JP2022150087A - Polyimide, crosslinked polyimide, adhesive film, laminate, coverlay film, copper foil with resin, metal-clad laminate, circuit board and multi-layer circuit board - Google Patents

Abstract

To provide an adhesive layer using polyimide containing dimer diamine as a raw material which further improves its dielectric characteristics and more effectively reduces transfer loss of a high frequency signal.SOLUTION: Polyimide contains: 60 mol% or more and 99 mol% or less a diamine residue derived from a dimer diamine composition containing dimer diamine, which contains a tetracarboxylic acid residue derived from a tetracarboxylic acid anhydride component and a diamine component, and is obtained by substituting a primary aminomethyl group or an amino group for each of two terminal carboxylic acid groups of a dimer acid, as a main component with respect to the total of diamine residues; and contains 1 mol% or more and 40 mol% or less of a diamine residue that is derived from a diamine compound, which has at least one or more cyclohexane skeletons or norbornane skeleton in the molecule and has a molecular weight of 100 or more and 533 or less.SELECTED DRAWING: None

Description

The present invention relates to a polyimide useful as a material for electronic parts, a crosslinked polyimide using the polyimide, an adhesive film, a laminate, a coverlay film, a resin-coated copper foil, a metal-clad laminate, a circuit board, and a multilayer circuit board.

In recent years, with the progress of miniaturization, weight reduction, and space saving of electronic devices, flexible printed circuit boards (FPCs) that are thin, lightweight, flexible, and have excellent durability even after repeated bending have been developed. Circuits are in increasing demand. Since FPCs can be mounted three-dimensionally and at high density even in a limited space, their applications are expanding, for example, to the wiring of moving parts of electronic devices such as HDDs, DVDs, and smartphones, as well as components such as cables and connectors. I'm doing it.

As one mode of FPC, there is a structure in which a circuit pattern is formed on a polyimide film having excellent heat resistance and flexibility, and a coverlay film having an adhesive layer on the surface thereof is laminated. Polyimide is used as the material for the adhesive layer of the cover lay film having such a structure. For example, Patent Document 1 discloses a crosslinked polyimide obtained by reacting a polyimide made from a dimer diamine derived from a dimer acid and an amino compound having at least two primary amino groups as functional groups. It has been proposed to apply it to the adhesive layer of the ray film. Here, dimer acid is obtained by Diels-Alder reaction using natural fatty acids such as soybean oil fatty acid, tall oil fatty acid, rapeseed oil fatty acid, and refined oleic acid, linoleic acid, linolenic acid, erucic acid, etc. as raw materials. It is known that the polybasic acid compound derived from the dimer acid can be obtained as a composition of the raw material fatty acid and the trimerized or higher fatty acid (for example, patent Reference 2).

Further, in Patent Document 3, it is proposed to lower the dielectric constant and the dielectric loss tangent by using a resin composition containing polyimide made from dimer diamine and fluororesin powder. However, Patent Document 3 does not disclose an example in which a dimer diamine and an aliphatic diamine other than dimer diamine are used in combination.
Furthermore, as a polyimide using an aliphatic diamine compound other than dimer diamine, for example, in Patent Documents 4 and 5, 4,4'-diaminodicyclohexylmethane (DCHM) is used to improve heat resistance, adhesiveness, and dielectric properties. It has been proposed to be a good polyimide. However, Patent Documents 4 and 5 do not disclose the dielectric properties of the examples using DCHM.

Japanese Unexamined Patent Application Publication No. 2013-1730 JP 2017-137375 A JP 2019-104843 A JP-A-2004-358961 Japanese Unexamined Patent Application Publication No. 2005-1380

As the performance of electronic devices increases, it is necessary to deal with higher frequency transmission signals. 2. Description of the Related Art If a transmission loss in a transmission path is large when transmitting a high-frequency signal, problems such as a loss of an electrical signal and an increase in signal delay time occur. Therefore, it will be important to further reduce the transmission loss of high-frequency signals in FPCs in the future, and there is a demand for an adhesive layer that exhibits excellent adhesiveness and low dielectric loss tangent.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to further improve the dielectric properties of an adhesive layer using a polyimide made from dimer diamine and to more effectively reduce the transmission loss of high-frequency signals.

As a result of extensive research, the present inventors have found that dielectric properties can be improved by introducing a residue derived from a specific alicyclic diamine compound into a polyimide using dimer diamine as a raw material. completed.

The polyimide of the present invention is a polyimide containing a tetracarboxylic acid residue derived from a tetracarboxylic dianhydride component and a diamine residue derived from a diamine component. The polyimide of the present invention is derived from a dimer-diamine composition containing as a main component a dimer-diamine in which two terminal carboxylic acid groups of a dimer acid are substituted with primary aminomethyl groups or amino groups with respect to all diamine residues. Derived from a diamine compound containing 60 mol% or more and 99 mol% or less of a diamine residue and having at least one cyclohexane skeleton or norbornane skeleton in the molecule and having a molecular weight in the range of 100 or more and 533 or less. 1 mol % or more and 40 mol % or less of diamine residues.

The polyimide of the present invention may have a weight average molecular weight (Mw) within the range of 10,000 to 60,000.

The polyimide of the present invention may have a weight average molecular weight (Mw) to number average molecular weight (Mn) ratio (Mw/Mn) of 1.5 or more and 2.5 or less.

The polyimide of the present invention may contain tetracarboxylic acid residues derived from benzophenonetetracarboxylic dianhydride in an amount of 10 mol % or more and 99 mol % or less of all tetracarboxylic acid residues. In this case, 1 mol % or more of at least one tetracarboxylic acid residue derived from a tetracarboxylic dianhydride represented by the following general formulas (1) and/or (2) may be contained.

In general formula (1), X represents a single bond or a divalent group selected from the following formula, and in general formula (2), the cyclic portion represented by Y is a 4-membered ring, a 5-membered ring , represents that a saturated cyclic hydrocarbon group selected from a 6-, 7-, or 8-membered ring is formed.

In the above formula, Z represents -C ₆ H ₄ -, -(CH ₂ )n- or -CH ₂ -CH(-O-C(=O)-CH ₃ )-CH ₂ -, where n is 1 Indicates an integer from ~20.

In the crosslinked polyimide of the present invention, a ketone group contained in the polyimide and an amino group of an amino compound having at least two primary amino groups as functional groups form a crosslinked structure through a C=N bond. is.

The adhesive film of the present invention contains any one of the above polyimides or crosslinked polyimides.

The adhesive film of the present invention has a dielectric loss tangent (Tan δ ₁ ) may be 0.002 or less, and the dielectric constant (ε ₁ ) may be 3.0 or less.

The adhesive film of the present invention has a dielectric loss tangent (Tan δ ₂ ) may be 0.002 or less, and the dielectric constant (ε ₂ ) may be 3.0 or less.

The laminate of the present invention is a laminate having a substrate and an adhesive layer laminated on at least one surface of the substrate, wherein the adhesive layer is made of the above adhesive film. Characterized by

The coverlay film of the present invention is a coverlay film having a coverlay film material layer and an adhesive layer laminated on the coverlay film material layer, wherein the adhesive layer comprises the adhesive film characterized by consisting of

The resin-coated copper foil of the present invention is a resin-coated copper foil obtained by laminating an adhesive layer and a copper foil, wherein the adhesive layer comprises the adhesive film.

The metal-clad laminate of the present invention is a metal-clad laminate having an insulating resin layer and a metal layer laminated on at least one surface of the insulating resin layer, wherein at least one of the insulating resin layers comprises and the above adhesive film.

The metal-clad laminate of the present invention comprises an insulating resin layer, an adhesive layer laminated on at least one surface of the insulating resin layer, and a metal layer laminated on the insulating resin layer via the adhesive layer. , wherein the adhesive layer comprises the adhesive film.

A metal-clad laminate of the present invention is a first single-sided metal-clad laminate having a first metal layer and a first insulating resin layer laminated on at least one surface of the first metal layer. ,
a second single-sided metal-clad laminate having a second metal layer and a second insulating resin layer laminated on at least one surface of the second metal layer;
arranged to abut on the first insulating resin layer and the second insulating resin layer and laminated between the first single-sided metal-clad laminate and the second single-sided metal-clad laminate A metal-clad laminate comprising an adhesive layer,
The adhesive layer is made of the adhesive film.

The metal-clad laminate of the present invention comprises a single-sided metal-clad laminate having an insulating resin layer and a metal layer laminated on one side of the insulating resin layer, and laminated on the other side of the insulating resin layer. and an adhesive layer, wherein the adhesive layer is made of the adhesive film.

The circuit board of the present invention is obtained by wiring the metal layer of the metal-clad laminate.

The circuit board of the present invention comprises a first base material, a wiring layer laminated on at least one surface of the first base material, and the wiring layer on the wiring layer side surface of the first base material. and an adhesive layer laminated so as to cover the substrate, wherein the adhesive layer is made of the adhesive film.

The circuit board of the present invention comprises a first base material, a wiring layer laminated on at least one surface of the first base material, and the wiring layer on the wiring layer side surface of the first base material. A circuit board comprising an adhesive layer laminated so as to cover the and a second base laminated on the surface of the adhesive layer opposite to the first base, The adhesive layer is characterized by comprising the adhesive film.

The circuit board of the present invention comprises: a first substrate; an adhesive layer laminated on at least one surface of the first substrate; A circuit board comprising: a second substrate laminated on a surface thereof; and wiring layers respectively laminated on surfaces of the first substrate and the second substrate opposite to the adhesive layer. and wherein the adhesive layer is made of the adhesive film.

A multilayer circuit board of the present invention is a multilayer circuit board comprising a laminate including a plurality of laminated insulating resin layers and at least one or more wiring layers embedded in the laminate,
At least one of the plurality of insulating resin layers is formed of an adhesive layer that has adhesiveness and covers the wiring layer, and the adhesive layer is made of the adhesive film. do.

The polyimide of the present invention can form a polyimide film with improved frequency dependence while maintaining a low dielectric loss tangent by using a combination of dimer diamine and a specific alicyclic diamine compound as raw materials for the polyimide. . Therefore, the polyimide film of the present invention can effectively reduce transmission loss in high-frequency signal transmission when applied to a circuit board or the like that transmits high-frequency signals in the GHz band (eg, 1 to 40 GHz). Become.

BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic diagram which shows the structure of the cross section of the laminated body which concerns on embodiment of this invention. BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic diagram which shows the structure of the cross section of the metal-clad laminated board which concerns on embodiment of this invention. FIG. 4 is a schematic diagram showing a cross-sectional configuration of a metal-clad laminate according to another embodiment of the present invention; FIG. 4 is a schematic diagram showing a cross-sectional configuration of a metal-clad laminate according to still another embodiment of the present invention; BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic diagram which shows the structure of the cross section of the circuit board which concerns on embodiment of this invention. It is a schematic diagram which shows the structure of the cross section of the circuit board which concerns on another embodiment of this invention. FIG. 4 is a schematic diagram showing a cross-sectional configuration of a circuit board according to still another embodiment of the present invention; 1 is a schematic diagram showing a cross-sectional configuration of a multilayer circuit board according to an embodiment of the present invention; FIG.

