JP2005307148A - Prepreg and metal foil-adhered lamination plate and printed circuit board using it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a copper-adhered lamination plate and a printed-circuit board each of which has a high moist heat resistance even when a thin fiber substrate is used and to provide a prepreg for obtaining them. <P>SOLUTION: A prepreg 100 has a fiber substrate and a resin composition which is impregnated in the substrate. The resin composition contains (a) a polyamideimide resin, (b) a thermosetting resin and (c) a phenolic antioxidant or a sulfuric antioxidant. <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.

  A printed circuit board is usually composed of an insulating substrate and a printed circuit provided on one or both sides of the substrate. As the substrate, for example, a laminate (printed wiring board laminate) obtained by stacking a predetermined number of prepregs impregnated with an electrically insulating resin as a matrix on a fiber base material, and heating and pressurizing them is used. . In the case where a printed circuit board is obtained by forming a printed circuit (printed circuit) by a subtractive method, a metal-clad laminate in which metal foil is laminated on one side or both sides of a substrate made of the above-described laminate plate is used. This metal-clad laminate is produced, for example, by stacking a metal foil such as a copper foil on the surface (one side or both sides) of a prepreg and heating and pressing it. 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 fluororesin or a polyphenylene ether resin may be used.

  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 proceeds from a pin insertion type to a surface mounting type, and further to an area array type represented by a BGA (ball grid array) using a substrate such as a plastic substrate made of a laminate as described above. It is out. When a bare chip is directly mounted on a substrate like a BGA, the connection between the bare chip and the substrate is generally performed by wire bonding by thermosonic bonding. For this reason, the board | substrate which mounts a bare chip will be exposed to 150 degreeC or more high temperature, and a certain amount of heat resistance is requested | required of the electrically insulating resin used for a board | substrate.

  By the way, from the viewpoint of environmental problems, lead-free solder has been developed. However, when mounting using lead-free solder, the substrate is required to have higher heat resistance because its melting temperature is high. Moreover, the request | requirement which makes the material of a board | substrate halogen-free is also increasing, and use of a brominated flame retardant has become difficult.

  In addition, the printed circuit board may require so-called repairability to remove the chip once mounted, but in order to remove the chip, the same level of heat is applied as when the chip is mounted, and the chip is mounted again. Heat will also be applied. Therefore, printed circuit boards that require repairability are also required to have durability (thermal shock resistance) against periodic thermal shock at high temperatures. If the thermal shock resistance is insufficient, peeling or the like tends to occur between the fiber base material and the resin when repaired.

  Thus, for example, a prepreg in which a fiber base material is impregnated with a resin composition containing a polyamideimide resin having excellent thermal shock resistance and the like as an essential component and a substrate obtained using the prepreg have been proposed (for example, see Patent Document 1). ).

On the other hand, as the density of wiring tends to increase, there is a tendency for insulation to deteriorate due to metal migration, which makes it difficult to achieve a satisfactory level of so-called electric corrosion resistance in printed circuit boards. Yes. For the purpose of improving the electric corrosion resistance, for example, a prepreg using an epoxy resin composition to which an antioxidant is added has been proposed (for example, see Patent Document 2).
JP 2003-55486 A Japanese Patent Laid-Open No. 3-43413

  A conventional substrate made of a laminate as described above is said to be a so-called rigid substrate, which is excellent in terms of thermal shock resistance, dimensional stability, etc., but has low flexibility. Along with the downsizing and high performance of electronic equipment, it is necessary to mount a printed circuit board on which many components are mounted in a limited space inside the housing. In the case of a printed circuit board on which a rigid substrate is used as a substrate and a large number of components are mounted, it is difficult to mount the printed circuit board inside a housing of a miniaturized electronic device.

  In order to mount printed circuit boards at high density in the case, for example, a method in which a plurality of printed circuit boards using a rigid substrate as a substrate is arranged in multiple stages and connected to each other via a wire harness or the like is used. There is. In addition, a rigid printed circuit board that is a printed circuit board using a flexible substrate made of polyimide as a substrate, a flexible printed circuit board (printed circuit board formed with a circuit on a flexible printed wiring board), and a conventional rigid substrate. In some cases, a rigid-flex printed circuit board that is connected to a printed circuit board (a printed circuit board formed with a circuit on a rigid printed wiring board) to be multilayered is used. However, in the case of such a printed circuit board configured by connecting a plurality of separate printed circuit boards to each other, the moisture and heat resistance is not always sufficient due to an adhesive layer or the like existing in the connection portion.

  Therefore, in a substrate made of a laminated plate, for example, it is considered possible to increase its flexibility while maintaining moisture and heat resistance by thinning the fiber base material. However, in the case of a substrate obtained by using a conventional prepreg, it has been clarified as a result of studies by the present inventors that the moisture and heat resistance tends to decrease when the thickness of the fiber base material is reduced. When the heat and humidity resistance is reduced, for example, a conductive breakdown of the printed circuit board is likely to occur in a high temperature and high humidity environment.

  The present invention has been made in view of the above circumstances, and provides a copper-clad laminate and a printed circuit board having high moisture and heat resistance even when a thin fiber substrate is used, and a prepreg for obtaining the same. The purpose is to do.

  In order to solve the above-mentioned problems, the present inventors have intensively studied, and the moisture resistance of the copper-clad laminate and the printed circuit board obtained by using a combination of specific components as the resin composition impregnated in the prepreg. The present inventors have found that the thermal properties are remarkably improved and have completed the present invention.

  That is, the present invention comprises a fiber substrate and a resin composition impregnated therein, wherein the resin composition comprises (a) a polyamideimide resin, (b) a thermosetting resin, and (c) a phenolic resin. A prepreg comprising an antioxidant or a sulfur-based antioxidant.

  According to the prepreg of the present invention, by adding the specific antioxidant to the resin composition containing a polyamide-imide resin and a thermosetting resin, even when a thin fiber substrate is used, A copper-clad laminate and a printed circuit board having high moisture and heat resistance can be obtained. Although the mechanism of the effect of improving heat and humidity resistance is not always clear, the presence of phenolic antioxidants or sulfur-based antioxidants in the system makes it difficult for metal migration to occur. The present inventors speculate that is expressed. In particular, a combination of a polyamide-imide resin and a thermosetting resin with a phenol-based antioxidant or a sulfur-based antioxidant exhibits synergistically high moisture and heat resistance.

