JP2005325203A - Prepreg, metal foil-clad laminated plate and printed circuit board obtained using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a printed circuit board which has a low elastic modulus, is excellent in dimensional stability and heat resistance and can be folded to be highly densely contained in a housing of an electronic apparatus, and a prepreg and a metal foil-clad laminated plate for obtaining the printed circuit board. <P>SOLUTION: The prepreg is obtained by impregnating a fibrous base material with a resin composition comprising a polyamide imide-resin, where the polyamide-imide resin has an imide bond and an amide bond derived from trimellitic acid and an amide bond derived from an aromatic dibasic carboxylic acid and the main chain of the polyamide-imide resin comprises at least an organopolysiloxane structure and an alkylene group and/or an oxyalkylene group. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a prepreg, a metal foil-clad laminate using the prepreg, and a printed circuit board.

  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 the printed circuit is formed by a subtractive method, a metal foil-clad laminate is used. This metal foil-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 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, lead-free solder has progressed from the viewpoint of environmental issues, and the melting temperature of solder has increased. As a result, higher heat resistance is required for the substrate, and the demand for halogen-free materials has increased, making it difficult to use bromine. The use of flame retardants has become difficult. 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 method for introducing an aramid structure into a polyamideimide having an organopolysiloxane structure has been proposed for the purpose of improving heat resistance and preventing warpage during film production (see, for example, Patent Documents 2 and 3).

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 2000-239340 A JP 2004-51714 A

  The present invention eliminates the above-mentioned problems of the prior art, and impregnates a thin fiber base material with a highly flexible resin excellent in adhesion to metal foil and fiber base material and excellent in heat resistance. A printed circuit board having a low rate, excellent dimensional stability and heat resistance, which can be bent when used as a printed circuit board, and can be stored in a casing of an electronic device with high density, and a prepreg and a metal foil tension for providing the printed circuit board A laminated board is provided.

The present invention relates to the following.
(1) In a prepreg formed by impregnating a fiber base material with a resin composition containing a polyamideimide resin, the polyamideimide resin contains an imide bond and an amide bond derived from trimellitic acid, and an amide derived from an aromatic divalent carboxylic acid A prepreg characterized in that it is a polyamide-imide resin having a bond, and the main chain of the polyamide-imide resin is a polyamide-imide resin having at least an organopolysiloxane structure and an alkylene group and / or an oxyalkylene group. .
(2) The prepreg according to item (1), wherein the resin composition containing a polyamideimide resin is a resin composition containing a thermosetting resin.
(3) The prepreg according to item (1) or (2), wherein the fiber base material is a glass cloth having a thickness of 5 to 100 μm.
(4) The prepreg according to item (1) or (3), wherein the polyamideimide resin is a polyamideimide resin obtained by reacting a mixture containing diimide dicarboxylic acid and aromatic dicarboxylic acid with a diisocyanate compound.
(5) The term (2), wherein the thermosetting resin is an epoxy resin having two or more glycidyl groups, and the resin composition is a resin composition containing a curing accelerator or a curing agent for the epoxy resin. Thru | or the prepreg in any one of (4).
(6) A metal foil-clad laminate obtained by stacking a predetermined number of the prepregs according to any one of items (1) to (5), placing metal foil on one side or both sides, and heating and pressing.
(7) A printed circuit board obtained by forming a circuit on the metal foil-clad laminate according to item (6).

  The metal foil-clad laminate and printed circuit board obtained by the prepreg in the present invention can be bent arbitrarily, have a low elastic modulus, and are excellent in dimensional stability, heat resistance, and PCT resistance.

  The polyamideimide resin used in the present invention is a polyamideimide having an imide bond and an amide bond derived from trimellitic acid and an amide bond derived from an aromatic divalent carboxylic acid, and the main chain of the polyamideimide resin is at least organo A polyamide-imide resin characterized by having a polysiloxane structure and an alkylene group and / or an oxyalkylene group. Such a polyamideimide resin is preferably a polyamideimide resin obtained by reacting a mixture containing diimide dicarboxylic acid and aromatic divalent carboxylic acid with a diisocyanate compound.