Embodiments of the present invention will be described with reference to the drawings as appropriate. A polyimide according to one embodiment of the present invention is an adhesive polyimide. Hereinafter, the polyimide of this embodiment may be referred to as "adhesive polyimide". The adhesive polyimide contains tetracarboxylic acid residues derived from a tetracarboxylic dianhydride component and diamine residues derived from a diamine component. When the tetracarboxylic dianhydride and diamine compound as raw materials are reacted in approximately equimolar amounts, the types of tetracarboxylic acid residues and diamine residues contained in the polyimide with respect to the types and molar ratios of raw materials and the molar ratio can be almost matched.
In the present invention, the term "polyimide" means a resin composed of a polymer having an imide group in its molecular structure, such as polyimide, polyetherimide, polyesterimide, polysiloxaneimide, and polybenzimidazoleimide, in addition to polyimide. .
The tetracarboxylic acid residue and diamine residue constituting the adhesive polyimide are described below together with the raw materials thereof.

(acid anhydride)
As the adhesive polyimide, tetracarboxylic dianhydrides that are generally used for thermoplastic polyimides can be used as raw materials without any particular restrictions. It is preferable to use a raw material containing 10 mol % or more and 99 mol % or less, more preferably 50 mol % or more and 99 mol % or less. In other words, the adhesive polyimide preferably contains tetracarboxylic acid residues derived from benzophenonetetracarboxylic dianhydride in the range of 10 mol% or more and 99 mol% or less with respect to all tetracarboxylic acid residues. , more preferably in the range of 50 mol % or more and 99 mol % or less. By containing tetracarboxylic acid residues derived from benzophenonetetracarboxylic dianhydride in the range of 10 mol% or more and 99 mol% or less in total with respect to all tetracarboxylic acid residues, adhesive polyimide Both flexibility and heat resistance can be easily achieved, and the carbonyl group (ketone group) contributes to the adhesiveness, so the adhesiveness of the adhesive polyimide can be improved. Here, if the total content of tetracarboxylic acid residues derived from benzophenonetetracarboxylic dianhydride is less than 10 mol% with respect to all tetracarboxylic acid residues, it becomes a cross-linking point in cross-linking formation described later. Since the number of ketone groups (carbonyl groups) is reduced, it is disadvantageous from the viewpoint of improving solder heat resistance. In addition, benzophenone tetracarboxylic dianhydride reacts with a ketone group (carbonyl group) present in the molecular skeleton and an amino group derived from a diamine compound to form a C=N bond, resulting in high molecular weight gelation. Therefore, the upper limit is made 99 mol % or less. Incidentally, benzophenonetetracarboxylic dianhydride is 3,3′,4,4′-, 2,3′,3,4′-, 2,2′,3,3′- or 2,3,3′- ,4'-benzophenonetetracarboxylic dianhydride can be used.

The adhesive polyimide is derived from a tetracarboxylic anhydride represented by the following general formula (1) and / or (2) as a tetracarboxylic acid residue derived from a tetracarboxylic anhydride other than the above The total content of tetracarboxylic acid residues is preferably 1 mol % or more, more preferably 10 mol % or more and 50 mol % or less. Since the tetracarboxylic anhydride represented by the general formula (1) and / or (2) does not have a functional group that reacts with the diamine residue derived from the diamine compound, benzophenonetetracarboxylic dianhydride By using it in combination with, the effect of improving the solder heat resistance can be obtained while suppressing the deterioration of solvent solubility.

In general formula (1), X represents a single bond or a divalent group selected from the following formula, and in general formula (2), the cyclic portion represented by Y is a 4-membered ring, a 5-membered ring , a cyclic saturated hydrocarbon group selected from a 6-, 7-, or 8-membered ring.

In the above formula, Z represents -C ₆ H ₄ -, -(CH ₂ )n- or -CH ₂ -CH(-O-C(=O)-CH ₃ )-CH ₂ -, where n is 1 Indicates an integer from ~20.

Examples of the tetracarboxylic anhydride represented by the general formula (1) include 3,3',4,4'-biphenyltetracarboxylic dianhydride (BPDA), 3,3',4,4' -diphenylsulfonetetracarboxylic dianhydride (DSDA), 4,4'-oxydiphthalic anhydride (ODPA), 4,4'-(hexafluoroisopropylidene)diphthalic anhydride (6FDA), 2,2-bis [4-(3,4-dicarboxyphenoxy)phenyl]propane dianhydride (BPADA), p-phenylenebis(trimellitic acid monoester acid anhydride) (TAHQ), ethylene glycol bisanhydrotrimellitate (TMEG) ) and the like.

Further, the tetracarboxylic anhydride represented by the general formula (2) includes, for example, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,3,4-cyclopentanetetracarboxylic acid dianhydride, 1,2,4,5-cyclohexanetetracarboxylic dianhydride, 1,2,4,5-cycloheptanetetracarboxylic dianhydride, 1,2,5,6-cyclooctanetetracarboxylic acid A dianhydride and the like can be mentioned.

The adhesive polyimide is derived from an acid anhydride other than the benzophenonetetracarboxylic dianhydride, the tetracarboxylic acid anhydrides represented by the general formulas (1) and (2), as long as the effects of the invention are not impaired. can contain tetracarboxylic acid residues such as Such tetracarboxylic acid residues are not particularly limited, but examples include pyromellitic dianhydride, 2,3′,3,4′-biphenyltetracarboxylic dianhydride, ,4'-diphenyl ether tetracarboxylic acid dianhydride, bis(2,3-dicarboxyphenyl) ether dianhydride, 3,3'',4,4''-, 2,3,3'',4' '- or 2,2'',3,3''-p-terphenyltetracarboxylic dianhydride, 2,2-bis(2,3- or 3,4-dicarboxyphenyl)-propane dianhydride , bis(2,3- or 3,4-dicarboxyphenyl)methane dianhydride, bis(2,3- or 3,4-dicarboxyphenyl)sulfone dianhydride, 1,1-bis(2,3 - or 3,4-dicarboxyphenyl)ethane dianhydride, 1,2,7,8-, 1,2,6,7- or 1,2,9,10-phenanthrene-tetracarboxylic dianhydride, 2,3,6,7-anthracenetetracarboxylic dianhydride, 2,2-bis(3,4-dicarboxyphenyl)tetrafluoropropane dianhydride, 1,2,5,6-naphthalenetetracarboxylic dianhydride anhydride, 1,4,5,8-naphthalenetetracarboxylic dianhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride, 4,8-dimethyl-1,2,3,5,6 ,7-hexahydronaphthalene-1,2,5,6-tetracarboxylic dianhydride, 2,6- or 2,7-dichloronaphthalene-1,4,5,8-tetracarboxylic dianhydride, 2 ,3,6,7- (or 1,4,5,8-) tetrachloronaphthalene-1,4,5,8- (or 2,3,6,7-) tetracarboxylic dianhydride, 2, 3,8,9-, 3,4,9,10-, 4,5,10,11- or 5,6,11,12-perylene-tetracarboxylic dianhydride, pyrazine-2,3,5, 6-tetracarboxylic dianhydride, pyrrolidine-2,3,4,5-tetracarboxylic dianhydride, thiophene-2,3,4,5-tetracarboxylic dianhydride, 4,4'-bis( Tetracarboxylic acid residues derived from aromatic tetracarboxylic dianhydrides such as 2,3-dicarboxyphenoxy)diphenylmethane dianhydride can be mentioned.

(diamine)
For the adhesive polyimide, any diamine compound generally used for thermoplastic polyimide can be used as a raw material without any particular limitation. Diamine residues derived from a dimer diamine composition containing dimer diamine substituted with a group as a main component within a range of 60 mol% or more and 99 mol% or less, preferably within a range of 70 mol% or more and 90 mol% or less contains. By containing the diamine residue derived from the dimer diamine composition within the above range, the solubility of the polyimide can be improved, and the dielectric constant and dielectric loss tangent can be lowered. When the content of diamine residues derived from the dimer diamine composition is less than 60 mol% relative to all diamine residues, the relative dielectric constant and dielectric loss tangent increase due to the relatively increased number of polar groups contained in the polyimide. easier to do. In addition, by containing the diamine residue derived from the dimer diamine composition in the above amount, the thermocompression bonding property is improved by lowering the glass transition temperature of the polyimide (lowering Tg) and the internal stress is reduced by lowering the elastic modulus. mitigation becomes possible. On the other hand, if the content of diamine residues derived from the dimer diamine composition exceeds 99 mol% relative to the total diamine residues, the mobility of the polyimide molecular chains is excessively increased, and the dielectric loss tangent may increase. .

The dimer diamine composition is a purified product containing the following component (a) as a main component and having controlled amounts of components (b) and (c).

(a) a dimer diamine;
The dimer diamine of component (a) means that the _two terminal carboxylic acid groups (--COOH) of the dimer acid are substituted with primary aminomethyl groups (--CH.sub.2--NH.sub.2) or amino groups _{( --NH.sub.2} ). means a diamine consisting of Dimer acid is a known dibasic acid obtained by an intermolecular polymerization reaction of unsaturated fatty acids, and its industrial production process is almost standardized in the industry. It is obtained by dimerization with Etc. Industrially obtained dimer acids are mainly composed of dibasic acids with 36 carbon atoms obtained by dimerizing unsaturated fatty acids with 18 carbon atoms such as oleic acid, linoleic acid and linolenic acid. To some extent, it contains any amount of monomeric acid (18 carbon atoms), trimer acid (54 carbon atoms), other polymerized fatty acids of 20 to 54 carbon atoms. Moreover, although a double bond remains after the dimerization reaction, in the present invention, the dimer acid includes the one which is further hydrogenated to reduce the degree of unsaturation. The dimer diamine of the component (a) is obtained by substituting the terminal carboxylic acid group of the dibasic acid compound having 18 to 54 carbon atoms, preferably 22 to 44 carbon atoms, with a primary aminomethyl group or an amino group. can be defined as the resulting diamine compound.

As a feature of the dimer diamine, properties derived from the dimer acid skeleton can be imparted. That is, the dimer diamine is a macromolecular aliphatic with a molecular weight of about 560-620, so that the molar volume of the molecule can be increased and the polar groups of the polyimide can be relatively reduced. Such features of the dimer acid-type diamine are considered to contribute to improving the dielectric properties by reducing the dielectric constant and the dielectric loss tangent while suppressing the deterioration of the heat resistance of the polyimide. In addition, since it has two freely moving hydrophobic chains having 7 to 9 carbon atoms and two chain aliphatic amino groups having a length close to 18 carbon atoms, it not only gives the polyimide flexibility, Since polyimide can have an asymmetric chemical structure or a non-planar chemical structure, it is thought that the dielectric constant of polyimide can be lowered.

The dimer-diamine composition used is obtained by increasing the dimer-diamine content of component (a) to 96% by weight or more, preferably 97% by weight or more, and more preferably 98% by weight or more by a purification method such as molecular distillation. It's good. By setting the dimer diamine content of the component (a) to 96% by weight or more, it is possible to suppress the spread of the molecular weight distribution of the polyimide. In addition, if technically possible, it is best that all (100% by weight) of the dimer diamine composition is composed of the dimer diamine of the component (a).

