the curing accelerator, alkyl group-substituted imidazole, benzimidazole and the like can be used as imidazoles.

  In the case of amines, the necessary amounts of these curing agents or curing accelerators are preferably such that the equivalent of the active hydrogen of the amine is approximately equal to the epoxy equivalent of the epoxy resin. In the case of imidazole, which is a curing accelerator, it is not simply an equivalent ratio with active hydrogen, but is empirically required to be 0.001 to 10 parts by weight per 100 parts by weight of the epoxy resin. In the case of polyfunctional phenols and acid anhydrides, 0.6 to 1.2 equivalents of phenolic hydroxyl groups and carboxyl groups are required for 1 equivalent of epoxy resin. If the amount of these curing agents or accelerators is small, uncured epoxy resin remains, and Tg (glass transition temperature) is low. If too large, unreacted curing agent and curing accelerator remain, and insulating properties are maintained. Decreases.

  The resin composition used in the present invention can also contain a high molecular weight resin component for the purpose of improving flexibility and heat resistance. As the resin for this purpose, it is preferable to use a resin having an amide group, an acrylic resin, or a polyamic acid.

  Examples of the resin having an amide group used in the present invention include a polyamideimide resin, a polyamide resin, and an amide epoxy resin, and a polyamideimide resin is preferable. As the polyamide-imide resin used in the present invention, a siloxane-modified polyamide-imide resin having a siloxane structure in the resin is more preferable. In particular, a mixture of a diamine having two or more aromatic rings and a siloxane diamine is reacted with trimellitic anhydride. It is preferable to obtain by reacting a mixture containing diimidedicarboxylic acid obtained in this way with an aromatic diisocyanate. Moreover, it is preferable that it is a polyamideimide resin which contains 70 mol% or more of polyamideimide molecules containing 10 or more amide groups in one molecule. The range can be obtained from the number of moles (A) of amide groups in the unit weight obtained separately from the chromatogram obtained from GPC of the polyamideimide resin. For example, the chromatograph obtained by GPC using the number of moles of amide groups contained in the polyamideimide (a) (A) as the molecular weight (C) of 10 × a / A of the polyamideimide resin containing 10 amide groups in one molecule. The region where the number average molecular weight of gram is C or more is defined as 70% or more. NMR, IR, hydroxamic acid-iron coloring reaction method, N-bromoamide method, etc. can be used for the determination method of the amide group.

  Further, the polyamic acid used in the present invention is preferably a polyamic acid containing a siloxane structure, and when the polyamic acid is further cyclized, the structures of the following general formulas (1) and (2) are used. It is more preferable that it is a polyamic acid that becomes a resin. The polyamic acid containing a siloxane structure is preferably a polyamic acid obtained by a reaction between a diamine and tetracarboxylic dianhydride.

（式中Ａｒ_１は４価の芳香族基を示し、Ｒ_１及びＲ_２は２価の炭化水素基を示し、Ｒ_３〜Ｒ_６は炭素数１〜６の炭化水素基を示し、ｎは１〜５０の整数を示す）

(In the formula, Ar ₁ represents a tetravalent aromatic group, R ₁ and R ₂ represent a divalent hydrocarbon group, R _{3 to} R ₆ represent a hydrocarbon group having 1 to ₆ carbon atoms, and n represents Represents an integer of 1 to 50)

（式中Ａｒ_１は４価の芳香族基を示し、Ａｒ_２は２価の芳香族基を示す）

(In the formula, Ar ₁ represents a tetravalent aromatic group, and Ar ₂ represents a divalent aromatic group)

  Examples of the tetracarboxylic dianhydride used in the present invention include 3,3 ′, 4,4′-diphenyl ether tetracarboxylic dianhydride and 3,3 ′, 4,4′-diphenylsulfone tetracarboxylic dianhydride. 3,3 ′, 4,4′-benzophenone tetracarboxylic dianhydride, 2,2 ′, 3,3′-benzophenone tetracarboxylic dianhydride, 3,3 ′, 4,4′-biphenyltetracarboxylic Acid dianhydride, 2,3,3 ′, 4′-biphenyltetracarboxylic dianhydride, pyromellitic dianhydride, 1,4,5,8-naphthalenetetracarboxylic dianhydride, 1,4 5,6-naphthalenetetracarboxylic dianhydride, 3,4,9,10-perylenetetracarboxylic dianhydride, 3,3,6,7-anthracenetetracarboxylic dianhydride, 1,2,7, 8-Fena Tren tetracarboxylic dianhydride, 4,4 '- such as (hexafluoro isopropylidene) phthalic dianhydride and the like. By introducing a siloxane structure into the polyamic acid that is a precursor of the polyimide resin, the metal foil with resin can be bent more easily.

