JP5784993B2 - Crosslinked polyimide resin, production method thereof, adhesive resin composition, cured product thereof, coverlay film, and circuit board - Google Patents

Description

  The present invention relates to a crosslinked polyimide resin useful as an adhesive in a circuit board such as a flexible printed wiring board, a method for producing the same, and use thereof.

  In recent years, with the progress of downsizing, weight reduction, and space saving of electronic devices, flexible printed wiring boards (FPCs) that are thin, light, flexible, and have excellent durability even after repeated bending are used. The demand for Circuits) is increasing. FPC can be mounted three-dimensionally and densely in a limited space. For example, it can be used for wiring of movable parts of electronic devices such as HDDs, DVDs, mobile phones, and parts such as cables and connectors. It is expanding.

  For the FPC, a coverlay film is used for the purpose of protecting the wiring portion. The coverlay film is formed by laminating a coverlay film material made of a synthetic resin such as a polyimide resin and an adhesive layer. In manufacturing an FPC, a coverlay film material is attached to a circuit board through an adhesive layer by using a method such as hot pressing. The adhesive layer is required to have high adhesion to both the circuit wiring pattern such as copper wiring and the film material for coverlay. As an adhesive for such a coverlay film, it can be processed under relatively low temperature thermocompression bonding conditions, and it has excellent heat resistance and other characteristics, and it can be used as a mixed resin of polyimide resin and epoxy resin having a siloxane unit. In addition, an adhesive resin composition for printed circuit boards, in which one or more plasticizers selected from phosphoric acid ester-based, phthalic acid ester-based, polyester-based and fatty acid ester-based materials are blended has been proposed (for example, Patent Document 1). ).

  On the other hand, bis (3,4-dicarboxyphenyl) ether dianhydride and a specific structure are used for the purpose of improving the low temperature sticking property, low hygroscopicity, adhesive force during heating, and PCT resistance of polyimide resin used for an adhesive film. A method for producing a polyimide resin in which another acid anhydride and / or another diamine is reacted after reacting with another siloxane diamine has been proposed (for example, Patent Document 2). In addition, in order to safely and stably produce a high molecular weight polyimide resin having a silicone structure in the main chain, silicone-based diamine and silicone-based acid dianhydride are mixed in a specific molar ratio range, and heat dehydration condensation is performed. There is also proposed a method for producing a polyimide resin in which an aromatic diamine is added to a reaction solution at a predetermined molar ratio and reacted to cause a molecular weight to be controlled after the reaction is continued until no increase occurs (for example, Patent Document 3).

JP-A-10-212468 JP 2006-117945 A JP 2004-359874 A

  Since processing of FPC includes a soldering process almost indispensable, the adhesive used for the coverlay film is required to have high solder heat resistance. In this regard, polyimide resin with relatively excellent heat resistance is a material suitable as an adhesive for the coverlay film, but if the solder heat resistance can be further improved, the function as an adhesive for the coverlay film will be improved. Can be increased.

  In addition, in-vehicle electronic devices for automobiles using FPC are repeatedly placed in a high temperature environment of about 150 ° C., the adhesive strength between the FPC coverlay film and the wiring is lowered over a long period of use, and the wiring protection function is provided. There has been a problem of a significant drop. With the expansion of FPC applications, it is expected that the number of scenes where FPC is used not only in in-vehicle electronic devices but also in severe temperature environments will continue to increase. For this reason, in an FPC used in a high temperature environment, it is strongly required to take measures against a decrease in the adhesive strength of the coverlay film.

  For these reasons, the present inventors have a C═N crosslinked structure in which an amino compound having at least two primary amino groups as functional groups is reacted with a ketone group previously contained in polyimidesiloxane. A crosslinked polyimide resin was proposed (PCT / JP2010 / 071538). Since this crosslinked polyimide resin is excellent in solder heat resistance and can maintain excellent adhesion performance over a long period of time even in a high temperature environment, it is highly useful as an adhesive for a coverlay film or the like. However, this cross-linked polyimide resin needs to increase the cross-linking ratio of polyimide siloxane and amino compound to a certain degree in order to develop practically required moisture-resistant soldering heat resistance, and for this reason, heating at 150 ° C. for 6 hours or more. Cost. If the time until the moisture-resistant solder heat resistance is acquired can be shortened, it is possible to improve the throughput of product manufacturing, and therefore there remains room for further improvement.

  Accordingly, an object of the present invention is to form a cross-linked polyimide capable of forming a cross-linked structure capable of exhibiting moisture-resistant solder heat resistance in a short time and capable of forming an adhesive layer that does not reduce adhesive strength even in a use environment that is repeatedly exposed to high temperatures. It is to provide a resin.

  As a result of intensive studies to solve the above problems, the present inventors introduced a functional group (hereinafter referred to as “hydrogen bond-forming group”) that enables hydrogen bonding in polyimidesiloxane after imidization. In this case, hydrogen bonds are generated between the main chains of the polyimide siloxane and the ketone groups of the adjacent polyimide siloxane chains are in close proximity. The present invention has been completed.

That is, the crosslinked polyimide resin of the present invention comprises the following components (A) and (B),
(A) a polyimidesiloxane having a ketone group and a hydrogen bond-forming group, and
(B) an amino compound having at least two primary amino groups as functional groups,
A cross-linked polyimide resin obtained by reacting
The amino group of the amino compound of the component (B) reacts with at least a part of the ketone group in the polyimide siloxane of the component (A) to form a C═N bond, so that the polyimide siloxane is formed by the amino compound. It has a cross-linked structure.

  In the cross-linked polyimide resin of the present invention, the polyimide siloxane may be a polyimide siloxane having structural units represented by the following general formulas (1) and (2). In this case, it is preferable that the molar ratio m of the structural unit is in the range of 0.75 to 1.0, and n is in the range of 0 to 0.25.

［式中、Ａｒは芳香族テトラカルボン酸無水物から誘導される４価の芳香族基、Ｒ_１はジアミノシロキサンから誘導される２価のジアミノシロキサン残基、Ｒ_２はジアミン化合物から誘導される２価のジアミン残基をそれぞれ表し、Ａｒ及び／又はＲ_２中にはケトン基及び水素結合形成基を含み、ｍ、ｎは各構成単位の存在モル比を示し、ｍは０．３５〜１．０の範囲内、ｎは０〜０．６５の範囲内である］

[Wherein Ar is a tetravalent aromatic group derived from an aromatic tetracarboxylic anhydride, R ₁ is a divalent diaminosiloxane residue derived from diaminosiloxane, and R ₂ is derived from a diamine compound. Each represents a divalent diamine residue, and Ar and / or R ₂ contains a ketone group and a hydrogen bond-forming group, m and n represent the molar ratio of each constituent unit, and m is 0.35 to 1 Within the range of 0.0, n is within the range of 0 to 0.65]

  In the crosslinked polyimide resin of the present invention, the polyimidesiloxane may be a polyimidesiloxane having structural units represented by the following general formulas (1) and (2). In this case, it is preferable that the molar ratio m of the structural unit is in the range of 0.75 or more and less than 1.0, and n is in the range of more than 0 and 0.25 or less.