(b) a monoamine compound obtained by substituting a primary aminomethyl group or an amino group for the terminal carboxylic acid group of a monobasic acid compound having 10 to 40 carbon atoms;
The monobasic acid compound having 10 to 40 carbon atoms is a monobasic unsaturated fatty acid having 10 to 20 carbon atoms derived from the dimer acid raw material, and a by-product during the production of dimer acid. is a mixture of monobasic acid compounds within the range of 21 to 40 carbon atoms. A monoamine compound is obtained by substituting the terminal carboxylic acid group of these monobasic acid compounds with a primary aminomethyl group or an amino group.

The monoamine compound of component (b) is a component that suppresses an increase in the molecular weight of polyimide. When polyamic acid or polyimide is polymerized, the monofunctional amino group of the monoamine compound reacts with the terminal acid anhydride group of polyamic acid or polyimide to seal the terminal acid anhydride group, thereby reducing the molecular weight of polyamic acid or polyimide. restrain the increase.

(c) an amine compound obtained by substituting a primary aminomethyl group or an amino group for the terminal carboxylic acid group of a polybasic acid compound having a hydrocarbon group within the range of 41 to 80 carbon atoms (wherein the dimer diamine except for);
The polybasic acid compound having a hydrocarbon group having 41 to 80 carbon atoms is mainly composed of a tribasic acid compound having 41 to 80 carbon atoms, which is a by-product of dimer acid production. It is a polybasic acid compound that Further, polymerized fatty acid other than dimer acid having 41 to 80 carbon atoms may be included. Amine compounds are obtained by substituting the terminal carboxylic acid groups of these polybasic acid compounds with primary aminomethyl groups or amino groups.

The amine compound (c) is a component that promotes an increase in the molecular weight of the polyimide. A trifunctional or higher functional amino group whose main component is a triamine derivative derived from trimer acid reacts with the terminal acid anhydride group of polyamic acid or polyimide to rapidly increase the molecular weight of polyimide. Amine compounds derived from polymerized fatty acids other than dimer acids having 41 to 80 carbon atoms also increase the molecular weight of polyimide and cause gelation of polyamic acid or polyimide.

When quantifying each component by measurement using gel permeation chromatography (GPC), the dimer diamine composition is added to facilitate confirmation of the peak start, peak top and peak end of each component of the dimer diamine composition. Samples treated with acetic anhydride and pyridine are used and cyclohexanone is used as internal standard. Using samples prepared in this way, each component is quantified by area percent of the GPC chromatogram. The peak start and peak end of each component are the minimum values of each peak curve, and the area percentage of the chromatogram can be calculated based on this.

Further, in the dimer diamine composition, the sum of components (b) and (c) should be 4% or less, preferably less than 4%, in terms of area percent in a chromatogram obtained by GPC measurement. By setting the total content of components (b) and (c) to 4% or less, it is possible to suppress broadening of the molecular weight distribution of the polyimide.

Also, the area percentage of the component (b) in the chromatogram is preferably 3% or less, more preferably 2% or less, and still more preferably 1% or less. By setting it in such a range, it is possible to suppress the decrease in the molecular weight of the polyimide, and further to widen the range of the molar ratio of the tetracarboxylic dianhydride component and the diamine component. In addition, the component (b) may not be contained in the dimer diamine composition.

The area percentage of component (c) in the chromatogram is 2% or less, preferably 1.8% or less, and more preferably 1.5% or less. Such a range can suppress a rapid increase in the molecular weight of the polyimide, and further suppress an increase in the dielectric loss tangent of the resin film over a wide frequency range. In addition, the (c) component may not be contained in the dimer diamine composition.

Further, when the area percent ratio (b/c) of the chromatograms of components (b) and (c) is 1 or more, the molar ratio of the tetracarboxylic dianhydride component and the diamine component (tetracarboxylic dianhydride component/diamine component) is preferably 0.97 or more and less than 1.0, and such a molar ratio makes it easier to control the molecular weight of the polyimide.

Further, when the area percent ratio (b/c) of the chromatograms of components (b) and (c) is less than 1, the molar ratio of the tetracarboxylic dianhydride component and the diamine component (tetracarboxylic dianhydride The ratio of polyimide component/diamine component) is preferably 0.97 or more and 1.1 or less, and such a molar ratio makes it easier to control the molecular weight of the polyimide.

The dimer-diamine composition is commercially available, and is preferably purified for the purpose of reducing components other than the dimer-diamine component (a). For example, the component (a) is preferably 96 area percent or more. . The purification method is not particularly limited, but known methods such as distillation and precipitation purification are suitable. Examples of commercially available dimer diamine compositions include PRIAMINE 1073 (trade name), PRIAMINE 1074 (trade name), and PRIAMINE 1075 (trade name) manufactured by Croda Japan.

In addition, the adhesive polyimide is a diamine compound (hereinafter referred to as "specific alicyclic Diamine residue derived from 1 mol% or more and 40 mol% or less, preferably 5 mol% or more and 30 mol% or less, more preferably 10 mol% or more It is contained within the range of 20 mol % or less. By using a combination of the dimer diamine composition and the specific alicyclic diamine as raw material monomers, it is possible to suppress the molecular motion of the polyimide molecular chains and reduce the dielectric loss tangent. That is, compared to the case where all of the diamine residues are diamine residues derived from the dimer diamine composition, by replacing a portion of the diamine residues with diamine residues derived from a specific alicyclic diamine, the polarity of the polyimide is reduced. It is thought that it is possible to suppress the motion of the entire polyimide molecular chain without reducing the dielectric loss tangent. In addition, the aliphatic nature of the polyimide as a whole is strengthened, and the decrease in polar groups makes it less polar, resulting in lower water absorption and hygroscopicity. be. If the content of diamine residues derived from a specific alicyclic diamine is less than 1 mol % relative to all diamine residues, the effect of lowering the dielectric loss tangent is not exhibited. On the other hand, when the content of diamine residues derived from a specific alicyclic diamine exceeds 40 mol% with respect to all diamine residues, the imide group concentration increases and the mobility of the polyimide molecular chains becomes active. dielectric loss tangent may increase.

The specific alicyclic diamine has a cyclohexane skeleton represented by (A) below or a norbornane skeleton represented by (B) below in the molecule. In the cyclohexane skeleton and norbornane skeleton of (A) and (B) below, the position of the bond, the position of the substituent, and the type of substituent are not limited.

The specific alicyclic diamine may have any overall structure as long as it has at least one or more cyclohexane skeletons or norbornane skeletons in the molecule. good. When the molecular weight of the specific alicyclic diamine is less than 100, the imide group concentration of the polyimide increases and the dielectric loss tangent may increase. When the molecular weight exceeds 533, the mobility of the polyimide molecular chains becomes active, and the dielectric loss tangent tends to increase. By having one or more cyclohexane skeletons or norbornane skeletons in the molecule, the molecular motion can be suppressed without increasing the polarity, thereby lowering the dielectric loss tangent. Examples of such specific alicyclic diamines include 1,4-cyclohexanediamine, 1,3-bis(aminomethyl)cyclohexane, 1,4-bis(aminomethyl)cyclohexane, 4,4′-methylenebis(2 -methylcyclohexylamine), 1,1-bis(4-aminophenyl)cyclohexane, bis(aminomethyl)norbornane, and the like. These can use 2 or more types together.

The adhesive polyimide may further contain diamine residues other than those mentioned above, as long as the effects of the invention are not impaired.

The adhesive polyimide can be produced by reacting the acid anhydride component and the diamine component in a solvent to form a polyamic acid, followed by heating and ring closure. For example, an acid anhydride component and a diamine component are dissolved in an organic solvent in approximately equimolar amounts and stirred at a temperature within the range of 0 to 100° C. for 30 minutes to 24 hours for a polymerization reaction to obtain a polyimide precursor. A polyamic acid is obtained. In the reaction, the reaction components are dissolved in the organic solvent so that the resulting precursor is within the range of 5 to 50% by weight, preferably within the range of 10 to 40% by weight. Examples of organic solvents used in the polymerization reaction include N,N-dimethylformamide (DMF), N,N-dimethylacetamide (DMAc), N,N-diethylacetamide, N-methyl-2-pyrrolidone (NMP), 2 -butanone, dimethylsulfoxide (DMSO), hexamethylphosphoramide, N-methylcaprolactam, dimethyl sulfate, cyclohexanone, methylcyclohexane, dioxane, tetrahydrofuran, diglyme, triglyme, methanol, ethanol, benzyl alcohol, cresol and the like. Two or more of these solvents can be used, and aromatic hydrocarbons such as xylene and toluene can also be used in combination. The amount of such an organic solvent to be used is not particularly limited, but the amount used is adjusted so that the concentration of the polyamic acid solution obtained by the polymerization reaction is about 5 to 50% by weight. is preferred.

It is usually advantageous to use the synthesized polyamic acid as a reaction solvent solution, but if necessary, it can be concentrated, diluted, or replaced with another organic solvent. Polyamic acid is also advantageously used because it is generally excellent in solvent solubility. The viscosity of the polyamic acid solution is preferably in the range of 500 mPa·s to 100000 mPa·s. If the thickness is out of this range, defects such as thickness unevenness and streaks are likely to occur in the film during the coating operation using a coater or the like.

The method of imidizing the polyamic acid to form a polyimide is not particularly limited, for example, a heat treatment such as heating for 1 to 24 hours under a temperature condition within the range of 80 to 400 ° C. in the solvent is preferably employed. be done. Moreover, the temperature may be heated under constant temperature conditions, or the temperature may be changed during the process.

In the adhesive polyimide, dielectric properties, thermal expansion coefficient, Physical properties such as tensile modulus and glass transition temperature can be controlled. When the adhesive polyimide has a plurality of structural units, they may be present as blocks or randomly, but preferably randomly.

The adhesive polyimide obtained as described above is a solvent-soluble polyimide that is soluble in an organic solvent such as N-methyl-2-pyrrolidone (NMP) by containing a certain amount or more of residues derived from dimer diamine. and is suitable for application to substrates such as metal foils.

The adhesive polyimide is preferably thermoplastic polyimide. Since the adhesive polyimide is thermoplastic, it is endowed with high adhesiveness and thermocompression bonding processability, making it possible to apply it as an adhesive layer. Here, the “thermoplastic polyimide” generally refers to a polyimide that can be softened by heating and solidified by cooling, which can be repeated, and whose glass transition temperature can be clearly confirmed. It means a polyimide whose glass transition temperature can be clearly confirmed in the temperature range. Further, the thermoplastic polyimide is preferably a polyimide whose glass transition temperature can be clearly confirmed in a temperature range of less than 100 ° C. from the viewpoint of thermocompression bonding at low temperatures, and is measured using a dynamic viscoelasticity measurement device (DMA). More preferably, it has a storage modulus of 1.0×10 ⁸ Pa or more at 30° C. and a storage modulus of less than 1.0×10 ⁷ Pa at the glass transition temperature +30° C. On the other hand, "non-thermoplastic polyimide" refers to polyimide that does not soften or exhibit adhesiveness when heated. C. storage modulus is 1.0×10 ⁹ Pa or more and storage modulus at 300° C. is 1.0×10 ⁸ Pa or more.

