JP4231511B2 - Polyimide film, polyimide metal laminate and method for producing the same - Google Patents

Description

  The present invention relates to a polyimide film, a polyimide metal laminate using the polyimide film, and a method for producing the same. More specifically, the present invention relates to a polyimide metal laminate having good adhesion through an adhesive layer between a polyimide film and a metal layer and suitable for a high-density circuit board material and a method for producing the same.

  Polyimide metal laminates are mainly used as circuit board materials, and are used for printed wiring board substrates, integrated suspension substrates, IC package wiring substrates, planar heating elements, LCD wiring substrates, and the like. . In recent years, as electronic devices are miniaturized and densified, use of polyimide metal laminates capable of high-density mounting of components and elements is increasing. Furthermore, in order to increase the density of the circuit, the circuit pattern line width is reduced to 10 μm to 50 μm. Therefore, a polyimide metal laminate having excellent adhesion of the metal layer to the polyimide film is desired. It was. In the use of this circuit board material, a polyimide film and a metal foil (for example, copper foil) are usually bonded and used via various adhesives. However, due to its chemical structure and high chemical resistance (solvent) stability, polyimide film often has insufficient adhesion to copper foil even through an adhesive. After the surface treatment (for example, coupling agent application treatment, sand blast treatment, corona discharge treatment, plasma treatment, alkali treatment, etc.), the metal foil is bonded via an adhesive.

  The polyimide film surface-treated by the coupling agent coating treatment may have a decrease in electrical characteristics due to Si residues. Moreover, the sandblasting process leaves a problem in the cleaning process for removing the abrasive attached to the polyimide film. On the other hand, corona discharge treatment and plasma treatment can be incorporated (in-line) into a film-forming apparatus because of the simplicity of the apparatus, and it is an advantageous treatment and a slight improvement in adhesion has been recognized. . However, when a metal foil is bonded to a polyimide film that has been subjected to corona discharge or plasma treatment using a polyimide-based adhesive as an adhesive, no improvement in adhesion is observed, and there is a problem as a practical treatment. there were.

In addition, a technique is known that can improve the adhesion with a metal layer by alkali-etching the surface of a polyimide film (see Patent Document 1, etc.). However, the content described in Patent Document 1 regarding the adhesion is only a description that the adhesion is improved only by treating the polyimide film with a simple alkaline aqueous solution, and the alkaline etching solution composition has not been studied at all. In some cases, the adhesion may be reduced.
JP-T-2004-533723

  An object of the present invention is to provide a polyimide film in which a metal foil can be bonded with high adhesion by a polyimide adhesive, and a metal layer on a layer made of a polyimide adhesive formed on the polyimide film. By arranging, it is providing the polyimide metal laminated body excellent in the adhesiveness of a metal layer and a polyimide film.

As a result of intensive studies to improve the above problems, the present inventors have found that the polyimide film surface-treated with an alkaline aqueous solution containing a permanganate adheres to the metal foil with good adhesion by a polyimide-based adhesive. I found it and came to the present invention.
Furthermore, by applying the polyimide film to a polyimide film, a layer containing a thermoplastic polyimide in contact with the polyimide film, and a metal layer disposed outside the layer containing the thermoplastic polyimide, the above-mentioned problem Has been found to be able to be solved, and the present invention has been reached.

That is, the first of the present invention relates to the following polyimide film.
[1] A polyimide film that is bonded with a polyimide-based adhesive and that is surface-treated with an alkaline aqueous solution containing a permanganate.
[2] The polyimide film according to [1], wherein the alkaline aqueous solution further contains a hydroxide.
[3] The polyimide film according to [2], wherein the weight ratio of permanganate to hydroxide contained in the alkaline aqueous solution is 9: 1 to 2: 8.
[4] The permanganate is at least one of potassium permanganate and sodium permanganate, and the hydroxide is at least one of potassium hydroxide and sodium hydroxide. The polyimide film according to [2] or [3].
[5] The polyimide film includes a polyimide that is a polycondensate of an acid dianhydride component and a diamine component, and 50 mol% or more of the acid dianhydride component is represented by the following general formula (1). The polyimide film according to any one of [1] to [4], wherein 50 mol% or more of the diamine component is a diamine represented by the following general formula (4).

（式（1）において、Ａは下記式（2）または下記一般式（3）を示す。）

(In the formula (1), A represents the following formula (2) or the following general formula (3).)

（式（4）において
ｎは０もしくは１の整数を示し、
−Ｘ−は−Ｏ−、−ＮＨＣ（＝Ｏ）−、または直接結合を示し、
Ｒは水素原子、ハロゲン原子、低級アルキル基、または低級アルコキシ基を示し、それぞれ同一であっても異なっていてもよい。）

(In formula (4), n represents an integer of 0 or 1,
-X- represents -O-, -NHC (= O)-, or a direct bond;
R represents a hydrogen atom, a halogen atom, a lower alkyl group, or a lower alkoxy group, which may be the same or different. )

  [6] The polyimide film according to any one of [1] to [5], wherein the polyimide-based adhesive includes a thermoplastic polyimide or a thermoplastic polyimide precursor and a bismaleimide represented by the following general formula (5). .