  The thickness of the fiber base material is preferably 5 to 100 μm. By using such a specific thin fiber substrate, a printed circuit board having greater flexibility can be obtained.

  Moreover, it is preferable that the fiber base material is a glass cloth because the handleability of the prepreg and the insulating property of the obtained printed circuit board are excellent.

  The phenolic antioxidant is also referred to as a hindered phenolic antioxidant. This phenolic antioxidant includes 2-t-butyl-4-methoxyphenol, 3-t-butyl-4-methoxyphenol, 2,6-di-t-butyl-4-ethylphenol, 2,2′- Methylene-bis (4-methyl-6-tert-butylphenol), 4,4′-thiobis- (3-methyl-6-tert-butylphenol), 4,4′-butylidenebis (3-methyl-6-tert-butylphenol) ), 1,1,3-tris (2-methyl-4-hydroxy-5-tert-butylphenyl) butane, 1,3,5-trimethyl-2,4,6-tris (3,5-di-t) A small amount selected from the group consisting of -butyl-4-hydroxybenzyl) benzene and tetrakis- [methylene-3- (3 ′, 5′-di-t-butyl-4′-hydroxyphenyl) propionate] methane. Both are preferably made of one compound. Of these, a mixture comprising 2-t-butyl-4-methoxyphenol and 3-t-butyl-4-methoxyphenol is generally referred to as butylated hydroxyanisole and used as an antioxidant.

  The sulfur-based antioxidant is also referred to as a sulfur organic compound-based antioxidant. The sulfur-based antioxidant is preferably composed of at least one of dilauryl 3,3'-thiodipropionate and distearyl 3,3'-thiodipropionate. Dilauryl 3,3′-thiodipropionate is sometimes referred to as dilauryl thiodipropionate, and distearyl 3,3′-thiodipropionate is referred to as distearyl thiodipropionate. There is also.

  The component (a) is preferably a polyamideimide resin (siloxane-modified polyamideimide resin) having a divalent group consisting of a polysiloxane chain in order to particularly increase the flexibility of the printed circuit board to be obtained.

  The component (a) is obtained by reacting trimellitic anhydride with a diamine mixture containing an aromatic diamine and a siloxane diamine represented by the following general formula (1a) or (1b) to obtain an imide group-containing dicarboxylic acid. It is preferable that it is a polyamide imide resin obtained by a manufacturing method provided with a 1st reaction process and the 2nd reaction process which makes diisocyanate react with the obtained imide group containing dicarboxylic acid.

[In the formulas (1a) and (1b), X ¹ 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 oxy group, a carbonyl group, A bond or a divalent group represented by the following general formula (11a) or (11b), wherein X ² is an aliphatic hydrocarbon group having 1 to 3 carbon atoms or a halogenated aliphatic hydrocarbon having 1 to 3 carbon atoms A group, a sulfonyl group, an oxy group or a carbonyl group, and R ¹ , R ² and R ³ each independently represents a hydrogen atom, a hydroxyl group, a methoxy group, a methyl group or a halogenated methyl group.

  However, Z shows a C1-C3 aliphatic hydrocarbon group, a C1-C3 halogenated aliphatic hydrocarbon group, a sulfonyl group, an oxy group, a carbonyl group, or a single bond. ]

  The component (a) is more preferably a polyamideimide resin having a structural unit represented by the following general formula (2). By using the polyamideimide resin having such a specific structure, it is possible to further increase the peel strength of the metal foil on the printed circuit board.

［式中、Ｘ^３及びＸ^４はそれぞれ独立に２価の有機基を示す。］

[Wherein, X ³ and X ⁴ each independently represent a divalent organic group. ]

  The component (b) is preferably an epoxy resin from the viewpoint that the solder heat resistance can be improved.

  The metal-clad laminate of the present invention comprises a substrate obtained by curing the resin composition by heating the prepreg of the present invention, and a metal foil provided on at least one surface of the substrate. It can be suitably used to obtain a printed circuit board. The printed circuit board of the present invention is obtained by forming a circuit on the metal-clad laminate of the present invention. These metal-clad laminates and printed circuit boards have high moisture and heat resistance even when a thin fiber base material is used by providing a cured product of the resin composition as a matrix of the substrate.

  According to the present invention, a copper-clad laminate and a printed circuit board having high moisture and heat resistance even when a thin fiber substrate is used, and a prepreg for obtaining the same are provided.

  FIG. 1 is a partial perspective view showing an embodiment of a prepreg according to the present invention. A prepreg 100 shown in FIG. 1 is a sheet-like prepreg composed of a fiber base material and a resin composition impregnated therein.

  The fiber base material in the prepreg 100 is a flexible fiber base material that can be bent arbitrarily. The thickness is preferably 5 to 100 μm. This increases the flexibility of the resulting printed circuit board and makes it particularly easy to bend it arbitrarily. In order to further increase the flexibility of the printed circuit board, the thickness is more preferably 5 to 50 μm, and further preferably 10 to 30 μm. Further, by using the fiber base material, it is possible to reduce a dimensional change accompanying heating, moisture absorption, and the like in the manufacturing process.

  The form of the fiber substrate is not particularly limited as long as it is used when producing a metal-clad laminate or a multilayer printed circuit board, but a fiber substrate such as a woven fabric or a nonwoven fabric is usually used. The fibers constituting the fiber substrate include glass, alumina, asbestos, boron, silica alumina glass, silica glass, tyrano, silicon carbide, silicon nitride, zirconia, and other inorganic fibers, aramid, polyether ether ketone, polyether imide , Organic fibers such as polyethersulfone, carbon and cellulose, or mixed papers thereof. Among these, glass fiber is preferable. In particular, glass cloth (glass fiber woven fabric) is preferably used as the fiber base material.

  The resin composition constituting the prepreg 100 contains (a) a polyamideimide resin, (b) a thermosetting resin, and a phenol-based antioxidant or a sulfur-based antioxidant.

  As the component (c), at least one of a phenol-based antioxidant and a sulfur-based antioxidant is used. In particular, it is more preferable to use a phenol-based antioxidant because it is possible to improve electrical insulation characteristics while suppressing deterioration of other characteristics such as drill workability.

