JP2021147610A - Polyimide, crosslinked polyimide, adhesive film, laminate, coverlay film, copper foil with resin, metal-clad laminate, circuit board and multilayer circuit board - Google Patents

Abstract

To further improve dielectric characteristics and effectively reduce transmission loss of a high-frequency signal, in an adhesive layer using polyimide containing dimer diamine as a raw material.SOLUTION: Polyimide satisfies the following a) to c): a) containing 60 mol% or more of a diamine residue derived from a dimer diamine composition containing dimer diamine as a main component obtained by substituting two terminal carboxylic acid groups of a dimer acid for a primer aminomethyl group or an amino group, with respect to the total diamine residues; b) having a percentage content of a carbon atom (excluding carbon atom of six-membered aromatic ring derived from dimer diamine composition) derived from a six-membered aromatic ring with respect to the total content of the total atoms in the polyimide of 12-40 wt.%; and c) having a weight average molecular weight of 5,000-200,000.SELECTED DRAWING: None

Description

The present invention relates to a polyimide useful as a material for electronic components, a crosslinked polyimide using the same, an adhesive film, a laminate, a coverlay film, a copper foil with resin, 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, a flexible printed wiring board (FPC) that is thin and lightweight, has flexibility, and has excellent durability even after repeated bending. The demand for Circuits) is increasing. Since FPC can be mounted three-dimensionally and at high density even in a limited space, its use is expanded to, for example, wiring of moving parts of electronic devices such as HDDs, DVDs, and smartphones, and parts such as cables and connectors. I'm doing it.

One aspect of FPC 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 is bonded to the surface thereof. Polyimide is used as the material of the adhesive layer of the coverlay film having such a structure. For example, a crosslinked polyimide obtained by reacting a polyimide made from a diamine compound derived from dimer acid and an amino compound having at least two primary amino groups as functional groups is used as an adhesive for a coverlay film. It has been proposed to apply to layers (eg, Patent Document 1).

Further, in a three-layer metal-clad laminate in which a metal layer to be wired and an insulating resin layer are bonded via an adhesive layer, which is a metal-clad laminate used as a material for a circuit board such as an FPC, an adhesive is used. It has been proposed to apply a polyimide to the layer containing a predetermined amount or more of a diamine residue derived from a diamine diamine in which the two terminal carboxylic acid groups of the dimer acid are replaced with a primary aminomethyl group or an amino group. (For example, Patent Document 2).

By the way, in addition to the above-mentioned high density, the high performance of the equipment has been advanced, so that it is also necessary to cope with the high frequency of the transmission signal. When transmitting a high-frequency signal, if the transmission loss in the transmission path is large, inconveniences such as loss of an electric signal and a long delay time of the signal occur. Therefore, it will be important to reduce transmission loss in FPC in the future. Therefore, in a circuit board including a polyimide insulating layer, a circuit wiring layer laminated on at least one surface thereof, and a coverlay film laminated on the circuit wiring layer, the thickness of the polyimide insulating layer and the coverlay film is increased. , It has been proposed to consider the relationship between the dielectric constant and the dielectric tangent (for example, Patent Document 3).

Japanese Unexamined Patent Publication No. 2013-1730 Japanese Unexamined Patent Publication No. 2018-140544 Japanese Unexamined Patent Publication No. 2016-192531

As in Patent Documents 1 and 2, the adhesive layer using polyimide made from diamine diamine exhibits excellent adhesiveness, low dielectric constant, and dielectric loss tangent, but it is intended to cope with high frequency transmission signals. Therefore, further improvement of the dielectric property is required.

Therefore, an object of the present invention is to further improve the dielectric properties of the adhesive layer using polyimide using diamine diamine as a raw material, and to more effectively reduce the transmission loss of high-frequency signals.

As a result of diligent research, the present inventors have found that the dielectric property of polyimide can be improved by controlling the amount of aromatic rings contained in the polyimide using diamine diamine as a raw material, and completed the present invention.

The polyimide of the present invention is a polyimide containing a tetracarboxylic acid residue derived from a tetracarboxylic acid anhydride component and a diamine residue derived from a diamine component. The polyimide of the present invention is characterized by satisfying the following conditions a to c.
a) For all diamine residues, diamine residues derived from a diamine diamine composition containing a diamine diamine in which two terminal carboxylic acid groups of dimer acid are replaced with a primary aminomethyl group or an amino group are used. Contains 60 mol% or more;
b) The content of carbon atoms derived from the 6-membered aromatic ring (excluding the carbon atoms of the 6-membered aromatic ring derived from the dimerdiamine composition) with respect to the total content of all the atoms in the polyimide is in the range of 12 to 40% by weight. Being inside;
c) The weight average molecular weight is in the range of 5,000 to 200,000.

The polyimide of the present invention may further satisfy the following condition d.
d) The following formula (i),
CM value = (C / Mw) x 10 ⁴ ... (i)
[In the formula, C means the weight content of carbon atoms derived from the 6-membered aromatic ring (excluding the carbon atoms of the 6-membered aromatic ring derived from the dimerdiamine composition) with respect to the total content of all the atoms in the polyimide. Mw means the weight average molecular weight of polyimide]
The CM value, which is an index indicating the amount of the 6-membered aromatic ring contained in the polyimide, calculated based on the above, is in the range of 3 to 38.

The polyimide of the present invention may further satisfy the following condition e.
e) The content of carbon atoms derived from the 6-membered aromatic ring (excluding the carbon atoms of the 6-membered aromatic ring derived from the dimer diamine composition) with respect to the total content of all atoms in the total diamine component of the raw material exceeds 0 32. Must be within the weight% or less range.

The polyimide of the present invention may further satisfy the following condition f.
f) The following formula (ii),
DM value = (D / Mw) x 10 ⁴ ... (ii)
[In the formula, D is the weight content of the 6-membered aromatic ring-derived carbon atom (excluding the 6-membered aromatic ring-derived carbon atom derived from the diamine composition) with respect to the total content of all atoms in the total diamine residue. Means, Mw means the weight average molecular weight of polyimide]
The DM value, which is an index indicating the amount of the 6-membered aromatic ring derived from the diamine component contained in the polyimide, calculated based on the above, is in the range of more than 0 and 32 or less.

The polyimide of the present invention is used with respect to the total amount of the diamine residues.
It may contain a diamine residue derived from the diamine diamine composition in the range of 60 mol% or more and 99 mol% or less.
It contains a diamine residue derived from at least one diamine compound selected from the diamine compounds represented by the following general formulas (B1) to (B7) in the range of 1 mol% or more and 40 mol% or less. There may be.

In the formulas (B1) to (B7), R ₁ independently represents a monovalent hydrocarbon group or an alkoxy group having 1 to 6 carbon atoms, and the linking group A independently represents -O-, -S-, and -CO-. , -SO-, -SO _2- , -COO-, -CH _2- , -C (CH ₃ ) _2- , -NH- or -CONH-, indicating a divalent group, n ₁ being independent. Indicates an integer from 0 to 4. However, the formula (B3) that overlaps with the formula (B2) is excluded, and the formula (B5) that overlaps with the formula (B4) is excluded.

The polyimide of the present invention contains tetracarboxylic acid residues derived from the tetracarboxylic dianhydride represented by the following general formulas (1) and / or (2) with respect to the total amount of the acid anhydride residues. It may contain 90 mol% or more in total.

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 or a 5-membered ring. , A cyclic saturated hydrocarbon group selected from a 6-membered ring, a 7-membered ring, or an 8-membered ring.

In the above formula, Z is _{-C 6 H 4 -, - (} CH 2) n- or _{-CH 2 -CH (-O-C (} = O) -CH 3) -CH 2 - are illustrated, n represents 1 Indicates an integer of ~ 20.

In the crosslinked polyimide of the present invention, any of the above-mentioned polyimides contains a ketone group in the molecule, and the amino group of the amino compound having the ketone group and at least two primary amino groups as functional groups. And form a crosslinked structure with a C = N bond.

The adhesive film of the present invention is characterized by containing any of the above-mentioned polyimides or crosslinked polyimides.

The adhesive film of the present invention has a dielectric loss tangent (Tanδ) at 10 GHz measured by a split post dielectric resonator (SPDR) after humidity control for 24 hours under a constant temperature and humidity condition (normal condition) of 23 ° C. and 50% RH. ₁ ) may be 0.005 or less, and the relative permittivity (E ₁ ) may be 3.0 or less.

The adhesive film of the present invention has a dielectric loss tangent (Tanδ) at 20 GHz measured by a split post dielectric resonator (SPDR) after humidity control for 24 hours under a constant temperature and humidity condition (normal condition) of 23 ° C. and 50% RH. ₂ ) may be 0.005 or less and the relative permittivity (E ₂ ) may be 3.0 or less.

The adhesive film of the present invention has a dielectric loss tangent (Tanδ) at 10 GHz measured by a split post dielectric resonator (SPDR) after humidity control for 24 hours under a constant temperature and humidity condition (normal condition) of 23 ° C. and 50% RH. The difference (Tanδ _{2- Tanδ 1 ) between 1} ) and the dielectric loss tangent (Tanδ ₂ ) at 20 GHz may be 0 or less.

The laminate of the present invention is a laminate having a base material and an adhesive layer laminated on at least one surface of the base material, and the adhesive layer is made from any of the above adhesive films. It is characterized by becoming.

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, and the adhesive layer is any one of the above. It is characterized by being composed of an adhesive film.

The copper foil with resin of the present invention is a copper foil with resin in which an adhesive layer and a copper foil are laminated, and the adhesive layer is made of any of the above adhesive films.

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, and at least one layer of the insulating resin layer is , It is characterized by being composed of any of the above-mentioned adhesive films.

The metal-clad laminate of the present invention includes 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 having the above, wherein the adhesive layer is made of any of the above adhesive films.

The metal-clad laminate of the present invention includes 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.
It was arranged so as to be in contact with the first insulating resin layer and the second insulating resin layer, and was laminated between the first single-sided metal-clad laminate and the second single-sided metal-clad laminate. A metal-clad laminate with an adhesive layer,
The adhesive layer is made of any of the above adhesive films.

The metal-clad laminate of the present invention has a single-sided metal-clad laminate having an insulating resin layer and a metal layer laminated on one surface of the insulating resin layer, and is laminated on the other surface of the insulating resin layer. It is characterized in that the adhesive layer is provided with the above-mentioned adhesive layer, and the adhesive layer is made of any of the above-mentioned adhesive films.

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

The circuit board of the present invention includes a first base material, a wiring layer laminated on at least one surface of the first base material, and the wiring layer on the surface of the first base material on the side of the wiring layer. A circuit board comprising an adhesive layer laminated so as to cover the above-mentioned adhesive layer, wherein the adhesive layer is made of any of the above-mentioned adhesive films.

The circuit board of the present invention includes a first base material, a wiring layer laminated on at least one surface of the first base material, and the wiring layer on the surface of the first base material on the side of the wiring layer. A circuit board comprising an adhesive layer laminated so as to cover the adhesive layer and a second base material laminated on a surface of the adhesive layer opposite to the first base material. The adhesive layer is made of any of the above adhesive films.

The circuit board of the present invention has a first base material, an adhesive layer laminated on at least one surface of the first base material, and an adhesive layer on the opposite side of the first base material. A circuit board including a second base material laminated on a surface and a wiring layer laminated on a surface of the first base material and the second base material opposite to the adhesive layer. The adhesive layer is made of any of the above adhesive films.

The multilayer circuit board of the present invention is a multilayer circuit board including a laminate including a plurality of laminated insulating resin layers and at least one or more wiring layers embedded inside the laminate.
At least one layer or more of the plurality of insulating resin layers is formed of an adhesive layer having adhesiveness and covering the wiring layer, and the adhesive layer is made of any of the above adhesive films. It is characterized by.

The polyimide of the present invention has a low dielectric constant and a low dielectric loss tangent while having excellent adhesiveness by controlling the amount of aromatic rings contained in the polyimide made from diamine diamine, and has a high frequency signal. Transmission loss in transmission can be effectively suppressed. Therefore, the polyimide of the present invention can effectively reduce the transmission loss when applied to a circuit board or the like that transmits a high-frequency signal having a frequency in the GHz band (for example, 1 to 20 GHz).