［式中、Ａｒは芳香族テトラカルボン酸無水物から誘導される４価の芳香族基、Ｒ_１はジアミノシロキサンから誘導される２価のジアミノシロキサン残基、Ｒ_２はジアミン化合物から誘導される２価のジアミン残基をそれぞれ表し、Ａｒ中にケトン基を、Ｒ_２中に水素結合形成基をそれぞれ含み、ｍ、ｎは各構成単位の存在モル比を示し、ｍは０．３５以上１．０未満の範囲内、ｎは０を超え０．６５以下の範囲内である］

[Wherein Ar is a tetravalent aromatic group derived from an aromatic tetracarboxylic anhydride, R ₁ is a divalent diaminosiloxane residue derived from diaminosiloxane, and R ₂ is derived from a diamine compound. Each represents a divalent diamine residue, Ar contains a ketone group, R ₂ contains a hydrogen bond-forming group, m and n represent the molar ratio of each constituent unit, and m is 0.35 or more and 1 Within the range of less than 0, n is in the range of more than 0 and not more than 0.65]

  In the crosslinked polyimide resin of the present invention, the hydrogen bond forming group in the polyimide siloxane may be —NHCO—.

  The crosslinked polyimide resin of the present invention may be one in which the polyimide siloxane is synthesized using a dihydrazide compound as a raw material.

  In the crosslinked polyimide resin of the present invention, the amino compound may be a dihydrazide compound.

  The crosslinked polyimide resin of the present invention further comprises a plate-like inorganic filler having an average particle diameter of 2 to 25 μm in an amount of 5 to 200 weights with respect to a total of 100 parts by weight of the component (A) and the component (B). It may be contained within the range of parts.

The adhesive resin composition of the present invention comprises the following components (A) and (B):
(A) a polyimidesiloxane having a weight average molecular weight of 20,000 to 150,000 having a ketone group and a hydrogen bond-forming group, and (B) an amino compound having at least two primary amino groups as functional groups,
Including
The component (B) is contained so that the total amount of the primary amino group is within the range of 0.004 mol to 1.5 mol with respect to 1 mol of the ketone group in the component (A). .

  In the adhesive resin composition of the present invention, the component (A) may be a polyimide siloxane having structural units represented by the following general formulas (1) and (2). In this case, it is preferable that the molar ratio m of the structural unit is in the range of 0.75 to 1.0, and n is in the range of 0 to 0.25.

［式中、Ａｒは芳香族テトラカルボン酸無水物から誘導される４価の芳香族基、Ｒ_１はジアミノシロキサンから誘導される２価のジアミノシロキサン残基、Ｒ_２はジアミン化合物から誘導される２価のジアミン残基をそれぞれ表し、Ａｒ及び／又はＲ_２中にはケトン基及び水素結合形成基を含み、ｍ、ｎは各構成単位の存在モル比を示し、ｍは０．３５〜１．０の範囲内、ｎは０〜０．６５の範囲内である］

[Wherein Ar is a tetravalent aromatic group derived from an aromatic tetracarboxylic anhydride, R ₁ is a divalent diaminosiloxane residue derived from diaminosiloxane, and R ₂ is derived from a diamine compound. Each represents a divalent diamine residue, and Ar and / or R ₂ contains a ketone group and a hydrogen bond-forming group, m and n represent the molar ratio of each constituent unit, and m is 0.35 to 1 Within the range of 0.0, n is within the range of 0 to 0.65]

  In the adhesive resin composition of the present invention, the component (A) may be a polyimide siloxane having structural units represented by the following general formulas (1) and (2). In this case, it is preferable that the molar ratio m of the structural unit is in the range of 0.75 or more and less than 1.0, and n is in the range of more than 0 and 0.25 or less.

［式中、Ａｒは芳香族テトラカルボン酸無水物から誘導される４価の芳香族基、Ｒ_１はジアミノシロキサンから誘導される２価のジアミノシロキサン残基、Ｒ_２はジアミン化合物から誘導される２価のジアミン残基をそれぞれ表し、Ａｒ中にケトン基を、Ｒ_２中に水素結合形成基をそれぞれ含み、ｍ、ｎは各構成単位の存在モル比を示し、ｍは０．３５以上１．０未満の範囲内、ｎは０を超え０．６５以下の範囲内である］

[Wherein Ar is a tetravalent aromatic group derived from an aromatic tetracarboxylic anhydride, R ₁ is a divalent diaminosiloxane residue derived from diaminosiloxane, and R ₂ is derived from a diamine compound. Each represents a divalent diamine residue, Ar contains a ketone group, R ₂ contains a hydrogen bond-forming group, m and n represent the molar ratio of each constituent unit, and m is 0.35 or more and 1 Within the range of less than 0, n is in the range of more than 0 and not more than 0.65]

  In the adhesive resin composition of the present invention, the hydrogen bond forming group in the component (A) may be -NHCO-.

  In the adhesive resin composition of the present invention, the component (A) may be synthesized using a dihydrazide compound as a raw material.

  In the adhesive resin composition of the present invention, the component (B) may be a dihydrazide compound.

  The adhesive resin composition of the present invention further comprises (C) a plate-like inorganic filler having an average particle diameter in the range of 2 to 25 μm with respect to a total of 100 parts by weight of the component (A) and the component (B). It may contain 5 to 200 parts by weight.

  The cured product of the present invention is obtained by curing the adhesive resin composition described above.

The coverlay film of the present invention is a coverlay film in which an adhesive layer and a film material layer for coverlay are laminated,
The adhesive layer is formed using the adhesive resin composition according to any one of the above.

  The circuit board of the present invention includes a base material, a wiring layer formed on the base material, and the coverlay film that covers the wiring layer.

The method for producing a crosslinked polyimide resin of the present invention comprises mixing an acid anhydride component having a ketone group, a diamine compound having a hydrogen bond-forming group and a diamine component containing diaminosiloxane, and imidizing by heating. Forming a polyimidesiloxane having a ketone group and a hydrogen bond-forming group;
Forming hydrogen bonds between adjacent main chains in the polyimidesiloxane; and
An amino group of an amino compound having at least two primary amino groups as a functional group is reacted with at least a part of the ketone group of the polyimide siloxane to form a C = N bond, and the polyimide siloxane is crosslinked with the amino compound. The process of
It has.