  The component (c) is not particularly limited as long as it is generally used as a phenol-based antioxidant or a sulfur-based antioxidant, such as a hindered phenol compound or a thioether compound derived from propionic acid, It is preferable that the varnish has good solubility in a solvent and has low coating property (usually 180 ° C. or less) and low volatility (sublimation property). As such a thing, a bisphenol type phenolic antioxidant is mentioned, for example.

  Specifically, phenolic antioxidants include 2-t-butyl-4-methoxyphenol, 3-t-butyl-4-methoxyphenol, 2,6-di-t-butyl-4-ethylphenol, 2 , 2′-methylene-bis (4-methyl-6-tert-butylphenol), 4,4′-thiobis- (3-methyl-6-tert-butylphenol), 4,4′-butylidenebis (3-methyl-6) -T-butylphenol), 1,1,3-tris (2-methyl-4-hydroxy-5-t-butylphenyl) butane, 1,3,5-trimethyl-2,4,6-tris (3,5 -Di-t-butyl-4-hydroxybenzyl) benzene and tetrakis- [methylene-3- (3 ', 5'-di-t-butyl-4'-hydroxyphenyl) propionate] methane selected from the group That is preferably made of at least one compound.

  On the other hand, the sulfur-based antioxidant is preferably composed of at least one compound of dilauryl 3,3'-thiodipropionate and distearyl 3,3'-thiodipropionate.

  (C) As an antioxidant of a component, the compound quoted above may be used independently and several types may be used together. Moreover, it is preferable that content of (c) component is 0.1-20 weight part with respect to 100 weight part of thermosetting resin of (b) component. When this content is less than 0.1 parts by weight, the insulating properties tend to be lowered, and even when the content exceeds 20 parts by weight, the insulating properties tend to be lowered.

  The polyamideimide resin as component (a) is preferably a polyamideimide resin having a divalent group consisting of a polysiloxane chain. In other words, the component (a) is preferably a siloxane-modified polyamideimide resin.

  Further, the component (a) is a trimellit anhydride in a mixture containing the aromatic diamine represented by the general formula (1a) or (1b) (a diamine having two or more aromatic rings) and a siloxane diamine. A polyamide obtained by a production method comprising: a first reaction step of obtaining an imide group-containing dicarboxylic acid (diimide dicarboxylic acid) by reacting an acid; and a second reaction step of reacting the obtained imide group-containing dicarboxylic acid with a diisocyanate. It is more preferable that it is an imide resin. The polyamideimide resin obtained by such a production method is a siloxane-modified polyamideimide resin having a divalent group consisting of a polysiloxane chain.

  In the first reaction step, the ratio (molar ratio, a / b) between the amount a of aromatic diamine a and the amount b of siloxane diamine is preferably 99.9 / 0.1-0 / 100, It is more preferably 95/5 to 30/70, and still more preferably 90/10 to 40/60. When the mixing ratio of siloxane diamine increases, the Tg of the cured product tends to decrease, and when it decreases, the organic solvent (varnish solvent) used to prepare the varnish of the resin composition tends to remain in the prepreg. .

  Examples of the aromatic diamine include 2,2-bis [4- (4-aminophenoxy) phenyl] propane (BAPP), bis [4- (3-aminophenoxy) phenyl] sulfone, and bis [4- (4- Aminophenoxy) phenyl] sulfone, 2,2-bis [4- (4-aminophenoxy) phenyl] hexafluoropropane, bis [4- (4-aminophenoxy) phenyl] methane, 4,4′-bis (4- Aminophenoxy) biphenyl, bis [4- (4-aminophenoxy) phenyl] ether, bis [4- (4-aminophenoxy) phenyl] ketone, 1,3-bis (4-aminophenoxy) benzene, 1,4- Bis (4-aminophenoxy) benzene, 2,2′-dimethylbiphenyl-4,4′-diamine, 2,2′-bis (trifluoro) Methyl) biphenyl-4,4′-diamine, 2,6,2 ′, 6′-tetramethyl-4,4′-diamine, 5,5′-dimethyl-2,2′-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, Examples include (3,3′-diamino) benzophenone, (4,4′-diamino) diphenylmethane, (4,4′-diamino) diphenyl ether, (3,3′-diamino) diphenyl ether, and the like. As aromatic diamine, these can be used individually or in combination.

  The siloxane diamine is not particularly limited as long as it is a diamine compound having a polysiloxane chain, and examples thereof include those represented by the following general formula (3a), (3b), (3c) or (3d).

In the above formulas (3a) to (3d), n ₁ , n ₂ , n ₃ and n ₄ each independently represent a positive integer. n ₁ , n ₂ , n ₃ and n ₄ are each preferably 1 to 50.

  Examples of the siloxane diamine represented by the general formula (3a) include “X-22-161AS” (amine equivalent 450), “X-22-161A” (amine equivalent 840), “X-22-161B” (amine). Equivalent 1500) (above trade name, manufactured by Shin-Etsu Chemical Co., Ltd.), “BY16-853” (amine equivalent 650), “BY16-853B” (amine equivalent 2200) (above trade name, manufactured by Toray Dow Corning Silicone Co., Ltd.) Etc. are available as commercial products.

  Examples of the siloxane diamine represented by the general formula (3d) include “X-22-9409” (amine equivalent 700), “X-22-1660B-3” (amine equivalent 2200) (above trade names, Shin-Etsu Chemical Co., Ltd.). Etc.) are commercially available.

  The diamine mixture used in the first reaction step may contain an aliphatic diamine in addition to the above diamine. As the aliphatic diamine, for example, a compound represented by the following general formula (4) can be used for the synthesis of a polyamideimide resin. By using the aliphatic diamine, it is possible to reduce the elastic modulus of the cured product of the resin composition while maintaining a high glass transition temperature, and it becomes even easier to bend the printed circuit board. Moreover, it is also possible to adjust the elasticity modulus of hardened | cured material by increasing / decreasing the ratio of the aliphatic diamine to the whole amine mixture.