It is a schematic diagram which shows the structure of the cross section of the laminated body which concerns on embodiment of this invention. It is a schematic diagram which shows the structure of the cross section of the metal-clad laminate which concerns on embodiment of this invention. It is a schematic diagram which shows the structure of the cross section of the metal-clad laminate which concerns on another Embodiment of this invention. It is a schematic diagram which shows the structure of the cross section of the metal-clad laminate which concerns on still another Embodiment of this invention. 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. It is a schematic diagram which shows the structure of the cross section of the circuit board which concerns on still another Embodiment of this invention. It is a schematic diagram which shows the structure of the cross section of the multilayer circuit board which concerns on embodiment of this invention. It is a drawing which schematically expressed the relationship between the aromatic ring concentration and the dielectric loss tangent in adhesive polyimide.

Embodiments of the present invention will be described with reference to the drawings as appropriate.

The polyimide according to the embodiment of the present invention is a polyimide having adhesiveness. Hereinafter, the polyimide of the present embodiment may be referred to as "adhesive polyimide". The adhesive polyimide contains a tetracarboxylic acid residue derived from the tetracarboxylic acid anhydride component and a diamine residue derived from the diamine component. In the present invention, the "tetracarboxylic acid residue" represents a tetravalent group derived from tetracarboxylic acid dianhydride, and the "diamine residue" is a divalent group derived from a diamine compound. Represents a group. When the tetracarboxylic acid anhydride and the diamine compound, which are the raw materials, are reacted in approximately equimolar amounts, the types of the tetracarboxylic acid residues and the diamine residues contained in the polyimide are determined with respect to the type and molar ratio of the raw materials. The molar ratio can be made almost compatible.
The term "polyimide" in the present invention means a resin composed of a polymer having an imide group in its molecular structure, such as polyamideimide, polyetherimide, polyesterimide, polysiloxaneimide, and polybenzimidazolimide, in addition to polyimide. ..

(Acid anhydride)
As the adhesive polyimide, tetracarboxylic acid anhydride generally used for thermoplastic polyimide can be used as a raw material without particular limitation, but the following general formula (1) and / or (for all tetracarboxylic acid anhydride components) It is preferable to use a raw material containing 90 mol% or more of the tetracarboxylic acid anhydride represented by 2) in total. In other words, the adhesive polyimide has a tetracarboxylic acid residue derived from the tetracarboxylic dianhydride represented by the following general formulas (1) and / or (2) with respect to all the tetracarboxylic acid residues. Is preferably contained in an amount of 90 mol% or more in total. A total of 90 mol% or more of tetracarboxylic acid residues derived from the tetracarboxylic acid anhydride represented by the following general formulas (1) and / or (2) is contained in the total tetracarboxylic acid residues. This is preferable because it is easy to achieve both the flexibility and heat resistance of the adhesive polyimide. If the total of the tetracarboxylic acid residues derived from the tetracarboxylic dianhydride represented by the following general formulas (1) and / or (2) is less than 90 mol%, the solvent solubility of the adhesive polyimide is lowered. It becomes a tendency.

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 or a 5-membered ring. , 6-membered ring, 7-membered ring or 8-membered ring.

In the above formula, Z is _{-C 6 H 4 -, - (} CH 2) n- or _{-CH 2 -CH (-O-C (} = O) -CH 3) -CH 2 - are illustrated, n represents 1 Indicates an integer of ~ 20.

Examples of the tetracarboxylic acid anhydride represented by the general formula (1) include 3,3', 4,4'-biphenyltetracarboxylic acid dianhydride (BPDA), 3,3', 4,4'. -Benzophenone tetracarboxylic acid anhydride (BTDA), 3,3', 4,4'-diphenylsulfone tetracarboxylic acid anhydride (DSDA), 4,4'-oxydiphthalic acid anhydride (ODPA), 4,4 '-(Hexafluoroisopropylidene) diphthalic anhydride (6FDA), 2,2-bis [4- (3,4-dicarboxyphenoxy) phenyl] propane dianhydride (BPADA), p-phenylenebis (trimerit) Acid monoesteric anhydride) (TAHQ), ethylene glycol bisamhydrotrimeritate (TMEG) and the like can be mentioned. Of these, 3,3', 4,4'-benzophenone tetracarboxylic dianhydride (BTDA) is particularly preferable. When BTDA is used, the carbonyl group (ketone group) contributes to the adhesiveness, so that the adhesiveness of the adhesive polyimide can be improved. Further, in BTDA, a ketone group existing in the molecular skeleton may react with an amino group of an amino compound for forming a crosslink, which will be described later, to form a C = N bond, and the effect of improving heat resistance is likely to be exhibited. .. From such a viewpoint, it is preferable to contain BTDA-derived tetracarboxylic acid residue in an amount of preferably 50 mol% or more, more preferably 60 mol% or more, based on the total tetracarboxylic acid residue.

Examples of the tetracarboxylic acid anhydride represented by the general formula (2) include 1,2,3,4-cyclobutanetetracarboxylic acid dianhydride and 1,2,3,4-cyclopentanetetracarboxylic acid. Dianhydride, 1,2,4,5-cyclohexanetetracarboxylic acid dianhydride, 1,2,4,5-cycloheptanetetracarboxylic acid dianhydride, 1,2,5,6-cyclooctanetetracarboxylic acid Bianhydrides and the like can be mentioned.

The adhesive polyimide contains tetracarboxylic acid residues derived from acid anhydrides other than the tetracarboxylic dianhydrides represented by the general formulas (1) and (2) above, as long as the effects of the invention are not impaired. Can be contained. Such tetracarboxylic acid residues are not particularly limited, but for example, pyromellitic acid dianhydride, 2,3', 3,4'-biphenyltetracarboxylic acid dianhydride, 2,2', 3 , 3'-or 2,3,3', 4'-benzophenone tetracarboxylic acid dianhydride, 2,3', 3,4'-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 Acid 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) sulfonate 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-anthracene tetracarboxylic dianhydride, 2,2-bis (3,4-Dicarboxyphenyl) Tetrafluoropropane dianhydride 1,2,5,6-naphthalene tetracarboxylic acid dianhydride 1,4,5,8-naphthalene tetracarboxylic acid dianhydride 2, 3,6,7-naphthalene tetracarboxylic acid dianhydride 4,8-dimethyl-1,2,3,5,6,7-hexahydronaphthalene-1,2,5,6-tetracarboxylic acid 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 acid dianhydride, pyrazine-2,3,5,6-tetracarboxylic acid dianhydride, pyrrolidine-2,3,4,5-tetracarboxylic Aromatic tetracarboxylic acid dianhydride such as acid dianhydride, thiophene-2,3,4,5-tetracarboxylic acid dianhydride, 4,4'-bis (2,3-dicarboxyphenoxy) diphenylmethane dianhydride. Examples include tetracarboxylic acid residues derived from the substance.

(Diamine)
As the adhesive polyimide, a diamine compound generally used for thermoplastic polyimide can be used as a raw material without particular limitation, but the two terminal carboxylic acid groups of dimer acid are primary aminomethyl groups or amino groups with respect to the total diamine component. A raw material containing 60 mol% or more of a diamine diamine composition containing a diamine diamine as a main component substituted with is used. In other words, the adhesive polyimide is a dimer in which the two terminal carboxylic acid groups of the diamine acid are replaced with a primary aminomethyl group or an amino group for all diamine residues, as described in the condition a described later. It contains 60 mol% or more of diamine residues derived from a diamine diamine composition containing diamine as a main component.

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

(A) Dimer diamine;
In the diamine diamine of the component (a), the two terminal carboxylic acid groups (-COOH) of the dimer acid are replaced with _{a primary aminomethyl group (-CH 2-} NH ₂ ) or an amino group (-NH _2). It means diamine. Dimeric acid is a known dibasic acid obtained by the intermolecular polymerization reaction of unsaturated fatty acids, and its industrial production process is almost standardized in the industry, and unsaturated fatty acids having 11 to 22 carbon atoms are clay-catalyzed. It is obtained by quantifying it with or the like. The industrially obtained dimer acid is mainly composed of a dibasic acid having 36 carbon atoms obtained by dimerizing an unsaturated fatty acid having 18 carbon atoms such as oleic acid, linolenic acid and linolenic acid. Depending on the degree, it contains an arbitrary amount of monomeric acid (18 carbon atoms), trimeric acid (54 carbon atoms), and other polymerized fatty acids having 20 to 54 carbon atoms. Further, although the double bond remains after the dimerization reaction, in the present invention, the dimer acid is also included in which the degree of unsaturation is lowered by the hydrogenation reaction. The dimer diamine of the component (a) is prepared by substituting the terminal carboxylic acid group of the dibasic acid compound in the range of 18 to 54 carbon atoms, preferably 22 to 44 carbon atoms with a primary aminomethyl group or an amino group. It can be defined as the resulting diamine compound.

As a characteristic of dimer diamine, it is possible to impart properties derived from the skeleton of dimer acid. That is, since dimer diamine is an aliphatic of macromolecules having a molecular weight of about 560 to 620, the molar volume of the molecule can be increased and the polar groups of polyimide can be relatively reduced. It is considered that such a feature of the dimer acid type diamine contributes to improving the dielectric property by reducing the dielectric constant and the dielectric loss tangent while suppressing the decrease in the heat resistance of the polyimide. Further, since it has two free-moving hydrophobic chains having 7 to 9 carbon atoms and two chain-like aliphatic amino groups having a length close to 18 carbon atoms, it not only gives flexibility to the polyimide, but also gives the polyimide flexibility. Since the polyimide can have an asymmetrical chemical structure or a non-planar chemical structure, it is considered that the polyimide can have a low dielectric constant.

The diamine diamine composition used is such that the diamine diamine content of the component (a) is increased to 96% by weight or more, preferably 97% by weight or more, more preferably 98% by weight or more by a purification method such as molecular distillation. That is good. By setting the diamine 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 polyimide. If technically possible, it is best that all (100% by weight) of the diamine diamine composition is composed of the diamine diamine of the component (a). The diamine diamine composition may contain a diamine diamine having a 6-membered aromatic ring as a molecular skeleton. In the polyimide of the present embodiment, attention is paid to the ratio of the aromatic monomer directly connected to the imide bond site, and the control is made. However, in the dimer diamine having a 6-membered aromatic ring, the 6-membered aromatic ring has 7 or more carbon atoms. Since it is an imide bond via a fat chain having a length of, it is not subject to control of the 6-membered aromatic ring in the polyimide of the present embodiment. Therefore, the 6-membered aromatic ring derived from dimer diamine is excluded from the conditions b, d, e and f in the adhesive polyimide. The ratio of aromatic rings derived from dimerdiamine is preferably 20 mol or less with respect to 1 mol of amino groups by quantification by 1 H-NMR.

(B) A monoamine compound obtained by substituting a terminal carboxylic acid group of a monobasic acid compound having 10 to 40 carbon atoms with a primary aminomethyl group or an amino group;
The monobasic acid compound in the range of 10 to 40 carbon atoms is a monobasic unsaturated fatty acid in the range of 10 to 20 carbon atoms derived from the raw material of dimer acid, and a by-product during the production of dimer acid. It is a mixture of monobasic acid compounds in the range of 21 to 40 carbon atoms. The 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 the component (b) is a component that suppresses an increase in the molecular weight of polyimide. During the polymerization of polyamic acid or polyimide, the monofunctional amino group of the monoamine compound reacts with the terminal acid anhydride group of the polyamic acid or polyimide to seal the terminal acid anhydride group, and the molecular weight of the polyamic acid or polyimide is sealed. Suppress the increase.

(C) An amine compound obtained by substituting a primary aminomethyl group or an amino group for a terminal carboxylic acid group of a polybasic acid compound having a hydrocarbon group in the range of 41 to 80 carbon atoms (however, the dimerdiamine). except for);
The polybasic acid compound having a hydrocarbon group in the range of 41 to 80 carbon atoms is mainly composed of a tribasic acid compound in the range of 41 to 80 carbon atoms, which is a by-product during the production of dimer acid. It is a polybasic acid compound. Further, it may contain a polymerized fatty acid other than dimer acid having 41 to 80 carbon atoms. The amine compound is obtained by substituting the terminal carboxylic acid group of these polybasic acid compounds with a primary aminomethyl group or an amino group.

