JP2005200532A - Prepreg and laminate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a prepreg bondable to smooth metal foils and excellent in heat resistance by impregnating a fibrous substrate with a resin which has excellent adhesion to metal foils and fibrous substrates, impregnation performance and heat stability. <P>SOLUTION: The prepreg is obtained by impregnating a fibrous substrate with a resin composition the indispensable ingredients of which are a polyamide resin and a heat-curable resin. The weight-average molecular weight of the polyamide resin is 5,000-50,000. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a prepreg and a metal foil-clad laminate.

  The laminate for a printed wiring board is obtained by stacking a predetermined number of prepregs each having an electrically insulating resin composition as a matrix and then heating and pressing to integrate them. 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 and heating and pressing. 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 widespread use of information terminal devices such as personal computers and mobile phones, printed wiring 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.

  Also, 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 must be chip mounted again afterwards. Then, 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.

  Further, with the increase in processing speed, the number of MPU I / Os has increased, and the number of terminals to be connected by wire bonding and the terminal width have been reduced. Adhesion with a metal foil subjected to circuit formation is desired to have an adhesive force higher than that of the prior art, and a roughened shape on the surface of the metal foil is also required in order to produce thinner wiring.

On the other hand, it is considered that surface smoothness is required for circuit conductors as the frequency of signals increases. Magnetic field lines are generated in the vicinity of the current in the conductor, but since the interference of the magnetic field lines is greater at the center of the conductor, the current is concentrated at the periphery and corners. This is called the skin effect, and this tendency increases as the frequency increases. It is thought that the smoother the surface of the conductor, the more the increase in resistance due to the skin effect can be suppressed, but the adhesion of the conventional electrically insulating resin is largely due to the anchor effect on the rough surface, which is contrary to the high frequency signal. It has become a thing.
The present inventors have found that this problem can be solved by using polyamideimide, but there are further problems in impregnation and the like.

JP 2003-55486 A

  The present invention eliminates the above-mentioned problems of the prior art, and impregnates the fiber base material with a resin excellent in adhesion to metal foil and fiber base material, impregnating property, and heat resistance. The present invention provides a prepreg and a metal foil-clad laminate that can be bonded together and have excellent heat resistance.

The present invention relates to the following.
1. A prepreg obtained by impregnating a fiber base material with a resin composition containing a polyamideimide resin and a thermosetting resin as essential components, wherein the weight average molecular weight of the polyamideimide resin is 50000 or less.
2. A prepreg obtained by impregnating a fiber base material with a resin composition containing a polyamideimide resin and a thermosetting resin as essential components, and the polyamideimide contains 50 mol% of polyamideimide having 10 or more amide groups in one molecule The prepreg according to 1, which is a polyamide-imide resin including the above.
3. The polyamideimide resin in the resin composition is a siloxane-modified polyamideimide resin having a weight average molecular weight of 50000 or less and containing 2% or more by mass of Si atoms based on siloxane bonds (O-Si-O) in the molecule. The prepreg according to 2.
4). Mixture containing diimide dicarboxylic acid obtained by reacting a mixture of diamine and siloxane diamine having two or more aromatic rings represented by general formula (1a) or (1b) with a siloxane-modified polyamideimide resin and trimellitic anhydride Item 3. The prepreg according to Item 1 or 2, which is a siloxane-modified polyamideimide resin obtained by reacting a diisocyanate compound with a thermosetting resin, which is an epoxy resin having two or more glycidyl groups.

[Wherein, X represents an aliphatic hydrocarbon group having 1 to 3 carbon atoms, a halogenated aliphatic hydrocarbon group having 1 to 3 carbon atoms, a sulfonyl group, an ether group, a carbonyl group, a single bond, or the following general formula (2a) Or a divalent group represented by (2b), Y is an aliphatic hydrocarbon group having 1 to 3 carbon atoms, a halogenated aliphatic hydrocarbon group having 1 to 3 carbon atoms, a sulfonyl group, an ether group, or a carbonyl group. R ¹ , R ² and R ³ are independent or the same and represent a hydrogen atom, a hydroxyl group, a methoxy group, a methyl group or a halogenated methyl group.