［式中、Ｘ^５はメチレン基、スルホニル基、オキシ基（エーテル基）、カルボニル基又は単結合を示し、Ｒ^４及びＲ^５はそれぞれ独立に水素原子、アルキル基又は置換基を有していてもよいフェニル基を示し、ｐは１〜５０の整数を示す。］

[Wherein, X ⁵ represents a methylene group, a sulfonyl group, an oxy group (ether group), a carbonyl group or a single bond, and R ⁴ and R ⁵ each independently have a hydrogen atom, an alkyl group or a substituent. And p represents an integer of 1 to 50. ]

As R < ⁴ > and R < ⁵ >, the phenyl group which may have a hydrogen atom, a C1-C3 alkyl group, or a substituent is preferable. Examples of the substituent for the phenyl group include an alkyl group having 1 to 3 carbon atoms and a halogen atom. In order to achieve both a low elastic modulus and a high Tg in the cured product, X ⁵ in the general formula (4) is preferably an oxy group. Commercially available products of aliphatic diamines in which X ⁵ is an oxy group include “Jeffamine D-400” (trade name, manufactured by Sun Techno Chemical Co., amine equivalent 400), “Jephamine D-2000” (trade name, Sun Techno Chemical). An amine equivalent 1000), etc. can be illustrated.

  As the diisocyanate used in the second reaction step, for example, a compound represented by the following general formula (5) can be used.

  As the diisocyanate represented by the general formula (5), an aliphatic diisocyanate or an aromatic diisocyanate can be used, but it is preferable to use an aromatic diisocyanate, and it is more preferable to use both in combination.

In the case of an aromatic diisocyanate, D in the general formula (5) is a divalent organic group having at least one aromatic ring. In particular, D is _{-C 6 H 4 -CH 2 -C 6} H 4 - a divalent group represented by tolylene group, is preferably selected from the group consisting of naphthylene group. More specifically, the aromatic diisocyanate includes 4,4′-diphenylmethane diisocyanate (MDI), 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, naphthalene-1,5-diisocyanate, 2,4. -Tolylene dimer etc. can be illustrated and it is especially preferable to use MDI. By using MDI as the aromatic diisocyanate, the flexibility of the cured product obtained from the resin composition containing the polyamideimide resin is improved, and the flexibility of the printed circuit board can be further increased.

  In the case of an aliphatic diisocyanate, D in the general formula (5) is a divalent aliphatic hydrocarbon group. In particular, D is preferably at least one group selected from the group consisting of a hexamethylene group, a 2,2,4-trimethylhexamethylene group and an isophorone group. That is, as the aliphatic diisocyanate, hexamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, isophorone diisocyanate and the like are preferable.

  When using together aromatic diisocyanate and aliphatic diisocyanate, it is preferable to add 5-10 mol% of aliphatic diisocyanate with respect to aromatic diisocyanate. Such combined use can further improve the heat resistance of the resulting polyamideimide resin.

  By using the raw materials as described above and adopting a production method including the first and second reaction steps, a polyamideimide resin that can be suitably used for the prepreg of the present invention is obtained. In addition, a 1st and 2nd reaction process can each be performed by conventionally well-known reaction conditions.

Moreover, it is preferable that the polyamide-imide resin of (a) component is a polyamide-imide resin which has a structural unit represented by the said General formula (2). In this case, the polyamideimide resin has a structural unit represented by the following general formula (6), for example. R ⁶ , R ⁷ , R ⁸ and R ⁹ in the following general formula (6) each independently represent a monovalent organic group. R ⁶ and R ⁷ , and R ⁸ and R ⁹ may be bonded to each other to form a cyclic structure. For example, R ⁶ and R ⁷ may be bonded to each other to form a benzene ring having a substituent. In addition, when the polyamidoimide resin of (a) component also has a bivalent group which consists of a polysiloxane chain in addition to the structural unit represented by the general formula (2), the polysiloxane chain is bonded to X ³ or X ⁴ doing.

  The polyamideimide resin having such a structural unit can be synthesized using, for example, an alicyclic diamine represented by the following chemical formula (7). For example, trimellitic anhydride is reacted with a diamine mixture containing an aromatic diamine represented by the general formula (1a) or (1b), a siloxane diamine, and an alicyclic diamine represented by the following chemical formula (7). A polyamideimide resin obtained by a production method comprising a first reaction step for obtaining an imide group-containing dicarboxylic acid and a second reaction step for reacting the obtained imide group-containing dicarboxylic acid with a diisocyanate is the above general formula (2 And a divalent group composed of a polysiloxane chain.

  As the alicyclic diamine (4,4′-diaminodicyclohexylmethane) represented by the chemical formula (7), for example, “Wandamine” (trade name, manufactured by Shin Nippon Rika Co., Ltd.) is available as a commercial product. is there.

  Examples of the thermosetting resin (b) include epoxy resins, polyimide resins, unsaturated polyester resins, polyurethane resins, bismaleimide resins, triazine-bismaleimide resins, and phenol resins. Among these, an epoxy resin which is a thermosetting resin having a functional group capable of reacting with an amide group in the polyamide-imide resin is preferable.

  The content of the component (b) is preferably 1 to 200 parts by weight, more preferably 3 to 100 parts by weight, and more preferably 10 to 60 parts by weight with respect to 100 parts by weight of the polyamideimide resin. Further preferred. When this content is less than 1 part by weight, the solvent resistance tends to be inferior, and when it exceeds 200 parts by weight, the Tg of the cured product is lowered by the unreacted thermosetting resin, and the heat resistance is lowered. Or the flexibility tends to decrease.

  Examples of the epoxy resin include polyglycidyl ether, polyglycidyl ester, polyglycidylamine (N-glycidyl derivative), and alicyclic epoxy resin. The polyglycidyl ether is obtained, for example, by reacting a polyhydric phenol such as bisphenol A, a novolac type phenol resin and an orthocresol novolac type phenol resin, or a polyhydric alcohol such as 1,4-butanediol, and epichlorohydrin, The polyglycidyl ester is obtained by reacting, for example, a polybasic acid such as phthalic acid or hexahydrophthalic acid with epichlorohydrin, and the N-glycidyl derivative is, for example, a compound having an amine, an amide or a heterocyclic nitrogen base. And epichlorohydrin.

  By using an epoxy resin as the thermosetting resin of the component (b), it can be cured at a temperature of 180 ° C. or less, and particularly excellent in thermal, mechanical and electrical properties by reacting with the amide group of the polyamide-imide resin. A printed circuit board can be obtained. The epoxy resin has two or more glycidyl groups, but more preferably has three or more. The suitable content of the epoxy resin varies depending on the number of glycidyl groups that the epoxy resin has. As the number of glycidyl groups possessed by the epoxy resin increases, the content thereof can be reduced.