The amine compound of the component (c) is a component that promotes an increase in the molecular weight of polyimide. A trifunctional or higher amino group containing a triamine derived from trimeric acid as a main component reacts with a polyamic acid or a terminal acid anhydride group of polyimide to rapidly increase the molecular weight of polyimide. Further, an amine compound derived from a polymerized fatty acid other than dimer acid having 41 to 80 carbon atoms also increases the molecular weight of the polyimide and causes gelation of the polyamic acid or the polyimide.

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

Further, the diamine diamine composition is preferably an area percentage of the chromatogram obtained by GPC measurement, and the total of the components (b) and (c) is 4% or less, preferably less than 4%. By setting the total of the components (b) and (c) to 4% or less, it is possible to suppress the spread of the molecular weight distribution of the polyimide.

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

The area percentage of the chromatogram of the component (c) is 2% or less, preferably 1.8% or less, and more preferably 1.5% or less. Within such a range, a rapid increase in the molecular weight of the polyimide can be suppressed, and an increase in the dielectric loss tangent of the resin film at a wide frequency range can be suppressed. The component (c) does not have to be contained in the diamine diamine composition.

When the area-percentage ratio (b / c) of the chromatograms of the components (b) and (c) is 1 or more, the molar ratio of the tetracarboxylic acid anhydride component and the diamine component (tetracarboxylic acid anhydride component / The 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.

When the area-percentage ratio (b / c) of the components (b) and (c) of the chromatogram is less than 1, the molar ratio of the tetracarboxylic acid anhydride component and the diamine component (tetracarboxylic acid anhydride component). The / 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.

As the diamine diamine composition, a commercially available product can be used, and it is preferable to purify the diamine diamine composition for the purpose of reducing the components other than the diamine diamine of the component (a). For example, the component may be 96% by weight or more in (a). preferable. The purification method is not particularly limited, but a known method such as a distillation method or precipitation purification is preferable. Examples of commercially available products of the diamine diamine composition include PRIAMINE 1073 (trade name), PRIAMINE 1074 (trade name), and PRIAMINE 1075 (trade name) manufactured by Croda Japan.

The adhesive polyimide may contain a diamine residue derived from a diamine component other than the above. Such diamine residues include, for example, bisaniline fluorene (BAFL), 9,9-bis (3-methyl-4-aminophenyl) fluorene, 9,9-bis (3-fluoro-4-aminophenyl). Fluorene, 9,9-bis [4- (aminophenoxy) phenyl] fluorene, and diamine residues derived from diamine compounds represented by the general formulas (B1) to (B7) are preferable. In particular, a diamine having a fluorene skeleton represented by BAFL contains four aromatic rings and can be advantageously used for the purpose of adjusting the aromatic ring concentration.

In the formulas (B1) to (B7), R ₁ independently represents a monovalent hydrocarbon group or an alkoxy group having 1 to 6 carbon atoms, and the linking group A independently represents -O-, -S-, and -CO-. , -SO-, -SO _2- , -COO-, -CH _2- , -C (CH ₃ ) _2- , -NH- or -CONH-, indicating a divalent group, n ₁ being independent. Indicates an integer from 0 to 4. However, the formula (B3) that overlaps with the formula (B2) is excluded, and the formula (B5) that overlaps with the formula (B4) is excluded. Here, "independently", in one of the above formulas (B1) ~ (B7), or in two or more, a plurality of linking groups A, a plurality of R ₁ or a plurality of n _1, the same However, it means that it may be different. In the above formulas (B1) to (B7), the hydrogen atom in the two terminal amino groups may be substituted, for example, -NR ₂ R ₃ (where R ₂ and R ₃ are independent. It may mean any substituent such as an alkyl group).

The diamine represented by the formula (B1) (hereinafter, may be referred to as "diamine (B1)") is an aromatic diamine having two benzene rings. This diamine (B1) has a high degree of flexibility due to an increase in the degree of freedom of the polyimide molecular chain by having an amino group directly linked to at least one benzene ring and a divalent linking group A at the meta position. It is considered that this contributes to the improvement of the flexibility of the polyimide molecular chain. Therefore, the use of diamine (B1) enhances the thermoplasticity of the polyimide. Here, as the linking group A, -O-, -CH _2- , -C (CH ₃ ) _2- , -CO-, -SO _2- , -S- are preferable.

Examples of the diamine (B1) include 3,3'-diaminodiphenylmethane, 3,3'-diaminodiphenylpropane, 3,3'-diaminodiphenylsulfide, 3,3'-diaminodiphenylsulfone, and 3,3'-diamino. Diphenyl ether, 3,4'-diaminodiphenyl ether, 3,4'-diaminodiphenylmethane, 3,4'-diaminodiphenylpropane, 3,4'-diaminodiphenylsulfide, 3,3'-diaminobenzophenone, (3,3'- Bisamino) diphenylamine and the like can be mentioned.

The diamine represented by the formula (B2) (hereinafter, may be referred to as "diamine (B2)") is an aromatic diamine having three benzene rings. This diamine (B2) has a high degree of flexibility due to an increase in the degree of freedom of the polyimide molecular chain by having an amino group directly linked to at least one benzene ring and a divalent linking group A at the meta position. It is considered that this contributes to the improvement of the flexibility of the polyimide molecular chain. Therefore, the use of diamine (B2) enhances the thermoplasticity of the polyimide. Here, as the linking group A, —O— is preferable.

Examples of the diamine (B2) include 1,4-bis (3-aminophenoxy) benzene, 3- [4- (4-aminophenoxy) phenoxy] benzeneamine, and 3- [3- (4-aminophenoxy) phenoxy]. Benzene amine and the like can be mentioned.

The diamine represented by the formula (B3) (hereinafter, may be referred to as "diamine (B3)") is an aromatic diamine having three benzene rings. This diamine (B3) has two divalent linking groups A directly linked to one benzene ring at the meta position of each other, so that the degree of freedom of the polyimide molecular chain is increased and the diamine has high flexibility. Therefore, it is considered that it contributes to the improvement of the flexibility of the polyimide molecular chain. Therefore, the use of diamine (B3) enhances the thermoplasticity of the polyimide. Here, as the linking group A, —O— is preferable.

Examples of the diamine (B3) include 1,3-bis (4-aminophenoxy) benzene (TPE-R), 1,3-bis (3-aminophenoxy) benzene (APB), and 4,4'-[2-]. Methyl- (1,3-phenylene) bisoxy] bisaniline, 4,4'-[4-methyl- (1,3-phenylene) bisoxy] bisaniline, 4,4'-[5-methyl- (1,3-phenylene) ) Benzene] Bisaniline and the like can be mentioned.

The diamine represented by the formula (B4) (hereinafter, may be referred to as "diamine (B4)") is an aromatic diamine having four benzene rings. This diamine (B4) has high flexibility because the amino group directly linked to at least one benzene ring and the divalent linking group A are in the meta position, which improves the flexibility of the polyimide molecular chain. It is thought to contribute. Therefore, the use of diamine (B4) enhances the thermoplasticity of the polyimide. Here, as the linking group A, -O-, -CH _2- , -C (CH ₃ ) _2- , -SO _2- , -CO-, and -CONH- are preferable.

Diamine (B4) includes bis [4- (3-aminophenoxy) phenyl] methane, bis [4- (3-aminophenoxy) phenyl] propane, bis [4- (3-aminophenoxy) phenyl] ether, and bis. Examples thereof include [4- (3-aminophenoxy) phenyl] sulfone, bis [4- (3-aminophenoxy)] benzophenone, and bis [4,4'-(3-aminophenoxy)] benzanilide.

The diamine represented by the formula (B5) (hereinafter, may be referred to as "diamine (B5)") is an aromatic diamine having four benzene rings. This diamine (B5) has two divalent linking groups A directly linked to at least one benzene ring at the meta position of each other, so that the degree of freedom of the polyimide molecular chain is increased and the diamine has high flexibility. It is considered that this contributes to the improvement of the flexibility of the polyimide molecular chain. Therefore, the use of diamine (B5) enhances the thermoplasticity of the polyimide. Here, as the linking group A, —O— is preferable.

Examples of the diamine (B5) include 4- [3- [4- (4-aminophenoxy) phenoxy] phenoxy] aniline and 4,4'-[oxybis (3,1-phenyleneoxy)] bisaniline. ..

The diamine represented by the formula (B6) (hereinafter, may be referred to as "diamine (B6)") is an aromatic diamine having four benzene rings. This diamine (B6) has high flexibility by having at least two ether bonds, and is considered to contribute to the improvement of the flexibility of the polyimide molecular chain. Therefore, the use of diamine (B6) enhances the thermoplasticity of the polyimide. Here, as the linking group A, -C (CH ₃ ) _2- , -O-, -SO _2- , and -CO- are preferable.

Examples of the diamine (B6) include 2,2-bis [4- (4-aminophenoxy) phenyl] propane (BAPP), bis [4- (4-aminophenoxy) phenyl] ether (BAPE), and bis [4). -(4-Aminophenoxy) phenyl] sulfone (BAPS), bis [4- (4-aminophenoxy) phenyl] ketone (BACK) and the like can be mentioned.

The diamine represented by the formula (B7) (hereinafter, may be referred to as "diamine (B7)") is an aromatic diamine having four benzene rings. Since this diamine (B7) has highly flexible divalent linking groups A on both sides of the diphenyl skeleton, it is considered to contribute to the improvement of the flexibility of the polyimide molecular chain. Therefore, the use of diamine (B7) enhances the thermoplasticity of the polyimide. Here, as the linking group A, —O— is preferable.

Examples of the diamine (B7) include bis [4- (3-aminophenoxy)] biphenyl and bis [4- (4-aminophenoxy)] biphenyl.

The adhesive polyimide contains a diamine residue derived from at least one diamine compound selected from diamine (B1) to diamine (B7), preferably 1 mol% or more and 40 mol% or less, based on all diamine residues. It is preferably contained within the range, more preferably within the range of 5 mol% or more and 35 mol% or less. Since diamines (B1) to diamines (B7) have a flexible molecular structure, the flexibility of the polyimide molecular chain is improved by using at least one diamine compound selected from these in an amount within the above range. And can impart thermoplasticity.

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

The adhesive polyimide can be produced by reacting the above-mentioned acid anhydride component and diamine component in a solvent to generate polyamic acid, and then heat-closing the ring. For example, the acid anhydride component and the diamine component are dissolved in an organic solvent in approximately equimolar amounts, and the mixture is stirred at a temperature in the range of 0 to 100 ° C. for 30 minutes to 24 hours to carry out a polymerization reaction to obtain a polyimide precursor. Polyamic acid is obtained. In the reaction, the reaction components are dissolved in the organic solvent so that the precursor produced is in the range of 5 to 50% by weight, preferably in the range of 10 to 40% by weight. Examples of the organic solvent 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, dimethylsulfate, cyclohexanone, methylcyclohexane, dioxane, tetrahydrofuran, diglime, triglime, methanol, ethanol, benzyl alcohol, cresol and the like can be mentioned. Two or more of these solvents can be used in combination, and aromatic hydrocarbons such as xylene and toluene can be used in combination. The amount of such an organic solvent used is not particularly limited, but it should be adjusted so that the concentration of the polyamic acid solution obtained by the polymerization reaction is about 5 to 50% by weight. Is preferable.

The synthesized polyamic acid is usually advantageous to be used as a reaction solvent solution, but can be concentrated, diluted or replaced with another organic solvent if necessary. In addition, polyamic acid is generally excellent in solvent solubility, and is therefore advantageously used. The viscosity of the polyamic acid solution is preferably in the range of 500 mPa · s to 100,000 mPa · s. If it is out of this range, defects such as thickness unevenness and streaks are likely to occur in the film during coating work by a coater or the like.

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

In the adhesive polyimide, the dielectric properties, the coefficient of thermal expansion, and the coefficient of thermal expansion can be determined by selecting the types of the acid anhydride component and the diamine component and the molar ratio of each when two or more kinds of the acid anhydride component or the diamine component are applied. Physical properties such as tensile elastic modulus and glass transition temperature can be controlled. When the adhesive polyimide has a plurality of structural units, it may exist as a block or randomly, but it is preferable that the adhesive polyimide exists randomly.

The imide group concentration of the adhesive polyimide is preferably 22% by weight or less, more preferably 20% by weight or less. Here, the "imide group concentration" means a value obtained by dividing the molecular weight of the imide base portion (-(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, the low hygroscopicity deteriorates due to the increase in polar groups, and the Tg and elastic modulus increase.