The adhesive polyimide preferably has a weight average molecular weight (Mw) within the range of 10,000 to 60,000. If the Mw of the adhesive polyimide is less than 10,000, it tends to become brittle when formed into a film. On the other hand, when the Mw exceeds 60,000, the varnish becomes highly viscous, and thickness unevenness tends to occur during coating. On the other hand, when Mw exceeds 60,000, the molecular chain length becomes long, so that the effect of introducing the alicyclic diamine becomes difficult to manifest, and the dielectric constant and the dielectric loss tangent tend to increase.
A more preferable range of Mw of the adhesive polyimide is in the range of 15,000 to 60,000, more preferably in the range of 18,000 to 50,000. If the Mw is less than 15,000, the number of highly polar acid terminals increases in the polyimide molecular chain, so that the dielectric constant and dielectric loss tangent tend to increase.

Further, the adhesive polyimide preferably has a ratio (Mw/Mn) of Mw to number average molecular weight (Mn) in the range of 1.5 to 2.5, more preferably in the range of 1.8 to 2.0. good.
The ratio Mw/Mn represents polydispersity, and the adhesive polyimide of the present embodiment preferably has a ratio Mw/Mn of 1.5 or more. Even if the Mn is about the same, the higher the degree of dispersion, the higher the frequency of high-molecular-weight substances. Therefore, the motion suppression due to the entanglement of molecules is enhanced, and the dielectric loss tangent can be lowered and the tear strength can be improved. In addition, since Mn represents the number of terminals of the polyimide chain more directly than Mw, the ratio Mw/Mn is set to 2.5 or less, and by balancing with Mn while ensuring a certain degree of dispersion, polyimide molecules It is possible to suppress an increase in the number of highly polar ends in the chain and suppress an increase in the dielectric constant and dielectric loss tangent. Control of Mn is possible by increasing the content of dimer diamine in the dimer diamine composition (that is, by reducing the trimer component and monomer component), thereby suppressing the spread of the molecular weight of the adhesive polyimide. can be done.

The imide group concentration of the adhesive polyimide is preferably 22% by weight or less, more preferably 18 to 22% by weight or less. Here, "imide group concentration" means a value obtained by dividing the molecular weight of the imide group (-(CO) ₂ -N-) in the polyimide by the molecular weight of the entire structure of the polyimide. When the imide group concentration exceeds 22% by weight, the molecular weight of the resin itself becomes small, and the low hygroscopicity deteriorates due to the increase in polar groups, resulting in an increase in Tg and elastic modulus.

Adhesive polyimides are most preferably fully imidized structures. However, part of the polyimide may be amic acid. The imidization rate is around 1015 cm ⁻¹ by measuring the infrared absorption spectrum of the polyimide thin film by the single reflection ATR method using a Fourier transform infrared spectrophotometer (commercial product: FT/IR620 manufactured by JASCO Corporation). can be calculated from the absorbance of C═O stretching derived from the imide group at 1780 cm ⁻¹ based on the benzene ring absorber of .

Adhesive polyimide is an optional component, for example, a plasticizer, other curing resin components such as epoxy resins, curing agents, curing accelerators, organic fillers, inorganic fillers, coupling agents, flame retardants, etc. By appropriately blending, It can be an adhesive composition.

(Crosslinking of adhesive polyimide)
When the adhesive polyimide has a ketone group, the amino of the ketone group and an amino compound having at least two primary amino groups as functional groups (hereinafter sometimes referred to as "crosslink-forming amino compound") A crosslinked structure can be formed by reacting the groups to form a C═N bond. A polyimide having such a crosslinked structure (hereinafter sometimes referred to as “crosslinked polyimide”) is an application example of adhesive polyimide and is a preferred form. Since the Mw varies greatly due to the formation of crosslinks, the Mw of the crosslinked polyimide is a different value from the Mw of the adhesive polyimide before the formation of the crosslinks. Moreover, an adhesive composition in which a cross-linking agent is blended with an adhesive polyimide having a ketone group is another application example of the adhesive polyimide, and is a preferred form. By forming a crosslinked structure, the heat resistance of the adhesive polyimide can be improved. Preferred tetracarboxylic dianhydrides for forming adhesive polyimides having ketone groups include, for example, 3,3′,4,4′-benzophenonetetracarboxylic dianhydride (BTDA), and diamine compounds such as Examples thereof include aromatic diamines such as 4,4'-bis(3-aminophenoxy)benzophenone (BABP) and 1,3-bis[4-(3-aminophenoxy)benzoyl]benzene (BABB).

For the purpose of forming a crosslinked structure, in particular, the BTDA residue derived from BTDA is preferably in the range of 50 mol% or more and 99 mol% or less, more preferably 60 mol%, relative to all tetracarboxylic acid residues. It is preferable to allow the crosslink-forming amino compound to act on the adhesive polyimide contained within the range of 99 mol % or less. In the present invention, "BTDA residue" means a tetravalent group derived from BTDA.

Examples of cross-linking amino compounds include (I) dihydrazide compounds, (II) aromatic diamines, and (III) aliphatic amines. Among these, dihydrazide compounds are preferred. Aliphatic amines other than dihydrazide compounds tend to form a crosslinked structure even at room temperature, and there is concern about the storage stability of varnishes. On the other hand, aromatic diamines require a high temperature to form a crosslinked structure. Thus, when a dihydrazide compound is used, both storage stability of the varnish and shortening of the curing time can be achieved. Examples of dihydrazide compounds include oxalic acid dihydrazide, malonic acid dihydrazide, succinic acid dihydrazide, glutaric acid dihydrazide, adipic acid dihydrazide, pimelic acid dihydrazide, suberic acid dihydrazide, azelaic acid dihydrazide, sebacic acid dihydrazide, dodecanedioic acid dihydrazide, and maleic acid. dihydrazide, fumaric dihydrazide, diglycolic acid dihydrazide, tartaric acid dihydrazide, malic acid dihydrazide, phthalic acid dihydrazide, isophthalic acid dihydrazide, terephthalic acid dihydrazide, 2,6-naphthoic acid dihydrazide, 4,4-bisbenzene dihydrazide, 1,4- Dihydrazide compounds such as naphthoic acid dihydrazide, 2,6-pyridinedioic acid dihydrazide, and itaconic acid dihydrazide are preferred. The above dihydrazide compounds may be used alone or in combination of two or more.

In addition, amino compounds such as (I) dihydrazide compounds, (II) aromatic diamines, and (III) aliphatic amines are, for example, a combination of (I) and (II), a combination of (I) and (III), Two or more types can also be used in combination across categories, such as combinations of (I), (II) and (III).

In addition, from the viewpoint of making the network structure formed by cross-linking by the cross-linking amino compound denser, the cross-linking amino compound used in the present invention has a molecular weight (when the cross-linking amino compound is an oligomer (weight average molecular weight) is preferably 5,000 or less, more preferably 90 to 2,000, still more preferably 100 to 1,500. Among these, a cross-linking amino compound having a molecular weight of 100 to 1,000 is particularly preferred. When the molecular weight of the cross-linking amino compound is less than 90, only one amino group of the cross-linking amino compound forms a C=N bond with the ketone group of the adhesive polyimide, and the surroundings of the remaining amino groups are steric. , the remaining amino groups tend to be less likely to form C=N bonds.

When cross-linking the ketone groups in the adhesive polyimide and the amino compound for cross-linking, the amino compound for cross-linking is added to the resin solution containing the adhesive polyimide to form cross-links with the ketone groups in the adhesive polyimide. condensation reaction with the primary amino group of the amino compound for use. Due to this condensation reaction, the resin solution is cured into a cured product. In this case, the amount of the cross-linking amino compound to be added is 0.004 mol to 1.5 mol, preferably 0.005 mol to 1.2 mol, in total of the primary amino group per 1 mol of the ketone group. More preferably 0.03 mol to 0.9 mol, most preferably 0.04 mol to 0.6 mol. If the amount of the cross-linking amino compound added is less than 0.004 mol in total for the primary amino group per 1 mol of the ketone group, the cross-linking by the cross-linking amino compound is not sufficient. Heat resistance tends to be difficult to develop, and if the amount of the amino compound for cross-linking exceeds 1.5 mol, the unreacted amino compound for cross-linking acts as a thermoplastic, reducing the heat resistance of the adhesive layer. tend to let

Condensation reaction conditions for crosslink formation are conditions under which the ketone group in the adhesive polyimide reacts with the primary amino group of the amino compound for crosslink formation to form an imine bond (C=N bond). There are no particular restrictions. The temperature of the heat condensation is, for example, 120° C. for reasons such as releasing water generated by the condensation to the outside of the system, or simplifying the condensation step when the heat condensation reaction is subsequently performed after the synthesis of the adhesive polyimide. It is preferably within the range of -220°C, more preferably within the range of 140-200°C. The reaction time is preferably about 30 minutes to 24 hours. The end point of the reaction, for example, using a Fourier transform infrared spectrophotometer (commercial product: FT/IR620 manufactured by JASCO Corporation), by measuring the infrared absorption spectrum, absorption derived from the ketone groups in the polyimide resin near 1670 cm ^-1 It can be confirmed by the decrease or disappearance of the peak and the appearance of an absorption peak derived from the imine group near 1635 cm ⁻¹ .

The heat condensation of the ketone group of the adhesive polyimide and the primary amino group of the amino compound for cross-linking can be carried out by, for example,
(1) A method of adding an amino compound for cross-linking and heating following the synthesis (imidization) of an adhesive polyimide,
(2) An excess amount of an amino compound is charged in advance as a diamine component, and following the synthesis (imidation) of an adhesive polyimide, the remaining amino compound that is not involved in imidization or amidation is used as an amino compound for forming crosslinks. a method of heating with an adhesive polyimide,
or
(3) After processing the adhesive polyimide solution (adhesive composition) to which the above amino compound for cross-linking is added (adhesive composition) into a predetermined shape (for example, after coating on an arbitrary substrate or after forming into a film) how to heat to
etc.

In order to impart heat resistance to the adhesive polyimide, an example of a crosslinked polyimide having a crosslinked structure formed by forming an imine bond has been described, but the method is not limited to this. Resin curing agents, maleimide, activated ester resins, compounds having unsaturated bonds such as resins having a styrene skeleton, etc., may be blended and cured.

[Adhesive composition]
Since the adhesive polyimide is solvent-soluble, it can be used in the form of a solvent-containing adhesive composition (polyimide solution). That is, the adhesive composition contains adhesive polyimide and a solvent capable of dissolving this adhesive polyimide. Moreover, the adhesive composition can contain an amino compound for cross-linking as an optional component. The adhesive composition contains adhesive polyimide as the main component of the resin component, preferably 70% by weight or more of the resin component, more preferably 90% by weight or more of the resin component, and most preferably as the entire resin component. In addition, the main component of the resin component means a component contained in an amount of 50% by weight or more with respect to the total resin component.