  In the synthesis of a siloxane-modified polyamideimide resin having a siloxane structure in the resin or a polyamic acid containing a siloxane structure, the mixing ratio of the diamine a having an aromatic ring and the siloxane diamine b is a / b = 99.9 / It is preferably 0.1 to 0/100 (molar ratio), more preferably a / b = 95/5 to 30/70, and even more preferably a / b = 90/10 to 40/60. . When the mixing ratio of siloxane diamine b increases, Tg tends to decrease. Moreover, when it decreases, when producing metal foil with resin, there exists a tendency for the amount of varnish solvent which remains in resin to increase.

  Examples of the aromatic diamine (a diamine having an aromatic ring) include (3,3′-diamino) diphenyl ether, m-phenylenediamine, p-phenylenediamine, 4,4′-diaminodiphenylmethane, and 4,4′-diaminodiphenyl. Propane, benzidine, 4,4'-diaminodiphenyl sulfide, 4,4'-diaminodiphenyl sulfone, 3,3'-diaminodiphenyl sulfone, 4,4'-diaminodiphenyl ether, 4,4'-diamino-p-terphenyl 2,2-bis [4- (4-aminophenoxy) phenyl] propane (BAPP), bis [4- (3-aminophenoxy) phenyl] sulfone, bis [4- (4-aminophenoxy) phenyl] sulfone, 2,2-bis [4- (4-aminophenoxy) phenyl] hexa Fluoropropane, 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 (trifluoromethyl) biphenyl-4,4′-diamine, 2,6,2 ′, 6′-tetramethylbiphenyl-4,4′-diamine, 5,5′-dimethyl-2,2 '-Sulphonyl-biphenyl-4,4'-diamine, 3,3'-dihydroxybiphenyl-4,4'-diamine, (4,4'-diamino) benzophenone (3,3'-diamino) benzophenone and the like.

  Examples of the siloxane diamine used in the present invention include the following general formulas (3) to (6). In the following general formulas (3) to (6), m and n are integers of 1 or more.

  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), (product name manufactured by Toray Dow Corning Silicone Co., Ltd.) and the like can be exemplified. As the siloxane diamine represented by the general formula (6), X-22-9409 (amine equivalent 700), X-22-1660B-3 (amine equivalent 2200) (above, trade name manufactured by Shin-Etsu Chemical Co., Ltd.) Etc. can be illustrated.

  In addition, an aliphatic diamine represented by the following general formula (7) may be used alone for the synthesis of a siloxane-modified polyamideimide resin having a siloxane structure in the resin or a polyamic acid containing a siloxane structure. It may be used in combination with an aromatic diamine.

Wherein X is a methylene group, sulfonyl group, ether group, carbonyl group or single bond, R ¹ and R ² are each a hydrogen atom, an alkyl group, a phenyl group or a substituted phenyl group, and p is an integer of 1 to 50 Indicates. Specific examples of R ¹ and R ² are preferably a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, a phenyl group, and a substituted phenyl group. The substituent that may be bonded to the phenyl group is 1 carbon atom. -3 alkyl groups, halogen atoms and the like can be exemplified. In the aliphatic diamine, X in the general formula (7) is preferably an ether group from the viewpoint of achieving both low elastic modulus and high Tg. Examples of such aliphatic diamines include Jeffamine D-400 (amine equivalent 400), Jeffamine D-2000 (amine equivalent 1000) or more and trade names of Sun Techno Chemical Co., Ltd.

  As the diisocyanate used in the method for producing the polyamideimide resin of the present invention, a compound represented by the following general formula (8) can be used.

In the formula, D is a divalent organic group having at least one aromatic ring or a divalent aliphatic hydrocarbon group, and is a group represented by —C ₆ H ₄ —CH ₂ —C ₆ H ₄ —. And at least one group selected from the group consisting of a tolylene group, a naphthylene group, a hexamethylene group, a 2,2,4-trimethylhexamethylene group and an isophorone group.

  As the diisocyanate represented by the general formula (8), an aliphatic diisocyanate or an aromatic diisocyanate can be used, but it is preferable to use an aromatic diisocyanate, and it is particularly preferable to use both in combination. Examples of aromatic diisocyanates include 4,4′-diphenylmethane diisocyanate (MDI), 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, naphthalene-1,5-diisocyanate, 2,4-tolylene dimer, and the like. As an example, it is particularly preferable to use MDI. By using MDI as the aromatic diisocyanate, the flexibility of the resulting polyamideimide resin can be improved.

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

  When using an aromatic diisocyanate and an aliphatic diisocyanate in combination, it is preferable to add the aliphatic diisocyanate to about 5 to 10 mol% with respect to the aromatic diisocyanate, and this combination further improves the heat resistance of the resulting polyamideimide resin. Can be made.