  The trimellitic acid-derived imide bond and amide bond are, for example, those represented by the following general formula (1), and the imide bond and amide bond were obtained by, for example, reaction of trimellitic acid and diamine. It is generated by dehydration ring closure reaction of amic acid.

  An amide bond derived from an aromatic divalent carboxylic acid is, for example, the one represented by the following general formula (2), and such a bond is generated by, for example, a reaction between a dicarboxylic acid and an isocyanate.

  In general formula (2), X is a divalent organic group having 1 to 4 aromatic rings, and when a plurality of aromatic rings are present, they may form a condensed ring. Specific examples of the amide bond derived from the aromatic divalent carboxylic acid represented by the general formula (2) include a bond represented by the following general formula (2a), a bond represented by the general formula (2b), and Examples thereof include a bond represented by the general formula (2c).

（式中Ｘは−Ｏ−、−ＣＯ−又は−ＳＯ_２−を示す。）

(Wherein X represents —O—, —CO— or —SO ₂ —).

  The amide bond derived from the aromatic divalent carboxylic acid preferably has an amide bond at the para-position or the 4,4'-position. By having an amide bond at such a position, the molecular orientation becomes high and the heat resistance of the polyamide-imide resin can be improved. By having an amide bond derived from an aromatic divalent carboxylic acid as described above in the polyamideimide resin, the orientation of the resulting polyamideimide is increased, and such polyamideimide resin is excellent in fiber and film moldability, It has high heat resistance.

  The organopolysiloxane structure in the polyamide-imide resin of the present invention is represented, for example, by the following general formula (3a).

In General Formula (3a), R ¹ and R ² are the same or different divalent organic groups, R ^{3 to} R ⁶ are the same or different monovalent organic groups, and n is an integer of 1 or more. The divalent organic group is preferably an alkylene group, a phenylene group or a substituted phenylene group, preferably having 1 to 6 carbon atoms, more preferably an alkylene group having 1 to 3 carbon atoms. More preferred. The monovalent organic group is preferably an alkyl group, a phenyl group or a substituted phenyl group, preferably has 1 to 6 carbon atoms, and more preferably is an alkyl group having 1 to 3 carbon atoms. And it is preferable that n is an integer of 1-50. In the present invention, it is particularly preferable that R ¹ and R ² are both propylene groups, and R ^{3 to} R ⁶ are all methyl groups.

Since the polyamide-imide resin of the present invention includes the above-described organopolysiloxane structure, the flexibility of the resulting polyamide-imide resin is improved, the drying property of the prepreg is increased, and the low volatile differentiation of the prepreg is facilitated. Further, the prepreg and the metal foil-clad laminate are reduced in elastic modulus. The main chain of the polyamide-imide resin of the present invention includes an alkylene group and / or an oxyalkylene group in addition to the above-described organopolysiloxane structure. That is, the main chain has any one of the following structures (I) to (III).
(I) an organopolysiloxane structure and an alkylene group,
(II) an organopolysiloxane structure and an oxyalkylene group,
(III) Organopolysiloxane structure, alkylene group and oxyalkylene group.

  Here, the alkylene group is preferably a linear or branched alkylene group, the alkylene group preferably has 1 to 12 carbon atoms, and the oxyalkylene group has preferably 1 to 6 carbon atoms, Furthermore, it is more preferable that it is 2-4. Two or more oxyalkylene groups may be repeated to form a polyoxyalkylene structure.

  The main chain of the polyamideimide resin is particularly preferably the above (III), and in this case, the alkylene group and the oxyalkylene group particularly preferably have a structure represented by the following general formulas (4a) to (4e). preferable.

（式中、ａは２〜７０の整数を示す。）

(Wherein, a represents an integer of 2 to 70)

（式中、ｂ、ｃ及びｄは１以上の整数を示し、ｂ＋ｃ＋ｄは５〜４０が好ましい。）

(In the formula, b, c and d represent an integer of 1 or more, and b + c + d is preferably 5 to 40.)

（式中、ｅは１〜３の整数を示す。）

(In the formula, e represents an integer of 1 to 3.)