（式（5）において
ｍは０〜４の整数を示し、
−Ｙ−は−Ｏ−、−ＳＯ_２−、−Ｓ−、−ＣＯ−、または直接結合を示し、複数のＹがある場合はそれぞれ同一であっても異なっていてもよく、
Ｒ１は水素原子、ハロゲン原子、炭化水素基を示し、それぞれ同一であっても異なっていてもよく、かつベンゼン環を構成するそれぞれ別個の炭素に結合している。）

(In Formula (5), m represents an integer of 0 to 4,
-Y- is _{-O -, - SO 2 -,} - S -, - CO-, or shows a direct bond, if there are multiple Y may be the each be the same or different,
R1 represents a hydrogen atom, a halogen atom, or a hydrocarbon group, which may be the same or different from each other, and is bonded to a separate carbon constituting the benzene ring. )

  [7] The polyimide film according to [6], wherein the bismaleimide is represented by the following general formula (5 ′).

（式（5’）において
ｍは０〜４の整数を示し、
−Ｙ−は−Ｏ−、−ＳＯ_２−、−Ｓ−、−ＣＯ−、または直接結合を示し、複数のＹがある場合はそれぞれ同一であっても異なっていてもよく、
Ｒ１は水素原子、ハロゲン原子、炭化水素基を示し、それぞれ同一であっても異なっていてもよく、かつベンゼン環を構成するそれぞれ別個の炭素に結合している。）

(In the formula (5 ′), m represents an integer of 0 to 4,
-Y- is _{-O -, - SO 2 -,} - S -, - CO-, or shows a direct bond, if there are multiple Y may be the each be the same or different,
R1 represents a hydrogen atom, a halogen atom, or a hydrocarbon group, which may be the same or different from each other, and is bonded to a separate carbon constituting the benzene ring. )

2nd of this invention is related with the following polyimide metal laminated bodies and its manufacturing method.
[8] The polyimide film according to [1], including a layer containing thermoplastic polyimide disposed on both sides or one side of the polyimide film, and a metal layer disposed outside the layer containing thermoplastic polyimide, Polyimide metal laminate.
[9] A step of preparing the polyimide film according to [1], a step of forming a layer containing a thermoplastic polyimide by applying a polyimide adhesive on one or both sides of the polyimide film, and the thermoplastic polyimide are included. Forming a metal layer on the outer side of the layer.

  By this invention, a polyimide film with high adhesiveness with the metal foil adhere | attached through the polyimide-type adhesive agent can be obtained. Moreover, the polyimide metal laminated body suitable for the substrate material of a high-density circuit can be provided by using the polyimide film.

  Below, the polyimide film of this invention, a polyimide metal laminated body, and the manufacturing method of a polyimide metal laminated body are demonstrated in detail.

1. Polyimide film of the present invention The polyimide film of the present invention is characterized in that one or both surfaces thereof are surface-treated with an alkaline aqueous solution containing a permanganate.

  Although the material of the polyimide film of this invention is not specifically limited, It is preferable that it is a film which consists of a resin composition containing a non-thermoplastic polyimide film. The non-thermoplastic polyimide contained in the resin composition is a polycondensate of a raw material composition containing an acid dianhydride component and a diamine component. The molar ratio of the acid dianhydride component and the diamine component contained in the raw material composition is preferably such that the acid dianhydride component: diamine component is 0.95: 1.00 to 1.00: 0.95, More preferably, it is 1.00: 1.00-0.985: 1.00.

  The acid dianhydride component contained in the non-thermoplastic polyimide raw material composition preferably contains an acid dianhydride represented by the following general formula (1). More preferably, 50 mol% or more of the acid dianhydride component is the acid dianhydride represented by the general formula (1). In general formula (1), A is a group represented by the following formula (2) or general formula (3).

  Preferable examples of the acid dianhydride represented by the general formula (1) include pyromellitic dianhydride and biphenyltetracarboxylic dianhydride.

  The acid dianhydride component contained in the raw material composition of the non-thermoplastic polyimide may be one kind of acid dianhydride, but may be a combination of two or more kinds of acid dianhydrides. Moreover, the acid dianhydride component contained in the raw material composition can also contain an acid dianhydride other than the acid dianhydride represented by the general formula (1). The content is a range that does not impair the effects of the present invention, and is preferably less than 50 mol% of the acid dianhydride component.

  On the other hand, the diamine component contained in the raw material composition of the non-thermoplastic polyimide preferably contains a diamine represented by the following general formula (4). More preferably, 50 mol% or more of the diamine component is the diamine represented by the general formula (4). In the general formula (4), n represents an integer of 0 or 1. —X— represents —O—, —NHC (═O) —, or a direct bond. R represents a hydrogen atom, a halogen atom, a lower alkyl group or a lower alkoxy group, which may be the same or different from each other.

  Preferred examples of the diamine represented by the general formula (4) include p-phenylenediamine, m-phenylenediamine, 4,4′-diaminodiphenyl ether, 3,4′-diaminodiphenyl ether, 3,3′-diaminodiphenyl ether, 4 , 4'-Diamino-2,2'-dimethylbiphenyl, 4,4'-diamino-3,3'-dimethylbiphenyl, 2-methoxy-4,4'-diaminobenzanilide, 2'-methoxy-4,4 '-Diaminobenzanilide and the like are included.