  As the acrylic resin contained in the resin composition of the resin-coated metal foil of the present invention, an acrylic monomer, a methacrylic acid monomer, acrylonitrile, an acrylic monomer having a glycidyl group, or a copolymer obtained by copolymerizing a plurality thereof is used. Is possible. The molecular weight is not particularly specified, but a standard polystyrene equivalent weight average molecular weight of 300,000 to 1,000,000, preferably 400,000 to 800,000 is used. It is preferable to add an epoxy resin, a curing agent, and a curing accelerator as appropriate to these acrylic resins. Examples of acrylic resins include HTR-860-P3 (trade name, manufactured by Nagase ChemteX Corporation, weight average molecular weight 850,000), HM6-1M50 (trade name, manufactured by Nagase ChemteX Corporation, weight average molecular weight 500,000), and the like. it can.

  In the present invention, an additive-type flame retardant can also be used for the purpose of improving flame retardancy. As the additive-type flame retardant used in the present invention, a filler containing phosphorus is preferable. As the phosphorus-containing filler, OP930 (trade name manufactured by Clariant, phosphorus content 23.5% by weight), HCA-HQ (Sanko Co., Ltd.) Product 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% by weight) or more, trade names made by Nissan Chemical Co., Ltd. and the like.

  As the metal foil of the resin-attached metal foil of the present invention, a copper foil or an aluminum foil is generally used. However, a metal foil having a thickness of 5 to 200 μm which is usually used for a laminate can be used, and a copper foil is preferable. Also, nickel, nickel-phosphorus, nickel-tin alloy, nickel-iron alloy, lead, lead-tin alloy, etc. are used as intermediate layers, and a 0.5-15 μm copper layer and a 10-300 μm copper layer are provided on both sides. Alternatively, a three-layer composite foil or a two-layer composite foil in which aluminum and copper foil are combined can be used.

  In the present invention, various resins and additives may be added to the resin composition as necessary, and mixed, dissolved, and dispersed in an organic solvent to form a varnish. Such an organic solvent is not limited as long as solubility is obtained, and examples thereof include dimethylacetamide, dimethylformamide, dimethyl sulfoxide, N-methyl-2-pyrrolidone, γ-butyrolactone, sulfolane, and cyclohexanone. It is done.

  Although the manufacturing method of the metal foil with resin of this invention is not restrict | limited in particular, For example, you may manufacture with the following manufacturing methods. The fiber base material is stacked on the metal foil, and the resin composition varnish is supplied from the fiber base material side and impregnated for coating, or the resin composition varnish is applied to the metal foil to a predetermined thickness. Then, the fiber base material is stacked and impregnated with the varnish of the resin composition, and then dried. In addition, as a method of applying the resin composition varnish to a predetermined thickness on the metal foil, a coater that normally allows the object to be coated (metal foil) to pass through the gap can be used, and the varnish state of the resin composition A comma coater is preferable when the thickness of the coating is 50 to 500 μm. In addition, the varnish of the resin composition is impregnated only in the fiber base material, dried in the range of 80 ° C. to 180 ° C. to produce a prepreg, and the metal foil and the prepreg are further cured with the prepreg. For example, you may heat-press in the range of 80 to 120 degreeC, and may manufacture metal foil with resin.

  The production conditions of the metal foil with resin are not particularly limited, but it is preferable that the organic solvent used for the varnish is volatilized by 80% by weight or more. For this reason, the production method and drying conditions are not limited, the drying temperature is 80 ° C. to 180 ° C., and the time is not particularly limited in view of the gelation time of the varnish. The amount of impregnation of the varnish is preferably 30 to 80% by weight with respect to the total amount of the varnish solid and the base material. In addition, by adding a siloxane structure to polyamic acid and polyamideimide resin with high heat resistance, the remaining organic solvent can be reduced, generating voids during heat treatment, and generating bulges due to organic solvent volatilization during the lamination process. Can be prevented, and the solder heat resistance can be further improved.

  A method for producing a metal-clad laminate using the resin-coated metal foil of the present invention is, for example, as follows. In the present invention, a laminate in which a copper foil is laminated on a metal foil with resin or two resin foils are laminated so that the resin surfaces face each other is usually 150 to 280 ° C., preferably 180 ° C. to 250 ° C. A metal-clad laminate can be produced by heating and pressing at a temperature of usually 0.5 to 20 MPa, preferably 1 to 8 MPa. By using a metal foil to form a metal-clad laminate, circuit processing can be applied to this to obtain a printed circuit board. As described above, the resin-coated metal foil of the present invention can be heat-treated to form a C-staged resin-coated metal foil. The heat treatment condition may be, for example, a metal foil with a resin in a C-stage state at a temperature in the range of usually 150 to 280 ° C, preferably 180 ° C to 250 ° C. And it is also possible to use a metal foil with a resin in a C-stage state and perform circuit processing on this to obtain a printed circuit board. For circuit processing, a subtractive method and an additive method, which are general methods, can be used.