  The crosslinked polyimide resin of the present invention has a structure in which an amino group of an amino compound reacts with at least a part of a ketone group in polyimidesiloxane to form a C═N bond, and at least a part of the polyimidesiloxane is crosslinked with an amino compound. For this reason, while being excellent in solder heat resistance, the adhesive bond layer which does not reduce the adhesive force with a metal wiring layer can be formed even if it is repeatedly placed in a high temperature environment. Therefore, the peel strength of the coverlay film formed with the adhesive layer using the crosslinked polyimide resin of the present invention can be increased, and the reliability of the circuit board using the coverlay film can be improved.

  In addition, since the crosslinked polyimide resin of the present invention uses a polyimide siloxane having a ketone group and a hydrogen bond-forming group, it exhibits excellent moisture soldering heat resistance not only in a state where curing due to crosslinking is completed, but also in the middle stage. be able to. Therefore, it is possible to achieve both excellent adhesion and solder heat resistance, and it is useful as an adhesive for coverlay films and the like.

  The method for producing a crosslinked polyimide resin of the present invention uses a polyimide siloxane having a ketone group and a hydrogen bond-forming group, so that even in the state of the composition before heating, the adjacent polyimide siloxane main chains are close to each other by hydrogen bonding. Become. Therefore, the ketone groups of polyimide siloxane come close to each other, and the cross-linking with the amino group of the amino compound can be promoted. Accordingly, it is possible to form a cross-link in a short time, and it is possible to shorten the heat treatment time required for curing.

4 is a graph showing the results of rheometer evaluation of samples in Test Example 1. 10 is a graph showing the results of rheometer evaluation of samples in Test Example 2.

[Crosslinked polyimide resin]
The crosslinked polyimide resin of the present invention comprises the following components (A) and (B),
(A) a polyimidesiloxane having a ketone group and a hydrogen bond-forming group, and
(B) an amino compound having at least two primary amino groups as functional groups,
Is a crosslinked polyimide resin obtained by reacting In the crosslinked polyimide resin of the present invention, the amino group of the amino compound (B) reacts with at least a part of the ketone group in the polyimide siloxane (A) to form a C = N bond. Thus, the polyimidesiloxane has a structure crosslinked with the amino compound.

In a preferred embodiment of the crosslinked polyimide resin of the present invention, the group Ar in the general formulas (1) and (2) is a tetravalent aromatic group derived from an aromatic tetracarboxylic anhydride, and the group R ₁ is It is a divalent diaminosiloxane residue derived from diaminosiloxane, and the group R ₂ is a divalent diamine residue derived from a diamine compound. In addition, Ar and / or R ₂ contains a ketone group and a hydrogen bond-forming group, and m indicating the molar ratio of the constituent units is in the range of 0.35 to 1.0, preferably 0.75 to 1. In the range of 0, n is in the range of 0 to 0.65, preferably in the range of 0 to 0.25. In a more preferred embodiment of the crosslinked polyimide resin of the present invention, the group Ar in the general formulas (1) and (2) may contain a ketone group, and the group R ₂ may contain a hydrogen bond forming group. In this case, m representing the molar ratio of the constituent units is in the range of 0.35 or more and less than 1.0, more preferably in the range of 0.75 or more and less than 1.0, and most preferably 0.75 or more and 0.99. Within the following range. Further, n indicating the molar ratio of the constituent units is in the range of more than 0 to 0.65 or less, more preferably in the range of more than 0 to 0.25, most preferably in the range of 0.01 to 0.25. Is within.

  In the crosslinked polyimide resin of the present invention, it is only necessary that the amino group of the amino compound of the component (B) reacts with at least a part of the ketone group in the polyimide siloxane of the component (A) to form a C = N bond. . The crosslinking formation rate (degree of curing) of the crosslinked polyimide resin does not have to be a state in which the curing of the polyimide resin by the crosslinking formation is completed, and may be any level that can ensure practically sufficient moisture-resistant soldering heat resistance. Whether the crosslinked polyimide resin has practically sufficient moisture-resistant soldering heat resistance can be determined using viscosity as an index, as will be described later.

[Polyimide siloxane]
The component (A) includes, for example, a polyimide siloxane having structural units represented by the general formulas (1) and (2), the group Ar and / or the group R ₂ , preferably a ketone group in the group Ar, This ketone group is involved in the reaction with the amino compound. In the structural units represented by the general formulas (1) and (2), examples of the aromatic tetracarboxylic acid for forming the group Ar containing a ketone group include 3,3 represented by the following formula (3): Mention may be made of ', 4,4'-benzophenonetetracarboxylic dianhydride (BTDA).

  In addition, in the structural units represented by the general formulas (1) and (2), examples of the aromatic tetracarboxylic acid used as a raw material for forming the group Ar include, in addition to those having the ketone group, for example, 3, 3 ', 4,4'-biphenyltetracarboxylic dianhydride (BPDA), 3,3', 4,4'-diphenylsulfone tetracarboxylic dianhydride (DSDA), pyromellitic dianhydride (PMDA) Etc. can be used. These can be used alone or in combination of two or more.

In the polyimidesiloxane having the structural units represented by the general formulas (1) and (2), examples of the “hydrogen bond forming group” include —NHCO—. By including such a hydrogen bond-forming group, a hydrogen bond is generated between adjacent polyimide siloxane chains, and the ketone groups that are the reaction points of the crosslinking reaction with the amino compound can be brought close to each other. The reaction is accelerated and the heating time until sufficient moisture-resistant soldering heat resistance is generated can be shortened. The hydrogen bond forming group may be contained in either one of the general formulas (1) and (2), or may be contained in both. In addition, the hydrogen bond-forming group may be contained in either the acid anhydride component represented by the group Ar or the diamine component represented by the group R ₁ or R _2. It is preferably contained in the group R ₂ in 2). The molar ratio of hydrogen bond-forming groups to all diamines is in the range of more than 0 and less than or equal to 1.3, more preferably more than 0 and less than 0 in order to efficiently form hydrogen bonds between the main chains of adjacent polyimidesiloxanes. .5 or less, and most preferably 0.02 or more and 0.5 or less.

In addition, examples of the group R ₁ in the structural unit represented by the general formula (1) include a diaminosiloxane residue derived from a diaminosiloxane represented by the following formula (4).