  The polyamideimide resin of the present invention is preferably produced by reacting dicarboxylic acid with diisocyanate. The dicarboxylic acid includes diimide dicarboxylic acid and aromatic dicarboxylic acid, and the diimide dicarboxylic acid includes at least a diamine having an organopolysiloxane structure and a diamine having an alkylene group and / or an oxyalkylene group. It is preferable that the amine mixture containing it is made to react with trimellitic anhydride.

  In the present invention, (1) an amine mixture of a diamine containing an organopolysiloxane structure (hereinafter referred to as “siloxane diamine”) and a diamine containing an alkylene group and / or an oxyalkylene group is reacted with trimellitic anhydride. A step of obtaining diimide dicarboxylic acid (hereinafter referred to as “diimide dicarboxylic acid production step”), (2) a carboxylic acid mixture containing dicarboxylic acid containing diimide dicarboxylic acid and aromatic dicarboxylic acid as essential components, and diisocyanate. And the step of reacting with each other (hereinafter referred to as “polyamideimide production step”).

  Examples of the siloxane diamine used in the present invention include the following general formulas (3) to (6).

  In addition, as siloxane diamine represented by the said General formula (3), X-22-161AS (amine equivalent 450), X-22-161A (amine equivalent 900), X-22-161B (amine equivalent 1500), (The above is a trade name manufactured by Shin-Etsu Chemical Co., Ltd.), BY16-853 (amine equivalent 650), BY16-853B (amine equivalent 2200), (above, product name manufactured by Toray Dow Corning Silicone Co., Ltd.) and the like. 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, trade name manufactured by Shin-Etsu Chemical Co., Ltd.). Etc. can be exemplified. Examples of the siloxane diamine include reactive silicon oil KF8010 (trade name, manufactured by Shin-Etsu Chemical Co., Ltd., amine equivalent 430).

  Examples of the diamine containing an alkylene group and / or oxyalkylene group used in the present invention include low-molecular diamines such as hexamethylene diamine, nonamethylene diamine, and diaminodiethyl ether, both-end aminated polyethylene, and both-end aminated polypropylene. Examples thereof include both terminal aminated oligomers and both terminal aminated polymers. As the diamine containing an alkylene group, the alkylene group preferably has 4 or more carbon atoms, more preferably 6 to 18 carbon atoms. In the present invention, it is particularly preferable to use a diamine having an alkylene group and an oxyalkylene group. Examples of the diamine include diamines of the following general formulas (6a) to (6e).

（式中、ａは２〜７０の整数を示す。）

(Wherein, a represents an integer of 2 to 70)

（式中、ｂ、ｃ及びｄは１以上の整数を示し、ｂ＋ｃ＋ｄは５〜４０が好ましい。）

(In the formula, b, c and d represent an integer of 1 or more, and b + c + d is preferably 5 to 40.)

（式中、ｅは１〜３の整数を示す。）

(In the formula, e represents an integer of 1 to 3.)

  The diamines represented by the general formulas (6a), (6b), (6c), and (6e) are Sun Techno Chemical as Jeffamine D series, Jeffamine ED series, Jeffamine XTJ-511, and Jeffamine XTJ-512. Supplied by the company.

  The molecular weight of the diamine having an alkylene group and / or an oxyalkylene group is preferably 30 to 20000, more preferably 50 to 5000, and particularly preferably 100 to 3000. By using a diamine having an alkylene group and an oxyalkylene group having a molecular weight within the above range, it effectively reduces the occurrence of wrinkles and warpage after drying when impregnating the obtained fiber base material. Is possible. Among these, a commercially available product, Jeffamine (manufactured by San Techno Chemical Co., Ltd.) is particularly preferable because it has an appropriate molecular weight and is excellent in the elastic modulus and dielectric constant of the resulting polyamideimide resin.

  Examples of the diamine containing an alkylene group and / or oxyalkylene group used in the present invention include aliphatic diamines. Examples of the aliphatic diamines include hexamethylene diamine, octamethylene diamine, decamethylene diamine, dodecamethylene diamine, and octadeca diamine. Examples include linear aliphatic diamines such as methylene diamine and terminal aminated polypropylene glycol. The aliphatic diamine preferably contains an ether group from the viewpoint of achieving both low elastic modulus and high Tg, and terminal aminated polypropylene glycol is preferred. As the terminal aminated polypropylene glycol, Jeffamine D-230, D-400, D-2000, and D-4000 (trade names, manufactured by Sun Techno Chemical Co., Ltd.) having different molecular weights are available.