  Moreover, it is possible to make a multilayer wiring board by laminating a resin-coated metal foil with a separately produced printed circuit board. At this time, in order to connect the circuits of each layer through the resin-coated metal foil, the method of connecting the holes for interlayer connection to the resin-coated metal foil with a laser in advance and connecting them with a conductive paste or plating, There is a method of using connection bumps provided in advance on the inner layer circuit of the circuit board, but there is no particular limitation.

Examples are described below, but the present invention is not limited to these examples.
(Synthesis Example 1)
BAPP (2,2-bis [4-) is a diamine having two or more aromatic rings in a 1-liter separable flask equipped with a 25 ml water meter with a cock connected to a reflux condenser, a thermometer, and a stirrer. (4-aminophenoxy) phenyl] propane) 41.0 g (0.50 mol), reactive silicone oil X-22-9409 (trade name, amine equivalent 2200, manufactured by Shin-Etsu Chemical Co., Ltd.) as a siloxane diamine 132.0 g (0 .50 mol) and TMA (trimellitic anhydride) 80.7 g (0.42 mol) as an aprotic polar solvent were charged with 573 g of NMP (N-methyl-2-pyrrolidone) 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 7.2 ml or more of water has accumulated in the moisture determination receiver and that no water is being distilled, remove the distillate that has accumulated in the moisture determination receiver, The temperature was raised to 0 ° C. to remove toluene. Thereafter, the solution was returned to room temperature (25 ° C.), and 55.0 g (0.22 mol) of MDI (4,4′-diphenylmethane diisocyanate) was added as an aromatic diisocyanate, followed by reaction at 190 ° C. for 2 hours. After completion of the reaction, an NMP solution of polyamideimide resin (resin content 33% by weight) was obtained.

(Synthesis Example 2)
14.9 g of DDS (diaminodiphenylsulfone) as a diamine having two or more aromatic rings in a 1-liter separable flask equipped with a 25 ml moisture meter with a cock connected to a reflux condenser, a thermometer, and a stirrer ( 0.06 mol), reactive silicone oil KF-8010 (trade name, manufactured by Shin-Etsu Chemical Co., Ltd., amine equivalent 430) 43.0 g (0.05 mol) as siloxane diamine, and Jeffamine D2000 (manufactured by Sun Techno Chemical Co., Ltd.) as aliphatic diamine Product name, amine equivalent 1000) 90.0 g (0.045 mol), Wandamine (trade name, manufactured by Shin Nippon Chemical Co., Ltd.) 11.5 g (0.055 mol), TMA (trimellitic anhydride) 80.7 g (0 .42 mol) as an aprotic polar solvent, NMP (N-methyl) Were charged 2-pyrrolidone) 690 g, it was stirred at 80 ° C. 30 min. 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 approximately 7.2 ml or more of water has accumulated in the moisture determination receiver and that no distillation of water has been observed, while removing the distillate accumulated in the moisture determination receiver, The temperature was raised to 0 ° C. to remove toluene. Then, the solution was returned to room temperature (25 ° C.), 55.1 g (0.22 mol) of MDI (4,4′-diphenylmethane diisocyanate) was added as an aromatic diisocyanate, and reacted at 190 ° C. for 2 hours. After completion of the reaction, an NMP solution of polyamideimide resin (resin content 28% by weight) was obtained.

Example 1
858 g of the total amount of NMP solution of the siloxane-modified polyamideimide resin of Synthesis Example 1 (resin solid content 33 wt%) and ZX1548-3 (trade name, manufactured by Tohto Kasei Co., Ltd.) as an epoxy resin 188.0 g (dimethyl resin having a resin solid content of 50 wt%) Acetamide solution) and 0.7 g of 1-cyanoethyl-2-ethyl-1-methylimidazole were mixed and stirred for about 1 hour until uniform, then allowed to stand at room temperature (25 ° C.) for 24 hours for defoaming. To obtain a resin composition varnish.

(Example 2)
NMP solution total amount 959g (resin solid content 28 wt%) of siloxane-modified polyamideimide resin of Synthesis Example 2 and NC resin (trade name made by Nippon Kayaku Co., Ltd.) 179.0g as epoxy resin (dimethylacetamide with resin solid content 50 wt%) Solution), 0.2 g of 1-cyanoethyl-2-phenylimidazole was mixed and stirred for about 1 hour until uniform, and then 56 g of OP930 (trade name, manufactured by Clariant) was added as a phosphorus-containing filler, and the mixture was further stirred for 1 hour. A 200-mesh nylon cloth was passed through and allowed to stand at room temperature (25 ° C.) to obtain a resin composition varnish.