  When an epoxy resin is used as the component (b), it is preferable to further contain an epoxy resin curing agent and / or curing accelerator in the resin composition. The epoxy resin curing agent and the curing accelerator are not particularly limited as long as they react with the epoxy resin or accelerate the curing of the epoxy resin. Moreover, you may use what has the function of both a hardening | curing agent and a hardening accelerator.

  As the curing agent, for example, amines, imidazoles, polyfunctional phenols, acid anhydrides and the like 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 novolak type phenol resin or resole which is a condensate with formaldehyde. Type phenol resins can be used, and as the acid anhydrides, phthalic anhydride, benzophenone tetracarboxylic dianhydride, methyl hymic acid and the like can be used. As the curing accelerator, alkyl group-substituted imidazole, benzimidazole and the like can be used as imidazoles.

  When the curing agent is an amine, the blending amount is preferably such that the active hydrogen equivalent and the epoxy equivalent of the epoxy resin are approximately equal. In addition, when the curing accelerator is imidazole, the blending amount is empirically set to 0.001 to 10 parts by weight with respect to 100 parts by weight of the epoxy resin, rather than simply having an equivalent ratio with active hydrogen. preferable. When the curing agent is polyfunctional phenols or acid anhydrides, the blending amount is an amount that is a ratio of 0.6 to 1.2 equivalents of phenolic hydroxyl groups or carboxyl groups with respect to 1 equivalent of epoxy resin. Is preferred. If the amount of these curing agents or accelerators is small, uncured epoxy resin tends to remain in the cured product, leading to a decrease in Tg (glass transition temperature). The promoter remains and the insulating property tends to decrease.

  The resin composition may further contain an additive type flame retardant for the purpose of improving flame retardancy. As the flame retardant, 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” (trade name, Sanko) (Phosphorus content: 9.6% by weight), “PMP-100” (phosphorus content: 13.8% by weight), “PMP-200” (phosphorus content: 9.3%) "PMP-300" (phosphorus content 9.8% by weight) (above trade name, manufactured by Nissan Chemical Industries, Ltd.). If the amount of the phosphorus-containing filler added is large, the flame retardancy is improved, but at the same time, the flexibility of the substrate is lowered and the heat resistance when the printed circuit board is obtained tends to be lowered. Therefore, the addition amount of the phosphorus-containing filler is preferably 0.1 to 10% by weight, more preferably 1 to 5% by weight, based on the resin solid content of the resin composition. By using such a phosphorus-containing filler or the like, a printed circuit board having a halogen-free and sufficient flame retardancy can be obtained.

  The prepreg 100 includes, for example, an impregnation step of impregnating a fiber base material with a varnish obtained by dissolving or dispersing a resin composition as described above in an organic solvent, and a drying step of removing (drying) the organic solvent. It can produce by the manufacturing method provided. As an organic solvent used for a varnish, what can melt | dissolve a resin composition is preferable. Examples of such an organic solvent include dimethylacetamide, dimethylformamide, dimethylsulfoxide, N-methyl-2-pyrrolidone, γ-butyrolactone, sulfolane, cyclohexanone, and the like.

  In the impregnation step, the fiber base material is impregnated with the varnish by a conventionally known method such as immersing the fiber base material in the varnish. The amount of the varnish impregnated is preferably such that the resin composition is 30 to 80% by weight with respect to the total amount of the resin composition (varnish resin solids) and the fiber base in the varnish.

  In a drying process, it is preferable to dry so that 80 weight% or more of the organic solvent used for the varnish may volatilize. Specifically, it is preferable to remove the organic solvent by heating to 80 to 180 ° C. Moreover, it is preferable to determine the heating time within a time range in which the varnish does not gel in consideration of the gel time of the varnish.

  Here, when the resin composition contains 100 parts by weight of the siloxane-modified polyamideimide resin and 1 to 200 parts by weight of the thermosetting resin, the volatilization rate of the organic solvent in the varnish can be particularly increased. . If the volatilization rate of the organic solvent is high, the organic solvent is removed at a low temperature of 150 ° C. or less, in which the curing reaction of the thermosetting resin is not accelerated so much in the drying step, and the residual rate is low, for example, 5% by weight or less. It becomes possible to become a level. By reducing the residual ratio of the organic solvent, it is possible to obtain a metal-clad laminate having good adhesion between the fiber substrate and the metal foil (such as copper foil) and the cured product of the resin composition. In addition, when the residual ratio of the organic solvent is small, generation of swelling due to volatilization of the organic solvent is suppressed in the lamination process with a metal foil such as a copper foil, and the solder resistance of the obtained metal-clad laminate is further improved. Can be.

  The metal-clad laminate of the present invention comprises a substrate obtained by curing the resin composition by heating the prepreg of the present invention, and a metal foil provided on at least one surface of the substrate. is there. The prepreg is preferably heated while being pressurized. In other words, this metal-clad laminate is preferably a metal-foil-clad laminate obtained by stacking a predetermined number of the prepregs of the present invention, placing metal foil on one side or both sides, and heating and pressing. The metal-clad laminate of the present invention is excellent in solder heat resistance and rich in flexibility by using the prepreg of the present invention. In addition, this metal-clad laminate is less likely to cause metal migration and has excellent insulating properties (electric corrosion resistance).

  FIG. 2 is a partial cross-sectional view showing an embodiment of a metal-clad laminate according to the present invention. The metal-clad laminate 200 is obtained by heating and pressurizing a laminate of a plurality of prepregs 100 to cure the resin composition contained in the prepreg 100, and is a sheet-like substrate made of a prepreg laminate. 30 and two metal foils 10 laminated on both sides of the substrate.

  The substrate 30 is made of a laminate in which a plurality of fiber reinforced resin layers 3 derived from the prepreg 100 are laminated. In order to increase the flexibility of the metal-clad laminate and the printed circuit board, the thickness of the substrate 30 is preferably 20 to 200 μm. In each fiber reinforced resin layer 3, the fiber base material is impregnated with a cured product of the resin composition as a matrix. In the cured product of the resin composition, a crosslinked structure is formed by, for example, a crosslinking reaction between a polyamideimide resin and an epoxy resin.