  In addition, in order to synthesize the polyamide-imide resin of the present invention, an aromatic diamine can be added as appropriate. 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 (trifluoro) Til) 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) diphenyl sulfone, (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 can be exemplified.

  In the step of producing diimidedicarboxylic acid from the amine mixture and trimellitic anhydride, an aprotic polar solvent is preferably used as the solvent. Examples of the aprotic polar solvent include dimethylacetamide, dimethylformamide, dimethylsulfoxide, N-methyl-2-pyrrolidone, 4-butyrolactone, sulfolane and the like. Among these, since the diimide dicarboxylic acid production step requires a high reaction temperature, it is particularly preferable to use N-methyl-2-pyrrolidone having a high boiling point and good solubility of the raw material and the resulting polymer.

  The combined weight of the amine mixture and trimellitic anhydride is preferably an amount corresponding to 10 to 70% by weight based on the weight of the solvent. If the amount is less than 10% by weight, a large amount of solvent is consumed, so the efficiency is poor. If the amount exceeds 70% by weight, the amine mixture and trimellitic anhydride cannot be completely dissolved, and it is difficult to perform a sufficient reaction. There is.

  The trimellitic anhydride is preferably used in a molar amount of 1.80 to 2.20 times the total number of moles of the amine mixture. By using 1.80 to 2.20 times the molar amount of trimellitic acid in the amine mixture, a reaction product (diimide dicarboxylic acid) having both carboxyl groups more reliably converted to a carboxyl group can be obtained in high yield. As a result, since the reactive site with diisocyanate can be increased, it is easy to obtain a high molecular weight polyamideimide resin, and the mechanical strength of the resulting polyamideimide resin can be further improved.

  The reaction temperature in the reaction between the amine mixture and trimellitic anhydride is preferably 50 to 150 ° C, and more preferably 50 to 90 ° C. At a temperature lower than 50 ° C, the reaction tends to be slow and industrially disadvantageous. At a temperature higher than 150 ° C, the reaction with a carboxyl group that does not cyclize proceeds and the reaction that forms an imide bond is inhibited. There is a tendency to.

  In the diimide dicarboxylic acid production step, the reaction of the amine mixture and trimellitic anhydride is considered to cause the anhydrous portion of trimellitic anhydride to once ring-open and then dehydrate and ring to form an imide bond. The reaction is preferably carried out at the end of the diimide dicarboxylic acid production step by adding an aromatic hydrocarbon azeotropic with water to the resulting reaction mixture and raising the temperature. By adding an aromatic hydrocarbon azeotropic with water to the reaction mixture, water generated by the dehydration ring-closing reaction can be efficiently removed. The dehydration cyclization reaction is preferably carried out until no water is generated. Completion of the dehydration ring-closing reaction can be carried out, for example, by confirming that a theoretical amount of water has been distilled off with a moisture determination receiver or the like.

  Examples of aromatic hydrocarbons that can be azeotroped with water include benzene, xylene, ethylbenzene, toluene, and the like. In particular, it is preferable to use toluene which has a low boiling point and is easy to be distilled off and has relatively low toxicity.

  The aromatic hydrocarbon that can be azeotroped with water is preferably added in an amount corresponding to 10 to 50% by weight based on the weight of the aprotic polar solvent. If the amount of aromatic hydrocarbon azeotropic with water is less than 10% by weight relative to the amount of aprotic polar solvent, the water removal effect tends to decrease, and if it exceeds 50% by weight, the product There is a tendency for certain diimide dicarboxylic acids to precipitate. The dehydration ring closure reaction is preferably performed at a reaction temperature of 120 to 180 ° C. If the temperature is lower than 120 ° C, water may not be sufficiently removed, and if the temperature is higher than 180 ° C, dissipation of aromatic hydrocarbons may not be prevented.

  Furthermore, it is preferable to remove the aromatic hydrocarbon azeotropic with water before the polyamide-imide resin production step. In the state containing aromatic hydrocarbons, the product polyamideimide resin may precipitate during the reaction. The method for removing the aromatic hydrocarbon is not particularly limited. For example, there is a method in which the aromatic hydrocarbon is distilled off by further raising the temperature after the dehydration ring-closing reaction.