  The diamine component contained in the raw material composition of the non-thermoplastic polyimide may be one kind of diamine, but may be a combination of two or more kinds of diamines. Further, the diamine component contained in the raw material composition may also include diamines other than the diamine represented by the general formula (4). The content is a range that does not impair the effects of the present invention, and is preferably less than 50 mol% of the diamine component.

  By using a polyimide film obtained from these raw material compositions, it is possible to further enjoy the effects of the present invention.

  The polyimide film surface-treated in the present invention may be a commercially available polyimide film, for example, Upilex (registered trademark) S, Upilex (registered trademark) SGA, Upilex (registered trademark) SN (Ube Industries, Ltd.) Product name, Kapton (registered trademark) H, Kapton (registered trademark) V, Kapton (registered trademark) EN (manufactured by Toray DuPont Co., Ltd., product name), Apical (registered trademark) AH, Apical (registered trademark) NPI, Apical (registered trademark) NPP, Apical (registered trademark) HP (trade name, manufactured by Kaneka Corp.), and the like.

  There is no restriction | limiting in particular in the thickness of the polyimide film of this invention, Although what is necessary is just to select suitably according to the use of the polyimide metal laminated body manufactured from it, etc., it is preferable that it is 5-250 micrometers.

  As described above, the surface of the polyimide film of the present invention is treated with an alkaline aqueous solution containing a permanganate, but the surface of the polyimide film to be treated may be either single-sided or double-sided. .

  The alkaline aqueous solution used for the surface treatment of the polyimide film may contain permanganate and be alkaline. The pH of the alkaline aqueous solution is preferably 9 or more. Preferable examples of permanganate contained in the alkaline aqueous solution include potassium permanganate, sodium permanganate and the like, and these may be used alone or in combination of two or more.

  The alkaline aqueous solution is preferably an aqueous solution containing a permanganate and a hydroxide. Preferable examples of the hydroxide include potassium hydroxide, sodium hydroxide and the like, but these may be used alone or in combination of two or more.

  The weight ratio of permanganate and hydroxide contained in the alkaline aqueous solution is preferably in the range of 9: 1 to 2: 8, more preferably in the range of 8: 2 to 3: 6. : More preferably in the range of 3 to 6: 4.

  The content of permanganate and hydroxide in the alkaline aqueous solution used for the surface treatment of the polyimide film is preferably 3% or more based on the total weight of the aqueous solution, and preferably 4% to 30%. %, Preferably 5% to 20%, and more preferably 6% to 15%.

  The alkaline aqueous solution may further contain other optional components.

  Means for treating the surface of the polyimide film with an alkaline aqueous solution is not particularly limited. For example, a method of immersing the polyimide film in an alkaline aqueous solution placed in a batch-type tank or the like; spraying or showering the alkaline aqueous solution on the polyimide film The method of spraying or spraying is mentioned. Moreover, you may process continuously by the roll-to-roll system which can be conveyed.

Since permanganic acid has a risk of burning or exploding due to an oxidizing action, when treating a polyimide film, the temperature of the alkaline aqueous solution is desirably 80 ° C. or less, preferably in the range of 50 ° C. to 80 ° C., More preferably, the temperature is in the range of 70 ° C to 80 ° C.
The treatment time is appropriately selected according to the temperature of the alkaline aqueous solution used for the treatment. By increasing the temperature of the alkaline aqueous solution, the processing capacity is improved and the processing time is shortened. For example, if the temperature of the liquid is 50 ° C. or higher, it may be about 0.5 to 20 minutes, and if it is 50 ° C. or lower, it may be about 5 to 40 minutes. In any case, since the polyimide-based adhesive can be applied to the surface of the processed polyimide film, it may be processed so that the applied adhesive adheres with good adhesiveness. If the treatment time is excessively long, problems such as a decrease in adhesiveness due to the adhesive may occur. It is preferable that the temperature of aqueous solution is adjusted with a processing apparatus.

The polyimide film of the present invention may be subjected to a swelling treatment before being surface-treated with an alkaline aqueous solution containing a permanganate. The swelling treatment can be performed with an alkaline solution. By the swelling treatment, the treatment ability of the surface treatment with an alkaline aqueous solution containing a permanganate can be improved.
The polyimide film of the present invention may be subjected to a reduction treatment after being surface-treated with an alkaline aqueous solution containing a permanganate. The reduction treatment can be performed with a solution containing a reducing agent. By the reduction treatment, permanganic acid and reaction by-products remaining on the film surface can be removed.

  The surface of the polyimide film of the present invention may be subjected to plasma treatment, corona discharge treatment, etc. in addition to surface treatment with an alkaline aqueous solution containing permanganate. Plasma treatment, corona discharge treatment, and the like may be performed before, after, or simultaneously with surface treatment with an alkaline aqueous solution containing a permanganate.

  The polyimide film of the present invention is used for any application, but the surface-treated film surface is characterized by high adhesiveness with a polyimide-based adhesive disposed on the surface. The polyimide adhesive contains at least a thermoplastic polyimide or a thermoplastic polyimide precursor. Therefore, the polyimide film of the present invention is formed by forming a layer (adhesive layer) containing thermoplastic polyimide by applying a polyimide adhesive on at least one surface thereof, and further forming a metal layer, A polyimide metal laminate is preferred.