  The metal-clad laminate is obtained by stacking metal foil on both surfaces of a laminate in which one or a plurality of (preferably five or less) prepregs 100 are laminated, and heating and pressurizing the metal foil. At this time, the heating temperature and pressure are not particularly limited, but the heating temperature is usually 150 to 280 ° C. (preferably 180 to 250 ° C.), and the pressure is usually 0.5 to 20 MPa (preferably 1 to 8 MPa). It is.

  As the metal foil 10, a copper foil or an aluminum foil is generally used, but a copper foil is preferable. As the copper foil, one having a thickness of 5 to 200 μm, which is usually used for a copper-clad laminate, can be used, but in order to increase the flexibility of the printed circuit board, the thickness is 5 to 18 μm. Is more preferable. Alternatively, 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.

  The embodiment of the metal-clad laminate is not limited to the above aspect. For example, using one prepreg 100, the substrate may be composed of one fiber reinforced resin layer, or a metal foil may be disposed only on one side of the substrate. It is also possible to obtain an insulating plate made of a laminate by heating and pressurizing only the prepreg 100 without laminating metal foils.

  FIG. 3 is a partial cross-sectional view showing an embodiment of a printed circuit board according to the present invention. A printed circuit board 300 shown in FIG. 3 is mainly composed of a substrate 30 similar to the above and two metal foils 10 laminated on both surfaces of the substrate 30. A part of the metal foil 10 is removed to form a wiring pattern. Furthermore, a plurality of through holes 70 are formed through the printed circuit board 300 in a direction substantially perpendicular to the main surface, and the metal plating layer 60 is provided on the hole walls of the through holes 70.

  The printed circuit board 300 is obtained by forming a circuit on the metal-clad laminate 200 described above. Circuit formation (circuit processing) can be performed by a conventionally known method such as a subtractive method. In addition, a predetermined circuit component (not shown) is usually mounted on the printed circuit board 300.

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

(Synthesis Example 1)
<First reaction step>
DDS (diaminodiphenylsulfone) which is an aromatic 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 12.4 g (0.05 mol), reactive silicone oil “KF-8010” which is a siloxane diamine (trade name, Shin-Etsu Chemical Co., Ltd., amine equivalent 430) 51.6 g (0.06 mol), “Jeffamine D- 2000 ”(trade name, manufactured by Sun Techno Chemical Co., Ltd., amine equivalent 1000) 72.0 g (0.036 mol),“ Wandamine ”(trade name, manufactured by Shin Nippon Chemical Co., Ltd.) 11.34 g (0.054 mol), TMA (anhydrous Trimellitic acid) 80.68 g (0.42 mol) and NMP (N-methyl) which is an aprotic polar solvent And 2-pyrrolidone) were charged 612g reaction mixture, which was stirred at 80 ° C. 30 min. Then, 150 ml of toluene which is an aromatic hydrocarbon azeotroped with water was added, and then the temperature of the reaction solution was raised and refluxed at about 160 ° C. for 2 hours. After confirming that approximately 7.2 ml or more of water has accumulated in the moisture determination receiver and that no distilling of water can be observed, while removing the distillate accumulated in the moisture determination receiver, The temperature of the reaction solution was raised to 0 ° C. to remove toluene.

<Second reaction step>
After returning the reaction solution to room temperature (25 ° C.), 60.1 g (0.24 mol) of MDI (4,4′-diphenylmethane diisocyanate), which is an aromatic diisocyanate, was added and reacted at 190 ° C. for 2 hours. After completion of the reaction, an NMP solution of a siloxane-modified polyamideimide resin having the structural unit of the general formula (1) was obtained.

(Synthesis Example 2)
<First reaction step>
BAPP (2,2-aromatic), an aromatic diamine having two or more aromatic rings, is added to 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. Bis [4- (4-aminophenoxy) phenyl] propane) 24.63 g (0.06 mol), reactive silicone oil “KF8010” (trade name, manufactured by Shin-Etsu Chemical Co., Ltd., amine equivalent 445) 124, a siloxane diamine .6 g (0.14 mol), 80.68 g (0.42 mol) of TMA (trimellitic anhydride) and 539 g of NMP (N-methyl-2-pyrrolidone) which is an aprotic polar solvent are used as a reaction solution. Was stirred at 80 ° C. for 30 minutes. Then, 150 ml of toluene which is an aromatic hydrocarbon azeotroped with water was added, and then the temperature was raised and refluxed at about 160 ° C. for 2 hours. After confirming that approximately 7.2 ml or more of water has accumulated in the moisture determination receiver and that no distilling of water can be observed, while removing the distillate accumulated in the moisture determination receiver, The temperature of the reaction solution was raised to 0 ° C. to remove toluene.

<Second reaction step>
After returning the reaction solution to room temperature (25 ° C.), 60.07 g (0.24 mol) of MDI (4,4′-diphenylmethane diisocyanate), which is an aromatic diisocyanate, was added and reacted at 190 ° C. for 2 hours. After completion of the reaction, an NMP solution of siloxane-modified polyamideimide resin was obtained.

(Example 1)
<Preparation of prepreg and copper clad laminate>
218.75 g of NMP solution of the siloxane-modified polyamideimide resin obtained in Synthesis Example 1 as the component (a) (resin solid content 32 wt%) and “NC3000” (epoxy resin as the thermosetting resin of component (b)) ( Trade name, manufactured by Nippon Kayaku Co., Ltd.) 60.0 g (dimethylacetamide solution having a resin solid content of 50% by weight), 0.3 g of 2-ethyl-4-methylimidazole as a curing accelerator, and phenolic component (c) A mixture prepared by mixing 0.5 g of 4,4′-butylidenebis (3-methyl-6-tert-butylphenol) as an antioxidant was stirred for about 1 hour until uniform. Thereafter, a slurry comprising 20 g of phosphorus-containing filler “OP930” (trade name, manufactured by Clariant) and 40 g of methyl ethyl ketone was added, and the mixture was further stirred for 1 hour and then allowed to stand at room temperature (25 ° C.) for 24 hours for defoaming. The resin composition varnish was obtained.