  Examples of the aromatic dicarboxylic acid used in the polyamideimide resin production step include terephthalic acid, isophthalic acid, (4,4′-dicarboxy) diphenyl ether, (4,4′-dicarboxy) diphenyl sulfone, (4,4 '-Dicarboxy) benzophenone, (3,3'-dicarboxy) benzophenone, 1,4-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid and the like can be mentioned, and phthalic acid, particularly terephthalic acid is preferably used. The carboxylic acid mixture may further contain an aliphatic dicarboxylic acid such as adipic acid or hexamethylene dicarboxylic acid.

Examples of the diisocyanate include 4,4′-diphenylmethane diisocyanate (hereinafter referred to as MDI), 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, naphthalene-1,5-diisocyanate, and o-xylylene diisocyanate. ,
Aromatic diisocyanates such as m-xylylene diisocyanate and 2,4-tolylene dimer, aliphatic diisocyanates such as hexamethylene diisocyanate, 4,4-methylenebis (cyclohexyl isocyanate) and isophorone diisocyanate can be used. In the method for producing a polyamide-imide resin according to the present invention, it is more preferable to use an aromatic diisocyanate because the heat resistance of the resulting polyamide-imide resin is further improved.

  The diisocyanate is preferably used in a molar amount of 0.9 to 1.3 times the total number of moles of diimide dicarboxylic acid and other dicarboxylic acids. By using a diisocyanate within the above range, the obtained polyamide-imide resin has a higher molecular weight, and the elasticity and mechanical strength of the polyamide-imide resin are more excellent.

  In the polyamideimide resin production step, it is preferable to carry out the reaction by adding a basic catalyst. In the presence of a basic catalyst, the reaction can be carried out at a reaction temperature at which the side reaction proceeds less than when no catalyst is added, and the side reaction is suppressed from proceeding. Can be obtained.

  Basic catalysts include amines such as trimethylamine, triethylamine, tripropylamine, tri (2-ethylhexyl) amine, trioctylamine, pyridine, 3,5-dimethylpyridine, 2,6-dimethylpyridine, 2,6- Pyridines such as dibutylpyridine and 2,6-tri (2-ethylhexyl) pyridine, or basic catalysts such as pyrazine can be used. In particular, it is preferable to use triethylamine which has a low boiling point and can be easily removed after the reaction.

  It is preferable that the basic catalyst is added in the number of moles corresponding to a molar ratio of 0.1 to 0.3 times the total number of moles of the amine mixture as a raw material. The reaction temperature in the step of producing the polyamideimide resin is preferably 70 to 190 ° C. when a basic catalyst is added. If it is less than 70 ° C, the reaction time tends to be long, and if it exceeds 190 ° C, reaction between diisocyanates occurs, the reaction efficiency is lowered, and the elasticity, dielectric constant and mechanical strength of the resulting polyamideimide resin tend to be lowered. is there.

  Examples of the thermosetting resin used in the present invention include epoxy resins, polyimide resins, unsaturated polyester resins, polyurethane resins, bismaleimide resins, triazine-bismaleimide resins, phenol resins, and the like. It is preferable to use 1 to 200 parts by weight of a thermosetting 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 polyamide-imide resin to improve thermal, mechanical, and electrical characteristics. Therefore, an epoxy resin having two or more glycidyl groups and a curing agent thereof, an epoxy resin having two or more glycidyl groups and its curing accelerator, or an epoxy resin having two or more glycidyl groups and a curing agent, curing acceleration It is more preferable to use an agent. 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.

  In the present invention, it is preferable to use 1 to 200 parts by weight of a thermosetting resin with respect to 100 parts by weight of the polyamideimide resin. However, if it is less than 1 part by weight, the solvent resistance is inferior. The curable resin is not preferable because Tg is lowered and heat resistance becomes insufficient or flexibility is lowered. Therefore, 3-100 weight part of thermosetting resins are more preferable with respect to 100 weight part of polyamideimide resin, and 10-60 weight part is especially more preferable.

  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 polyamideimide resin.