The adhesive polyimide is most preferably a completely imidized structure. However, a 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 (commercially available: FT / IR620 manufactured by Nippon Spectroscopy). It can be calculated from the absorbance of C = O expansion and contraction derived from the imide group of ^{1780 cm -1} based on the benzene ring absorber of.

The adhesive polyimide is appropriately blended with other curing resin components such as a plasticizer and an epoxy resin, a curing agent, a curing accelerator, an organic filler, an inorganic filler, a coupling agent, a solvent, a flame retardant, and the like as optional components. Can be used as an adhesive polyimide composition.

(Crosslink formation of adhesive polyimide)
When the adhesive polyimide has a ketone group, the amino of the amino compound having the ketone group and at least two primary amino groups as functional groups (hereinafter, may be 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, may be referred to as “crosslinked polyimide”) is an application example of an adhesive polyimide, and is in a preferable form. Since the weight average molecular weight fluctuates greatly depending on the formation of the crosslink, it is sufficient that the adhesive polyimide before the formation of the crosslink satisfies the condition c, and the crosslinked polyimide does not have to satisfy these conditions. Further, an adhesive resin 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 in a preferable form. By forming the crosslinked structure, the heat resistance of the adhesive polyimide can be improved. Preferred tetracarboxylic acid anhydrides for forming an adhesive polyimide having a ketone group include, for example, 3,3', 4,4'-benzophenone tetracarboxylic acid dianhydride (BTDA), and diamine compounds include, for example. Aromatic diamines such as 4,4'-bis (3-aminophenoxy) benzophenone (BABP) and 1,3-bis [4- (3-aminophenoxy) benzoyl] benzene (BABB) can be mentioned.

For the purpose of forming a crosslinked structure, the above-mentioned adhesiveness containing BTDA residues derived from BTDA in an amount of preferably 50 mol% or more, more preferably 60 mol% or more, particularly with respect to all tetracarboxylic acid residues. It is preferable to allow the crosslink-forming amino compound to act on the polyimide. In the present invention, the "BTDA residue" means a tetravalent group derived from BTDA.

Examples of the crosslink-forming amino compound include (I) a dihydrazide compound, (II) an aromatic diamine, and (III) an aliphatic amine. Among these, a dihydrazide compound is preferable. Aliphatic amines other than dihydrazide compounds tend to form crosslinked structures even at room temperature, and there is a concern about storage stability of varnishes, while aromatic diamines need to be heated to a high temperature in order to form crosslinked structures. As described above, when the dihydrazide compound is used, both the storage stability of the varnish and the shortening of the curing time can be achieved at the same time. Examples of the dihydrazide compound include dihydrazide oxalic acid, dihydrazide malonate, dihydrazide succinic acid, dihydrazide glutalide, adipic acid dihydrazide, dihydrazide dihydric acid, dihydrazide dihydranoate, dihydrazide azelaide, dihydrazide sebacic acid, and dihydrazide sevacinate. Dihydrazide, dihydrazide fumarate, diglycolic acid dihydrazide, tartrate dihydrazide, malic acid dihydrazide, phthalic acid dihydrazide, isophthalic acid dihydrazide, terephthalic acid dihydrazide, 2,6-naphthoediic acid dihydrazide, 4,4-bisbenzenedihydrazide, 1,4 Dihydrazide compounds such as −naphthoic acid dihydrazide, 2,6-pyridinediic acid dihydrazide, and itaconic acid dihydrazide are preferred. The above dihydrazide compounds may be used alone or in combination of two or more.

Further, the amino compounds such as (I) dihydrazide compound, (II) aromatic diamine, and (III) aliphatic amine are, for example, a combination of (I) and (II), a combination of (I) and (III), and the like. It is also possible to use two or more combinations across categories, such as the combination of (I), (II) and (III).

Further, from the viewpoint of making the network structure formed by the cross-linking by the cross-linking amino compound more dense, the cross-linking amino compound used in the present invention has a molecular weight (when the cross-linking amino compound is an oligomer). The weight average molecular weight) is preferably 5,000 or less, more preferably 90 to 2,000, and even more preferably 100 to 1,500. Among these, an amino compound for cross-linking having a molecular weight of 100 to 1,000 is particularly preferable. 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 periphery of the remaining amino groups is steric. Since it becomes bulky, the remaining amino groups tend to be difficult to form a C = N bond.

When cross-linking the ketone group in the adhesive polyimide and the cross-linking amino compound, the above-mentioned cross-linking amino compound is added to the resin solution containing the adhesive polyimide to form a cross-link with the ketone group in the adhesive polyimide. The primary amino group of the amino compound for use is subjected to a condensation reaction. By this condensation reaction, the resin solution is cured to become a cured product. In this case, the amount of the amino compound for forming a bridge is 0.004 mol to 1.5 mol, preferably 0.005 mol to 1.2 mol, in total of the primary amino group with respect to 1 mol of the ketone group. It can be more preferably 0.03 mol to 0.9 mol, and most preferably 0.04 mol to 0.6 mol. If the amount of the cross-linking amino compound added so that the total number of primary amino groups is less than 0.004 mol with respect to 1 mol of the ketone group, the cross-linking by the cross-linking amino compound is not sufficient, and therefore after curing. The heat resistance tends to be difficult to develop, and when the amount of the cross-linking amino compound added exceeds 1.5 mol, the unreacted cross-linking amino compound acts as a thermoplastic agent, and the heat resistance as the adhesive layer is lowered. Tend to let.

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

The thermal condensation of the ketone group of the adhesive polyimide and the primary amino group of the above-mentioned amino compound for forming a crosslink is, for example,
(1) A method of adding an amino compound for cross-linking and heating following the synthesis (imidization) of adhesive polyimide.
(2) An excess amount of an amino compound is charged in advance as a diamine component, and following the synthesis (imidization) of the adhesive polyimide, the remaining amino compound that is not involved in imidization or amidation is used as an amino compound for cross-linking formation. And heating with adhesive polyimide,
Or
(3) A method of heating an adhesive polyimide composition to which the above-mentioned amino acid for cross-linking is added after processing it into a predetermined shape (for example, after applying it to an arbitrary substrate or forming it into a film).
It can be done by such as.

In order to impart heat resistance to the adhesive polyimide, an example of a crosslinked polyimide having a crosslinked structure by forming an imine bond has been described, but the present invention is not limited to this, and examples of the polyimide curing method include epoxy resin and epoxy. It is also possible to blend and cure a compound having an unsaturated bond such as a resin curing agent, maleimide, an activated ester resin, or a resin having a styrene skeleton.

The adhesive polyimide of the present embodiment satisfies the following conditions a to c.

Condition a)
For all diamine residues, 60 mol of diamine residues derived from a diamine diamine composition containing diamine diamine as a main component, in which the two terminal carboxylic acid groups of dimer acid are replaced with primary aminomethyl groups or amino groups. % Or more;
The content of the diamine residue derived from the diamine composition with respect to the total diamine residue is 60 mol% or more, preferably in the range of 60 to 99 mol%, more preferably in the range of 65 to 95 mol%, and further. The relative permittivity and dielectric tangent of the polyimide can be lowered, preferably in the range of 70 to 90 mol%. When the content of the diamine residue derived from the diamine diamine composition is less than 60 mol%, the relative permittivity and the dielectric loss tangent tend to increase due to the relative increase in the polar groups contained in the polyimide. When the content of the diamine residue derived from the diamine diamine composition exceeds 99 mol% with respect to the total diamine residue, the motility of the molecular chain of the polyimide may be excessively increased and the dielectric loss tangent may be increased. .. Further, by containing dimer diamine in the above amount, the dielectric property of the polyimide is improved, the thermocompression bonding property is improved by lowering the glass transition temperature of the polyimide (lower Tg), and the internal stress is lowered by lowering the elastic modulus. Can be alleviated.

Condition b)
The content of carbon atoms derived from the 6-membered aromatic ring (excluding the carbon atoms of the 6-membered aromatic ring derived from the dimerdiamine composition) with respect to the total content of all the atoms in the polyimide is in the range of 12 to 40% by weight. Being;
The content of carbon atoms derived from the 6-membered aromatic ring means the content of the aromatic ring contained in the adhesive polyimide (aromatic ring concentration). By setting the content of carbon atoms derived from the 6-membered aromatic ring to the range of 12 to 40% by weight, the movement of the molecule is restricted by the interaction between the aromatic rings in the polyimide, and the effect of low dielectric loss tangent is exhibited. do. If the content of the carbon atom derived from the 6-membered aromatic ring is less than 12% by weight, the movement of the molecular chain of the polyimide cannot be suppressed, so that the dielectric loss tangent becomes high. When the content of carbon atoms derived from the 6-membered aromatic ring exceeds 40% by weight, the polarity of the molecule becomes large and the dielectric loss tangent becomes high. The content of carbon atoms derived from the 6-membered aromatic ring is preferably in the range of 17 to 38% by weight, more preferably in the range of 20 to 30% by weight.

Condition c)
The weight average molecular weight is in the range of 5,000 to 200,000;
When the weight average molecular weight of the adhesive polyimide is less than 5,000, it tends to be fragile when it is formed into a film. On the other hand, when the weight average molecular weight exceeds 200,000, the viscosity becomes high when the varnish is used, and the thickness unevenness tends to occur at the time of coating.
The weight average molecular weight of the adhesive polyimide is preferably in the range of 10,000 to 60,000, more preferably in the range of 20,000 to 55,000. When the weight average molecular weight is less than 10,000, the relative permittivity and the dielectric loss tangent may easily increase due to the increase in the highly polar ends in the polyimide molecular chain. When the weight average molecular weight exceeds 60,000, the molecular chain length becomes long and it becomes difficult to form an ordered structure, so that the relative permittivity and the dielectric loss tangent may easily increase.

It is preferable that the polyimide of the present embodiment further satisfies any one or more of the following conditions d, e, and f.

Condition d)
The following formula (i),
CM value = (C / Mw) x 10 ⁴ ... (i)
[In the formula, C means the weight content of carbon atoms derived from the 6-membered aromatic ring (excluding the carbon atoms of the 6-membered aromatic ring derived from the dimerdiamine composition) with respect to the total content of all the atoms in the polyimide. Mw means the weight average molecular weight of polyimide]
The CM value, which is an index indicating the amount of 6-membered aromatic rings contained in the polyimide, calculated based on the above, is in the range of 3 to 38;
Keeping the CM value within an appropriate range is effective for reducing the dielectric loss tangent of polyimide. When the CM value is less than 3, the aromatic ring concentration is reduced, so that the molecular motility is increased and the dielectric loss tangent is increased. do. On the other hand, when the CM value exceeds 38, the aromatic ring concentration becomes excessive, the polarity becomes high, and the dielectric loss tangent increases.

Condition e)
The weight content of carbon atoms derived from the 6-membered aromatic ring (excluding the carbon atoms of the 6-membered aromatic ring derived from the dimer diamine composition) with respect to the total content of all atoms in the total diamine component of the raw material exceeds 0 and is 32 weights. Must be within the range of% or less;
In the adhesive polyimide, by controlling the content of aromatic rings within an appropriate range, the movement of molecules is restricted by the interaction between aromatic rings in the polyimide, and the effect of low dielectric loss tangent is exhibited. For this purpose, it is effective to keep the content of carbon atoms derived from the 6-membered aromatic ring within the above range with respect to the total content of carbon atoms in the diamine component of the raw material. When the content of the carbon atom derived from the 6-membered aromatic ring in the total diamine component of the raw material exceeds 32% by weight, the polarity of the obtained polyimide molecule becomes large and the dielectric loss tangent becomes high.

Condition f)
The following formula (ii),
DM value = (D / Mw) x 10 ⁴ ... (ii)
[In the formula, D is the weight content of the 6-membered aromatic ring-derived carbon atom (excluding the 6-membered aromatic ring-derived carbon atom derived from the diamine composition) with respect to the total content of all atoms in the total diamine residue. Means, Mw means the weight average molecular weight of polyimide]
The DM value, which is an index indicating the amount of 6-membered aromatic rings derived from the diamine component contained in the polyimide, calculated based on the above, is in the range of more than 0 and 32 or less;
For the same reason as in condition e, it is effective to keep the content of carbon atoms derived from the 6-membered aromatic ring in the diamine residue within the above range with respect to the total content of all atoms in the polyimide.