2. Polyimide metal laminate of the present invention The polyimide metal laminate of the present invention includes the polyimide film of the present invention described above; a layer containing thermoplastic polyimide provided on at least one surface of the polyimide film (hereinafter, this layer is referred to as “ And may be referred to as a "thermoplastic polyimide layer"); and a metal layer disposed on the outside of the thermoplastic polyimide layer. The polyimide metal laminate of the present invention is only required to have a thermoplastic polyimide layer and a metal layer laminated on the surface-treated surface of the polyimide film, and is laminated on both sides even if laminated on only one side. Also good.

  The thermoplastic polyimide layer contained in the polyimide metal laminate of the present invention can be an adhesive layer that improves the adhesion between the film and the metal layer. The polyimide metal laminate of the present invention only needs to have at least one thermoplastic polyimide layer, and may have two or more thermoplastic polyimide layers. The thickness of the thermoplastic polyimide layer (when there are a plurality of thermoplastic polyimide layers, the total thickness of those layers) is selected depending on the intended use of the polyimide metal laminate to be produced, but is not limited, but from 0.5 μm to A range of 10 μm is preferred.

  The thermoplastic polyimide layer contained in the polyimide metal laminate of the present invention is a layer made of a resin composition containing thermoplastic polyimide. The resin composition may contain bismaleimide in addition to the thermoplastic polyimide (bismaleimide will be described later).

  The thermoplastic polyimide is obtained by subjecting a raw material composition containing a tetracarboxylic dianhydride component and a diamine component to a polycondensation reaction. The molar ratio of the tetracarboxylic dianhydride component and the diamine component contained in the raw material composition is preferably in the range of tetracarboxylic dianhydride component: diamine component = 0.90 to 1.10, more preferably 0.95. ˜1.00, particularly preferably 0.97 to 1.00. The thermoplastic polyimide is preferably a polymer having an imide structure in the main chain and having a glass transition temperature in the range of 130 ° C. to 350 ° C., and the elastic modulus rapidly decreases in this temperature range. A known thermoplastic polyimide may be used.

The tetracarboxylic dianhydride component contained in the raw material composition of the thermoplastic polyimide is not particularly limited, and known tetracarboxylic dianhydride components can be used. Specific examples thereof include 3, 3 ′, 4,4′-benzophenonetetracarboxylic dianhydride, pyromellitic dianhydride, 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride, diphenylsulfonetetracarboxylic dianhydride, oxy-4 , 4'-diphthalic dianhydride, 2,2-bis [4- (3,4-dicarboxyphenoxy) phenyl] propane dianhydride, ethylene glycol bistrimellitic dianhydride, 2,2-bis (3 , 4-Dicarboxyphenyl) -1,1,1,3,3,3-hexafluoropropane dianhydride, 2,2 ′, 3,3′-benzophenone tetracarboxylic dianhydride, 1,2- Bis (3,4-dicarboxybenzoyl) benzene Anhydride, 1,3-bis (3,4-dicarboxybenzoyl) benzene dianhydride, 1,4-bis (3,4-dicarboxybenzoyl) benzene dianhydride, 2,2′-bis ((3 , 4-Dicarboxy) phenoxy) benzophenone dianhydride, 2,3′-bis ((3,4-dicarboxy) phenoxy) benzophenone dianhydride, 2,4′-bis ((3,4-dicarboxy) Phenoxy) benzophenone dianhydride, 3,3′-bis ((3,4-dicarboxy) phenoxy) benzophenone dianhydride, 3,4′-bis ((3,4-dicarboxy) phenoxy) benzophenone dianhydride 4,4′-bis ((3,4-dicarboxy) phenoxy) benzophenone dianhydride and the like are included.
Preferably 3,3 ′, 4,4′-benzophenonetetracarboxylic dianhydride, pyromellitic dianhydride, 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride, diphenylsulfonetetracarboxylic acid It is preferable to include at least one tetracarboxylic dianhydride selected from dianhydrides.

  The tetracarboxylic dianhydride component contained in the thermoplastic polyimide raw material composition may be one type of tetracarboxylic dianhydride or a combination of two or more types of tetracarboxylic dianhydrides. Good.