［ここで、Ｒ_３及びＲ_４は、それぞれ、酸素原子を含有していてもよい２価の有機基を示し、Ｒ_５〜Ｒ_８は、それぞれ炭素数１〜６の炭化水素基を示し、平均繰り返し数であるｍ_１は、１〜２０である］

[Wherein R ₃ and R ₄ each represent a divalent organic group that may contain an oxygen atom, R _{5 to} R ₈ each represent a hydrocarbon group having 1 to 6 carbon atoms, M ₁ that is the average number of repetitions is ₁ to 20]

In particular, as the group R ₁ , R ₃ and R ₄ in the formula (4) are each a divalent hydrocarbon group, and R _{5 to} R ₈ are each 1 to 1 carbon atoms in order to impart solubility of the polyimide. 6 having a mean repeating number of m ₁ of 5 to 15 is preferable.

  The above-mentioned diaminosiloxane residue is a group having a siloxane bond (Si-O-Si) obtained by removing an amino group from diaminosiloxane. By increasing the ratio of this siloxane bond, a plasticizer can be added. Sufficient flexibility is imparted to the adhesive layer, and warping of the coverlay film can be suppressed. Moreover, since many plastic groups are contained in the plasticizer, as an advantage of not containing the plasticizer, an adhesive using polyimidesiloxane having the structural units represented by the general formulas (1) and (2) It is mentioned that the amount of polar groups contained in the resin composition can be suppressed. For this reason, in this invention, the value of m in Formula (1) shall be 0.35 or more, Preferably it is 0.75 or more. If the value of m is less than 0.35, the warp suppressing effect cannot be sufficiently obtained. In addition, it is considered that increasing the siloxane bond also has an effect of reducing curing shrinkage due to a decrease in the imide bond site of polyimidesiloxane.

Thus, by introducing the siloxane skeleton into the polyimide using the diaminosiloxane represented by the above general formula (4), the resulting polyimidesiloxane is given fluidity at the time of thermocompression bonding, and on the printed circuit wiring. Fillability can be improved. As a specific example of the diaminosiloxane represented by the general formula (4), diaminosiloxanes represented by the following formulas (5) to (9) are preferable, and among these, the formula (5) or the formula (6) The aliphatic diaminosiloxane represented is more preferred. These diaminosiloxanes can be blended in combination of two or more. Moreover, when mix | blending in combination of 2 or more types of diaminosiloxane, 90 weight part or more of aliphatic diaminosiloxane represented by Formula (5) or Formula (6) is mix | blended with respect to 100 weight part of all the diaminosiloxanes. Is preferred. In the equation (4) to Formula (9), _{m 1} is an average repeating number is in the range of 1 to 20, preferably in the range of 5-15. When m ₁ is smaller than _1, the filling property when the adhesive is used is lowered, and when it exceeds 20, the adhesive property is lowered.

In the structural unit represented by the general formula (2), examples of the group R ₂ containing a ketone group (a divalent diamine residue derived from a diamine compound) include those represented by the following formulas (10) and (11). And aromatic diamines. These can be used alone or in combination of two or more.

［ここで、Ｒ_９は独立に炭素数１〜６の１価の炭化水素基又はアルコキシ基を示し、ＸはＣＯを示し、ｎ_１は独立に０〜４の整数を示す］

[Wherein R ₉ independently represents a monovalent hydrocarbon group or alkoxy group having 1 to 6 carbon atoms, X represents CO, and n ₁ independently represents an integer of 0 to 4]

Examples of the aromatic diamine for forming the group R ₂ represented by the above formulas (10) and (11) include 4,4′-bis (3-aminophenoxy) benzophenone (BABP), 1,3- Bis [4- (3-aminophenoxy) benzoyl] benzene (BABB) and the like can be mentioned.

In the structural unit represented by the general formula (2), as a diamine compound that is a raw material for forming the group R ₂ having a hydrogen bond-forming group, for example, when the hydrogen bond-forming group is a —NHCO— group May include dihydrazide compounds. Specific examples of the dihydrazide compound include dodecanedioic acid dihydrazide and adipic acid dihydrazide, which are aliphatic dihydrazides, and isophthalic acid dihydrazide, which is an aromatic dihydrazide. Among these, dodecanedioic acid dihydrazide and adipic acid dihydrazide which are aliphatic dihydrazides are preferable.

Further, in the structural unit represented by the general formula (2), as other diamine compound which is a raw material for forming the group R ₂ , for example, 2,2-bis (4-aminophenoxyphenyl) propane (BAPP ) 2,2′-divinyl-4,4′-diaminobiphenyl (VAB), 2,2′-dimethyl-4,4′-diaminobiphenyl (m-TB), 2,2′-diethyl-4,4 '-Diaminobiphenyl, 2,2', 6,6'-tetramethyl-4,4'-diaminobiphenyl, 2,2'-diphenyl-4,4'-diaminobiphenyl, 9,9-bis (4-amino And aromatic diamines such as phenyl) fluorene. These aromatic diamines can be used alone or in combination of two or more.

  As for the above-mentioned acid anhydride and diamine, which are the raw materials for polyimide siloxane, only one kind thereof may be used or two or more kinds may be used in combination. In addition, acid anhydrides and diamines other than those described above can be used in combination.

[Synthesis of polyimide siloxane]
(A) The polyimidesiloxane of a component can be manufactured by making the said aromatic tetracarboxylic anhydride, diaminosiloxane, and diamine react in a solvent, producing | generating the polyamic acid which is precursor resin, and carrying out ring closure by heating. For example, it is a polyimide precursor by dissolving an acid anhydride component and a diamine component in an approximately equimolar amount in an organic solvent and stirring and polymerizing at a temperature in the range of 0 to 100 ° C. for 30 minutes to 24 hours. A polyamic acid is obtained. In the reaction, the reaction components are dissolved so that the precursor to be produced is in the range of 5 to 30% by weight, preferably in the range of 10 to 20% by weight in the organic solvent. Examples of the organic solvent used for the polymerization reaction include N, N-dimethylformamide, N, N-dimethylacetamide (DMAC), N-methyl-2-pyrrolidone, 2-butanone, dimethyl sulfoxide, dimethyl sulfate, cyclohexanone, and dioxane. , Tetrahydrofuran, diglyme, triglyme and the like. Two or more of these solvents can be used in combination, and further, aromatic hydrocarbons such as xylene and toluene can be used in combination.

  The synthesized precursor is usually advantageously used as a reaction solvent solution, but can be concentrated, diluted, or replaced with another organic solvent if necessary. Moreover, since a precursor is generally excellent in solvent solubility, it is advantageously used. The method for imidizing the precursor is not particularly limited, and for example, heat treatment in which heating is performed in the solvent at a temperature within the range of 80 to 300 ° C. for 1 to 24 hours is suitably employed.