(Example 3)
340.0 g of EPICLON 153 (trade name, manufactured by Dainippon Ink Co., Ltd.) as an epoxy resin, 181 g of FG-2000 (trade name, manufactured by Teijin Chemicals Ltd.) as a curing agent, 1-cyanoethyl-2-phenylimidazole as a curing accelerator, After dissolving 0 g in 600.0 g of methyl isobutyl ketone, 287.0 g of HTR-860-P3 (trade name: 15 wt% methyl ethyl ketone solution manufactured by Nagase ChemteX Corporation) was added as an acrylic resin, and the mixture was further stirred for 1 hour. A resin composition varnish was obtained.

Example 4
300 g of BREN-S (trade name, manufactured by Nippon Kayaku Co., Ltd.) as an epoxy resin, 181.0 g of FG-2000 (trade name, manufactured by Teijin Chemicals Ltd.) as a curing agent, and 1-cyanoethyl-2-ethyl-1 as a curing accelerator -After dissolving 1.0 g of methylimidazole in 600.0 g of methyl isobutyl ketone, 287.0 g of HTR-860-P3 (trade name: 15 wt% methyl ethyl ketone solution manufactured by Nagase ChemteX Corporation) was added as an acrylic resin. The resin composition varnish was stirred for 1 hour.

(Example 5)
In a 1 liter separable flask, 31.0 g (0.10 mol) of 3,3 ′, 4,4′-diphenyl ether tetracarboxylic dianhydride (OPDA) and 250 g of NMP (N-methyl-2-pyrrolidone) were placed. Stir at room temperature. 34.4 g (0.04 mol) of reactive silicone oil KF-8010 (trade name, manufactured by Shin-Etsu Chemical Co., Ltd., amine equivalent 430) was added dropwise as a siloxane diamine using a dropping funnel, and the reaction solution was ice-cooled with stirring. Then, 24.6 g (0.06 mol) of BAPP (2,2-bis [4- (4-aminophenoxy) phenyl] propane) as an aromatic diamine was added and stirred at room temperature (25 ° C.) for 2 hours to obtain a polyamic acid. Got. This was made into the resin composition varnish.

(Example 6)
Into a 1 liter separable flask was placed 32.2 g (0.10 mol) of 3,3 ′, 4,4′-benzophenonetetracarboxylic dianhydride (BTDA) and 300 g of NMP (N-methyl-2-pyrrolidone). Stir at room temperature. Reactive silicon oil X-22-161B (trade name, manufactured by Shin-Etsu Chemical Co., Ltd., amine equivalent 1560) 124.8 g (0.04 mol) as siloxane diamine was dropped using a dropping funnel, and the reaction solution was stirred. Ice-cooled, 24.6 g (0.06 mol) of BAPP (2,2-bis [4- (4-aminophenoxy) phenyl] propane) as an aromatic diamine was added, and the mixture was stirred at room temperature (25 ° C.) for 2 hours. A polyamic acid was obtained. This was made into the resin composition varnish.

(Example 7)
Into a 1 liter separable flask, 29.4 g (0.10 mol) of 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride (BPDA) and 300 g of NMP (N-methyl-2-pyrrolidone) were placed. Stir at room temperature. 72.0 g (0.04 mol) of reactive silicone oil X-22-161A (trade name, amine equivalent 900, manufactured by Shin-Etsu Chemical Co., Ltd.) was added dropwise as a siloxane diamine using a dropping funnel, and this reaction solution was stirred. Ice-cooled, 24.6 g (0.06 mol) of BAPP (2,2-bis [4- (4-aminophenoxy) phenyl] propane) as an aromatic diamine was added, and the mixture was stirred at room temperature (25 ° C.) for 2 hours. A polyamic acid was obtained. This was made into the resin composition varnish.

(Production of metal foil with resin)
A resin composition produced in Examples 1 to 4 by superposing a glass cloth (trade name 1027 manufactured by Asahi Schavel Co., Ltd.) having a thickness of 20 μm on electrolytic copper foil F2-WS-18 (trade name manufactured by Furukawa Electric Co., Ltd.). The varnish was applied so that the thickness after drying was 50 μm, heated at 150 ° C. for 15 minutes, and dried to obtain a metal foil with a resin having a resin content of 70% by weight (B stage state).