[Adhesive resin composition]
Since the adhesive polyimide is solvent-soluble, it can be used in the form of a solvent-containing composition. That is, the adhesive resin composition contains an adhesive polyimide and a solvent capable of dissolving the adhesive polyimide. In addition, the adhesive resin composition can contain an amino compound for forming a crosslink as an optional component. The adhesive resin composition contains, 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 the adhesive polyimide as all of the resin components. The main component of the resin component means a component contained in an amount of more than 50% by weight based on the total resin component.

The solvent is not particularly limited as long as it can dissolve adhesive polyimide. For example, N, N-dimethylformamide (DMF), N, N-dimethylacetamide (DMAc), N, N-diethylacetamide, N- Methyl-2-pyrrolidone (NMP), 2-butanone, dimethyl sulfoxide (DMSO), hexamethylphosphoramide, N-methylcaprolactam, dimethylsulfate, cyclohexanone, methylcyclohexane, dioxane, tetrahydrofuran, diglime, triglime, methanol, ethanol, Benzyl alcohol, cresol, acetone and the like can be mentioned. Two or more of these solvents can be used in combination, and aromatic hydrocarbons such as xylene and toluene can be used in combination.

In the adhesive resin composition, the blending ratio of the adhesive polyimide and the solvent is not particularly limited as long as the composition can be maintained at a viscosity that allows coating. The viscosity of the adhesive resin composition is preferably in the range of, for example, 500 mPa · s to 100,000 mPa · s. If it is out of this range, defects such as uneven thickness and streaks are likely to occur in the resin film during the coating operation.

The adhesive resin composition contains, as an optional component, other curing resin components such as a plasticizer and an epoxy resin, a curing agent, a curing accelerator, an organic filler, an inorganic filler, and a coupling agent as long as the effects of the invention are not impaired. , Flame retardant and the like can be appropriately blended.

[Adhesive film]
The adhesive film according to the embodiment of the present invention is the adhesive polyimide or the crosslinked polyimide processed into a film. The adhesive film contains the above-mentioned adhesive polyimide or crosslinked 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 all of the resin components. The film contained is not particularly limited. The main component of the resin component means a component contained in an amount of more than 50% by weight based on the total resin component. The adhesive film may be a film (sheet) made of adhesive polyimide or crosslinked polyimide, and for example, a base material of an inorganic material such as a copper foil or a glass plate, a polyimide film, a polyamide film, or a polyester film. It may be in a state of being laminated on a resin base material such as a film. As an optional component, the adhesive film may appropriately contain other curing resin components such as a plasticizer and an epoxy resin, a curing agent, a curing accelerator, an organic filler, an inorganic filler, a coupling agent, a flame retardant, and the like. ..

_{The adhesive film has a dielectric loss tangent (Tanδ 1} ) at 10 GHz measured by a split post dielectric resonator (SPDR) after humidity control for 24 hours under constant temperature and humidity conditions (normal condition) of 23 ° C. and 50% RH. It is preferably 0.005 or less and the relative permittivity (E ₁ ) is 3.0 or less. If the dielectric loss tangent (Tan δ ₁ ) and the relative permittivity (E ₁ ) exceed the above values, it leads to an increase in dielectric loss when applied to a circuit board, resulting in inconvenience such as loss of electrical signals on the transmission path of high-frequency signals. Is likely to occur.

_{Further, the adhesive film has a dielectric loss tangent (Tanδ 2} ) at 20 GHz measured by a split post dielectric resonator (SPDR) after humidity control for 24 hours under a constant temperature and humidity condition (normal state) of 23 ° C. and 50% RH. ) Is 0.005 or less, and the relative permittivity (E ₂ ) is preferably 3.0 or less. If the dielectric loss tangent (Tan δ ₂ ) and the relative permittivity (E ₂ ) exceed the above values, it leads to an increase in dielectric loss when applied to a circuit board, resulting in inconvenience such as loss of electrical signals on the transmission path of high-frequency signals. Is likely to occur.

_{Further, the adhesive film has a dielectric loss tangent (Tanδ 1} ) at 10 GHz measured by a split post dielectric resonator (SPDR) after humidity control for 24 hours under a constant temperature and humidity condition (normal condition) of 23 ° C. and 50% RH. ) And the dielectric loss tangent (Tanδ ₂ ) at 20 GHz, preferably the difference (Tanδ _{2- Tanδ 1} ) is 0 or less. When the difference (Tanδ _{2- Tanδ 1} ) is 0 or less, it means that the transmission loss at 10 to 20 GHz does not increase, but is the same or rather decreases.

The tensile elastic modulus of the adhesive film is preferably 3000 MPa or less, preferably 100 MPa or more and 2500 MPa or less, and more preferably 200 MPa or more and 2000 MPa or less. When the tensile elastic modulus is less than 100 MPa, the film is likely to be wrinkled, and the handleability may be deteriorated due to the occurrence of air biting during lamination. Further, if the tensile elastic modulus exceeds 3000 MPa, warpage occurs and dimensional stability is lowered when the base material and the adhesive film are laminated. By setting the tensile elastic modulus as described above, it is possible to obtain a laminate having good handleability, suppressing warpage, and excellent dimensional stability.

The method for producing the adhesive film of the present embodiment is not particularly limited, and the following methods [1] to [3] can be exemplified.
[1] Adhesive polyimide is applied to an arbitrary substrate in a solution state (for example, in the state of an adhesive resin composition) to form a coating film, which is dried at a temperature of, for example, 80 to 180 ° C. A method of forming a film and then peeling it off from the substrate as needed.
[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 in which a solution of polyamic acid, which is a precursor of adhesive polyimide, is applied to an arbitrary base material, dried, and then the gel film of polyamic acid is peeled off from the base material and imidized to obtain an adhesive film.
The method of applying the adhesive polyimide solution (or polyamic acid solution) on the substrate is not particularly limited, and for example, it can be applied with a coater such as a comma, a die, a knife, or a lip.

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]
As shown in FIG. 1, for example, the laminated body 100 according to the embodiment of the present invention has a base material 10 and an adhesive layer 20 laminated on at least one surface of the base material 10. The adhesive layer 20 is made of the above-mentioned adhesive film. The laminated body 100 may include any layer other than the above. Examples of the base material 10 in the laminate 100 include a base material of an inorganic material such as a copper foil and a glass plate, and a base material of a resin material such as a polyimide film, a polyamide film, and a polyester film. The laminated body 100 can be manufactured according to any one of [1] to [3] of the above-mentioned method for manufacturing an adhesive film, except that it does not peel off from the base material 10. Further, the laminate 100 may be manufactured by separately preparing the base material 10 and the adhesive film and bonding them together.
Preferred embodiments of the laminate 100 include a coverlay film, a copper foil with a resin, and the like.

(Coverlay film)
Although not shown, the coverlay film which is one aspect of the laminated body 100 is a coverlay film material layer as a base material 10 and an adhesive layer laminated on one side of the coverlay film material layer. The adhesive layer 20 is made of the above-mentioned adhesive film. The coverlay film may contain any layer other than the above.

The material of the coverlay film material layer is not particularly limited, and for example, a polyimide-based film such as a polyimide resin, a polyetherimide resin, or a polyamide-imide resin, a polyamide-based film, or a polyester-based film can be used. Among these, it is preferable to use a polyimide-based film having excellent heat resistance. Further, the coverlay film material layer may contain a black pigment in order to effectively exhibit light-shielding property, hiding property, design property, etc., and the surface thereof is within a range that does not impair the effect of improving the dielectric property. It can contain any component such as a matte pigment that suppresses the gloss of.

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

The coverlay film of the present embodiment can be produced by the method exemplified below.
First, as a first method, a polyimide to be an adhesive layer 20 is put on 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 resin composition is preferable. ), And then dried at a temperature of, for example, 80 to 180 ° C. to form the adhesive layer 20 to form a coverlay film having a coverlay film material layer and an adhesive layer 20.

Further, as a second method, the polyimide for the adhesive layer 20 is applied on an arbitrary base material in a solution state (for example, a varnish containing a solvent is preferable, and an adhesive resin composition is preferable). Then, for example, after drying at a temperature of 80 to 180 ° C., the adhesive film for the adhesive layer 20 is formed by peeling off, and this adhesive film is combined with the film material layer for the coverlay, for example, 60 to 220. A coverlay film can be formed by heat-bonding at a temperature of ° C.

(Copper foil with resin)
Although not shown, the copper foil with resin, which is another aspect of the laminated body 100, is obtained by laminating the adhesive layer 20 on at least one side of the copper foil as the base material 10, and the adhesive layer 20 adheres to the above. It consists of an agent film. The resin-coated copper foil of the present embodiment may contain any layer other than the above.

The thickness of the adhesive layer 20 in the resin-attached copper foil is preferably in the range of 0.1 to 125 μm, more preferably in the range of 0.3 to 100 μm, for example. If the thickness of the adhesive layer 20 does not reach the above lower limit value, problems such as insufficient adhesiveness cannot be ensured may occur. On the other hand, if the thickness of the adhesive layer 20 exceeds the above upper limit value, problems such as deterioration of dimensional stability occur. Further, from the viewpoint of low dielectric constant and low dielectric loss tangent, the thickness of the adhesive layer 20 is preferably 3 μm or more.

The material of the copper foil in the copper foil with resin is preferably one containing copper or a copper alloy as a main component. The thickness of the copper foil is preferably 35 μm or less, more preferably in the range of 5 to 25 μm. From the viewpoint of production stability and handleability, the lower limit of the thickness of the copper foil is preferably 5 μm. The copper foil may be a rolled copper foil or an electrolytic copper foil. Further, as the copper foil, a commercially available copper foil can be used.

The copper foil with resin may be prepared, for example, by sputtering a metal on an adhesive film to form a seed layer and then forming a copper layer by, for example, copper plating, or the adhesive film and the copper foil. May be prepared by laminating by a method such as thermal pressure bonding. Further, in the copper foil with resin, in order to form the adhesive layer 20 on the copper foil, a coating liquid of adhesive polyimide or its precursor is cast and dried to form a coating film, and then necessary heat treatment is performed. May be prepared.

[Metal-clad laminate]
(First aspect)
The metal-clad laminate according to the embodiment of the present invention includes an insulating resin layer and a metal layer laminated on at least one surface of the insulating resin layer, and at least one layer of the insulating resin layer is described above. It consists of an adhesive film. The metal-clad laminate of the present embodiment may include any layer other than the above.

(Second aspect)
The metal-clad laminate according to another embodiment of the present invention includes, for example, as shown in FIG. 2, an insulating resin layer 30, an adhesive layer 20 laminated on at least one surface of the insulating resin layer 30, and the adhesive layer 20. It is a so-called three-layer metal-clad laminate 101 including a metal layer M laminated on the insulating resin layer 30 via an adhesive layer 20, and the adhesive layer 20 is made of the above-mentioned adhesive film. .. The three-layer metal-clad laminate 101 may include any layer 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 one side of the insulating resin layer 30 via the adhesive layer 20. 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 processing a wiring circuit by etching the metal layer M of the three-layer metal-clad laminate 101 or the like.

The insulating resin layer 30 in the three-layer metal-clad laminate 101 is not particularly limited as long as it is made of a resin having electrical insulating properties, and is, for example, polyimide, epoxy resin, phenol resin, polyethylene, polypropylene, or polytetra. Fluoroethylene, silicone, ETFE and the like can be mentioned, but it is preferably composed of polyimide. The polyimide layer constituting the insulating resin layer 30 may be a single layer or a plurality of 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 preferably in the range of, for example, 1 to 125 μm, and more preferably in the range of 5 to 100 μm. If the thickness of the insulating resin layer 30 does not reach the above lower limit value, problems such as insufficient electrical insulation cannot be ensured may occur. On the other hand, if the thickness of the insulating resin layer 30 exceeds the above upper limit value, problems such as warpage of the metal-clad laminate are likely to occur.

The thickness of the adhesive layer 20 in the three-layer metal-clad laminate 101 is preferably in the range of 0.1 to 125 μm, more preferably in 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 does not reach the above lower limit value, there may be a problem that sufficient adhesiveness cannot be guaranteed. On the other hand, if the thickness of the adhesive layer 20 exceeds the above upper limit value, problems such as deterioration of dimensional stability occur. Further, from the viewpoint of reducing the dielectric constant and the low 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.