  (A) When preparing the polyimide siloxane component, the blending ratio of the acid anhydride component and the diamine component as raw materials is not particularly limited, for example, the terminal substituent of the polyimide siloxane is an amino group, That is, from the viewpoint of sealing the acid anhydride group with diamine and suppressing the polarity of the crosslinked polyimide resin, the molar ratio of acid anhydride component: diamine component is 1.000: 1.001 to 1.0: 1. .2 is preferred.

In addition, (A) component polyimide siloxane has an imide structure obtained by reaction with aromatic tetracarboxylic anhydride, diaminosiloxane and diamine compound, for example, when used as an adhesive for coverlay film, A completely imidized structure is most preferred to suppress copper diffusion. However, a part of the polyimide may be amic acid. The imidation ratio was measured at about 1015 cm ⁻¹ by measuring the infrared absorption spectrum of the polyimide thin film by a single reflection ATR method using a Fourier transform infrared spectrophotometer (commercial product: FT / IR620 manufactured by JASCO Corporation). Based on the absorbance of C═O stretching derived from an imide group of 1780 cm ⁻¹ , based on the benzene ring absorber.

[Hydrogen bond formation]
Since the polyimidesiloxane obtained as described above has a hydrogen bond-forming group in the molecular structure, hydrogen bonds are generated between adjacent polyimidesiloxane main chains even at room temperature. For example, when the hydrogen bond forming group contained in the polyimide siloxane is an —NHCO— group, a hydrogen bond is generated between the NH group of one adjacent polyimide siloxane chain and the CO group of the other polyimide siloxane chain. . As a result, many polyimide siloxane chains can be brought close to a certain degree of orientation, and the adjacent polyimide siloxane chains can be brought close to each other as a reaction point for a crosslinking reaction with an amino compound. Such hydrogen bond formation proceeds by keeping polyimide siloxane in a solvent solution state, and sufficient hydrogen bonds can be formed to promote the imine crosslinking reaction.

[Amino compound]
In the crosslinked polyimide resin of the present invention, as the amino compound having at least two primary amino groups as functional groups, which is the other component (B) to be reacted with the ketone group of the polyimide siloxane of the above component (A), Examples include (I) aromatic diamine, (II) diaminosiloxane, (III) aliphatic amine, (IV) dihydrazide compound, and the like.

(I) Aromatic diamine:
Examples of the aromatic diamine include those represented by the following formulas (12) and (13).

［ここで、Ｒ_１０は独立に炭素数１〜６の１価の炭化水素基又はアルコキシ基を示し、Ｚは単結合又は炭素数１〜１５の２価の炭化水素基、Ｏ、Ｓ、ＣＯ、ＳＯ、ＳＯ_２、ＮＨ若しくはＣＯＮＨから選ばれる２価の基を示し、ｎ_２は独立に０〜４の整数を示す］

[Wherein R ₁₀ independently represents a monovalent hydrocarbon group or alkoxy group having 1 to 6 carbon atoms, and Z represents a single bond or a divalent hydrocarbon group having 1 to 15 carbon atoms, O, S, CO , SO, SO ₂ , NH or CONH represents a divalent group, and n ₂ independently represents an integer of 0 to 4]

  Examples of such aromatic diamines include 4,4′-diaminodiphenyl ether, 2′-methoxy-4,4′-diaminobenzanilide, 1,4-bis (4-aminophenoxy) benzene, 1,3- Bis (4-aminophenoxy) benzene, 2,2′-bis [4- (4-aminophenoxy) phenyl] propane, 2,2′-dimethyl-4,4′-diaminobiphenyl, 3,3′-dihydroxy- Preferred examples include 4,4′-diaminobiphenyl, 4,4′-diaminobenzanilide, bisaniline fluorene and the like.

  Further, other examples of the aromatic diamine include 2,2-bis- [4- (3-aminophenoxy) phenyl] propane, bis [4- (4-aminophenoxy) phenyl] sulfone, bis [4- (3 -Aminophenoxy) phenyl] sulfone, bis [4- (4-aminophenoxy)] biphenyl, bis [4- (3-aminophenoxy) biphenyl, bis [1- (4-aminophenoxy)] biphenyl, bis [1- (3-Aminophenoxy)] biphenyl, bis [4- (4-aminophenoxy) phenyl] methane, bis [4- (3-aminophenoxy) phenyl] methane, bis [4- (4-aminophenoxy) phenyl] ether Bis [4- (3-aminophenoxy) phenyl] ether, bis [4- (4-aminophenoxy)] benzophenone, bis 4- (3-aminophenoxy)] benzophenone, bis [4,4 ′-(4-aminophenoxy)] benzanilide, bis [4,4 ′-(3-aminophenoxy)] benzanilide, 9,9-bis [4 -(4-aminophenoxy) phenyl] fluorene, 9,9-bis [4- (3-aminophenoxy) phenyl] fluorene, 2,2-bis- [4- (4-aminophenoxy) phenyl] hexafluoropropane, 2,2-bis- [4- (3-aminophenoxy) phenyl] hexafluoropropane, 4,4′-methylenedi-o-toluidine, 4,4′-methylenedi-2,6-xylidine, 4,4′- Methylene-2,6-diethylaniline, 4,4′-diaminodiphenylpropane, 3,3′-diaminodiphenylpropane, 4,4′-diamino Diphenylethane, 3,3′-diaminodiphenylethane, 4,4′-diaminodiphenylmethane, 3,3′-diaminodiphenylmethane, 4,4′-diaminodiphenyl sulfide, 3,3′-diaminodiphenyl sulfide, 4,4 ′ -Diaminodiphenyl sulfone, 3,3'-diaminodiphenyl sulfone, 4,4'-diaminodiphenyl ether, 3,3-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, benzidine, 3,3'-diaminobiphenyl, 3,3 '-Dimethyl-4,4'-diaminobiphenyl, 3,3'-dimethoxybenzidine, 4,4' '-diamino-p-terphenyl, 3,3' '-diamino-p-terphenyl, m-phenylenediamine , P-phenylenediamine, 2,6-diaminopyridy 1,4-bis (4-aminophenoxy) benzene, 1,3-bis (4-aminophenoxy) benzene, 4,4 ′-[1,4-phenylenebis (1-methylethylidene)] bisaniline, 4, 4 ′-[1,3-phenylenebis (1-methylethylidene)] bisaniline, bis (p-aminocyclohexyl) methane, bis (p-β-amino-t-butylphenyl) ether, bis (p-β-methyl) -Δ-aminopentyl) benzene, p-bis (2-methyl-4-aminopentyl) benzene, p-bis (1,1-dimethyl-5-aminopentyl) benzene, 1,5-diaminonaphthalene, 2,6 -Diaminonaphthalene, 2,4-bis (β-amino-t-butyl) toluene, 2,4-diaminotoluene, m-xylene-2,5-diamine, p-xylene-2,5-di Examples include amines, m-xylylenediamine, p-xylylenediamine, 2,6-diaminopyridine, 2,5-diaminopyridine, 2,5-diamino-1,3,4-oxadiazole, piperazine and the like. it can. The above aromatic diamines may be used alone or in combination of two or more.