However, Z is a C1-C3 aliphatic hydrocarbon group, a C1-C3 halogenated aliphatic hydrocarbon group, a sulfonyl group, an ether group, a carbonyl group, or a single bond. ]
5). Item 5. The prepreg according to any one of Items 1 to 4, wherein the thermosetting resin contains an epoxy resin having two or more glycidyl groups and a curing accelerator or curing agent thereof.
6). Item 6. A laminate obtained by heating and pressing the prepreg according to any one of Items 1 to 5.
7). 6. A laminate obtained by heating and pressurizing a metal foil having a surface roughness Rz ≦ 3.0 and the prepreg according to Items 1 to 5.

  The prepreg in the present invention can be bonded to a smooth metal foil, and the obtained metal foil-clad laminate is excellent in heat resistance.

The resin composition used in the present invention has high flowability of the B-stage resin by setting the weight average molecular weight of the polyamideimide to 50000 or less, whereby the prepreg of the present invention has good circuit fillability. Thereby, the prepreg of the present invention can be easily used not only as a core substrate but also as a multilayer substrate. In addition, in this invention, the weight average molecular weight uses the conversion value obtained with respect to the standard polystyrene in 25 degreeC using GPC (gel permeation chromatography). As an eluent, a solution obtained by dissolving 0.06 mol / L of phosphoric acid and 0.03 mol / L of lithium bromide monohydrate in a mixed solution of tetrahydrofuran / dimethylformamide = 50/50 (volume ratio) is used.
The polyamideimide resin used in the present invention is preferably a siloxane-modified polyamideimide having a siloxane structure in the resin, and particularly a diimide obtained by reacting a mixture of a diamine having two or more aromatic rings and a siloxane diamine with trimellitic anhydride. It is preferably obtained by reacting a mixture containing a dicarboxylic acid 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 polyamideimide. For example, the chromatogram obtained by GPC using the number of moles of amide groups contained in polyamideimide (a) (A) as the molecular weight (C) of polyamideimide containing 10 amide groups per molecule from 10 × a / A. It is defined that the region where the number average molecular weight of C is C or more is 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.
In the siloxane-modified polyamideimide having a siloxane structure in the resin, the mixing ratio of diamine a and siloxane diamine b having two or more aromatic rings is a / b = 99.9 / 0.1 to 0/100 (moles). Ratio), preferably a / b = 95/5 to 30/70, and 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 becomes small, when producing a prepreg, there exists a tendency for the amount of varnish solvents which remain | survives in resin to increase.
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-amino). Phenoxy) phenyl] sulfone, 2,2-bis [4- (4-aminophenoxy) phenyl] hexafluoropropane, bis [4- (4-aminophenoxy) phenyl] methane, 4,4′-bis (4-amino) Phenoxy) 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′-tetramethyl-4,4′-diamine, 5,5′-dimethyl-2,2′-sulfonyl-biphenyl-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 used in the present invention include the following.

  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) ( Examples thereof include Shin-Etsu Chemical Co., Ltd., BY16-853 (amine equivalent 650), BY16-853B (amine equivalent 2200), and the like (manufactured by Toray Dow Corning Silicone Co., Ltd.). 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) (above, manufactured by Shin-Etsu Chemical Co., Ltd.), and the like. It can be illustrated.

As the aliphatic diamine, a compound represented by the following general formula (7) can be used.

[Wherein X represents a methylene group, sulfonyl group, ether group, carbonyl group or single bond, R1 and R2 each represents a hydrogen atom, an alkyl group, a phenyl group or a substituted phenyl group, and p represents an integer of 1 to 50. Show. ]
Specific examples of R1 and R2 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 preferably 1 to 3 carbon atoms. And an alkyl group, a halogen atom, and the like.
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) and Jeffamine D-2000 (amine equivalent 1000).

  As the diisocyanate used in the method for producing the polyamideimide 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 can be improved.

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

When aromatic diisocyanate and 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, and this combination further improves the heat resistance of the polyamideimide obtained. be able to.