  Further, a 12 μm thick electrolytic copper foil (Furukawa Electric Co., Ltd., trade name F2-WS-12) and a 28 μm thick glass cloth (Asahi Schavel Co., Ltd., trade name 1037) are layered to form a polyamic of Example 5. A glass cloth is impregnated with an acid NMP solution (resin composition varnish) so that the thickness of the resin composition after impregnation and drying is 50 μm, and dried at 150 ° C. for 15 minutes. Produced. Furthermore, it processed for 60 minutes on 250 degreeC heating conditions after that, and was set as the metal foil with a resin of a C stage state.

  Also, a 12 μm thick electrolytic copper foil (Furukawa Electric Co., Ltd., trade name F2-WS-12) and a 28 μm thick glass cloth (Asahi Schavel Co., Ltd., trade name 1037) are layered to form the polyamic of Example 6. A glass cloth is impregnated with an acid NMP solution (resin composition varnish) so that the thickness of the resin composition after impregnation and drying is 40 μm, and dried at 150 ° C. for 15 minutes. Produced. Furthermore, it processed for 60 minutes on 250 degreeC heating conditions after that, and was set as the metal foil with a resin of a C stage state.

  Also, a 12 μm thick electrolytic copper foil (Furukawa Electric Co., Ltd., trade name F2-WS-12) and a 28 μm thick glass cloth (Asahi Schavel Co., trade name 1037) are stacked to form the polyamic of Example 7. A glass cloth is impregnated with an acid NMP solution (resin composition varnish) so that the thickness of the resin composition after impregnation and drying is 40 μm, and dried at 150 ° C. for 15 minutes. Produced. Furthermore, it processed for 60 minutes on 250 degreeC heating conditions after that, and was set as the metal foil with a resin of a C stage state.

(Production of double-sided copper-clad laminate)
The resin-coated metal foils of Examples 1 to 4 were stacked so that the resin surfaces were aligned, and press-laminated under the conditions shown in Table 1 below to prepare a double-sided copper-clad laminate.

(Comparative Example 1)
The resin composition varnish produced in Example 1 was applied onto electrolytic copper foil F2-WS-18 so that the thickness after drying was 50 μm, heated at 150 ° C. for 15 minutes, and dried to include a fiber substrate. A resin-added metal foil (B stage state) having a resin content of 70% by weight was obtained. Further, the metal foils with resin were stacked so that the resin surfaces were combined, and press laminated under the conditions shown in Table 1 below to prepare a double-sided copper-clad laminate.

(Comparative Example 2)
The resin composition varnish produced in Example 1 was applied onto electrolytic copper foil F2-WS-18 so that the thickness after drying was 50 μm, heated at 150 ° C. for 15 minutes, and dried to include a fiber substrate. A resin-added metal foil (B stage state) having a resin content of 70% by weight was obtained. Further, the metal foils with resin were stacked so that the resin surfaces were combined, and press laminated under the conditions shown in Table 1 below to prepare a double-sided copper-clad laminate.

(Comparative Example 3)
On the electrolytic copper foil (product name F2-WS-12, manufactured by Furukawa Electric Co., Ltd.) having a thickness of 12 μm, the polyamic acid NMP solution (resin composition varnish) of Example 6 has a thickness after drying of 40 μm. And dried at 150 ° C. for 15 minutes to prepare a metal foil with a resin (B stage state) that does not contain a fiber base material. Furthermore, the thermosetting process was performed at 200 degreeC for 60 minutes, and it was set as the metal foil with resin of the C stage state which does not contain a fiber base material.

(Measurement of elastic modulus)
The resin compositions of Examples 1 to 7 and Comparative Examples 1 to 3 are placed on an electrolytic copper foil (Furukawa Electric Co., Ltd., trade name F2-WS-12) having a thickness of 12 μm so that the sample thickness is about 50 to 100 μm. It was coated and cured under the following conditions. Examples 1-2 were heated at 150 ° C. for 15 minutes, then heated at 230 ° C. for 60 minutes, Examples 3-4 were heated at 150 ° C. for 15 minutes, then heated at 180 ° C. for 60 minutes, and Examples 5-7 were After heating at 150 ° C. for 15 minutes, heating at 250 ° C. for 60 minutes, Comparative Example 1 is heated at 150 ° C. for 15 minutes and then heated at 230 ° C. for 60 minutes, Comparative Example 2 is heated at 150 ° C. for 15 minutes and then 180 ° C. And Comparative Example 3 was heated at 150 ° C. for 15 minutes and then heated at 250 ° C. for 60 minutes. Thereafter, the cured resin obtained by removing the copper foil by etching was used as a test substrate. This test substrate was cut out to about 30 mm × 5 mm and measured using a dynamic viscoelasticity measuring device Regel-E-4000 manufactured by UBM under the conditions of a measurement length of 20 mm and a measurement frequency of 10 Hz. The elastic modulus at 25 ° C. of the obtained dynamic viscoelastic curve was taken as a measured value. The results are shown in Table 2.