Specific examples of the diamine component contained in the thermoplastic polyimide raw material composition include 1,3-bis (3-aminophenoxy) benzene, 4,4′-bis (3-aminophenoxy) biphenyl, and 1,3-bis. (3- (3-aminophenoxy) phenoxy) benzene, bis (3- (3-aminophenoxy) phenyl) ether, bis (3- (3- (3-aminophenoxy) phenoxy) phenyl) ether, o-phenylenediamine , P-phenylenediamine, m-phenylenediamine, 4,4'-diaminodiphenylmethane, 3,4'-diaminodiphenylmethane, 3,3'-diaminodiphenylmethane, 4,4'-diaminodiphenyl ether, 3,3'-diaminodiphenyl ether 3,4′-diaminodiphenyl ether, 4,4′-diaminobenzophenone, 3,4′-diaminobenzophenone, bis (4- Minophenyl) sulfone, bis (4- (3-aminophenoxy) phenyl) sulfone, bis (3-aminophenyl) sulfide, bis (4-aminophenyl) sulfide, 1,3-bis (4- (4-aminophenoxy) -α, α-Dimethylbenzyl) benzene, 2,2-bis (4-aminophenoxyphenyl) propane, 1,3-bis (1- (4- (4-aminophenoxy) phenyl) -1-methylethyl) benzene 1,4-bis (1- (4- (4-aminophenoxy) phenyl) -1-methylethyl) benzene, 1,4-bis (1- (4- (3-aminophenoxy) phenyl) -1- Methylethyl) benzene, 2,2-bis (3- (3-aminophenoxy) phenyl) -1,1,1,3,3,3-hexafluoropropane, 2,2-bis (3- (4-amino) Phenoxy) phenyl) -1,1,1,3,3,3-hexafur Ropuropan the like.
Preferably, 1,3-bis (3-aminophenoxy) benzene, 4,4′-bis (3-aminophenoxy) biphenyl, 4,4′-diaminodiphenyl ether, 3,3′-diaminodiphenyl ether, 3,4′- It is preferable to use at least one diamine selected from diaminodiphenyl ether and 1,3-bis (3- (3-aminophenoxy) phenoxy) benzene.

  One type of diamine may be sufficient as the diamine component contained in the raw material composition of a thermoplastic polyimide, and the combination of 2 or more types of diamine may be sufficient as it.

  A preferred combination of the acid dianhydride component and the diamine component contained in the thermoplastic polyimide raw material composition is 1,3-bis (3-aminophenoxy) benzene and 3,3 ′, 4,4′-benzophenonetetra. Carboxylic dianhydride; or 4,4′-diaminodiphenyl ether and / or 3,4′-diaminodiphenyl ether and / or 3,3′-diaminodiphenyl ether and diphenylsulfone tetracarboxylic dianhydride. It is preferable that 50 mol% or more of the total of the diamine component and the acid dianhydride component contained in the thermoplastic polyimide raw material composition is these diamine and acid dianhydride.

  In addition to the thermoplastic polyimide, bismaleimide may be blended in the resin composition constituting the thermoplastic polyimide layer. The content of bismaleimide contained in the resin composition may be about 0.1 to 50% by weight, preferably about 1 to 40% by weight, and about 5 to 30% by weight. Is more preferable.

The blended bismaleimide is preferably represented by the following general formula (5). In the general formula (5), m represents an integer of 0 to 4; -Y- is _{-O -, - SO 2 -,} - S -, - CO-, or shows a direct bond, when there are multiple Y May be the same or different; R 1 represents a hydrogen atom, a halogen atom, or a hydrocarbon group, and may be the same or different. Each R1 is bonded to a separate carbon constituting the benzene ring.

The blended bismaleimide is more preferably represented by the following general formula (5 ′). In General Formula (5 ′), m represents an integer of 0 to 4; —Y— represents —O—, —SO ₂ —, —S—, —CO—, or a direct bond, and there are a plurality of Y. Each case may be the same or different; R 1 represents a hydrogen atom, a halogen atom, or a hydrocarbon group, and may be the same or different. Each R1 is bonded to a separate carbon constituting the benzene ring.

  Specific examples of the bismaleimide compounded include 1,3-bis (3-maleimidophenoxy) benzene, bis (3- (3-maleimidophenoxy) phenyl) ether and 1,3-bis (3- (3-maleimide). Phenoxy) phenoxy) benzene, bis (3- (3- (3-maleimidophenoxy) phenoxy) phenyl) ether, 1,3-bis (3- (3- (3- (3-maleimidophenoxy) phenoxy) phenoxy) benzene, N, N′-p-phenylene bismaleimide, N, N′-m-phenylene bismaleimide, bis (4-maleimidophenyl) methane, N, N′-4,4′-diphenyl ether bismaleimide, N, N′-3, 4'-diphenyl ether bismaleimide, N, N'-3,3'-diphenyl ketone bismaleimide, 2,2-bis (4- (4-maleimidophenoxy) phenyl) propane, 2,2-bis 4- (3-maleimidophenoxy) phenyl) propane, 4,4′-bis (3-maleimidophenoxy) biphenyl, 2,2-bis (4- (3-maleimidophenoxy) phenyl) -1,1,1,3 , 3,3-hexafluoropropane, bis (4- (3-maleimidophenoxy) phenyl) ketone, bis (4- (3-maleimidophenoxy) phenyl) sulfide, bis (4- (3-maleimidophenoxy) phenyl) sulfone However, it is not limited to these. More preferred is 1,3-bis (3-maleimidophenoxy) benzene.

  The metal layer contained in the polyimide metal laminate of the present invention is disposed outside the thermoplastic polyimide layer. “Arranged outside the thermoplastic polyimide layer” includes being disposed in direct contact with the thermoplastic polyimide layer or disposed through an intermediate layer. The “intermediate layer” is, for example, a resin layer, and may be an adhesive layer or a non-adhesive layer. The metal layer is preferably arranged in direct contact with the thermoplastic polyimide layer.