  Examples of the thermosetting resin used in the present invention include an epoxy resin, a polyimide resin, an unsaturated polyester resin, a polyurethane resin, a bismaleimide resin, a triazine-bismaleimide resin, a phenol resin, and the like. The thermosetting resin is used in an amount of 1 to 200 parts by weight. In the present invention, a thermosetting resin having an organic group capable of reacting with an amide group in the siloxane-modified polyamideimide resin is preferable, and an epoxy resin having a glycidyl group is preferable. In the present invention, 1 to 200 parts by weight of a thermosetting resin is used with respect to 100 parts by weight of the siloxane-modified polyamideimide resin. However, if it is less than 1 part by weight, the solvent resistance is inferior. Tg is lowered by the conductive resin, heat resistance is insufficient, and flexibility is not preferable. Therefore, the thermosetting resin is preferably 3 to 100 parts by weight, more preferably 5 to 80 parts by weight with respect to 100 parts by weight of the siloxane-modified polyamideimide resin.

  In the present invention, using an epoxy resin as a thermosetting resin can be cured at a temperature of 180 ° C. or less, and reacts with an amide group of a siloxane-modified polyamideimide resin to exhibit thermal, mechanical, and electrical characteristics. Preferably, an epoxy resin having two or more glycidyl groups and a curing agent thereof, an epoxy resin having two or more glycidyl groups and a curing accelerator thereof, or an epoxy resin having two or more glycidyl groups and a curing agent, It is preferable to use 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.

  Epoxy resins include polyglycidyl ethers and phthalic acids obtained by reacting polychlorophenols such as bisphenol A, novolac phenol resins, orthocresol novolac 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.

  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 amines, dicyandiamide, diaminodiphenylmethane, guanylurea, etc. can be used. As polyfunctional phenols, hydroquinone, resorcinol, bisphenol A and their halogen compounds, and novolak-type phenol resins that are condensates with formaldehyde, resole 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 epoxy equivalent of the epoxy resin is preferably taken into account because it can also react with the amide group of the siloxane-modified polyamideimide resin.

  In the present invention, a prepreg can be prepared by impregnating and drying a varnish obtained by mixing, dissolving, and dispersing a heat-resistant resin composition for prepreg in an organic solvent. 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.

  A heat-resistant resin composition for obtaining a prepreg is a resin composition containing 100 parts by weight of a siloxane-modified polyamideimide resin and 1 to 200 parts by weight of a thermosetting resin, and has a fast volatilization rate of a varnish solvent and is thermosetting. The residual solvent content can be reduced to 5% by weight or less even at a low temperature of 150 ° C. or less that does not promote the curing reaction of the conductive resin, and a heat-resistant adhesive sheet having good adhesion to the fiber substrate and the copper foil is obtained. Can do. This is because the polyamideimide resin with high heat resistance is modified with siloxane, and the residual solvent content can be reduced, preventing the occurrence of swelling due to solvent volatilization in the lamination process with copper foil, and solder heat resistance. It can be made excellent.

  A base material is impregnated with a varnish of a heat resistant resin composition, and dried in a range of 80 ° C. to 180 ° C. to produce a prepreg. Although it will not restrict | limit especially if it is used when manufacturing a metal foil clad laminated board and a multilayer printed wiring board as a base material, 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. As the base material used for the prepreg, a glass cloth of 30 μm to 200 μm is particularly preferably used.

  The production conditions of the prepreg are not particularly limited, but it is preferable that the 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.

  Moreover, it is preferable that the amount of impregnation of a varnish shall be 35-70 weight% of varnish solid content with respect to the total amount of a varnish solid content and a base material.

  The manufacturing method of an insulating board, a laminated board, or a metal-clad laminated board is as follows. In the present invention, a metal foil is laminated on one or both sides of the prepreg or a laminate obtained by laminating a plurality of the prepregs, if necessary, and usually at a temperature in the range of 150 to 280 ° C, preferably 180 ° C to 250 ° C, usually 0. An insulating plate, a laminate or a metal-clad laminate can be produced by heat and pressure molding at a pressure in the range of 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 the metal foil used in 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. 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.