(Measurement of linear thermal expansion coefficient)
The copper of the double-sided copper clad laminates of Examples 1 to 4 and Comparative Examples 1 to 2 was removed by etching to obtain a test substrate. Moreover, the copper of the metal foil with a resin (copper foil) of the C-stage state of Examples 5-7 and Comparative Example 3 was removed by etching to obtain a test substrate. This test substrate was cut out to 5 mm × 20 mm, and the linear thermal expansion coefficient was measured by a thermomechanical analyzer (TMA) under conditions of a tensile mode and a temperature rising rate of 10 ° C./min. The results are shown in Table 2.

(Measurement of dimensional change during moisture absorption)
The copper of the double-sided copper clad laminates of Examples 1 to 4 and Comparative Examples 1 to 2 was removed by etching to obtain a test substrate. This test substrate was dried at 105 ° C. for 1 hour, cut into 250 mm × 250 mm, drilled with a 2 mmφ drill at 100 mm intervals, and the distance between centers of the drill holes was measured with a three-dimensional measuring device. Then, using a pressure cooker, moisture was absorbed for 2 hours under conditions of 121 ° C. saturation, and the surface moisture was wiped off. Then, the distance between the centers of the drill holes was measured again with a three-dimensional measuring device. The dimensional change rate during moisture absorption was determined from the distance between the centers of the drill holes before and after moisture absorption. The results are shown in Table 2.

(Evaluation of impact resistance)
Conventional drilling, plating, photolithography on double-sided copper-clad laminates of Examples 1-4 and Comparative Examples 1-2, and metal foils (copper foils) with resin in the C-stage state of Examples 5-7 and Comparative Example 3 A printed circuit board with four rows of daisy chain patterns having 250 connection holes with a diameter of 0.25 mm is manufactured by the process, and the start point and the end point of each are connected by lead wires with solder, and the initial resistance as a conduction pattern of one row with 1000 holes Was measured. Thereafter, each printed circuit board was mounted in a predetermined housing and dropped a predetermined number of times from a height of 1.5 m, and the presence or absence of disconnection and the resistance value were measured. After dropping 1000 times, the change rate of the resistance value is within 10%, and over 10% is made x. The results are shown in Table 2.

(Evaluation of embeddability)
Resin-coated metal foils of Examples 1 to 4 and Comparative Examples 1 to 2 on an inner layer circuit board (conductor thickness: 12 μm) on which comb-shaped patterns having lines / spaces of 50 μm / 50 μm, 75 μm / 75 μm, and 100 μm / 100 μm were formed ( The copper foil was stacked so that the circuit surface of the inner circuit board and the resin surface of the resin-attached metal foil (copper foil) were put together and laminated and pressed under the conditions shown in Table 1. The copper foil of the obtained laminated board was removed by etching, and the embedding property of the resin in the inner layer circuit of the inner layer circuit board was visually evaluated. ○: No voids or blurs, ×: Voids or blurs. The results are shown in Table 2.

(Measurement of peel strength of copper foil)
Metal foil adhesion strength (copper foil drawing) of double-sided copper-clad laminates of Examples 1 to 4 and Comparative Examples 1 to 2 and metal foils with resin (copper foil) in the C-stage state of Examples 5 to 7 and Comparative Example 3 Peel strength) was measured. The results are shown in Table 2.

(Evaluation of solder heat resistance)
The double-sided copper-clad laminates of Examples 1 to 4 and Comparative Examples 1 to 2, and the metal foils with a C-stage resin (copper foil) of Examples 5 to 7 and Comparative Example 3 were 260 ° C., 288 ° C. and 300 ° C. It was immersed in a solder bath at 0 ° C. and the solder heat resistance was evaluated. Table 2 shows the time until abnormalities such as blistering and peeling were observed when immersed in a 300 ° C. solder bath.

(Evaluation of 180 degree bendability)
The copper of the double-sided copper clad laminates of Examples 1 to 4 and Comparative Examples 1 to 2 was removed by etching to obtain a test substrate. Moreover, the copper of the metal foil with a resin (copper foil) of the C-stage state of Examples 5-7 and Comparative Example 3 was removed by etching to obtain a test substrate. This test substrate was bent 180 degrees so that the glass rod having a diameter of 2 mm and the inside of the bent portion of the test substrate were brought into contact with no gap, and the presence or absence of cracks or breakage of the test substrate was examined. ○: No cracks or breakage, ×: Cracks or breakage. The results are shown in Table 2.

(Dust generation evaluation)
The resin-coated metal foils of Examples 1 to 7 and Comparative Examples 1 to 3 (B stage state) were cut into a predetermined size with a cutter, and the presence or absence of generation of resin powder was examined. ○: Resin powder was not generated, and X: Resin powder was generated. The results are shown in Table 2.