The solvent is not particularly limited as long as it can dissolve the adhesive polyimide. methyl-2-pyrrolidone (NMP), 2-butanone, dimethylsulfoxide (DMSO), hexamethylphosphoramide, N-methylcaprolactam, dimethyl sulfate, cyclohexanone, methylcyclohexane, dioxane, tetrahydrofuran, diglyme, triglyme, methanol, ethanol, benzyl alcohol, cresol, acetone and the like. Two or more of these solvents can be used in combination, and aromatic hydrocarbons such as xylene and toluene can also be used in combination.

In the adhesive composition, the compounding ratio of the adhesive polyimide and the solvent is not particularly limited as long as the viscosity of the composition can be maintained to the extent that it can be coated. The viscosity of the adhesive composition is preferably within the range of, for example, 500 mPa·s to 100000 mPa·s. If the thickness is out of this range, defects such as thickness unevenness and streaks are likely to occur in the resin film during the coating operation.

The adhesive composition may contain optional components, such as plasticizers, other curing resin components such as epoxy resins, curing agents, curing accelerators, organic fillers, inorganic fillers, coupling agents, as long as the effects of the invention are not impaired. Solvents, flame retardants, and the like can be appropriately blended.

[Polyimide film/adhesive film]
A polyimide film according to one embodiment of the present invention is obtained by processing the above adhesive polyimide or crosslinked polyimide into a film shape. The polyimide constituting the polyimide film contains a diamine residue derived from a dimer diamine composition in a range of 60 mol% to 99 mol% with respect to all diamine residues, and a diamine derived from a specific alicyclic diamine The residue is contained within the range of 1 mol % or more and 40 mol % or less.

The polyimide film preferably has a dielectric loss tangent (Tan δ ₁ ) at 10 GHz measured by a split post dielectric resonator (SPDR) after conditioning for 24 hours under constant temperature and humidity conditions (normal state) of 23 ° C. and 50% RH. is 0.002 or less, more preferably 0.0018 or less, and the dielectric constant (ε ₁ ) is 3.0 or less, preferably 2.6 or less. If the dielectric loss tangent (Tan δ ₁ ) and the relative dielectric constant (ε ₁ ) exceed the above values, the dielectric loss will increase when applied to a circuit board, and the frequency will be in the GHz band (for example, 1 to 40 GHz). Inconveniences such as loss of electric signals tend to occur on the transmission path.

Polyimide films also exhibit characteristic dielectric properties of low frequency dependence. For example, the dielectric loss tangent (Tan δ ₂ ) at 20 GHz measured by a split post dielectric resonator (SPDR) after conditioning the polyimide film for 24 hours under constant temperature and humidity conditions (normal state) of 23 ° C. and 50% RH is , the dielectric loss tangent (Tan δ ₁ ) at a frequency of 10 GHz, preferably 0.002 or less, more preferably 0.0019 or less, and the dielectric constant (ε ₂ ) of 3.0 or less, preferably 2.0. It should be 6 or less.

A preferred form of polyimide film is an adhesive film. The adhesive film preferably contains 70% by weight or more of the resin component as a main component, more preferably 90% by weight or more of the resin component, and most preferably as the entire resin component, the above adhesive polyimide or crosslinked polyimide. It is not particularly limited as long as it contains the film. In addition, the main component of the resin component means a component contained in an amount of 50% by weight or more with respect to the total resin component. The adhesive film may be a film (sheet) made of adhesive polyimide or crosslinked polyimide. It may be in a state of being laminated on a resin substrate such as a film. The adhesive film can be appropriately blended with optional components such as plasticizers, other curing resin components such as epoxy resins, curing agents, curing accelerators, organic fillers, inorganic fillers, coupling agents, flame retardants, and the like. .

The method for producing the adhesive film of the present embodiment is not particularly limited, but the following methods [1] to [3] can be exemplified.
[1] An arbitrary base material is coated with an adhesive polyimide in the form of a solution (for example, the state of an adhesive composition) to form a coating film, which is dried at a temperature of, for example, 80 to 180 ° C. to form a film. A method of peeling off from the base material as necessary after curing.
[2] A method in which a solution of polyamic acid, which is a precursor of adhesive polyimide, is applied to an arbitrary base material, dried, imidized to form a film, and then peeled off from the base material as necessary.
[3] A method of applying and drying a solution of polyamic acid, which is a precursor of adhesive polyimide, to an arbitrary base material, then peeling off the polyamic acid gel film from the base material and imidizing it to form an adhesive film.
The method of applying the adhesive polyimide solution (or the polyamic acid solution) onto the base material is not particularly limited, and it can be applied, for example, by a comma, die, knife, lip coater, or the like.

Next, a laminate, a metal-clad laminate, a circuit board, and a multilayer circuit board, which are preferred embodiments to which an adhesive film is applied, will be described with specific examples.

[Laminate]
A laminate 100 according to one embodiment of the present invention, for example, as shown in FIG. The adhesive layer 20 is made of the above adhesive film. Note that the laminate 100 may include arbitrary layers other than those described above. Examples of the substrate 10 in the laminate 100 include inorganic material substrates such as copper foil and glass plates, and resin material substrates such as polyimide films, polyamide films, and polyester films. The laminate 100 can be produced according to any one of [1] to [3] of the method for producing an adhesive film, except that it is not separated from the base material 10 . Alternatively, the laminate 100 may be manufactured by separately preparing the substrate 10 and the adhesive film and bonding them together.
Preferred embodiments of the laminate 100 include a coverlay film, a resin-coated copper foil, and the like.

[Coverlay film]
Although not shown, the coverlay film, which is one aspect of the laminate 100, includes a coverlay film material layer as the base material 10 and an adhesive layer laminated on one side of the coverlay film material layer. 20, and the adhesive layer 20 is made of the adhesive film. In addition, the coverlay film may contain arbitrary layers other than the above.

The material of the coverlay film material layer is not particularly limited, but polyimide films such as polyimide resins, polyetherimide resins, and polyamideimide resins, polyamide films, polyester films, and the like can be used, for example. Among these, it is preferable to use a polyimide film having excellent heat resistance. In addition, the coverlay film material may contain a black pigment in order to effectively exhibit light-shielding properties, concealability, and design properties. Optional ingredients such as matte pigments to suppress gloss can be included.

The thickness of the coverlay film material layer is not particularly limited, but is preferably in the range of 5 μm or more and 100 μm or less, for example.
Although the thickness of the adhesive layer 20 is not particularly limited, it is preferably in the range of 10 μm or more and 75 μm or less, for example.

The coverlay film of this embodiment can be manufactured by the method illustrated below.
First, as a first method, polyimide, which will be the adhesive layer 20, is applied to one side of a film material layer for a coverlay in a solution state (for example, a varnish containing a solvent is preferable, and an adhesive composition is preferable). and then dried at a temperature of, for example, 80 to 180° C. to form the adhesive layer 20 , thereby forming a coverlay film having the coverlay film material layer and the adhesive layer 20 .

As a second method, the polyimide for the adhesive layer 20 is applied in the form of a solution (for example, a varnish containing a solvent, preferably an adhesive composition) on an arbitrary base material. , for example, after drying at a temperature of 80 to 180° C., the resin film for the adhesive layer 20 is formed by peeling, and this resin film is bonded to the film material layer for the coverlay at a temperature of, for example, 60 to 220° C. A coverlay film can be formed by thermocompression bonding.

[Copper foil coated with resin]
The resin-coated copper foil, which is another aspect of the laminate 100, is a copper foil with an adhesive layer 20 laminated on at least one side of the copper foil as the base material 10, although not shown. It consists of an agent film. In addition, the resin-coated copper foil of the present embodiment may include arbitrary layers other than those described above.

The thickness of the adhesive layer 20 in the resin-coated copper foil is preferably, for example, within the range of 0.1 to 125 μm, more preferably within the range of 0.3 to 100 μm. If the thickness of the adhesive layer 20 is less than the above lower limit, problems such as insufficient adhesion may occur. On the other hand, if the thickness of the adhesive layer 20 exceeds the above upper limit, problems such as reduced dimensional stability will occur. Moreover, from the viewpoint of lowering the dielectric constant and the dielectric loss tangent, it is preferable to set the thickness of the adhesive layer 20 to 3 μm or more.

The material of the copper foil in the resin-coated copper foil preferably contains copper or a copper alloy as a main component. The thickness of the copper foil is preferably 35 μm or less, more preferably within the range of 5 to 25 μm. The lower limit of the thickness of the copper foil is preferably 5 μm from the viewpoint of production stability and handling. The copper foil may be rolled copper foil or electrolytic copper foil. Moreover, as a copper foil, the copper foil marketed can be used.

The resin-coated copper foil may be prepared, for example, by sputtering a metal onto an adhesive film to form a seed layer, followed by forming a copper layer, for example, by copper plating, or by combining an adhesive film and a copper foil. may be prepared by laminating by a method such as thermocompression bonding. Furthermore, in order to form the adhesive layer 20 on the copper foil with resin, a coating liquid of adhesive polyimide or its precursor is cast, dried to form a coating film, and then subjected to necessary heat treatment. may be prepared using

[Metal clad laminate]
(First aspect)
A metal-clad laminate according to an embodiment of the present invention comprises an insulating resin layer and a metal layer laminated on at least one surface of the insulating resin layer, at least one of the insulating resin layers comprising the above-mentioned It consists of an adhesive film. In addition, the metal-clad laminate of the present embodiment may contain arbitrary layers other than those described above.

(Second aspect)
A metal-clad laminate according to another embodiment of the present invention comprises an insulating resin layer 30, an adhesive layer 20 laminated on at least one surface of the insulating resin layer 30, and A so-called three-layer metal-clad laminate 101 including a metal layer M laminated on an insulating resin layer 30 via an adhesive layer 20, and the adhesive layer 20 is made of the adhesive film. . In addition, the three-layer metal-clad laminate 101 may contain arbitrary layers other than the above. In the three-layer metal-clad laminate 101, the adhesive layer 20 may be provided on one side or both sides of the insulating resin layer 30, and the metal layer M may be provided on one side or both sides of the insulating resin layer 30 with the adhesive layer 20 interposed therebetween. It suffices if it is provided on both sides. That is, the three-layer metal-clad laminate 101 may be a single-sided metal-clad laminate or a double-sided metal-clad laminate. A single-sided FPC or a double-sided FPC can be manufactured by etching the metal layer M of the three-layer metal-clad laminate 101 for wiring circuit processing.

The insulating resin layer 30 in the three-layer metal-clad laminate 101 is not particularly limited as long as it is made of an electrically insulating resin. Examples include fluoroethylene, silicone, ETFE, etc., but it is preferably composed of polyimide. The polyimide layer forming the insulating resin layer 30 may be a single layer or multiple layers, but preferably includes a non-thermoplastic polyimide layer.

The thickness of the insulating resin layer 30 in the three-layer metal-clad laminate 101 is, for example, preferably within the range of 1 to 125 μm, more preferably within the range of 5 to 100 μm. If the thickness of the insulating resin layer 30 is less than the above lower limit, problems such as insufficient electrical insulation may occur. On the other hand, if the thickness of the insulating resin layer 30 exceeds the above upper limit, problems such as warping of the metal-clad laminate will occur.