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, for example, 0.1 to 3.0, and is 0. The range of .15 to 2.0 is more preferable. With such a ratio, the warp of the three-layer metal-clad laminate 101 can be suppressed. Further, the insulating resin layer 30 may contain a filler, if necessary. Examples of the filler include silicon dioxide, aluminum oxide, magnesium oxide, beryllium oxide, boron nitride, aluminum nitride, silicon nitride, aluminum fluoride, calcium fluoride, and metal salts of organic phosphinic acid. These can be used alone or in admixture of two or more.

(Third aspect)
The metal-clad laminate according to still another embodiment of the present invention is, for example, as shown in FIG. 3, a laminated metal formed by laminating at least two single-sided metal-clad laminates via an adhesive layer 20. It is a tension laminated board 102. The bonding type 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. An adhesive layer 20 laminated between the 42 and the adhesive layer 20 is provided, and the adhesive layer 20 is made of the above-mentioned 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 abut the first insulating resin layer 31 and the second insulating resin layer 32. The bonded metal-clad laminate 102 may include any layer other than the 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 of the three-layer metal-clad laminate 101 of the second aspect. good.
In the bonding type metal-clad laminate 102, a first single-sided metal-clad laminate 41 and a second single-sided metal-clad laminate 42 are prepared, respectively, and the first insulating resin layer 31 and the second insulating resin layer 32 are formed. It can be manufactured by arranging and adhering an adhesive film between the two.

(Fourth aspect)
In the metal-clad laminate according to still another embodiment of the present invention, for example, as shown in FIG. 4, the insulating resin layer 33 and the metal layer M laminated on one surface of the insulating resin layer 33 are provided. A single-sided metal-clad laminate 103 with an adhesive layer comprising a single-sided metal-clad laminate and an adhesive layer 20 laminated on the other surface of the insulating resin layer 33, wherein the adhesive layer 20 is described above. It consists of an adhesive film. The metal-clad laminate 103 with an adhesive layer may include any layer other than the above.
The insulating resin layer 33 in the metal-clad laminate 103 with an adhesive layer may have the same configuration as the insulating resin layer 30 in the three-layer metal-clad laminate 101 of the second aspect.
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 adhering an adhesive film to the side of the insulating resin layer 33.

In any of the above-exemplified metal-clad laminates of the first to fourth aspects, the material of the metal layer M (including the first metal layer M1 and the second metal layer M2; the same applies hereinafter) is used. The present invention is not particularly limited, and examples thereof include copper, stainless steel, iron, nickel, beryllium, aluminum, zinc, indium, silver, gold, tin, zirconium, tantalum, titanium, lead, magnesium, manganese, and alloys thereof. Of these, copper or copper alloys are particularly preferable. The material of the wiring layer in the circuit board 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 a metal foil such as a copper foil is used, it is preferably 35 μm or less, and more preferably 5 to 25 μm. From the viewpoint of production stability and handleability, the lower limit of the thickness of the metal foil is preferably 5 μm. When a copper foil is used, it may be a rolled copper foil or an electrolytic copper foil. Further, as the copper foil, a commercially available copper foil can be used. Further, the metal foil may be subjected to surface treatment with, for example, siding, aluminum alcoholate, aluminum chelate, silane coupling agent or the like for the purpose of rust prevention treatment or improvement of adhesive strength.

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

(Second aspect)
The circuit board 200 according to another embodiment of the present invention includes, for example, as shown in FIG. 5, a first base material 11 and a wiring layer 50 laminated on at least one surface of the first base material 11. The adhesive layer 20 is 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 adhesive layer 20 is made of the adhesive film. .. The circuit board 200 may include any layer other than the above.
The first base material 11 in the circuit board 200 may have the same structure as the insulating resin layer of the metal-clad laminate. In the circuit board 200, an adhesive film is attached to the wiring layer 50 side of the circuit board including the first base material 11 and the wiring layer 50 laminated on at least one surface of the first base material 11. Can be manufactured by

(Third aspect)
The circuit board 201 according to still another embodiment of the present invention has a wiring layer 50 laminated on at least one surface of the first base material 11 and the first base material 11, as shown in FIG. 6, for example. And, on the surface of the first base material 11 on the side of the wiring layer 50, the adhesive layer 20 laminated so as to cover the wiring layer 50, and on the surface of the adhesive layer 20 opposite to the first base material 11. The second base material 12 and the laminated second base material 12 are provided, and the adhesive layer 20 is made of the above-mentioned adhesive film. The circuit board 201 may include any layer other than the above. The first base material 11 and the second base material 12 in the circuit board 201 may have the same configuration as the insulating resin layer of the metal-clad laminate.
The circuit board 201 is provided with an adhesive film on the wiring layer 50 side of the circuit board including the first base material 11 and the wiring layer 50 laminated on at least one surface of the first base material 11. It can be manufactured by laminating the second base material 12.

(Fourth aspect)
The circuit board 202 according to still another embodiment of the present invention has an adhesive layer laminated on at least one surface of the first base material 11 and the first base material 11, as shown in FIG. 7, for example. 20 and the second base material 12 laminated on the surface of the adhesive layer 20 opposite to the first base material 11, and the adhesive layer of the first base material 11 and the second base material 12. The wiring layers 50 and 50 laminated on the surface opposite to the 20 are provided, and the adhesive layer 20 is made of the adhesive film. The circuit board 202 may include any layer other than the above. The first base material 11 and the second base material 12 in the circuit board 202 may have the same configuration as the insulating resin layer of the metal-clad laminate.
The circuit board 202 includes a first circuit board including 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. A second circuit board having a wiring layer 50 laminated on at least one surface of the second base material 12 is prepared, and the first base material 11 of the first circuit board and the first base material 12 are prepared. It can be manufactured by arranging and adhering an adhesive film between the second base material 12 of the circuit board 2 and the second base material 12.

[Multilayer circuit board]
The multilayer circuit board according to the 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 has a plurality of insulation layers. At least one or more of the resin layers are 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. The multilayer circuit board of the present embodiment may include any layer other than the above.
For example, as shown in FIG. 8, the multilayer circuit board 203 of the present embodiment has at least two or more insulating resin layers 34 and at least two or more wiring layers 50, and at least one of the wiring layers 50. The layer is covered with an adhesive layer 20. The adhesive layer 20 that covers 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. Further, the multilayer circuit board 203 may optionally have a wiring layer 50 exposed on the surface of the multilayer circuit board 203. Further, it may have an interlayer connection electrode (via electrode) in contact with the wiring layer 50. The wiring layer 50 has a conductor circuit formed in a predetermined pattern on one side or both sides of the insulating resin layer 34. The conductor circuit may be one in which a pattern is formed on the surface of the insulating resin layer 34, or one in which a pattern is formed in a damascene (embedded) manner. The insulating resin layer 34 in the multilayer circuit board 203 may have the same configuration 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 include the adhesive layer 20 containing the adhesive polyimide whose aromatic ring concentration is controlled, the transmission loss can be reduced even in high frequency transmission.

[Action]
FIG. 9 is a drawing schematically showing the relationship between the aromatic ring concentration and the dielectric loss tangent in the adhesive polyimide of the present invention. The vertical axis of FIG. 9 is the dielectric loss tangent at 10 GHz measured by the same method as in the examples below, and the horizontal axis is the weight content of carbon atoms derived from the 6-membered aromatic ring with respect to the total content of all atoms in the polyimide. It means the rate (aromatic ring concentration). Aromatic rings such as benzene rings vibrate due to high frequencies, increasing heat loss. Therefore, as a general tendency, the dielectric loss tangent increases as the concentration of the aromatic ring contained in the polyimide increases. However, in the adhesive polyimide, if the aromatic ring concentration is in the range of 12 to 40% by weight, the dielectric loss tangent does not increase even if the aromatic ring concentration increases, but rather the dielectric loss tangent decreases up to a certain aromatic ring concentration. It was found to show a tendency to do. The cause of such behavior is not yet clear, but it can be reasonably interpreted as follows.
The adhesive polyimide uses a dimer diamine composition as a raw material and has a relatively low aromatic ring concentration as compared with a polyimide using an aromatic diamine as a raw material. It is presumed that if the concentration of the aromatic ring is gradually increased from the state where the concentration of the aromatic ring is low in this way, the movement of the molecule is restricted by the interaction between the aromatic rings, and the dielectric loss tangent is further suppressed. Then, it is considered that the dielectric loss tangent is sufficiently low until the aromatic ring concentration reaches 40% by weight.

Examples will be shown below, and the features of the present invention will be described in more detail. However, the scope of the present invention is not limited to the examples. In the following examples, various measurements and evaluations are as follows unless otherwise specified.

[Measuring method of amine value]
Approximately 2 g of the dimerdiamine composition is weighed in a 200-250 mL triangular flask, using phenolphthalein as an indicator, and 0.1 mol / L potassium hydroxide solution is added dropwise until the solution turns pale pink. , Dissolve in about 100 mL of neutralized butanol. Add 3 to 7 drops of phenolphthalein solution to it, and titrate with stirring with 0.1 mol / L ethanolic potassium hydroxide solution until the sample solution turns pale pink. Add 5 drops of bromophenol blue solution to it, and titrate with stirring with 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 x C ₂ )-(V ₁ x C ₁ )} x M _KOH / m ... (1)
Here, the amine value is a value represented by mg-KOH / g, and M _KOH has a molecular weight of potassium hydroxide of 56.1. V and C are the volumes and concentrations of the solutions 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. Further, m is the sample weight expressed in grams.

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

[Calculation method of CM value]
Weight content of 6-membered aromatic ring-derived carbon atoms (excluding 6-membered aromatic ring-derived carbon atoms derived from the dimer diamine composition) with respect to the weight average molecular weight (Mw) of the polyimide and the total content of all atoms in the polyimide (excluding the carbon atoms of the 6-membered aromatic ring) From _{the relationship with C p} ), the CM value was calculated based on the following equation.
CM = (C _p / Mw) x 10 ⁴ ... (i)

[Calculation method of DM value]
The content of carbon atoms derived from a 6-membered aromatic ring (excluding carbon atoms of a 6-membered aromatic ring derived from a diamine diamine composition) with respect to the weight average molecular weight (Mw) of polyimide and the total content of all atoms in the total diamine component. From the relationship with (C _d ), the DM value was calculated based on the following formula.
DM = (C _d / Mw) x 10 ⁴ ... (ii)

[Calculation of aromatic ring ratio of diamine diamine composition]
The aromatic ring ratio of the diamine diamine composition was calculated by the following procedure. First, about 50 μl of the diamine diamine composition was dissolved in 550 μl of THF-d8 to prepare a sample. The prepared sample was subjected to liquid 1H-NMR measurement at room temperature using an FT-NMR apparatus (JEM-ECA400 manufactured by JEOL). The integral value of the 1H peak derived from the aromatic ring found at 6.6 to 7.2 ppm, as opposed to the integral value of the 1H peak derived from the _{CH 2} group directly connected _{to the NH 2} groups found at 2.6 to 2.9 ppm. From the ratio, the aromatic ring ratio was calculated as shown in the following formula.
Aromatic ring ratio [mol%] = (Z / Y) x 100
[Here, Y means the integral value of the 1H peak at 2.6 to 2.9 ppm, and Z means the integral value of the 1H peak (derived from the aromatic ring) at 6.6 to 7.2 ppm. ]

[Calculation of area percentage of GPC and chromatogram]
(A) Dimerdiamine (b) A monoamine compound obtained by substituting a terminal carboxylic acid group of a monobasic acid compound in the range of 10 to 40 carbon atoms with a primary aminomethyl group or an amino group (c) 41 carbon atoms. An amine compound obtained by substituting a primary aminomethyl group or an amino group for a terminal carboxylic acid group of a polybasic acid compound having a hydrocarbon group in the range of -80 (excluding the dimerdiamine).