  Some of these one side or both sides are subjected to a roughening treatment for forming fine irregularities on the surface in order to improve adhesion with an adhesive resin such as a prepreg. These scales of surface roughness include arithmetic average roughness Ra, root mean square roughness Rq, and ten-point average roughness Rz used in ISO and JIS. These numerical values indicate that the smaller the surface roughness, the smaller the surface roughness. When Rz is used as the surface roughness, Rz ≦ 3.0 is essential for obtaining the effects of the present invention, and preferably Rz ≦ 2.0. Such a surface may be further subjected to a rust prevention treatment or an adhesion treatment with a coupling agent, but can be used irrespective of the presence or absence of these treatments.

Examples are described below, but the present invention is not limited to these examples.
Example 1
225 g of an NMP solution of a siloxane-modified polyamideimide resin having a weight average molecular weight of 28000 and 52 amide groups in one molecule (resin solid content: 40% by weight) and YDCN-500 (trade name, manufactured by Tohto Kasei Co., Ltd., cresol novolak type) (Epoxy resin) 20 g (dimethylacetamide solution with a resin solid content of 50% by weight) and 1.0 g of 2-ethyl-4-methylimidazole were blended, stirred for about 1 hour until the resin became uniform, and then 24 for defoaming. The resin composition varnish was left standing at room temperature for a time.
Example 2
225 g of NMP solution of siloxane-modified polyamideimide resin having a weight average molecular weight of 30000 and 38 amide groups in one molecule (resin solid content 40 wt%) and DER331L as epoxy resin (trade name, manufactured by Dow Chemical Co., Ltd., bisphenol A type epoxy resin) ) 20 g (dimethylacetamide solution with a resin solid content of 50% by weight) and 1.0 g of 2-ethyl-4-methylimidazole were mixed and stirred for about 1 hour until the resin became homogeneous, then for 24 hours for defoaming, The resin composition varnish was left standing at room temperature.
Examples 3-7
NMP solution of various polyamideimide resins shown in Table 1 and 200 g (resin solid content 40% by weight) and DER331L (trade name, manufactured by Dow Chemical Co., Ltd., bisphenol A type epoxy resin) as an epoxy resin 20 g (resin solid content 50% by weight) Dimethylacetamide solution) and 1.0 g of 2-ethyl-4-methylimidazole, and the mixture was stirred for about 1 hour until the resin became homogeneous, and then allowed to stand at room temperature for 24 hours for defoaming. It was a varnish.
(Preparation of prepreg and metal foil-clad laminate)
The glass fabric (WEA101-053F036) having a thickness of about 0.02 mm was impregnated with the varnishes produced in Examples 1 to 7, and then heated and dried at 150 ° C. for 15 minutes to obtain a prepreg having a resin content of 50% by weight.

3. Electrolytic copper foil (F0-WS-12, manufactured by Furukawa Electric Co., Ltd., Rz = 1.2 μm) having a thickness of 12 μm is stacked on both sides of the prepreg so that the adhesive surface is aligned with the prepreg, and 230 ° C. for 90 minutes. A double-sided copper-clad laminate was produced under a press condition of 0 MPa.
(Evaluation)
As a result of measuring the metal foil adhesion strength (peeling strength) of the obtained metal foil-clad laminate, 0.6 to 0.8 kN in any combination of F0-WS-12 and any of the prepregs of Examples 1 to 7 / M.

  As a result of immersing in a solder bath at 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.

Comparative Example 1
A resin composition was prepared in the same manner as in Example 1 except that a polymiamideimide having a weight average molecular weight of 4000 and 2 amide groups in one molecule was used to prepare a prepreg. Although the adhesiveness with copper foil was evaluated, only 0.1 kN / m adhesive strength was obtained with F0-WS-12 foil.
Comparative Example 2
A resin composition was prepared in the same manner as in Example 1 except that a polyamideimide having a molecular weight of 70000 and an amide group number of 122 in one molecule was used. An attempt was made to produce a prepreg by impregnating a glass cloth with a resin, but the resin was not impregnated and a large number of bubbles were observed. No further evaluation was performed.
Comparative Example 3
A commercially available prepreg E-67 (0.1 mm) was used, F0-WS-12 was superimposed on both sides, and pressed under the conditions of 180 ° C./4 MPa / 90 minutes to obtain a substrate with double-sided copper foil. As a result of evaluating the adhesiveness, only an adhesive force of 0.2 kN / m was obtained with F0-WS-12.
(Evaluation of circuit formability)
Electrolytic copper foil F0-WS-12 (Rz = 1.2 μm) is overlapped on both sides of the prepreg produced from the resin composition of Example 1, and double-sided copper-clad laminates are pressed at 230 ° C. for 90 minutes and 4.0 MPa. Was made.