  Although the kind of metal which comprises a metal layer is not specifically limited, Copper, copper alloy, aluminum, nickel, stainless steel, titanium, or iron etc. are mentioned. Since the metal layer can be etched to form an electronic circuit, the metal layer is preferably made of a metal having high conductivity. From this viewpoint, the metal layer is preferably a layer made of copper.

  The thickness of the metal layer is not limited as long as it can be used in the form of a tape, but is preferably in the range of 2 μm to 150 μm.

  The polyimide metal laminate of the present invention is excellent in adhesion of the metal layer to the polyimide film. “Excellent adhesion” includes, for example, that the peel strength of the metal layer is high. This is also shown in the examples described later. Therefore, the polyimide metal laminate of the present invention is suitably used as a circuit material substrate.

  The mechanism by which the adhesion of the metal layer to the polyimide film is not necessarily clear, but a portion of the polyimide group on the polyimide film surface is hydrolyzed to partially generate an amide group; the polyimide applied to the polyimide film When the thermoplastic polyimide or thermoplastic polyimide precursor contained in the adhesive is cured, the anchor effect between the amide group generated on the polyimide film surface is obtained, and the polyimide film and the thermoplastic polyimide layer It is estimated that the adhesion of the metal layer disposed on the thermoplastic polyimide layer and the polyimide film is enhanced, and the effects of the present invention are exhibited.

3. Method for Producing Polyimide Metal Laminate of the Present Invention The metal laminate of the present invention can be produced by any method. For example, the aforementioned surface-treated polyimide film is prepared; It can be manufactured by applying and drying a polyimide-based adhesive to form a thermoplastic polyimide layer; forming a metal layer by thermally pressing a metal foil to the formed thermoplastic polyimide layer.

  Moreover, the metal laminated body of this invention can be manufactured also by providing a metal layer only in the single side | surface of a polyimide film, and providing only arbitrary resin layers in the other side.

  On the other hand, the metal laminate of the present invention prepared the above-mentioned surface-treated polyimide film; prepared a polyimide film corresponding to the above-mentioned thermoplastic polyimide layer, and surface-treated the surface-treated polyimide film. It may be manufactured by forming a thermoplastic polyimide layer by thermocompression bonding to the surface; forming a metal layer by thermocompression bonding a metal foil to the formed thermoplastic polyimide layer. Alternatively, the surface-treated polyimide film, the polyimide film corresponding to the thermoplastic polyimide layer, and the metal foil may be simultaneously heat-pressed to produce the metal laminate of the present invention.

  Furthermore, a surface-treated polyimide film and a laminate prepared by applying at least one thermoplastic polyimide layer to a metal foil in advance are prepared; and the thermoplastic polyimide layer of the prepared laminate is formed on the surface of the polyimide film. You may manufacture the metal laminated body of this invention by thermocompression-bonding to the processed surface.

The metal laminate of the present invention may be manufactured by forming one or two or more intermediate layers on the thermoplastic polyimide layer, and forming a metal layer by heat-pressing a metal foil on the intermediate layer. Good. The intermediate layer is, for example, a resin layer, and can be formed by thermocompression bonding a polyimide adhesive layer or a film to the formed thermoplastic polyimide layer.
Furthermore, at least one or more thermoplastic polyimide layers and at least one or two or more intermediate layers are applied to the metal layer in advance to form a laminate; the thermoplastic polyimide layer of the formed laminate is formed into the polyimide film. The metal laminate of the present invention may be produced by thermocompression bonding to the surface-treated surface.

The polyimide-based adhesive applied to the polyimide film, the metal foil or the like preferably contains thermoplastic polyimide or a thermoplastic polyimide precursor (for example, polyamic acid), and more preferably contains bismaleimide.
A polyimide-based adhesive is applied to a polyimide film to form a thermoplastic polyimide layer; or is made into a thin film in advance or applied to a metal foil to form a laminate and is thermocompression bonded to the polyimide film to form a thermoplastic polyimide. Form a layer. Preferably, the polyimide adhesive is applied to a polyimide film to form a thermoplastic polyimide layer. The means for applying the polyimide adhesive is not particularly limited, but may be applied by using a known method such as a die coater, a comma coater, a roll coater, a gravure coater, a curtain coater, or a spray coater after being dissolved in a solvent. (Hereinafter, a solution of a polyimide adhesive dissolved in a solvent may be referred to as “varnish”). The means for applying can be appropriately selected and used according to the thickness of the thermoplastic polyimide layer to be formed, the viscosity of the varnish, and the like.
It is preferable that the density | concentration of the polyimide or polyimide precursor contained in a varnish is 3-50 weight% with respect to the total weight of the varnish which is a solution, More preferably, it is 5-30 weight%, More preferably, it is 10-20. % By weight.

  A polyimide precursor solution obtained by polycondensation reaction of a raw material composition containing a tetracarboxylic dianhydride component, a diamine component and a solvent, or a polyimide solution obtained by imidizing a polyimide precursor contained in the solution May be used as a varnish.