GPC prepared a sample by diluting a 100 mg solution of a 20 mg diamine diamine composition pretreated with 200 μL acetic anhydride, 200 μL pyridine and 2 mL THF with 10 mL THF (containing 1000 ppm cyclohexanone). The prepared sample was manufactured by Tosoh Corporation, trade name: HLC-8220GPC, column: TSK-gel G2000HXL, G1000HXL, flow volume: 1 mL / min, column (oven) temperature: 40 ° C., injection volume: 50 μL. Measured in. Cyclohexanone was treated as a standard substance to correct the outflow 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) is provided so that the peak top of the main peak is 18 minutes to 19 minutes and the peak start to peak end of the main peak excluding the cyclohexanone peak is 2 minutes to 4 minutes and 30 seconds. )-(C)
(A) 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 where the retention time at the main peak is late;
(C) A component represented by a GPC peak detected earlier than the minimum value on the time side where the retention time at the main peak is earlier;
Was detected.

[Measurement of relative permittivity and dielectric loss tangent]
Using a vector network analyzer (manufactured by Agent, trade name; vector network analyzer E8633C) and an SPDR resonator, the resin sheet was allowed to stand for 24 hours under the conditions of temperature; 23 ° C. and humidity; 50%, and then the ratio at a frequency of 10 GHz. The permittivity (ε ₁ ) and the dielectric loss tangent (Tan δ ₁ ), and the relative permittivity (ε ₂ ) and the dielectric loss tangent (Tan δ ₂ ) at a frequency of 20 GHz were measured. Further, the R value, which is an index of the frequency dependence of the dielectric loss tangent, was calculated by the following equation.
R value = Tanδ _{2- Tanδ 1}

[Glass transition temperature (Tg)]
The glass transition temperature (Tg) is a temperature rise rate of 5 ° C./ The measurement was performed in minutes. The temperature at which the inflection point of elongation at the time of temperature rise is defined as the glass transition temperature.

[Tension modulus]
The tensile elastic modulus was measured by the following procedure. First, a test piece (width 12.7 mm × length 127 mm) was prepared from a resin sheet using a tension tester (manufactured by Orientec Co., Ltd., trade name; Tencilon). Using this test piece, a tensile test was performed at 50 mm / min to determine the tensile elastic modulus at 25 ° C.

[Warp evaluation method]
The warpage was evaluated by the following method. A polyimide solution is applied on a 25 μm-thick polyimide film (manufactured by Toray DuPont, trade name; Kapton 100EN) or on a 12 μm copper foil so that the thickness after drying is 25 μm, and a test piece is prepared. Was produced. In this state, place the polyimide film or copper foil on the lower surface, measure the average of the warped heights at the four corners of the test piece, and measure 5 mm or less as "good" and 5 mm or more as "impossible". bottom.

The abbreviations used in this example indicate the following compounds.
BTDA: 3,3', 4,4'-benzophenone tetracarboxylic acid dianhydride BPDA: 3,3', 4,4'-biphenyltetracarboxylic acid dianhydride ODPA: 4,4'-oxydiphthalic acid anhydride BPADA : 2,2-Bis [4- (3,4-dicarboxyphenoxy) phenyl] Propane dianhydride DDA: Dimerdiamine with 36 carbon atoms (manufactured by Crowder Japan Co., Ltd., trade name: PRIAMINE 1074 distilled and purified, amine Valuation: 210 mgKOH / g, mixture of cyclic and chain dimerdiamine, component (a); 97.9% by weight, component (b); 0.3%, component (c); 1.8%, aromatic Ring ratio; 8.2 mol%)
BAFL: Bisaniline Fluorene APB: 1,3-bis (3-aminophenoxy) Benzene BAPP: 2,2-bis [4- (4-aminophenoxy) phenyl] Propane N-12: Dihydrazide dodecanedioic acid 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 D ₅₀ ; 2 μm)
SR-3000: Phosphoric acid ester (manufactured by Daihachi Chemical Industry Co., Ltd., trade name; SR-3000, non-halogen aromatic condensed phosphoric acid ester, phosphorus content; 7.0%)
The molecular weight of the DDA was calculated by the following formula.
Molecular weight = 56.1 × 2 × 1000 / amine value

[Example 1]
In a 1000 ml separable flask, 46.43 g BTDA (0.1441 mol), 68.60 g DDA (0.1284 mol), 4.97 g BAFL (0.0143 mol) 168 g NMP and 112 g xylene. The mixture was charged and mixed well at 40 ° C. for 1 hour to prepare a polyamic acid solution. This polyamic acid solution was heated to 190 ° C., heated for 5 hours, stirred, and 98 g of xylene was added to complete imidization of polyimide solution 1 (solid content; 30% by weight, weight average molecular weight; 28,850, 6). The member aromatic ring content C _d ; 5.59%, C _p ; 21.57%, DM value; 1.9, CM value; 7.5) were prepared.

[Examples 2 to 18]
Polyimide solutions 2 to 18 were prepared in the same manner as in Example 1 except that the raw material compositions shown in Tables 1 and 2 were used.

[Example 19]
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 120 ° C. for 10 minutes, and dried. By peeling the adhesive layer from the release PET film 1, an adhesive film 19 having a thickness of 25 μm was obtained. The various evaluation results of the adhesive film 19 are as follows.
ε ₁ ; 2.6, Tan δ ₁ ; 0.0017 _, ε ₂ ; 2.6, Tan δ ₂ ; 0.0014, R value; -0.0003, Tg; 45 ° C, tensile modulus; 630 MPa

[Examples 20 to 36]
Adhesive films 20 to 36 were obtained in the same manner as in Example 19 except that the polyimide solutions 2 to 18 were used. The results of various characteristic evaluations are shown in Table 3.

[Example 37]
Add 1.1 g of N-12 (0.004 mol) to 100 g of polyimide solution 1 (30 g as solid content), and add 7.5 g of OP935, 2.0 g of NMP and 12.0 g of xylene to dilute. Then, the adhesive composition 37 was prepared by further stirring for 1 hour.

[Examples 38 to 54]
Adhesive compositions 38-54 were prepared in the same manner as in Example 37, except that polyimide solutions 2-18 were used.

[Example 55]
Add 0.6 g of N-12 (0.002 mol) to 100 g of polyimide solution 17 (30 g as solid content) and add 7.5 g of OP935, 1.5 g of NMP and 11.4 g of xylene to dilute. Then, the adhesive composition 55 was prepared by further stirring for 1 hour.

[Example 56]
Add 1.1 g of N-12 (0.004 mol) to 100 g of polyimide solution 11 (30 g as solid content), add 6.0 g of SR-3000, 0.3 g of NMP and 10.3 g of xylene. The adhesive composition 56 was prepared by diluting the mixture and stirring the mixture for 1 hour.

[Example 57]
The adhesive composition 37 is applied to one side of the release PET film 1, dried at 80 ° C. for 15 minutes to obtain a resin sheet 57 having an adhesive layer thickness of 25 μm, and then the adhesive layer is removed from the release PET film 1. An adhesive film 57 having a thickness of 25 μm was obtained by peeling from the adhesive film 57.

[Examples 58 to 76]
Resin sheets 58 to 76 were obtained in the same manner as in Example 57, except that the adhesive compositions 38 to 56 were used, and then adhesive films 58 to 76 were obtained.

[Example 77]
Adhesive composition 37 of polyimide film 1 (manufactured by Toray DuPont, trade name; Kapton 50EN, ε ₁ = 3.6, tan δ ₁ = 0.0084, length x width x thickness = 200 mm x 300 mm x 12 μm) It was applied to one side and dried at 80 ° C. for 15 minutes to obtain a coverlay film 77 having an adhesive layer thickness of 25 μm. The warped state of the obtained coverlay film 77 was "good".

[Examples 78 to 81]
Coverlay films 78 to 81 were obtained in the same manner as in Example 77, except that the adhesive compositions 40, 54, 55 and 56 were used. The warped states of the obtained coverlay films 78 to 81 were all “good”.

[Example 82]
The release PET film 1 was laminated so as to be in contact with the adhesive layer side of the coverlay film 77, and pressure-bonded using a vacuum laminator at a temperature of 160 ° C. and a pressure of 0.8 MPa for 2 minutes. Then, the adhesive composition 37 was applied to the polyimide film 1 side of the coverlay film 77 in which the release PET film 1 was pressure-bonded to the adhesive layer side so that the thickness after drying was 25 μm, and dried at 80 ° C. for 15 minutes. Was done. Then, the adhesive composition 37 was laminated on the coated and dried surface so that the release PET film 1 was in contact with the surface, and pressure-bonded to both sides of the polyimide film at a temperature of 160 ° C. and a pressure of 0.8 MPa for 2 minutes using a vacuum laminator. A laminate 82 with a polyimide adhesive layer provided with an adhesive layer was obtained.

[Examples 83 to 86]
The polyimide adhesive layered laminates 83 to 86 were provided in the same manner as in Example 82, except that the coverlay films 78, 79, 80 or 81 were used and the adhesive compositions 40, 54, 55 or 56 were applied. Obtained.

[Example 87]
The adhesive composition 37 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 87 having an adhesive layer thickness of 25 μm. The warped state of the obtained copper foil 87 with resin was “good”.

[Examples 88 to 91]
Copper foils 88 to 91 with resin were obtained in the same manner as in Example 87, except that the adhesive compositions 40, 54, 55 or 56 were used. The warped states of the obtained resin-attached copper foils 88 to 91 were all “good”.

[Example 92]
The adhesive composition 37 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 92 having an adhesive layer thickness of 50 μm. The warped state of the obtained copper foil 92 with resin was “good”.

[Example 93]
The adhesive composition 37 was further applied to the surface of the adhesive layer of the resin-attached copper foil 92 and dried at 80 ° C. for 30 minutes to obtain a resin-attached copper foil 93 having a total thickness of the adhesive layer of 100 μm. .. The warped state of the obtained copper foil 93 with resin was “good”.

[Example 94]
The adhesive composition 37 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 to obtain an adhesive film 94 having a thickness of 50 μm. Got

Adhesive film 94, 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 an electrolytic copper foil with a thickness of 12 μm. A film 94 and an electrolytic copper foil having a thickness of 12 μm are sequentially laminated, pressure-bonded at a temperature of 160 ° C. and a pressure of 0.8 MPa for 2 minutes using a vacuum laminator, then heated from room temperature to 160 ° C. and heat-treated at 160 ° C. for 4 hours. A copper-clad laminate 94 was obtained.

[Examples 95-98]
Copper-clad laminates 95 to 98 were obtained in the same manner as in Example 94, except that the adhesive compositions 40, 54, 55, and 56 were used.

[Example 99]
Laminated on an electrolytic copper foil having a thickness of 12 μm so that the adhesive layer side of the coverlay film 77 is in contact with the copper foil, pressure-bonded at a temperature of 160 ° C. and a pressure of 0.8 MPa for 2 minutes using a vacuum laminator, and then from room temperature to 160. The temperature was raised to ° C. and heat treatment was performed at 160 ° C. for 2 hours to obtain a copper-clad laminate 99.

[Examples 100 to 103]
Copper-clad laminates 100 to 103 were obtained in the same manner as in Example 99, except that the coverlay films 78, 79, 80, and 81 were used.

[Example 104]
An adhesive film 57 is laminated on a rolled copper foil having a thickness of 12 μm, laminated so that the polyimide film 1 side of the coverlay film 77 is in contact with the adhesive film 57, and further laminated on the adhesive layer side of the coverlay film 77 with a thickness of 12 μm. The rolled copper foils of No. A plate 104 was obtained.

[Examples 105-108]
Examples except that the adhesive films 60, 74, 75, and 76 were used instead of the adhesive film 57, and the coverlay films 78, 79, 80, and 81 were used instead of the coverlay film 77, respectively. Copper-clad laminates 105 to 108 were produced in the same manner as in 104.

[Example 109]
Two sheets of copper foil 93 with resin are prepared, and a polyimide film 3 (manufactured by DuPont, trade name; Kapton 200-EN, thickness 50 μm, ε ₁ = 3.6) is placed on the adhesive layer side of the two sheets of copper foil 93 with resin. , _{Tan δ 1} = 0.0084), and using a vacuum laminator, the temperature is 160 ° C, the pressure is 0.8 MPa, the pressure is crimped for 5 minutes, the temperature is raised from room temperature to 160 ° C, and the heat treatment is performed at 160 ° C for 4 hours. Then, a copper-clad laminate 109 was obtained.