  In the present invention, a prepreg can be prepared by impregnating and drying a varnish obtained by mixing, dissolving and dispersing a 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.

  The resin composition for obtaining the prepreg is preferably a resin composition containing 100 parts by weight of a polyamideimide resin and 1 to 200 parts by weight of a thermosetting resin, whereby the volatilization rate of the varnish solvent is fast and the thermosetting It is possible to reduce the residual solvent content 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 resin, and to obtain a metal foil-clad laminate having good adhesion to the fiber base material and copper foil Can do.

  In the present invention, a fiber base material is impregnated with a varnish of a resin composition and dried 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 circuit board as a fiber 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 a fiber base material used for a prepreg, it is preferable that thickness is 5-100 micrometers, and 5-50 micrometers is more preferable. A glass cloth having a thickness of 5 to 100 μm is particularly preferably used. By using a glass cloth having a thickness of 5 to 100 μm, it is possible to obtain a printed circuit board that can be bent arbitrarily, and it is possible to reduce dimensional changes associated with temperature, moisture absorption, and the like in the manufacturing process.

  The production conditions of the prepreg are not particularly limited, but it is preferable that the solvent used for the varnish of the resin composition 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 30-80 weight% of varnish resin solid content with respect to the total amount of varnish resin solid content and a fiber base material.

  The manufacturing method of an insulating board, a laminated board, or a metal foil tension 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 foil-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 as a metal foil-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. A metal foil of 5 to 200 μm which is usually used for a laminate can be used, but 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.

Examples are described below, but the present invention is not limited to these examples.
(Synthesis Example 1)
Reactive silicone oil KF8010 (trade name, amine, manufactured by Shin-Etsu Chemical Co., Ltd.) as a siloxane diamine 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 Equivalent 430) 34.4 g (0.04 mol), Jeffamine XDJ542 (trade name, amine equivalent 1000, manufactured by Sun Techno Chemical Co., Ltd.) as a diamine containing an alkylene group and an oxyalkylene group, TMA (anhydrous trioxide) Mellitic acid) 20.17 g (0.105 mol) and 282 g of NMP (N-methyl-2-pyrrolidone) 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 1.8 ml or more of water has accumulated in the moisture determination receiver and that no water has been 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.), 8.31 g (0.05 mol) of isophthalic acid, 8.31 g (0.05 mol) of terephthalic acid, and MDI (4,4′-diphenylmethane diisocyanate) as an aromatic diisocyanate. 3 g (0.165 mol) and 1.52 g of triethylamine as a basic catalyst were added and reacted at 130 ° C. for 4 hours. After completion of the reaction, an NMP solution of polyamideimide resin was obtained.

(Synthesis Example 2)
Reactive silicone oil KF8010 (trade name, amine, manufactured by Shin-Etsu Chemical Co., Ltd.) as a siloxane diamine 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 Equivalent 430) 68.8 g (0.08 mol), Jeffamine XDJ542 (trade name, amine equivalent 1000, manufactured by Sun Techno Chemical Co., Ltd.) as a diamine containing an alkylene group and an oxyalkylene group, TMA (anhydrous trioxide) Mellitic acid) 40.34 g (0.21 mol) and NMP (N-methyl-2-pyrrolidone) 527 g 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 3.6 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.), 8.31 g (0.05 mol) of isophthalic acid, 8.31 g (0.05 mol) of terephthalic acid, and MDI (4,4′-diphenylmethane diisocyanate) as an aromatic diisocyanate. 07 g (0.24 mol) and 2.42 g of triethylamine as a basic catalyst were added and reacted at 130 ° C. for 4 hours. After completion of the reaction, an NMP solution of polyamideimide resin was obtained.