  The applied varnish is dried and cured as necessary. Drying includes removing a solvent contained in the varnish, and curing includes imidizing a polyimide precursor (for example, polyamic acid). Drying and curing of the applied varnish can be performed using a normal heating and drying furnace. The atmosphere in the drying furnace is preferably filled with air, inert gas (nitrogen, argon, etc.), or the like. The drying and curing temperatures are appropriately selected according to the boiling point of the solvent, but are preferably in the range of 60 ° C to 600 ° C. The drying and curing time is appropriately selected depending on the thickness of the thermoplastic polyimide layer to be formed, the solid content concentration of the varnish, and the type of the solvent, and is preferably about 0.05 to 500 minutes.

  The polyimide metal laminate of the present invention is produced by thermocompression bonding of a metal foil to a thermoplastic polyimide layer provided on the surface-treated surface of the polyimide film; or heat applied to the metal foil. It is preferable to heat and pressure-bond a plastic polyimide layer or the like to the surface-treated surface of the polyimide film. A known metal foil can be used as the metal foil to be thermocompression bonded. Examples of known metal foils include rolled copper foil, electrolytic copper foil, copper alloy foil, Al foil, Ni foil, stainless steel foil, titanium foil, iron foil, etc., preferably rolled copper foil or electrolytic copper foil It is.

  Although there is no restriction | limiting in the means to heat-press metal foil to a thermoplastic polyimide layer, For example, a hot press method and / or a lamination method are mentioned as a typical method.

The heat press method is, for example, a thermoplastic polyimide layer on a polyimide film and a metal foil, or a thermoplastic polyimide layer on a metal foil and the polyimide film cut out and stacked according to the size of the press part of the press machine, respectively. This is a method of combining and heat-pressing with a heating press. As heating temperature, the range of 150 to 600 degreeC is desirable. The applied pressure is not limited, but is preferably in the range of 0.1 to 500 kg / cm ² . The pressurization time is not particularly limited.

  The thermal laminating method is not particularly limited, but a polyimide film provided with a thermoplastic polyimide layer and a metal foil, or a metal foil provided with a thermoplastic polyimide layer and a polyimide film are sandwiched and bonded between rolls. It is a method to do. A metal roll, a rubber roll, etc. can be utilized for a roll. Although there is no restriction | limiting in the material of a roll, Steel materials and stainless steel materials can be used as a metal roll. It is preferable to use a roll whose surface is treated with chrome plating or the like. As the rubber roll, it is preferable to use a roll in which heat-resistant silicon rubber or fluorine-based rubber is disposed on the surface of the metal roll. The laminating temperature is preferably in the range of 100 ° C to 300 ° C. As a heating method, a radiation heating method such as far infrared, an induction heating method, or the like can be used in addition to the conductive heating method.

  It is also preferable to heat anneal after heat lamination. As a heating device, a normal heating furnace, an autoclave, or the like can be used. The thermal annealing can be performed in an atmosphere such as air or inert gas (nitrogen, argon). As a heating method, either a method of continuously heating the film or a method of leaving the film in a heating furnace while being wound around a core is preferable. As the heating method, a conductive heating method, a radiant heating method, a combination method thereof, and the like are preferable. The heating temperature is preferably in the range of 200 ° C to 600 ° C. The heating time is preferably in the range of 0.05 minutes to 5000 minutes.

Hereinafter, the present invention will be described more specifically based on Examples and Comparative Examples, but the scope of the present invention is not limited by these. In addition, evaluation of the adhesiveness (peel strength) of the metal layer of a polyimide metal laminated body and a polyimide film in an Example and a comparative example is based on the following method.
[Evaluation of peel strength]
For a polyimide metal laminate sample (length 100 mm, width 3.2 mm), the thermoplastic polyimide layer and the polyimide film layer are peeled off from the end of the short side according to the method specified in JIS C-6471, and the stress is measured. The measured value was used as an index of peel strength. The peeling angle was 90 ° and the peeling speed was 50 mm / min.

<Synthesis example of thermoplastic polyimide precursor>
69.16 g of 1,3-bis (3-aminophenoxy) benzene and 75.85 g of 3,3 ′, 4,4′-benzophenonetetracarboxylic dianhydride were weighed and placed in a 1000 ml separable flask. Were dissolved in 822 g of N, N′-dimethylacetamide under a nitrogen stream. After dissolution, stirring was continued at 60 ° C. for 6 hours to carry out a polymerization reaction to obtain a polyamic acid solution. The polyamic acid content of the polyamic acid solution was 15% by weight. A bismaleimide compound-containing thermoplastic polyimide precursor varnish was obtained by adding 13.24 g of 1,3-bis (3-maleimidophenoxy) benzene to a part of 500 g of the obtained varnish and stirring and dissolving at room temperature.

Example 1
<Manufacture of polyimide film>
A commercially available non-thermoplastic polyimide film (manufactured by Toray DuPont Co., Ltd .: trade name Kapton (registered trademark) 80EN, thickness: 20 μm) was pre-treated as Macudizer 9221S (450 ml / L) and Macudizer 9276 (50 ml / L). ) (All manufactured by Nihon McDermid Co., Ltd.) Aqueous solution at 45 ° C. for 3 minutes, followed by washing with water.

  Thereafter, as a treatment with an alkaline aqueous solution containing a permanganate, an immersion treatment and a water washing treatment were performed for 5 minutes at 75 ° C. in an aqueous solution composed of potassium permanganate (90 g / L) and sodium hydroxide (10 g / L).