[Example 110]
Adhesive composition 55 is applied to a resin layer (polyimide) of a single-sided copper-clad laminate 1 (manufactured by Nittetsu Chemical & Materials Co., Ltd., trade name; Espanex MC12-25-00UEM, length x width x thickness = 200 mm x 300 mm x 25 μm). ) Side was applied and dried at 80 ° C. for 30 minutes to obtain a copper-clad laminate 110 with an adhesive layer having an adhesive layer thickness of 50 μm. The copper-clad laminate 110 with an adhesive layer is laminated so that the surface of another single-sided copper-clad laminate 1 is in contact with the resin layer side, and the temperature is 160 ° C. and the pressure is 4 using a small precision press machine. The copper-clad laminate 110 was obtained by crimping at 0.0 MPa for 120 minutes.

[Example 111]
Two copper-clad laminates with adhesive layers 110 are laminated so that the surfaces on the adhesive layer side are in contact with each other, and pressure-bonded at a temperature of 160 ° C., a pressure of 4.0 MPa for 120 minutes using a small precision press, and then copper-clad. A laminated plate 111 was obtained.

[Example 112]
An adhesive film 73 is laminated on the resin layer side of the single-sided copper-clad laminate 1, and further laminated on the resin layer side of the single-sided copper-clad laminate 1 so that the resin layer side of the single-sided copper-clad laminate 1 is in contact with the adhesive film 73. A copper-clad laminate 112 was obtained by pressure-bonding at a temperature of 160 ° C. and a pressure of 4.0 MPa for 120 minutes.

[Example 113]
The adhesive composition 37 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 to obtain an adhesive film 113 having a thickness of 15 μm. Got

An adhesive film 113 is laminated on the resin layer side of the single-sided copper-clad laminate 1, and further laminated on the resin layer side of the single-sided copper-clad laminate 1 so that the resin layer side of the single-sided copper-clad laminate 1 is in contact with the adhesive film 113. A copper-clad laminate 113 was obtained by pressure bonding at a temperature of 160 ° C. and a pressure of 4.0 MPa for 120 minutes.

[Example 114]
A double-sided copper-clad laminate 2 (manufactured by Nittetsu 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 114A was obtained.

The copper foil on one side of the double-sided copper-clad laminate 2 was removed by etching to obtain a copper-clad laminate 114B.

The adhesive film 73 is sandwiched between the surface of the wiring board 114A on the conductor circuit layer side and the surface of the copper-clad laminate 114B on the resin layer side, and in a laminated state, the temperature is 160 ° C., the pressure is 4.0 MPa, and the pressure is 120 minutes. Thermocompression bonding was performed to obtain a multilayer circuit board 114.

[Example 115]
Insulation of liquid crystal polymer film (manufactured by Kuraray, trade name; CT-Z, thickness: 50 μm, CTE; 18 ppm / K, thermal deformation temperature: 300 ° C., ε ₁ = 3.40, tan δ ₁ = 0.0022) A copper-clad laminate 115 used as a base material and provided with electrolytic copper foils having a thickness of 18 μm on both sides thereof was prepared, and the copper foils on one side were subjected to circuit processing by etching to form a conductor circuit layer 115A. Got

The copper foil on one side of the copper-clad laminate 115 was removed by etching to obtain a copper-clad laminate 115B.

The adhesive film 73 is sandwiched between the surface of the wiring board 115A on the conductor circuit layer side and the surface of the copper-clad laminate 115B on the insulating substrate layer side, and in a laminated state, the temperature is 160 ° C. and the pressure is 4.0 MPa. , Thermocompression bonding for 120 minutes to obtain a multilayer circuit board 115.

Although the embodiments of the present invention have been described in detail for the purpose of exemplification, the present invention is not limited to the above embodiments and can be modified in various ways.

10 ... base material, 11 ... first base material, 12 ... second base material, 20 ... adhesive layer, 30, 33, 34 ... insulating resin layer, 31 ... first insulating resin layer, 32 ... second Insulating resin layer, 41 ... 1st single-sided metal-clad laminate, 42 ... 2nd single-sided metal-clad laminate, 50 ... wiring layer, M ... metal layer, M1 ... first metal layer, M2 ... second Metal layer, 100 ... Laminated body, 101 ... Three-layer metal-clad laminate, 102 ... Laminated metal-clad laminate, 103 ... Metal-clad laminate with adhesive layer, 200, 201, 202 ... Circuit board, 203 ... Multilayer Circuit board

Claims (23)

A polyimide containing a tetracarboxylic acid residue derived from the tetracarboxylic acid anhydride component and a diamine residue derived from the diamine component, and the following conditions a to c;
a) For all diamine residues, diamine residues derived from a diamine diamine composition containing a diamine diamine in which two terminal carboxylic acid groups of dimer acid are replaced with a primary aminomethyl group or an amino group are used. Contains 60 mol% or more;
b) The content of carbon atoms derived from the 6-membered aromatic ring (excluding the carbon atoms of the 6-membered aromatic ring derived from the dimerdiamine composition) with respect to the total content of all the atoms in the polyimide is in the range of 12 to 40% by weight. Being inside;
c) The weight average molecular weight is in the range of 5,000 to 200,000;
A polyimide characterized by satisfying. Further, the following condition d;
d) The following formula (i),
CM value = (C / Mw) x 10 ⁴ ... (i)
[In the formula, C means the weight content of carbon atoms derived from the 6-membered aromatic ring (excluding the carbon atoms of the 6-membered aromatic ring derived from the dimerdiamine composition) with respect to the total content of all the atoms in the polyimide. Mw means the weight average molecular weight of polyimide]
The CM value, which is an index indicating the amount of 6-membered aromatic rings contained in the polyimide, calculated based on the above, is in the range of 3 to 38;
The polyimide according to claim 1, wherein the polyimide is characterized by satisfying the above conditions. Further, the following condition e;
e) The content of carbon atoms derived from the 6-membered aromatic ring (excluding the carbon atoms of the 6-membered aromatic ring derived from the dimer diamine composition) with respect to the total content of all atoms in the total diamine component of the raw material exceeds 0 32. Must be in the range of% by weight or less;
The polyimide according to claim 1 or 2, wherein the polyimide satisfies the above conditions. Further, the following condition f;
f) The following formula (ii),
DM value = (D / Mw) x 10 ⁴ ... (ii)
[In the formula, D is the weight content of the 6-membered aromatic ring-derived carbon atom (excluding the 6-membered aromatic ring-derived carbon atom derived from the diamine composition) with respect to the total content of all atoms in the total diamine residue. Means, Mw means the weight average molecular weight of polyimide]
The DM value, which is an index indicating the amount of 6-membered aromatic rings derived from the diamine component contained in the polyimide, calculated based on the above, is in the range of more than 0 and 32 or less;
The polyimide according to any one of claims 1 to 3, wherein the polyimide satisfies. For the total amount of the diamine residue
The diamine residue derived from the diamine diamine composition is contained in the range of 60 mol% or more and 99 mol% or less.
The diamine residue derived from at least one diamine compound selected from the diamine compounds represented by the following general formulas (B1) to (B7) is contained in the range of 1 mol% or more and 40 mol% or less. The polyimide according to any one of claims 1 to 4, which is characteristic.

[In the formulas (B1) to (B7), R ₁ independently represents a monovalent hydrocarbon group or an alkoxy group having 1 to 6 carbon atoms, and the linking group A independently represents -O-, -S-, and -CO. _{-, - SO -, - SO} 2 -, - COO -, - CH 2 -, - C (CH 3) 2 -, - NH- or a divalent group selected from -CONH-, _{n 1} is independently Indicates an integer from 0 to 4. However, the formula (B3) that overlaps with the formula (B2) is excluded, and the formula (B5) that overlaps with the formula (B4) is excluded. ] For the total amount of the acid anhydride residue
Claims 1 to 5 include a total of 90 mol% or more of tetracarboxylic acid residues derived from the tetracarboxylic dianhydride represented by the following general formulas (1) and / or (2). The polyimide according to any one of the above items.

[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 or a 5-membered ring. It represents forming a cyclic saturated hydrocarbon group selected from a ring, a 6-membered ring, a 7-membered ring, or an 8-membered ring. ]

[In the above formula, Z is _{-C 6 H 4 -, - (} CH 2) n- or _{-CH 2 -CH (-O-C (} = O) -CH 3) -CH 2 - are illustrated, n represents Indicates an integer of 1 to 20. ] The polyimide according to any one of claims 1 to 6 contains a ketone group in the molecule.
A crosslinked polyimide in which the ketone group and the amino group of an amino compound having at least two primary amino groups as functional groups form a crosslinked structure by a C = N bond. An adhesive film containing the polyimide according to any one of claims 1 to 6 or the crosslinked polyimide according to claim 7. _{The dielectric loss tangent (Tanδ 1} ) at 10 GHz measured by a split post dielectric resonator (SPDR) is 0.005 or less after humidity control for 24 hours under a constant temperature and humidity condition (normal condition) of 23 ° C. and 50% RH. The adhesive film according to claim 8, wherein the relative dielectric constant (E _{1) is 3.0 or less. The dielectric loss tangent (Tanδ 2} ) at 20 GHz measured by a split post dielectric resonator (SPDR) is 0.005 or less after humidity control for 24 hours under a constant temperature and humidity condition (normal state) of 23 ° C. and 50% RH. The adhesive film according to claim 8 or 9, wherein the relative permittivity (E _{2) is 3.0 or less. Dielectric loss tangent at 10 GHz (Tan δ 1} ) measured by a split post dielectric resonator (SPDR) and dielectric loss tangent at 20 GHz (Tanδ 1) after humidity control for 24 hours under constant temperature and humidity conditions (normal condition) of 23 ° C. and 50% RH. The adhesive film according to any one of claims 8 to 10, wherein the difference from Tanδ _{2 ) (Tanδ 2- Tanδ 1) is 0 or less.} A laminate having a base material and an adhesive layer laminated on at least one surface of the base material.
A laminate characterized in that the adhesive layer is made of the adhesive film according to any one of claims 8 to 11. 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 8 to 11. A copper foil with a resin in which an adhesive layer and a copper foil are laminated.
A copper foil with a resin, wherein the adhesive layer is made of the adhesive film according to any one of claims 8 to 11. 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 characterized in that at least one layer of the insulating resin layer is made of the adhesive film according to any one of claims 8 to 11. 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. hand,
A metal-clad laminate characterized in that the adhesive layer is made of the adhesive film according to any one of claims 8 to 11. 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.
It was arranged so as to be in contact with the first insulating resin layer and the second insulating resin layer, and was laminated between the first single-sided metal-clad laminate and the second single-sided metal-clad laminate. A metal-clad laminate with an adhesive layer,
A metal-clad laminate characterized in that the adhesive layer is made of the adhesive film according to any one of claims 8 to 11. A single-sided metal-clad laminate having an insulating resin layer, a metal layer laminated on one surface of the insulating resin layer, and an adhesive layer laminated on the other surface of the insulating resin layer are provided. , A metal-clad laminate characterized in that the adhesive layer is made of the adhesive film according to any one of claims 8 to 11. A circuit board obtained by wiring processing the metal layer of the metal-clad laminate according to claim 15. The first base material, the wiring layer laminated on at least one surface of the first base material, and the surface of the first base material on the side of the wiring layer were laminated so as to cover the wiring layer. A circuit board with an adhesive layer.
A circuit board characterized in that the adhesive layer is made of the adhesive film according to any one of claims 8 to 11. The first base material, the wiring layer laminated on at least one surface of the first base material, and the surface of the first base material on the side of the wiring layer were laminated so as to cover the wiring layer. A circuit board comprising an adhesive layer and a second base material laminated on a surface of the adhesive layer opposite to the first base material.
A circuit board characterized in that the adhesive layer is made of the adhesive film according to any one of claims 8 to 11. A first base material, an adhesive layer laminated on at least one surface of the first base material, and a second base material laminated on the surface of the adhesive layer opposite to the first base material. A circuit board comprising the first base material and a wiring layer laminated on the surfaces of the first base material and the second base material opposite to the adhesive layer.
A circuit board characterized in that the adhesive layer is made of the adhesive film according to any one of claims 8 to 11. A multilayer circuit board including a laminate including a plurality of laminated insulating resin layers and at least one or more wiring layers embedded inside the laminate.
At least one layer or more of the plurality of insulating resin layers is formed of an adhesive layer having adhesiveness and covering the wiring layer.
A multilayer circuit board characterized in that the adhesive layer is made of the adhesive film according to any one of claims 8 to 11.

Images