(Synthesis Example 3)
Reactive silicon oil X-22-161A (manufactured by Shin-Etsu Chemical Co., Ltd.) as a siloxane diamine 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 Product name, amine equivalent 900), 72.0 g (0.04 mol), Jeffamine XD542 as a diamine containing an alkylene group and an oxyalkylene group (trade name, amine equivalent 1000, manufactured by Sun Techno Chemical Co.) 20.0 g (0.01 mol) , TMA (trimellitic anhydride) 20.17 g (0.105 mol) and 362 g of NMP (N-methyl-2-pyrrolidone) 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 1.8 ml or more of water has accumulated in the moisture determination receiver and that no water has been 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.), 8.31 g (0.05 mol) of isophthalic acid, 8.31 g (0.05 mol) of terephthalic acid, and MDI (4,4′-diphenylmethane diisocyanate) as an aromatic diisocyanate. 3 g (0.165 mol) and 1.52 g of triethylamine as a basic catalyst were added and reacted at 130 ° C. for 4 hours. After completion of the reaction, an NMP solution of polyamideimide resin was obtained.

(Comparative Synthesis Example 1)
Reactive silicone oil KF8010 (trade name, amine, manufactured by Shin-Etsu Chemical Co., Ltd.) as a siloxane diamine 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 Equivalent 430) 86.0 g (0.10 mol), TMA (trimellitic anhydride) 40.34 g (0.21 mol), and NMP (N-methyl-2-pyrrolidone) 432 g as an aprotic polar solvent were charged 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 3.6 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.), 8.31 g (0.05 mol) of isophthalic acid, 8.31 g (0.05 mol) of terephthalic acid, and MDI (4,4′-diphenylmethane diisocyanate) as an aromatic diisocyanate. 07 g (0.24 mol) and 2.42 g of triethylamine as a basic catalyst were added and reacted at 130 ° C. for 4 hours. After completion of the reaction, an NMP solution of polyamideimide resin having no alkylene group or oxyalkylene group was obtained.

(Comparative Synthesis Example 2)
Reactive silicone oil KF8010 (trade name, amine, manufactured by Shin-Etsu Chemical Co., Ltd.) as a siloxane diamine 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 Equivalent 430) 51.6 g (0.06 mol), BAPP (2,2-bis [4- (4-aminophenoxy) phenyl] propane) 57.47 g (0.14 mol), TMA (trimellitic anhydride) 80. 68 g (0.42 mol) and 583 g of NMP (N-methyl-2-pyrrolidone) 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 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. Thereafter, the solution was returned to room temperature (25 ° C.), 60.07 g (0.24 mol) of MDI (4,4′-diphenylmethane diisocyanate) as aromatic diisocyanate and 2.42 g of triethylamine as basic catalyst were added at 130 ° C. The reaction was performed for 4 hours. After completion of the reaction, an NMP solution of polyamideimide resin having no alkylene group or oxyalkylene group was obtained.

(Example 1)
250.0 g of NMP solution of polyamideimide resin of Synthesis Example 1 (resin solid content 32 wt%) and NC3000H (epoxy resin, Nippon Kayaku Co., Ltd. trade name) 40.0 g (resin solid content 50 wt%) as thermosetting resin % Dimethylacetamide solution) and 0.2 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 (25 ° C.) for 24 hours for defoaming. Thus, a resin composition varnish was obtained.

(Example 2)
A resin composition varnish was produced in the same manner as in Example 1 except that the polyamideimide resin of Synthesis Example 2 was used instead of the polyamideimide resin of Synthesis Example 1.

(Example 3)
A resin composition varnish was produced in the same manner as in Example 1 except that the polyamideimide resin of Synthesis Example 3 was used instead of the polyamideimide resin of Synthesis Example 1.

(Comparative Example 1)
A resin composition varnish was produced in the same manner as in Example 1 except that the polyamideimide resin of Comparative Synthesis Example 1 was used instead of the polyamideimide resin of Synthesis Example 1.

(Comparative Example 2)
A resin composition varnish was produced in the same manner as in Example 1 except that the polyamideimide resin of Comparative Synthesis Example 2 was used instead of the polyamideimide resin of Synthesis Example 1.

  The resin composition varnishes produced in Examples 1 to 3 and Comparative Examples 1 and 2 were impregnated in a glass cloth having a thickness of 0.028 mm (trade name: 1037 manufactured by Asahi Sebel Co., Ltd.), then heated at 150 ° C. for 15 minutes and dried. Thus, a prepreg having a resin content of 70% by weight was obtained.