  Then, it was immersed for 5 minutes at 45 ° C. in an aqueous solution of Macudizer 9279 (100 ml / L) and sulfuric acid (20 ml / L) manufactured by Nippon Macder Mid Co., Ltd., and further washed with water.

<Formation of thermoplastic polyimide layer>
The thermoplastic polyimide precursor varnish synthesized in the above synthesis example was applied on both surfaces of each treated polyimide film using a reverse roll coater, dried and cured to form a thermoplastic polyimide layer. The thickness of the formed thermoplastic polyimide layer was 2 μm. The drying and curing were performed by heat treatment stepwise at 100 ° C., 150 ° C., 200 ° C., and 250 ° C. for 5 minutes each.

<Formation of metal layer>
A cushioning material (manufactured by Kinyo Co., Ltd., trade name: Kinyo Board) is formed by superimposing a rolled copper foil (made by Nikko Materials Co., Ltd., trade name: BHY-22B-T, thickness: 18 μm) on the formed thermoplastic polyimide layer. F200), and heat-pressed for 4 hours under the conditions of 300 ° C. and 25 kg / cm ² with a heating press.
Thus, a polyimide metal laminate composed of “rolled copper foil / thermoplastic polyimide / Kapton (registered trademark) 80EN / thermoplastic polyimide / rolled copper foil” was produced.

Examples 2-4
A polyimide metal laminate was produced in the same manner as in Example 1 except that the composition of the alkaline aqueous solution containing permanganate for treating the polyimide film was changed as shown in Table 1.

Comparative Examples 1 and 2
A polyimide metal laminate was produced in the same manner as in Example 1 except that the composition of the aqueous solution for treating the polyimide film was changed as shown in Table 1.

Comparative Example 3
A polyimide metal laminate was produced in the same manner as in Example 1 except that each treatment (pretreatment, treatment with an alkaline aqueous solution containing permanganate, and reduction treatment) was not performed on the polyimide film.

<Evaluation of polyimide metal laminate>
The peel strength was measured as described above using the obtained polyimide metal laminate. The results are shown in Table 1.

  The polyimide metal laminate produced by the method of the present invention is usefully used as a printed wiring board substrate, an integrated suspension substrate, an IC package wiring substrate, a planar heating element, an LCD wiring substrate, and the like. The

Claims (9)

A polyimide film to be bonded by a polyimide adhesive, wherein a surface on which the polyimide adhesive is disposed is surface-treated with an alkaline aqueous solution containing a permanganate.   The polyimide film according to claim 1, wherein the alkaline aqueous solution further contains a hydroxide.   The polyimide film according to claim 2, wherein a weight ratio of permanganate to hydroxide contained in the alkaline aqueous solution is 9: 1 to 2: 8. The permanganate is at least one of potassium permanganate and sodium permanganate, and the hydroxide is at least one of potassium hydroxide and sodium hydroxide. 3. The polyimide film according to 3. The polyimide film includes a polyimide that is a polycondensate of an acid dianhydride component and a diamine component,
50 mol% or more of the acid dianhydride component is an acid dianhydride represented by the following general formula (1), and 50 mol% or more of the diamine component is a diamine represented by the following general formula (4). The polyimide film as described in any one of Claims 1-4.

(In the formula (1), A represents the following formula (2) or the following general formula (3).)

(In formula (4), n represents an integer of 0 or 1,
-X- represents -O-, -NHC (= O)-, or a direct bond;
R represents a hydrogen atom, a halogen atom, a lower alkyl group, or a lower alkoxy group, which may be the same or different. ) The said polyimide adhesive is a polyimide film as described in any one of Claims 1-5 containing the bismaleimide shown by a thermoplastic polyimide or a thermoplastic polyimide precursor, and the following general formula (5).

(In Formula (5), m represents an integer of 0 to 4,
-Y- is _{-O -, - SO 2 -,} - S -, - CO-, or shows a direct bond, if there are multiple Y may be the each be the same or different,
R1 represents a hydrogen atom, a halogen atom, or a hydrocarbon group, which may be the same or different from each other, and is bonded to a separate carbon constituting the benzene ring. ) The polyimide film according to claim 6, wherein the bismaleimide is represented by the following general formula (5 ′).

(In the formula (5 ′), m represents an integer of 0 to 4,
-Y- is _{-O -, - SO 2 -,} - S -, - CO-, or shows a direct bond, if there are multiple Y may be the each be the same or different,
R1 represents a hydrogen atom, a halogen atom, or a hydrocarbon group, which may be the same or different from each other, and is bonded to a separate carbon constituting the benzene ring. ) The polyimide film according to claim 1,
A polyimide metal laminate comprising: a layer containing thermoplastic polyimide disposed on the surface-treated surface of the polyimide film; and a metal layer disposed outside the layer containing thermoplastic polyimide. Preparing a polyimide film according to claim 1;
Applying a polyimide-based adhesive to the surface-treated surface of the polyimide film to form a layer containing thermoplastic polyimide, and forming a metal layer outside the layer containing thermoplastic polyimide,
The manufacturing method of the polyimide metal laminated body containing this.