(II) Diaminosiloxane:
As diaminosiloxane, diaminosiloxane represented by the following general formula (14) or an oligomer thereof is preferably exemplified.

（ここで、Ｒ_１１及びＲ_１２は２価の炭化水素基を示し、Ｒ_１３〜Ｒ_１６は炭素数１〜６の炭化水素基を示し、ｍ_１は１〜２０の数、好ましくは１〜１０の数を示す。）

(Here, R ₁₁ and R ₁₂ represent a divalent hydrocarbon group, R _{13 to} R ₁₆ represent a hydrocarbon group having 1 to 6 carbon atoms, and m ₁ represents a number of ₁ to 20, preferably 1 to 1. Indicates a number of 10.)

  Examples of such diaminosiloxanes include diaminopropyltetramethyldisiloxane and diaminosiloxanes represented by the above general formulas (5) to (9). The above diaminosiloxanes may be used alone or in combination of two or more.

(III) Aliphatic amines:
Examples of the aliphatic amine include 1,4-diaminobutane, 1,5-diaminopentane, 1,6-diaminohexane, 2-methyl-1,5-diaminopentane, 1,7-diaminoheptane, and 1,8. -Diaminooctane, 1,3-bis (aminomethyl) cyclohexane, 1,4-bis (aminomethyl) cyclohexane, 1,9-diaminononane, 1,10-diaminodecane, 1,11-diaminoundecane, 1,12- Diaminoalkanes such as diaminododecane, 4,4′-methylenebiscyclohexylamine, tris (2-aminoethyl) amine, N, N′-bis (2-aminoethyl) -1,3-propanediamine, bis (3 -Aminopropyl) ethylenediamine, 1,4-bis (3-aminopropyl) piperazine, diethylenetriamine, N-methyl-2,2'-dia Nodiethylamine, 3,3′-diaminodipropylamine, amines containing nitrogen atoms such as N, N-bis (3-aminopropyl) methylamine, bis (3-aminopropyl) ether, 1,2-bis Amines containing oxygen atoms such as (2-aminoethoxy) ethane, 3,9-bis (3-aminopropyl) -2,4,8,10-tetraoxaspiro [5.5] -undecane, Examples include amines having a sulfur atom such as 2'-thiobis (ethylamine). These aliphatic amines may be used alone or in combination of two or more.

(IV) Dihydrazide compound:
Examples of the dihydrazide compound include those represented by the following general formula (15).

In the general formula (15), examples of R ₁₇ include a single bond, an aliphatic group, and an aromatic group. What is preferable as R ₁₇ is described with reference to examples of dihydrazide compounds. For example, oxalic acid dihydrazide, malonic acid dihydrazide, succinic acid dihydrazide, glutaric acid dihydrazide, adipic acid dihydrazide, pimelic acid dihydrazide, suberic acid dihydrazide, azelaic acid dihydrazide, sebacic acid dihydrazide dihydrazide, maleic acid dihydrazide Diglycolic acid dihydrazide, tartaric acid dihydrazide, malic acid dihydrazide, phthalic acid dihydrazide, isophthalic acid dihydrazide, terephthalic acid dihydrazide, 2,6-naphthodioic acid dihydrazide, 4,4-bisbenzene dihydrazide, 1,4-naphthoic acid dihydrazide, 2,6-pyridinediacid dihydrazide, itaconic acid dihydrazide and the like can be mentioned. The above dihydrazide compounds may be used alone or in combination of two or more.

  Of the amino compounds having at least two primary amino groups as functional groups as described above, dihydrazide compounds are most preferable. When the dihydrazide compound is used, the curing time of the adhesive resin composition can be shortened as compared with the case where another amino compound is used. This is because the product obtained by reacting the primary amino group of the dihydrazide compound with the ketone group has a semicarbazone-like molecular structure, and forms a dimer structure by hydrogen bonding between NHs between molecules. Because the stability of the product is improved, the equilibrium of the reaction is biased toward the product side, and the reverse reaction in the direction of generating the ketone group of the polyimidesiloxane that is the raw material and the amino group of the dihydrazide compound is less likely to occur. It is considered a thing.

  In addition, amino compounds such as (I) aromatic diamine, (II) diaminosiloxane, (III) aliphatic amine, and (IV) dihydrazide compound are, for example, combinations of (I) and (II), (I) and ( It can also be used in combination of two or more types across categories, such as combinations with (III), combinations of (I), (II) and (III), and combinations of (I) to (IV). In particular, by combining the amino compound of (I), (II) or (III) and the dihydrazide compound of (IV) at a predetermined blending ratio, taking advantage of the properties of the amino compound of (I) to (III) It is expected to obtain an effect of shortening the curing time depending on the blending ratio of the dihydrazide compound (IV).

  Further, from the viewpoint of making the network structure formed by crosslinking of the amino compound more dense, the amino compound used in the present invention has a molecular weight (weight average molecular weight when the amino compound is an oligomer) of 5,000 or less. It is preferably 90 to 2,000, more preferably 100 to 1,500. Among these, amino compounds having a molecular weight of 100 to 1,000 are particularly preferable. When the molecular weight of the amino compound is less than 90, one amino group of the amino compound only forms a C = N bond with the ketone group of the polyimide siloxane, and the remaining amino group is sterically bulky so that it remains. The amino group tends to be difficult to bond C═N.

[Method for producing crosslinked polyimide resin]
The method for producing a crosslinked polyimide resin of the present invention comprises mixing the acid anhydride component having a ketone group, the diamine compound having a hydrogen bond-forming group and a diamine component containing diaminosiloxane, which is the component (A), A step of imidizing by heating to form a polyimidesiloxane having a ketone group and a hydrogen bond-forming group;
Forming hydrogen bonds between adjacent main chains in the polyimidesiloxane;
By reacting at least a part of the ketone group of the polyimidesiloxane with the amino group of the amino compound having at least two primary amino groups as the functional group as the component (B), a C═N bond is formed, and the polyimidesiloxane is formed. And a step of crosslinking with an amino compound. Specifically, an amino acid containing at least two primary amino groups of component (B) as a functional group in a resin solution containing polyimide siloxane of component (A) and having hydrogen bonds formed between the main chains. It is produced by adding a compound and subjecting some or all of the ketone groups of polyimidesiloxane to a condensation reaction with the primary amino group of the amino compound. By this condensation reaction, cross-linking formation proceeds between polyimide siloxane chains, and the adhesive resin composition is gradually cured according to the degree of cross-linking formation. In this case, the primary amino group in total is 0.004 mol to 1.5 mol, preferably 0.005 mol to 1.2 mol, more preferably 0.03 mol to 0.00 mol per mol of the ketone group. It is preferable to add the amino compound so as to be 9 mol, particularly preferably 0.04 mol to 0.5 mol. The addition amount of the amino compound in which the primary amino group is less than 0.004 mol in total with respect to 1 mol of the ketone group is not sufficient for crosslinking of the polyimide siloxane with the amino compound. Solder heat resistance tends to be difficult to develop in the cured product after curing, and when the added amount of amino compound exceeds 1.5 mol, the unreacted amino compound acts as a thermoplastic agent, and solder heat resistance in the cured product. There is a tendency to lower the long-term heat resistance at high temperatures.