The thickness of the adhesive layer 20 in the three-layer metal-clad laminate 101 is, for example, preferably within the range of 0.1 to 125 μm, more preferably within the range of 0.3 to 100 μm. In the three-layer metal-clad laminate 101 of the present embodiment, if the thickness of the adhesive layer 20 is less than the above lower limit, problems such as insufficient adhesion may occur. On the other hand, if the thickness of the adhesive layer 20 exceeds the above upper limit, problems such as reduced dimensional stability will occur. From the viewpoint of reducing the dielectric constant and dielectric loss tangent of the entire insulating layer, which is a laminate of the insulating resin layer 30 and the adhesive layer 20, the thickness of the adhesive layer 20 is preferably 3 μm or more.

Further, the ratio of the thickness of the insulating resin layer 30 to the thickness of the adhesive layer 20 (thickness of the insulating resin layer 30/thickness of the adhesive layer 20) is preferably in the range of 0.1 to 3.0, for example. It is more preferably in the range of 0.15 to 2.0. Warping of the three-layer metal-clad laminate 101 can be suppressed by using such a ratio. Moreover, the insulating resin layer 30 may contain a filler if necessary. Examples of fillers include silicon dioxide, aluminum oxide, magnesium oxide, beryllium oxide, boron nitride, aluminum nitride, silicon nitride, aluminum fluoride, calcium fluoride, metal salts of organic phosphinic acids, and the like. These can be used singly or in combination of two or more.

(Third aspect)
A metal-clad laminate according to still another embodiment of the present invention is, for example, as shown in FIG. A tension laminate 102 is shown. The laminated metal-clad laminate 102 includes a first single-sided metal-clad laminate 41, a second single-sided metal-clad laminate 42, a first single-sided metal-clad laminate 41, and a second single-sided metal-clad laminate. and an adhesive layer 20 laminated between 42, the adhesive layer 20 being made of the adhesive film.
Here, the first single-sided metal-clad laminate 41 has a first metal layer M1 and a first insulating resin layer 31 laminated on at least one surface of the first metal layer M1. ing. The second single-sided metal-clad laminate 42 has a second metal layer M2 and a second insulating resin layer 32 laminated on at least one surface of the second metal layer M2. The adhesive layer 20 is arranged so as to contact the first insulating resin layer 31 and the second insulating resin layer 32 . Note that the laminated metal-clad laminate 102 may contain arbitrary layers other than those described above.

The first insulating resin layer 31 and the second insulating resin layer 32 in the laminated metal-clad laminate 102 have the same configuration as the insulating resin layer 30 in the three-layer metal-clad laminate 101 of the second embodiment. good.
For the lamination-type metal-clad laminate 102, a first single-sided metal-clad laminate 41 and a second single-sided metal-clad laminate 42 are prepared, and the first insulating resin layer 31 and the second insulating resin layer 32 are laminated. It can be manufactured by placing an adhesive film between and laminating.

(Fourth aspect)
A metal-clad laminate according to still another embodiment of the present invention, for example, as shown in FIG. and an adhesive layer 20 laminated on the other surface of the insulating resin layer 33, wherein the adhesive layer 20 is the above It consists of an adhesive film. In addition, the metal-clad laminate 103 with an adhesive layer may contain arbitrary layers other than the above.
The insulating resin layer 33 in the adhesive layer-attached metal-clad laminate 103 may have the same configuration as the insulating resin layer 30 in the three-layer metal-clad laminate 101 of the second embodiment.
The metal-clad laminate 103 with an adhesive layer can be manufactured by preparing a single-sided metal-clad laminate having an insulating resin layer 33 and a metal layer M, and bonding an adhesive film to the insulating resin layer 33 side.

In the metal-clad laminate of any one of the first to fourth embodiments illustrated above, the material of the metal layer M (including the first metal layer M1 and the second metal layer M2; the same shall apply hereinafter) includes: Examples include, but are not limited to, copper, stainless steel, iron, nickel, beryllium, aluminum, zinc, indium, silver, gold, tin, zirconium, tantalum, titanium, lead, magnesium, manganese, and alloys thereof. Among these, copper or a copper alloy is particularly preferable. The material of the wiring layer in the circuit board, which will be described later, is also the same as that of the metal layer M.

The thickness of the metal layer M is not particularly limited, but when using a metal foil such as a copper foil, the thickness is preferably 35 μm or less, more preferably in the range of 5 to 25 μm. The lower limit of the thickness of the metal foil is preferably 5 μm from the viewpoint of production stability and handling. When copper foil is used, it may be rolled copper foil or electrolytic copper foil. Moreover, as a copper foil, the copper foil marketed can be used. In addition, the metal foil may be subjected to surface treatment with, for example, siding, aluminum alcoholate, aluminum chelate, silane coupling agent, etc., for the purpose of rust prevention treatment and adhesion strength improvement.

[Circuit board]
(First aspect)
A circuit board according to an embodiment of the present invention is formed by wiring the metal layer of the metal-clad laminate of any one of the above-described embodiments. A circuit board such as an FPC can be manufactured by patterning one or more metal layers of a metal-clad laminate into a wiring layer (conductor circuit layer) by a conventional method. In addition, the circuit board may be provided with a coverlay film that covers the wiring layer.

(Second aspect)
A circuit board 200 according to another embodiment of the present invention includes, for example, a first base material 11 and a wiring layer 50 laminated on at least one surface of the first base material 11, as shown in FIG. and an adhesive layer 20 laminated so as to cover the wiring layer 50 on the wiring layer 50 side surface of the first base material 11, and the adhesive layer 20 is made of the adhesive film. . Note that the circuit board 200 may include arbitrary layers other than those described above.
The first base material 11 in the circuit board 200 may have the same configuration as the insulating resin layer of the metal-clad laminate. The circuit board 200 includes a first base material 11 and a wiring layer 50 laminated on at least one surface of the first base material 11, and an adhesive film is attached to the wiring layer 50 side of the circuit board. can be manufactured by

(Third aspect)
A circuit board 201 according to still another embodiment of the present invention includes, for example, a first base material 11 and a wiring layer 50 laminated on at least one surface of the first base material 11, as shown in FIG. , the adhesive layer 20 laminated so as to cover the wiring layer 50 on the surface of the first base material 11 on the wiring layer 50 side, and the surface of the adhesive layer 20 opposite to the first base material 11 and a laminated second base material 12, and the adhesive layer 20 is made of the adhesive film. Note that the circuit board 201 may include arbitrary layers other than those described above. The first base material 11 and the second base material 12 in the circuit board 201 may have the same structure as the insulating resin layer of the metal-clad laminate.
The circuit board 201 is provided on the wiring layer 50 side of the circuit board provided with the first base material 11 and the wiring layer 50 laminated on at least one surface of the first base material 11 via an adhesive film. It can be manufactured by laminating the second base material 12 .

(Fourth aspect)
A circuit board 202 according to still another embodiment of the present invention includes, for example, a first base material 11 and an adhesive layer laminated on at least one surface of the first base material 11, as shown in FIG. 20, the second base material 12 laminated on the surface of the adhesive layer 20 opposite to the first base material 11, and the adhesive layers of the first base material 11 and the second base material 12 Wiring layers 50 and 50 are laminated on the surface opposite to 20, and the adhesive layer 20 is made of the adhesive film. Note that the circuit board 202 may include arbitrary layers other than those described above. The first base material 11 and the second base material 12 in the circuit board 202 may have the same structure as the insulating resin layer of the metal-clad laminate.
The circuit board 202 includes a first base material 11, a wiring layer 50 laminated on at least one surface of the first base material 11, and a second base material 12. , and a wiring layer 50 laminated on at least one surface of the second base material 12 are prepared, respectively, and the first base material 11 of the first circuit board and the second circuit board are prepared. It can be manufactured by arranging an adhesive film between two circuit boards and the second base material 12 and laminating them together.

[Multilayer circuit board]
A multilayer circuit board according to one embodiment of the present invention includes a laminate in which a plurality of insulating resin layers are laminated, and one or more wiring layers embedded in the laminate, and comprises a plurality of insulating resin layers. At least one or more of the resin layers is formed of an adhesive layer 20 that has adhesiveness and covers the wiring layer, and the adhesive layer 20 is made of the adhesive film. In addition, the multilayer circuit board of the present embodiment may include arbitrary layers other than the above.
For example, as shown in FIG. 8, the multilayer circuit board 203 of the present embodiment has at least two insulating resin layers 34 and at least two wiring layers 50. At least one of the wiring layers 50 The layers are covered with an adhesive layer 20 . The adhesive layer 20 covering the wiring layer 50 may partially cover the surface of the wiring layer 50 or may cover the entire surface of the wiring layer 50 . Moreover, the multilayer circuit board 203 may optionally have a wiring layer 50 exposed on the surface of the multilayer circuit board 203 . Moreover, it may have an interlayer connection electrode (via electrode) in contact with the wiring layer 50 . The wiring layer 50 is formed by forming a conductor circuit in a predetermined pattern on one side or both sides of the insulating resin layer 34 . The conductive circuit may be patterned on the surface of the insulating resin layer 34, or may be patterned in a damascene (embedded) manner. The insulating resin layer 34 of the circuit board 203 may have the same structure as the insulating resin layer of the metal-clad laminate.

Since the circuit board and the multilayer circuit board of each of the above embodiments are provided with the adhesive layer 20 containing adhesive polyimide, transmission loss can be reduced even in high-frequency transmission.

EXAMPLES Examples are given below to more specifically describe the features of the present invention. However, the scope of the present invention is not limited to the examples. In the following examples, unless otherwise specified, various measurements and evaluations are as follows.

[Method for measuring amine value]
About 2 g of the dimer diamine composition was weighed into a 200-250 mL Erlenmeyer flask, phenolphthalein was used as an indicator, and a 0.1 mol/L ethanolic potassium hydroxide solution was added dropwise until the solution exhibited a light pink color. , in about 100 mL of neutralized butanol. Add 3 to 7 drops of phenolphthalein solution thereto, and titrate with stirring with 0.1 mol/L ethanolic potassium hydroxide solution until the sample solution turns pale pink. Five drops of bromophenol blue solution are added thereto, and titration is performed with stirring with a 0.2 mol/L hydrochloric acid/isopropanol solution until the sample solution turns yellow.
The amine value is calculated by the following formula (1).
Amine value = {(V ₂ ×C ₂ )−(V ₁ ×C ₁ )}×M _KOH /m (1)
Here, the amine value is a value expressed in mg-KOH/g, and M _KOH is the molecular weight of potassium hydroxide, 56.1. Further, V and C are the volume and concentration of the solution used for titration, respectively, and the subscripts 1 and 2 are 0.1 mol/L ethanolic potassium hydroxide solution and 0.2 mol/L hydrochloric acid/isopropanol solution, respectively. represents Additionally, m is the sample weight in grams.

[Measurement of weight average molecular weight (Mw) of polyimide]
The weight average molecular weight was measured by gel permeation chromatography (manufactured by Tosoh Corporation, using HLC-8220GPC). Polystyrene was used as a standard substance, and tetrahydrofuran (THF) was used as a developing solvent.

[Measurement of number average molecular weight (Mn) of polyimide]
The number average molecular weight was measured by gel permeation chromatography (manufactured by Tosoh Corporation, using HLC-8220GPC). Polystyrene was used as a standard substance, and tetrahydrofuran (THF) was used as a developing solvent.