  For comparison, a similar double-sided copper-clad laminate was prepared by using an electrolytic copper foil (12 μm, Rz = 6.5 μm) as an electrolytic copper foil for comparison.

  Comb patterns with L / S of 20 μm / 20 μm, 30 μm / 30 μm, 40 μm / 40 μm, 50 μm / 50 μm are formed by normal registration, and after etching unnecessary portions of copper with ferric chloride aqueous solution, the resist is peeled off The circuit was formed.

  The obtained circuit was observed with a microscope, and the circuit forming property was evaluated from the shape of the line. With a copper foil of Rz = 6.5 μm, it took time to remove the residual copper derived from the rough surface of the copper foil, and as a result, a tendency was observed that the top of the line became a thin bowl shape. For this reason, 50 μm / 50 μm was the limit to obtain a good circuit. In the copper foil-clad laminate using a copper foil of Rz = 1.2 μm, the remaining copper could be removed in a short time and the circuit cross section was close to a rectangle. The circuit formability was 20 μm / 20 μm.

Claims (7)

  A prepreg obtained by impregnating a fiber base material with a resin composition containing a polyamideimide resin and a thermosetting resin as essential components, and the weight average molecular weight of the polyamideimide resin is 5,000 to 50,000.   A prepreg obtained by impregnating a fiber base material with a resin composition containing a polyamideimide resin and a thermosetting resin as essential components, and the polyamideimide resin contains 70 mol of polyamideimide having 10 or more amide groups in one molecule. The prepreg according to claim 1, which is a polyamideimide resin containing at least%.   The polyamideimide resin in the resin composition is a siloxane-modified polyamideimide resin having a weight average molecular weight of 5,000 to 50,000 and containing 2% or more of Si atoms based on siloxane bonds (O-Si-O) in the molecule. Or the prepreg of 2. Mixture containing diimide dicarboxylic acid obtained by reacting a mixture of diamine and siloxane diamine having two or more aromatic rings represented by general formula (1a) or (1b) with a siloxane-modified polyamideimide resin and trimellitic anhydride The prepreg according to any one of claims 1 to 3, which is a siloxane-modified polyamideimide resin obtained by reacting a diisocyanate compound with a diisocyanate compound, wherein the thermosetting resin is an epoxy resin having two or more glycidyl groups.

[Wherein, X represents an aliphatic hydrocarbon group having 1 to 3 carbon atoms, a halogenated aliphatic hydrocarbon group having 1 to 3 carbon atoms, a sulfonyl group, an ether group, a carbonyl group, a single bond, or the following general formula (2a) Or a divalent group represented by (2b), Y is an aliphatic hydrocarbon group having 1 to 3 carbon atoms, a halogenated aliphatic hydrocarbon group having 1 to 3 carbon atoms, a sulfonyl group, an ether group, or a carbonyl group. R ¹ , R ² and R ³ are independent or the same and represent a hydrogen atom, a hydroxyl group, a methoxy group, a methyl group or a halogenated methyl group.

However, Z is a C1-C3 aliphatic hydrocarbon group, a C1-C3 halogenated aliphatic hydrocarbon group, a sulfonyl group, an ether group, a carbonyl group, or a single bond. ]   The prepreg according to any one of claims 1 to 4, wherein the thermosetting resin contains an epoxy resin having two or more glycidyl groups and a curing accelerator or a curing agent thereof.   A laminate obtained by heating and pressing the prepreg according to claim 1.   A metal foil-clad laminate obtained by heating and pressing a metal foil having a surface roughness of Rz ≦ 3.0 μm and the prepreg according to claim 1.