  Further, the curing by the condensation reaction is not particularly limited as long as the conditions allow the ketone group in the polyimidesiloxane and the primary amino group of the amino compound to react to form an imine bond (C═N bond). Depending on the type of amino compound, for example, when an aliphatic amine is used, it can be condensed with a ketone group in polyimide siloxane even at room temperature, but it is preferable to promote the condensation reaction by heating. When an aliphatic amine is used as the amino compound, it is preferable to perform heat condensation within a range of 60 to 200 ° C, for example. When an aromatic amine is used, heat condensation is performed within a range of 120 to 220 ° C, for example. It is preferable to carry out. The temperature of the heat condensation is, for example, 120 for the purpose of releasing water generated by the condensation out of the system or simplifying the condensation step when the heat condensation reaction is subsequently performed after the synthesis of the polyimidesiloxane. Within the range of -220 degreeC is preferable, and the inside of the range of 140-200 degreeC is more preferable. The reaction time is preferably about 0.5 to 24 hours. From the viewpoint of obtaining practically sufficient moisture-resistant soldering heat resistance by a short heat treatment, it is preferable to heat at 160 ° C. or higher for 0.5 hour or longer. From the viewpoint of obtaining practically sufficient moisture-absorbing solder heat resistance by a lower temperature heat treatment, it is desirable to heat at 150 ° C. or higher for 1 hour or longer.

The end point of the condensation reaction is derived from the ketone group in polyimidesiloxane near 1670 cm ⁻¹ by measuring the infrared absorption spectrum using, for example, a Fourier transform infrared spectrophotometer (commercial product: FT / IR620 manufactured by JASCO Corporation). It can be confirmed by the decrease or disappearance of the absorption peak and the appearance of an absorption peak derived from an imine group near 1635 cm ⁻¹ , or by using a Raman spectrophotometer (commercial product: NRS-3100 manufactured by JASCO Corporation). By measuring the spectrum, it can be confirmed by the appearance of a peak derived from an imine group in the vicinity of 1567 cm ⁻¹ . Further, whether or not a practically sufficient moisture-resistant soldering heat resistance can be expressed by heat treatment at 160 ° C. for 2 hours can be determined by using the viscosity of the formed crosslinked polyimide resin as an index. For example, when the molecular weight of the polyimide resin is in the range of 70,000 to 140,000, it is preferable that the viscosity of the polyimide resin added with a crosslinking agent at a temperature of 260 ° C. is 1 × 10 ⁵ Pa · s or more. If the viscosity of the cross-linked polyimide resin at a temperature of 260 ° C. is 1 × 10 ⁵ Pa · s or more, it can be considered that the cross-linking is formed to such an extent that practically sufficient moisture-resistant soldering heat resistance can be obtained. The reason why the viscosity of the cross-linked polyimide resin is employed as the threshold value in this way is that it is difficult to directly measure the cross-linking formation rate due to the C = N bond. Second, since the cross-linking formation rate (ketone group consumption rate) necessary to obtain practically sufficient moisture-resistant solder heat resistance varies depending on the molecular weight of the cross-linked polyimide resin, it is simply determined by the cross-linking formation rate. It is difficult to judge the moisture-resistant solder heat resistance in the crosslinked polyimide resin of the invention. However, if the viscosity of the crosslinked polyimide resin at a temperature of 260 ° C. is 1 × 10 ⁵ Pa · s or more, it is considered that the practically sufficient moisture-resistant soldering heat resistance has been obtained. The viscosity at this time is adopted as a standard for judging the end point of the curing by the condensation reaction. Therefore, the end point of the condensation reaction does not necessarily mean that all of the ketone groups are consumed and further curing does not proceed, but a cured product having practically sufficient properties (especially moisture solder heat resistance) ( It means the time when a semi-cured product is obtained.

The heat condensation of the ketone group of polyimidesiloxane and the primary amino group of the amino compound is, for example,
(A) Following the synthesis (imidation) of polyimide siloxane, adding an amino compound and heating,
(B) charging an excess amount of an amino compound in advance as a diamine component and heating the polyimide siloxane together with the remaining amino compound not involved in imidization (or amidation) following the synthesis (imidization) of the polyimide siloxane; Or
(C) heating after processing the polyimidesiloxane composition to which the amino compound has been added into a predetermined shape (for example, after being applied to an arbitrary base material or after being formed into a film),
Etc.

  In the case of (b) above, the excess amino compound is consumed in the reaction of sealing the acid anhydride group as a terminal substituent during the production of polyimidesiloxane, and the molecular weight of the resulting polyimidesiloxane may be extremely reduced. Therefore, it tends to be difficult to obtain sufficient heat resistance in the cured product. Therefore, it is preferable to use the method [the above (b)] in which an excess amount of an amino compound is previously charged as long as the effect of the present invention is not impaired. In order to effectively react at least two primary amino groups in an amino compound with a ketone group to form a C═N bond, the amino compound is synthesized from polyimide siloxane as in (a) or (c) above. It is preferable to add after completing (imidization). In the case of (c) above, the heat condensation is performed by, for example, the heat of heat treatment performed when the adhesive layer of the coverlay film is formed from a composition in which an amino compound and polyimide siloxane are mixed, or the adhesive layer is formed. After that, it can also be performed by using heat at the time of thermocompression bonding to the circuit board having the wiring layer.

[Inorganic filler]
The crosslinked polyimide resin of the present invention can contain a plate-like inorganic filler having an average particle diameter in the range of 2 to 25 μm as an arbitrary component (C). (C) When the inorganic filler of component (C) is blended, when the cross-linked polyimide resin is used for an adhesive layer of a coverlay film, for example, the permeation of oxygen in the atmosphere is blocked by the inorganic filler having gas barrier properties. The oxidation of copper wiring and the diffusion of copper are suppressed, and long-term heat resistance can be improved.