[Calculation of molecular weight distribution of polyimide]
Using the results obtained by GPC measurement, the molecular weight distribution of polyimide was calculated from Mw/Mn.

[Measurement of viscosity]
Using an E-type viscometer (DV-II+ProCP type), the viscosity (cP) of the polyimide solution immediately after polymerization was measured under the conditions of temperature: 25° C., number of revolutions: 100 RPM, measurement time: 2 minutes.

[Measurement of dielectric constant and dielectric loss tangent]
Using a vector network analyzer (manufactured by Agilent, trade name: vector network analyzer E8363C) and an SPDR resonator, the resin sheet was left for 24 hours under conditions of temperature: 23 ° C. and humidity: 50%. Dielectric constant (ε ₁ ) and dielectric loss tangent (Tan δ ₁ ), and relative dielectric constant (ε ₂ ) and dielectric loss tangent (Tan δ ₂ ) at a frequency of 20 GHz were measured.

[Glass transition temperature (Tg)]
The glass transition temperature (Tg) was measured by using a thermomechanical analyzer (TMA: manufactured by Netsch, trade name: TMA4000SA) on a resin sheet with a size of 5 mm × 20 mm from 0 ° C. to 300 ° C. at a heating rate of 5 ° C./ Measurements were made in minutes. The temperature at which the elongation becomes an inflection point when the temperature is raised was defined as the glass transition temperature.

[Tensile modulus]
Tensile modulus was measured by the following procedure. First, a test piece (width 12.7 mm×length 127 mm) was produced from a resin sheet using a tension tester (manufactured by Orientec, trade name: Tensilon). Using this test piece, a tensile test was performed at 50 mm/min to determine the tensile modulus at 25°C.

[Warpage evaluation method]
The evaluation of warpage was performed by the following method. A 25 μm thick polyimide film (manufactured by Toray DuPont, trade name: Kapton 100EN) or a 12 μm copper foil is coated with a polyimide solution so that the thickness after drying is 25 μm, and a test piece is prepared. was made. In this state, place the polyimide film or copper foil on the bottom surface, measure the average warped height of the four corners of the test piece, 5 mm or less is "good", more than 5 mm is "fail" did.

[Calculation of area percent of GPC and chromatogram]
For GPC, 20 mg of the dimer diamine composition was pretreated with 200 μL of acetic anhydride, 200 μL of pyridine and 2 mL of THF, and 100 mg of the solution was diluted with 10 mL of THF (containing 1000 ppm of cyclohexanone) to prepare samples. The prepared sample was manufactured by Tosoh Corporation, trade name; using HLC-8220GPC, column: TSK-gel G2000HXL, G1000HXL, flow rate: 1 mL / min, column (oven) temperature: 40 ° C., injection volume: 50 μL. measured in In addition, cyclohexanone was treated as a standard substance for correction of effluent time.

At this time, the peak top of the main peak of cyclohexanone is adjusted so that the retention time is 27 minutes to 31 minutes, and the peak end is 2 minutes from the peak start of the main peak of cyclohexanone, and the peak of cyclohexanone is excluded. Each of the above components (a ) ~ (c) as
(a) the component represented by the main peak;
(b) A component represented by a GPC peak detected at a time later than the minimum value on the time side with a slow retention time in the main peak;
(c) A component represented by a GPC peak detected at an earlier time than the minimum value on the time side where the retention time in the main peak is early;
detected.

The abbreviations used in the examples represent the following compounds.
BTDA: 3,3',4,4'-benzophenonetetracarboxylic dianhydride DDA: Aliphatic diamine having 36 carbon atoms (manufactured by Croda Japan Co., Ltd., trade name; PRIAMINE 1074 distilled and purified, amine value: 210 mg KOH/ g, mixture of dimer diamine of cyclic structure and chain structure, component (a); 97.9%, component (b); 0.3%, component (c); 1.8%)
1,3-BAC: 1,3-bis(aminomethyl)cyclohexane 1,4-BAC: 1,4-bis(aminomethyl)cyclohexane DMDC: 4,4′-methylenebis(2-methylcyclohexylamine)
BAN: bis (aminomethyl) norbornane BAPC: 1,1-bis (4-aminophenyl) cyclohexane N-12: dodecanedioic acid dihydrazide NMP: N-methyl-2-pyrrolidone OP935: aluminum salt of phosphinic acid (manufactured by Clariant , trade name; Exolit OP935, aluminum diethylphosphinate, phosphorus content 23%, average particle size 2 μm)
In the above DDA, "%" of component (a), component (b), and component (c) means area percent of chromatogram in GPC measurement. Further, the molecular weight of DDA was calculated by the following formula.
Molecular weight = 56.1 x 2 x 1000/amine value

[Example 1]
In a 500 ml separable flask, 12.96 g BTDA (0.04017 mol), 17.00 g DDA (0.03182 mol), 1.133 g 1,3-BAC (0.00795 mol), 44 g NMP and 29 g of xylene were added and well mixed at 40° C. for 1 hour to prepare a polyamic acid solution. The polyamic acid solution was heated to 190° C., heated and stirred for 5 hours, and 20 g of xylene was added to complete imidization. viscosity; 4,366 cP) was prepared.

[Examples 2 to 6]
Polyimide solutions 2 to 6 were prepared in the same manner as in Example 1, except that the raw material compositions shown in Table 1 were used.

(Comparative example 1)
A polyimide solution 7 was prepared in the same manner as in Example 1, except that the raw material composition shown in Table 1 was used.

[Example 7]
A polyimide solution 1 was applied to one side of a release PET film 1 (manufactured by Higashiyama Film Co., Ltd., trade name: HY-S05, length x width x thickness = 200 mm x 300 mm x 25 μm), dried at 100 ° C. for 5 minutes, By drying at 120° C. for 5 minutes and peeling the adhesive layer from the release PET film 1, a resin sheet 8 having a thickness of 25 μm was obtained. Various evaluation results of the resin sheet 8 are as follows.
ε ₁ ; 2.7, Tan δ ₁ ; 0.0019 _, ε ₂ ; 2.7, Tan δ ₂ ; 0.0018, Tg; 46.1°C, Tensile elastic modulus; 1060 MPa

[Examples 8 to 12]
Resin sheets 9 to 13 were obtained in the same manner as in Example 7, except that polyimide solutions 2 to 6 were used. Various evaluation results of resin sheets 9 to 13 are shown in Table 2.

(Comparative example 2)
A resin sheet 14 was obtained in the same manner as in Example 7, except that the polyimide solution 7 was used. Various evaluation results of the resin sheet 14 are shown in Table 2.

[Example 13]
100 g of polyimide solution 1 (30 g as solids) was blended with 1.1 g of N-12 (0.004 mol) and diluted with 7.5 g of OP935, 0.5 g of NMP and 10.5 g of xylene. and further stirred for 1 hour to prepare an adhesive composition 13.

[Example 14]
The adhesive composition 13 is applied to one side of the release PET film 1, dried at 80° C. for 15 minutes, and the adhesive layer is peeled off from the release PET film 1, thereby forming an adhesive film 14 having a thickness of 25 μm. got

[Example 15]
Adhesive composition 13 was applied to polyimide film 1 (manufactured by Toray DuPont, trade name: Kapton 50EN, ε ₁ =3.6, tan δ ₁ =0.0084, length × width × thickness = 200 mm × 300 mm × 12 µm). It was applied to one side and dried at 80° C. for 15 minutes to obtain a coverlay film 15 having an adhesive layer thickness of 25 μm. The warpage state of the obtained coverlay film 15 was "good".

[Example 16]
The release PET film 1 was laminated so as to be in contact with the adhesive layer side of the coverlay film 15, and pressure-bonded using a vacuum laminator at a temperature of 160° C. and a pressure of 0.8 MPa for 2 minutes. After that, the adhesive composition 13 is applied to the polyimide film 1 side of the coverlay film 15 with the release PET film 1 pressure-bonded to the adhesive layer side so that the thickness after drying becomes 25 μm, and dried at 80° C. for 15 minutes. did Then, the adhesive composition 13 is laminated so that the release PET film 1 is in contact with the coated and dried surface of the adhesive composition 13, and the pressure is applied for 2 minutes at a temperature of 160 ° C. and a pressure of 0.8 MPa using a vacuum laminator. A polyimide adhesive laminate 16 having an adhesive layer was obtained.

[Example 17]
The adhesive composition 13 was applied to one side of an electrolytic copper foil having a thickness of 12 μm and dried at 80° C. for 15 minutes to obtain a resin-coated copper foil 17 having an adhesive layer having a thickness of 25 μm. The warping state of the obtained resin-coated copper foil 17 was "good".

[Example 18]
The adhesive composition 13 was applied to one side of an electrolytic copper foil having a thickness of 12 μm and dried at 80° C. for 30 minutes to obtain a resin-coated copper foil 18 having an adhesive layer having a thickness of 50 μm. The warping state of the obtained resin-coated copper foil 18 was "good".

[Example 19]
An adhesive composition 13 was further applied to the surface of the adhesive layer of the resin-coated copper foil 18 and dried at 80° C. for 30 minutes to obtain a resin-coated copper foil 19 having a total adhesive layer thickness of 100 μm. . The warping state of the obtained resin-coated copper foil 19 was "good".

[Example 20]
The adhesive composition 13 is applied to one side of the release PET film 1, dried at 80° C. for 30 minutes, and the adhesive layer is peeled off from the release PET film 1, thereby forming an adhesive film 20 having a thickness of 50 μm. got

[Example 21]
Adhesive film 20, polyimide film 2 (manufactured by DuPont, trade name: Kapton 100-EN, thickness 25 μm, ε ₁ =3.6, tan δ ₁ =0.0084), adhesive on 12 μm thick electrolytic copper foil. A film 20 and an electrolytic copper foil with a thickness of 12 μm were laminated in order, and after crimping for 2 minutes at a temperature of 160° C. and a pressure of 0.8 MPa using a vacuum laminator, the temperature was raised from room temperature to 160° C. and heat treatment was performed at 160° C. for 4 hours. Thus, a copper-clad laminate 21 was obtained.

[Example 22]
The cover lay film 15 was laminated on an electrolytic copper foil having a thickness of 12 μm so that the adhesive layer side of the cover lay film 15 was in contact with the copper foil, and was crimped using a vacuum laminator at a temperature of 160° C. and a pressure of 0.8 MPa for 2 minutes. C. and heat-treated at 160.degree. C. for 2 hours to obtain a copper-clad laminate 22.

[Example 23]
An adhesive film 14 is laminated on a rolled copper foil having a thickness of 12 μm, and the polyimide film 1 side of the cover lay film 15 is laminated so as to be in contact with the adhesive film 14 . After laminating the rolled copper foils in order using a vacuum laminator at a temperature of 160 ° C. and a pressure of 0.8 MPa for 2 minutes, the temperature is raised from room temperature to 160 ° C., heat treated at 160 ° C. for 2 hours, copper clad lamination A plate 23 was obtained.