(Measurement of water absorption)
The copper of the resin-attached metal foil (copper foil) in the C stage state of Examples 5 to 7 and Comparative Example 3 was removed by etching to obtain a test substrate. The test substrate was absorbed for 2 hours under a condition of 121 ° C. saturation using a pressure cooker, and the water absorption was determined. The results are shown in Table 2.

(Evaluation of curling of metal foil with resin)
The curl state of the metal foil with resin (B stage state) of Examples 1 to 7 and Comparative Examples 1 to 3 was evaluated. The results are shown in Table 2.

  It turned out that the metal foil with a resin (B stage state) containing the fiber base material produced using the resin composition varnish of Examples 1-7 does not have curls or the like and has no problem in appearance. On the other hand, as shown in Comparative Examples 1 to 3, when the resin composition varnish was directly applied to the copper foil, the curl was seen with the resin surface inside, and the curl was also large.

  Metal foil adhesion strength (copper foil peeling strength) of the prepared double-sided copper-clad laminate and metal foil with a resin in the C-stage state (copper foil) was 0.9 to 1.2 kN / m. Moreover, as a result of immersing in a solder bath of 260 ° C., 288 ° C. and 300 ° C. and measuring solder heat resistance, no abnormality such as blistering or peeling was observed at any temperature for 5 minutes or more. In addition, in the C-staged resin-attached metal foil (copper foil) of Comparative Example 3, curling occurs with the copper foil facing outside during the thermosetting treatment, and a flat resin-attached metal foil (copper foil) is obtained. Therefore, evaluation of solder heat resistance was not possible. In addition, the water absorption of Examples 5-7 was 0.88-0.96 weight%. And in the comparative example 3 which does not contain a fiber base material, it was 1.81 weight%.

  The elastic modulus of the cured resin obtained by curing the resin compositions of Examples 1 to 7 was 0.8 to 1.5 GPa. The linear thermal expansion coefficient of the test substrate using a cured resin (resin composition) having an elastic modulus of 0.8 to 1.5 GPa was a small value of 9 to 16 ppm in Examples 1 to 7, In Comparative Examples 1 and 2 that did not include a fiber substrate, they were as large as 150 ppm and 300 ppm, respectively. In Comparative Example 3, it was 30 ppm. Further, the dimensional change rate during moisture absorption was as small as 0.01% to 0.02% in Examples 1 to 4, but was large as 0.5% and 0.2% in Comparative Examples 1 and 2. .

When bending was performed at 180 degrees, it was possible to fold all of Examples 1 to 7 and Comparative Examples 1 to 3 without causing cracks or the like. Moreover, when metal foil with resin was cut out to the predetermined | prescribed magnitude | size with the cutter, generation | occurrence | production of resin powder etc. was not seen in any of Examples 1-7 and Comparative Examples 1-3. Further, the embedding property of the inner layer circuit was good in each of Examples 1 to 4 and Comparative Examples 1 and 2. Moreover, also about impact resistance, all of Examples 1-7 and Comparative Examples 1-2 were favorable. In addition, in the C-staged resin-coated metal foil (copper foil) of Comparative Example 3, during the thermosetting treatment, curling occurs with the copper foil facing outside, and a flat printed circuit board cannot be obtained, resulting in impact resistance. Evaluation of was impossible.

Claims (9)

A metal foil with a resin obtained by laminating a fiber base material impregnated with a resin composition and a metal foil, and an elastic modulus of a cured resin obtained by curing the resin composition is 0.1 GPa or more at 25 ° C., Metal foil with resin which is 1.5 GPa or less.   The metal foil with a resin according to claim 1, wherein the fiber substrate is a fiber substrate having a thickness of 50 µm or less.   The metal foil with a resin according to claim 1 or 2, wherein the resin composition is a resin composition containing a thermosetting resin.   The metal foil with a resin according to claim 3, wherein the thermosetting resin is a thermosetting resin containing a resin having a glycidyl group.   The resin-coated metal foil according to any one of claims 1 to 4, wherein the resin composition is a resin composition containing a resin having an amide group.   The resin-coated metal foil according to any one of claims 1 to 5, wherein the resin composition is a resin composition containing an acrylic resin.   The resin-coated metal foil according to any one of claims 1 to 6, wherein the resin composition is a resin composition containing a polyamic acid.   A metal foil with a resin according to any one of claims 1 to 7, wherein the fiber base material is impregnated with the resin composition from the fiber base side in a state where the metal foil and the fiber base material are stacked, and then dried. Metal foil with resin.   A metal foil with a resin according to any one of claims 1 to 7, wherein the resin composition is applied on the metal foil, and thereafter the resin composition is impregnated with a fiber base material and dried. Metal foil.