  The resin composition varnish obtained was impregnated into a 28 μm-thick glass cloth (“1037”, trade name, manufactured by Asahi Schavel Co., Ltd.) and then dried by heating at 150 ° C. for 15 minutes. A prepreg having a content ratio of 70% by weight (based on the weight of the entire prepreg) was obtained. A laminated body in which an electrolytic copper foil having a thickness of 12 μm (“F2-WS-12”, trade name, manufactured by Furukawa Electric Co., Ltd.) is stacked on both sides of one prepreg so that its adhesive surface is combined with the prepreg, A double-sided copper-clad laminate was produced by heating and heating at 230 ° C. for 90 minutes and 4.0 MPa pressing conditions. Also, a double-sided copper-clad laminate in which 8 sheets of this prepreg are stacked and 12 μm thick electrolytic copper foil (“F2-WS-12” (trade name), manufactured by Furukawa Electric Co., Ltd.) is laminated on both sides in the same manner as above Was made.

(Evaluation of double-sided copper-clad laminate)
The following (1) to (4) are evaluated using a double-sided copper-clad laminate produced with one prepreg, and the following (5) and (6) are used with a double-sided copper-clad laminate produced with 8 prepregs. ) Was evaluated.

(1) Copper foil peeling strength The obtained double-sided copper-clad laminate was subjected to a 90 ° peeling test, and the maximum load at that time was defined as the copper foil peeling strength.

(2) Solder heat resistance After dipping in a solder bath at 260 ° C. and 300 ° C., the time (seconds) until abnormalities such as blistering and peeling occurred after the start of immersion was measured.

(3) Flexibility (flexibility)
The laminate from which the copper foil was removed by etching was bent, and the flexibility was evaluated by the presence or absence of breakage at that time.
A: No breakage, B: Some breakage, C: Breakage.

(4) Flame retardancy A UL94 VTM test was conducted and flame retardancy was evaluated according to the following procedure.
First, the laminated board from which the copper foil of the double-sided copper clad laminated board was removed by etching was cut into a length of 200 mm and a width of 50 mm, and this was wound around a mandrel having a diameter of 12.7 mm, and the position 125 mm from one end was laminated. After being fixed with tape so as not to be peeled off, the mandrel was pulled out to obtain a cylindrical test piece. Then, with the test piece in a vertical state, the upper end of the test piece was closed and fixed with a spring, and the lower end was measured with a methane gas burner for 20 seconds of blue flame with an indirect flame for 3 seconds. When the combustion distance was 100 mm or less, the flame retardancy was set to VTM-0.

(5) Thermal shock test Circuit processing was performed on the double-sided copper-clad laminate to prepare a daisy chain pattern test piece. Each test piece was subjected to a thermal shock test with −65 ° C./30 minutes and 125 ° C./30 minutes as one cycle for 1000 cycles, the change in resistance value was measured, and the following criteria were evaluated.
OK: Resistance value change within 10%, NG: Resistance value change more than 10%.

(6) Days until continuity failure Drilling through-holes with a hole spacing of 350 μm using a 0.9 mm diameter drill on a double-sided copper-clad laminate under conditions of a rotational speed of 60000 rpm and a feed rate of 1.800 mm / min. After that, through-hole plating was performed, and further printed processing was performed to produce a printed circuit board. Then, using this printed circuit board as a test piece, the insulation resistance when 100 V is applied in an 85 ° C./90% RH atmosphere is measured over time, and the number of days until conduction breakdown occurs between through holes / through holes is obtained. It was. At this time, insulation resistance was measured for 400 through-holes (200 places between through-holes / through-holes), and conduction breakdown occurred when a through-hole with an insulation resistance value of less than 1 × 10 ⁸ Ω was observed. Judged to be a thing. The evaluation results are shown in Table 1.

(Example 2)
The thermosetting resin of component (b) is epoxy resin “DER331L” (trade name, manufactured by Dow Chemical Co., Ltd.) 60.0 g (dimethylacetamide solution having a resin solid content of 50% by weight), and component (c) is phenol. 1,1,3-tris (2-methyl-4-hydroxy-5-t-butylphenyl) butane 0.5 g, which is an antioxidant, and phosphorus-containing filler "OP930" (trade name, manufactured by Clariant) A varnish of the resin composition was obtained in the same manner as in Example 1 except that 15 g and 30 g of methyl ethyl ketone were added as a slurry.
Using the obtained resin composition varnish, a prepreg and a copper clad laminate were prepared and evaluated in the same manner as in Example 1. The evaluation results are shown in Table 1.

(Example 3)
The thermosetting resin of the component (b) is an epoxy resin “ZX-15548-2” (trade name, manufactured by Tohto Kasei Co., Ltd.) 60.0 g (dimethylacetamide solution having a resin solid content of 50% by weight), and (c ) A resin composition varnish was prepared in the same manner as in Example 1 except that 0.5 g of dilauryl 3,3′-thiopropionate as a sulfur-based antioxidant was used.
Using the obtained resin composition varnish, a prepreg and a copper clad laminate were prepared and evaluated in the same manner as in Example 1. The evaluation results are shown in Table 1.

Example 4
The resin composition varnish was prepared in the same manner as in Example 1 except that 200.0 g of NMP solution of the siloxane-modified polyamideimide resin obtained in Synthesis Example 2 (35% by weight of resin solid content) was used as the component (a). Obtained.
Using the obtained resin composition varnish, a prepreg and a copper clad laminate were prepared and evaluated in the same manner as in Example 1. The evaluation results are shown in Table 1.

(Example 5)
The resin composition varnish was prepared in the same manner as in Example 2 except that 200.0 g of the siloxane-modified polyamideimide resin NMP solution obtained in Synthesis Example 2 (35% by weight of resin solid content) was used as the component (a). Obtained.
Using the obtained resin composition varnish, a prepreg and a copper clad laminate were prepared and evaluated in the same manner as in Example 1. The evaluation results are shown in Table 1.

(Comparative Example 1)
The varnish of the resin composition was the same as in Example 1 except that 4,4′-butylidenebis (3-methyl-6-tert-butylphenol), which is the phenolic antioxidant as the component (c), was not blended. Got.
Using the obtained resin composition varnish, a prepreg and a copper clad laminate were prepared and evaluated in the same manner as in Example 1. The evaluation results are shown in Table 1.

(Comparative Example 2)
(C) As in Example 2, except that 1,1,3-tris (2-methyl-4-hydroxy-5-tert-butylphenyl) butane, which is a phenolic antioxidant as a component, was not blended. Thus, a varnish of the resin composition was obtained.
Using the obtained resin composition varnish, a prepreg and a copper clad laminate were prepared and evaluated in the same manner as in Example 1. The evaluation results are shown in Table 1.