[Example 24]
Two resin-coated copper foils 17 were prepared, and a polyimide film 3 (manufactured by DuPont, trade name: Kapton 200-EN, thickness 50 μm, ε ₁ =3.6) was applied to the adhesive layer side of the two resin-coated copper foils 17 . , tan δ ₁ = 0.0084) are in contact with each other, and press-bonded for 5 minutes at a temperature of 160°C and a pressure of 0.8 MPa using a vacuum laminator, then heated from room temperature to 160°C and heat-treated at 160°C for 4 hours. Then, a copper-clad laminate 24 was obtained.

[Example 25]
Adhesive composition 13 is applied to the resin layer side of a single-sided copper-clad laminate 1 (manufactured by Nippon Steel Chemical & Materials, trade name; Espanex MC12-25-00UEM, length x width x thickness = 200 mm x 300 mm x 25 μm). It was applied and dried at 80° C. for 30 minutes to obtain an adhesive-attached copper-clad laminate 25 having an adhesive layer thickness of 50 μm. The resin layer side of the single-sided copper-clad laminate 1 is laminated to the adhesive layer side of the adhesive-attached copper-clad laminate 25, and pressed using a small precision press at a temperature of 160° C. and a pressure of 4.0 MPa. After pressing for 120 minutes, a copper-clad laminate 25 was obtained.

[Example 26]
Two adhesive-attached copper-clad laminates 17 are laminated so that the surfaces on the adhesive layer side are in contact with each other, and are press-bonded using a small precision press at a temperature of 160° C. and a pressure of 4.0 MPa for 120 minutes to form a copper-clad laminate. A plate 26 was obtained.

[Example 27]
An adhesive film 14 is laminated on the resin layer side of the single-sided copper-clad laminate 1, and further laminated thereon so that the resin layer side of the single-sided copper-clad laminate 1 is in contact with the adhesive film 14, followed by a small precision press. was pressed for 120 minutes at a temperature of 160° C. and a pressure of 4.0 MPa to obtain a copper-clad laminate 27 .

[Example 28]
The adhesive composition 13 is applied to one side of the release PET film 1, dried at 80° C. for 15 minutes, and the adhesive layer is peeled off from the release PET film 1, thereby forming an adhesive film 28 having a thickness of 15 μm. got

[Example 29]
An adhesive film 28 is laminated on the resin layer side of the single-sided copper-clad laminate 1, and further laminated thereon so that the resin layer side of the single-sided copper-clad laminate 1 is in contact with the adhesive film 28, followed by a small precision press. was pressed for 120 minutes at a temperature of 160° C. and a pressure of 4.0 MPa to obtain a copper-clad laminate 29 .

[Example 30]
A double-sided copper-clad laminate 2 (manufactured by Nippon Steel Chemical & Materials Co., Ltd., trade name: Espanex MB12-25-00UEG) was prepared, and the copper foil on one side was subjected to circuit processing by etching to form a conductor circuit layer. A wiring board 30A was obtained.

The copper foil on one surface of the double-sided copper-clad laminate 2 was removed by etching to obtain a copper-clad laminate 30B.

The adhesive film 14 was sandwiched between the conductor circuit layer side surface of the wiring board 30A and the resin layer side surface of the copper-clad laminate 30B, and in a laminated state, the temperature was 160° C. and the pressure was 4.0 MPa for 120 minutes. A multilayer circuit board 30 was obtained by thermocompression bonding.

[Example 31]
Liquid crystal polymer film (manufactured by Kuraray Co., Ltd., trade name: CT-Z, thickness: 50 μm, coefficient of thermal expansion (CTE): 18 ppm/K, heat distortion temperature: 300° C., ε ₁ =3.40, tan δ ₁ =0. 0022) is used as an insulating base material, and a copper-clad laminate 31 having 18 μm-thick electrolytic copper foil provided on both sides thereof is prepared, and the copper foil on one side is subjected to circuit processing by etching to form a conductor circuit layer. A formed wiring board 31A was obtained.

The copper foil on one side of the copper-clad laminate 31 was removed by etching to obtain a copper-clad laminate 31B.

The adhesive film 14 was sandwiched between the conductive circuit layer side surface of the wiring board 31A and the insulating substrate layer side surface of the copper-clad laminate 31B, and in a laminated state, the temperature was 160° C. and the pressure was 4.0 MPa. , and thermocompression bonding for 120 minutes to obtain a multilayer circuit board 31 .

Although the embodiments of the present invention have been described above in detail for the purpose of illustration, the present invention is not limited to the above embodiments and various modifications are possible.

DESCRIPTION OF SYMBOLS 10... Base material 11... 1st base material 12... 2nd base material 20... Adhesive bond layer 30, 33, 34... Insulating resin layer 31... First insulating resin layer 32... Second 41 First single-sided metal-clad laminate 42 Second single-sided metal-clad laminate 50 Wiring layer M Metal layer M1 First metal layer M2 Second Metal layer 100 Laminate 101 Three-layer metal-clad laminate 102 Laminated metal-clad laminate 103 Metal-clad laminate with adhesive layer 200, 201, 202 Circuit board 203 Multi-layer circuit board

Claims (20)

A polyimide containing a tetracarboxylic acid residue derived from a tetracarboxylic anhydride component and a diamine residue derived from a diamine component,
60 mol of diamine residues derived from a dimer-diamine composition containing dimer-diamine as a main component in which two terminal carboxylic acid groups of a dimer acid are substituted with primary aminomethyl groups or amino groups with respect to all diamine residues 1% or more and 99 mol% or less of a diamine residue derived from a diamine compound having at least one cyclohexane skeleton or norbornane skeleton in the molecule and having a molecular weight of 100 or more and 533 or less Polyimide characterized by containing within the range of mol% or more and 40 mol% or less. 2. The polyimide according to claim 1, wherein the weight average molecular weight (Mw) is in the range of 10,000 to 60,000. 3. The polyimide according to claim 1, wherein the ratio (Mw/Mn) of weight average molecular weight (Mw) to number average molecular weight (Mn) is in the range of 1.5 to 2.5. Containing 10 mol% or more and 99 mol% or less of a tetracarboxylic acid residue derived from benzophenonetetracarboxylic dianhydride with respect to all tetracarboxylic acid residues, the following general formula (1) and / or 1 mol% or more of at least one tetracarboxylic acid residue derived from the tetracarboxylic dianhydride represented by (2). Polyimide as described.

[In the general formula (1), X represents a single bond or a divalent group selected from the following formula, and in the general formula (2), the cyclic portion represented by Y is a 4-membered ring, a 5-membered ring, It represents forming a cyclic saturated hydrocarbon group selected from a ring, a 6-membered ring, a 7-membered ring and an 8-membered ring. ]

[In the above formula, Z represents -C ₆ H ₄ -, -(CH ₂ )n- or -CH ₂ -CH(-O-C(=O)-CH ₃ )-CH ₂ -, where n is Indicates an integer from 1 to 20. ] A crosslinked polyimide in which a ketone group contained in the polyimide according to claim 4 and an amino group of an amino compound having at least two primary amino groups as functional groups form a crosslinked structure through a C═N bond. An adhesive film comprising the polyimide according to any one of claims 1 to 4 or the crosslinked polyimide according to claim 5. Dielectric loss tangent (Tan δ ₁ ) at 10 GHz measured by a split post dielectric resonator (SPDR) after conditioning for 24 hours under constant temperature and humidity conditions (normal state) of 23°C and 50% RH is 0.002 or less. 7. The adhesive film according to claim 6, wherein the adhesive film has a dielectric constant (ε ₁ ) of 3.0 or less. Dielectric loss tangent (Tan δ ₂ ) at 20 GHz measured by a split post dielectric resonator (SPDR) after conditioning for 24 hours under constant temperature and humidity conditions (normal state) of 23 ° C. and 50% RH is 0.002 or less. 8. The adhesive film according to claim 6 or 7, characterized in that it has a dielectric constant (ε ₂ ) of 3.0 or less. A laminate having a substrate and an adhesive layer laminated on at least one surface of the substrate,
A laminate, wherein the adhesive layer comprises the adhesive film according to any one of claims 6 to 8. A coverlay film having a coverlay film material layer and an adhesive layer laminated on the coverlay film material layer,
A coverlay film, wherein the adhesive layer comprises the adhesive film according to any one of claims 6 to 8. A resin-coated copper foil obtained by laminating an adhesive layer and a copper foil,
A resin-coated copper foil, wherein the adhesive layer comprises the adhesive film according to any one of claims 6 to 8. A metal-clad laminate having an insulating resin layer and a metal layer laminated on at least one surface of the insulating resin layer,
A metal-clad laminate, wherein at least one of the insulating resin layers comprises the adhesive film according to any one of claims 6 to 8. A metal-clad laminate having an insulating resin layer, an adhesive layer laminated on at least one surface of the insulating resin layer, and a metal layer laminated on the insulating resin layer via the adhesive layer, ,
A metal-clad laminate, wherein the adhesive layer comprises the adhesive film according to any one of claims 6 to 8. a first single-sided metal-clad laminate having a first metal layer and a first insulating resin layer laminated on at least one surface of the first metal layer;
a second single-sided metal-clad laminate having a second metal layer and a second insulating resin layer laminated on at least one surface of the second metal layer;
arranged to abut on the first insulating resin layer and the second insulating resin layer and laminated between the first single-sided metal-clad laminate and the second single-sided metal-clad laminate A metal-clad laminate comprising an adhesive layer,
A metal-clad laminate, wherein the adhesive layer comprises the adhesive film according to any one of claims 6 to 8. A single-sided metal-clad laminate having an insulating resin layer and a metal layer laminated on one side of the insulating resin layer; and an adhesive layer laminated on the other side of the insulating resin layer. 9. A metal-clad laminate, wherein said adhesive layer comprises the adhesive film according to any one of claims 6 to 8. A circuit board obtained by wiring the metal layer of the metal-clad laminate according to any one of claims 12 to 15. A first base material, a wiring layer laminated on at least one surface of the first base material, and a wiring layer laminated on a surface of the first base material on the wiring layer side so as to cover the wiring layer A circuit board comprising an adhesive layer,
A circuit board, wherein the adhesive layer comprises the adhesive film according to any one of claims 6 to 8. A first base material, a wiring layer laminated on at least one surface of the first base material, and a wiring layer laminated on a surface of the first base material on the wiring layer side so as to cover the wiring layer A circuit board comprising an adhesive layer and a second substrate laminated on a surface of the adhesive layer opposite to the first substrate,
A circuit board, wherein the adhesive layer comprises the adhesive film according to any one of claims 6 to 8. A first substrate, an adhesive layer laminated on at least one surface of the first substrate, and a second substrate laminated on the surface of the adhesive layer opposite to the first substrate and a wiring layer laminated on each of the surfaces of the first base material and the second base material opposite to the adhesive layer,
A circuit board, wherein the adhesive layer comprises the adhesive film according to any one of claims 6 to 8. A multilayer circuit board comprising a laminate including a plurality of laminated insulating resin layers and at least one or more wiring layers embedded in the laminate,
At least one or more of the plurality of insulating resin layers is formed of an adhesive layer that has adhesiveness and covers the wiring layer,
A multilayer circuit board, wherein the adhesive layer comprises the adhesive film according to any one of claims 6 to 8.

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