  An electrolytic copper foil (trade name: F2-WS-12, manufactured by Furukawa Electric Co., Ltd.) having a thickness of 12 μm is stacked on both sides of this prepreg so that the adhesive surface is aligned with the prepreg, and 230 ° C., 90 minutes, 4.0 MPa pressing conditions A double-sided copper-clad laminate was prepared. The evaluation shown below was performed using the produced double-sided copper-clad laminate. Moreover, the external appearance of the produced prepreg was evaluated. The results are shown in Table 1.

(Evaluation item)
(1) The copper foil peeling strength of the obtained double-sided copper-clad laminate was measured.
(2) As solder heat resistance, it was immersed in a solder bath at 260 ° C., 288 ° C. and 300 ° C., and the time until occurrence of abnormalities such as blistering and peeling was measured.
(3) The flexibility (foldability) of the double-sided copper clad laminate from which the copper foil was removed by etching was evaluated. ○: No break, ×: Break
(4) As moisture resistance, the copper foil on one side is removed by etching, subjected to moisture absorption treatment at 121 ° C. saturation condition for 1 hour, and then immersed in a solder bath at 260 ° C. for 20 seconds to check for abnormalities such as swelling and peeling. Observed. ○: No abnormality, ×: Abnormal.
(5) The elastic modulus at 250 ° C. of the resin composition used in each prepreg was measured. The resin compositions obtained in Examples 1 to 3 and Comparative Examples 1 and 2 were applied to a release PET (polyethylene terephthalate) film so that the thickness after drying was about 80 μm, and the circulation temperature was 130 ° C. for 15 minutes. After drying in an air dryer, it was peeled off from the PET film and further heat treated at 230 ° C. for 60 minutes to prepare a sample. The sample was measured by a dynamic viscoelasticity measuring device (DVE, manufactured by Rheology Co., Ltd.) from room temperature to 350 ° C. under the condition of 5 ° C./min, and the elastic modulus of the resin was measured.

  The copper foil peel strength was 1.0 to 1.2 kN / m in any combination with the prepregs of Examples 1 to 3. Moreover, as a result of immersing in a solder bath of 260 ° C., 288 ° C., and 300 ° C. and measuring the solder heat resistance, no abnormality such as blistering or peeling was observed at any temperature for 5 minutes or more. In Examples 1 to 3, the elastic modulus was small and was 15 to 30 MPa. Therefore, it was rich in flexibility and could be bent arbitrarily. As the moisture resistance, no abnormality such as swelling or peeling was observed. The prepreg also did not wrinkle after drying.

On the other hand, both Comparative Examples 1 and 2 have a large elastic modulus, 100 and 500 MPa, and the flexibility is insufficient. In Comparative Example 2, the base material breaks when bent, and in Comparative Example 1, resin and glass cloth are used. Cracked. In terms of moisture resistance, in Comparative Examples 1 and 2, swelling occurred between the copper foil and the base material. In addition, each prepreg was wrinkled in the coating direction after drying.

Claims (7)

  In a prepreg formed by impregnating a fiber base material with a resin composition containing a polyamideimide resin, the polyamideimide resin has an imide bond and an amide bond derived from trimellitic acid and an amide bond derived from an aromatic divalent carboxylic acid. A prepreg characterized by being a polyamide-imide resin, wherein the main chain of the polyamide-imide resin is a polyamide-imide resin having at least an organopolysiloxane structure and an alkylene group and / or an oxyalkylene group.   The prepreg according to claim 1, wherein the resin composition containing a polyamideimide resin is a resin composition containing a thermosetting resin.   The prepreg according to claim 1 or 2, wherein the fiber base material is a glass cloth having a thickness of 5 to 100 µm.   The prepreg according to claim 1 or 3, wherein the polyamideimide resin is a polyamideimide resin obtained by reacting a mixture containing diimide dicarboxylic acid and aromatic divalent carboxylic acid with a diisocyanate compound.   The thermosetting resin is an epoxy resin having two or more glycidyl groups, and the resin composition is a resin composition containing a curing accelerator or a curing agent for the epoxy resin. The prepreg according to crab.   A metal foil-clad laminate obtained by stacking a predetermined number of the prepregs according to any one of claims 1 to 5, placing a metal foil on one side or both sides thereof, and heating and pressing. A printed circuit board obtained by forming a circuit on the metal foil-clad laminate according to claim 6.