(Comparative Example 3)
A varnish of a tree and a fat composition was obtained in the same manner as in Example 3 except that dilauryl 3,3′-thiopropionate, which is a sulfur-based antioxidant as the component (c), was not blended.
Using the obtained resin composition varnish, a prepreg and a copper clad laminate were prepared and evaluated in the same manner as in Example 1. The evaluation results are shown in Table 1.

(Comparative Example 4)
The varnish of the resin composition was the same as in Example 4 except that 4,4′-butylidenebis (3-methyl-6-tert-butylphenol), which is the phenolic antioxidant as the component (c), was not blended. Got.
Using the obtained resin composition varnish, a prepreg and a copper clad laminate were prepared and evaluated in the same manner as in Example 1. The evaluation results are shown in Table 1.

(Comparative Example 5)
(C) Example 5, except that 1,1,3-tris (2-methyl-4-hydroxy-5-t-butylphenyl) butane, which is a hindered phenolic antioxidant as a component, was not blended Similarly, a resin composition varnish was obtained.
Using the obtained resin composition varnish, a prepreg and a copper clad laminate were prepared and evaluated in the same manner as in Example 1. The evaluation results are shown in Table 1.

As shown in Table 1, in the copper clad laminates of Comparative Examples 1 to 5 in which the antioxidant of component (c) was not blended, conduction breakdown occurred in a short period. In contrast, the copper-clad laminates of Examples 1 to 5 did not cause conduction breakdown even after 60 days, and maintained high insulation characteristics even under high temperature and high humidity. The insulation resistance values of Examples 1 to 5 were 1 × 10 ¹¹ Ω or more even after 60 days had elapsed.

  The double-sided copper-clad laminates of Examples 1 to 5 have good copper foil peel strength, showing a high value of 0.8 to 1.1 kN / m and good solder heat resistance (260 ° C. solder, 300 ° C. solder) ) Was good with no abnormalities such as blistering and peeling for 5 minutes or longer at any temperature. Moreover, the burning distance of the test piece by these V94 tests of UL94 is 100 mm or less, and all the flame retardances are VTM-0. Also in the thermal shock test, the connection reliability is within 10% of the resistance value change in 1000 cycles. It was good. Moreover, the double-sided copper clad laminates of Examples 1 to 5 were rich in flexibility and could be bent arbitrarily.

It is a fragmentary perspective view which shows one Embodiment of the prepreg by this invention. It is a fragmentary sectional view showing one embodiment of a metal tension laminate sheet by the present invention. 1 is a partial cross-sectional view illustrating an embodiment of a printed circuit board according to the present invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 3 ... Fiber reinforced resin layer, 10 ... Metal foil, 30 ... Board | substrate, 60 ... Metal plating layer, 70 ... Through-hole, 100 ... Pre-preg, 200 ... Metal-clad laminate, 300 ... Printed circuit board.

Claims (10)

A fiber base material, and a resin composition impregnated therein,
The resin composition is
(A) a polyamideimide resin;
(B) a thermosetting resin;
(C) A prepreg containing a phenol-based antioxidant or a sulfur-based antioxidant.   The prepreg of Claim 1 whose thickness of the said fiber base material is 5-100 micrometers.   The prepreg according to claim 1 or 2, wherein the fiber base material is a glass cloth. The phenolic antioxidant is 2-t-butyl-4-methoxyphenol, 3-t-butyl-4-methoxyphenol, 2,6-di-t-butyl-4-ethylphenol, 2,2′-. Methylene-bis (4-methyl-6-tert-butylphenol), 4,4′-thiobis- (3-methyl-6-tert-butylphenol), 4,4′-butylidenebis (3-methyl-6-tert-butylphenol) ), 1,1,3-tris (2-methyl-4-hydroxy-5-tert-butylphenyl) butane, 1,3,5-trimethyl-2,4,6-tris (3,5-di-t) At least one selected from the group consisting of -butyl-4-hydroxybenzyl) benzene and tetrakis- [methylene-3- (3 ′, 5′-di-t-butyl-4′-hydroxyphenyl) propionate] methane. It consists of compounds,
The said sulfur-type antioxidant consists of at least one compound among dilauryl 3,3'- thiodipropionate and distearyl 3,3'- thiodipropionate, In any one of Claims 1-3. The prepreg as described.   The prepreg according to any one of claims 1 to 4, wherein the component (a) is a polyamide-imide resin having a divalent group composed of a polysiloxane chain. The component (a) is
A first reaction step of obtaining an imide group-containing dicarboxylic acid by reacting trimellitic anhydride with a diamine mixture containing an aromatic diamine and a siloxane diamine represented by the following general formula (1a) or (1b);
The prepreg as described in any one of Claims 1-5 which is a polyamide imide resin obtained with a manufacturing method provided with the 2nd reaction process which makes diisocyanate react with the said imide group containing dicarboxylic acid.

[In the formulas (1a) and (1b), X ¹ 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 oxy group, a carbonyl group, A bond or a divalent group represented by the following general formula (11a) or (11b), wherein X ² is an aliphatic hydrocarbon group having 1 to 3 carbon atoms or a halogenated aliphatic hydrocarbon having 1 to 3 carbon atoms A group, a sulfonyl group, an oxy group or a carbonyl group, and R ¹ , R ² and R ³ each independently represents a hydrogen atom, a hydroxyl group, a methoxy group, a methyl group or a halogenated methyl group.

However, Z shows a C1-C3 aliphatic hydrocarbon group, a C1-C3 halogenated aliphatic hydrocarbon group, a sulfonyl group, an oxy group, a carbonyl group, or a single bond. ] The prepreg according to any one of claims 1 to 5, wherein the component (a) is a polyamideimide resin having a structural unit represented by the following general formula (2).

[Wherein, X ³ and X ⁴ each independently represent a divalent organic group. ]   The prepreg according to any one of claims 1 to 7, wherein the component (b) is an epoxy resin. A substrate obtained by curing the resin composition by heating the prepreg according to any one of claims 1 to 8,
A metal-clad laminate comprising: a metal foil provided on at least one surface of the substrate.   A printed circuit board obtained by forming a circuit on the metal-clad laminate according to claim 9.

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