  As the inorganic filler of component (C), it is preferable to use a plate-like material in order to impart sufficient gas barrier properties to the adhesive layer. Here, the “plate shape” is used to mean, for example, a flat shape, a flat plate shape, a flake shape, a scale shape, etc., and the thickness of the inorganic filler is sufficiently smaller than the major axis or minor axis of the plane portion (preferably 1/2 or less). In particular, it is preferable to use a scale-like inorganic filler. From another viewpoint, “plate-like” means that the ratio of the major axis to the thickness (major axis / thickness) of the filler particles is preferably 5 or more, more preferably 10 or more, and still more preferably 15 or more. In the plate-like inorganic filler, the relationship between the long diameter and the average particle diameter is preferably long diameter ≧ average particle diameter> 0.4 × long diameter, more preferably long diameter ≧ average particle diameter ≧ 0.5 ×. It is good that it is a long diameter. In the present invention, the major axis (or minor axis) and thickness of the filler particles, and the ratio of the major axis to the thickness are the average values when ten arbitrary fillers are measured with a stereomicroscope. If the shape of the inorganic filler is not plate-like, for example, it is spherical, the gas barrier property of the adhesive layer is lowered, the oxidation of the wiring layer proceeds, and the adhesive strength of the coverlay film may be reduced. It does not preclude blending inorganic fillers having a shape other than the plate shape as long as the effect of blending the plate filler is not impaired.

  As the inorganic filler of component (C), it is preferable to use an insulating inorganic filler such as talc, mica, sericite, clay, kaolin and the like.

  The inorganic filler preferably has an average particle size calculated by a laser diffraction method in the range of 2 to 25 μm, and more preferably in the range of 5 to 20 μm. Here, the particle size of the inorganic filler is based on the average value of the longitudinal diameters of the particles. When the average particle diameter exceeds the upper limit, the surface roughness of the adhesive layer of the coverlay film tends to occur. When the average particle diameter is less than the lower limit, it is difficult to obtain the effect of suppressing oxygen transmission.

  In addition, the particle size distribution of the inorganic filler is preferably 60% or more, more preferably 65% or more, and preferably the particle size of 20 μm or more is 10% or less on a number basis. When the inorganic filler having a particle diameter of 10 μm or less is less than 60%, when the adhesive resin composition is formed into a film, the fillers are arranged in layers, and protrusions appear on the film surface, which causes the film surface to become rough. In addition, if the inorganic filler having a particle size of 20 μm or more exceeds 10%, protrusions appear on the film surface, causing the surface of the film to become rough. For example, when a thin film of 15 μm or less is produced, the surface tends to be rough. Cheap. Moreover, 0.1-100 micrometers is preferable and, as for the frequency distribution of the particle size of an inorganic filler, 0.5-70 micrometers is more preferable. If the frequency distribution exceeds the upper limit, the surface of the adhesive layer tends to be rough, and if the frequency distribution is lower than the lower limit, it is difficult to obtain the effect of suppressing oxygen transmission.

  (C) The compounding quantity of the inorganic filler of a component is 5-200 weight part with respect to a total of 100 weight part of the said (A) component and (B) component, Preferably it is 10-150 weight part, Furthermore, Preferably it is 30-100 weight part, It is 40-80 weight part desirably. When the blending amount of the inorganic filler is less than 5 parts by weight with respect to 100 parts by weight of the total of the component (A) and the component (B), the blending effect cannot be obtained, and the effect of suppressing oxygen permeation cannot be obtained. Moreover, when the compounding quantity of an inorganic filler exceeds 200 weight part with respect to a total of 100 weight part of said (A) component and (B) component, an adhesive bond layer will become weak, As a result, cohesive failure in an adhesive bond layer As a result, the apparent adhesiveness is significantly reduced. In the present invention, a plate-like inorganic filler is used, but it is also possible to use a non-plate-like inorganic filler in combination. When the inorganic filler that is not plate-shaped is used in combination, the total amount of the inorganic filler (plate-shaped and other shapes total) exceeds 200 parts by weight with respect to 100 parts by weight of the total of component (A) and component (B). It is preferable not to do so.

[Action]
The reaction between the ketone group of the polyimide siloxane of the component (A) and the primary amino group of the amino compound is a dehydration condensation reaction, and the carbon atom of the ketone group and the nitrogen atom of the primary amino group in the polyimide siloxane are As a result of forming a C = N bond, it is considered that a chain polyimidesiloxane is crosslinked with an amino compound to form a network polymer. And by including a hydrogen bond forming group in the polyimide siloxane of the said (A) component, a hydrogen bond arises between adjacent polyimide siloxane chains prior to a crosslinking reaction, and becomes a reaction point of a crosslinking reaction with an amino compound. The ketone groups can be brought close together. As a result, the crosslinking reaction by the amino compound is promoted, and the heating time until a practically sufficient moisture-resistant soldering heat resistance is obtained can be shortened. Usually, since polyimidesiloxane hardly causes intermolecular interaction, it is difficult to control the orientation of polyimidesiloxane, but by including a group capable of hydrogen bonding in the main chain, hydrogen bonding can be generated. Furthermore, when a crosslinked structure of a ketone group and an amino compound occurs, not only the apparent high molecular weight in polyimide siloxane but also the polyimide siloxane molecules can be constrained to some extent, thus improving the heat resistance, It is considered that extremely excellent solder heat resistance can be obtained. In addition, the vicinity of the nitrogen atom in the C = N bond becomes three-dimensionally bulky, thereby reducing the nucleophilic ability of the copper atom of the polar group contained in the crosslinked polyimide resin, so that the copper adhesive layer from the copper wiring It is thought that the effect of suppressing the decrease in the adhesive strength when used in a high temperature environment can be obtained. For these reasons, the amino compound used in the present invention needs to have at least two amino groups, and the number of amino groups is preferably 2 to 5, more preferably 2 to 3. In addition, in an amino compound having three or more amino groups, the cross-linked structure after the two amino groups form a C═N bond becomes three-dimensionally bulky, so that the remaining unreacted amino group is a ketone group. It is particularly preferable that the number of amino groups is 2. Furthermore, from the viewpoint of shortening the curing time of the adhesive resin composition as described above, it is most preferable to use a dihydrazide compound as the amino compound.

[Adhesive resin composition]
The adhesive resin composition of the present invention contains the polyimidesiloxane [(A) component] and an amino compound [(B) component] having at least two primary amino groups as functional groups as essential components. To do. This adhesive resin composition is obtained by mixing or kneading the component (A) and the component (B) and / or heating in a state containing the component (A) and the component (B), so that the polyimide siloxane And the primary amino group of the amino compound undergo a condensation reaction to form a C═N bond. That is, the adhesive resin composition of the present invention changes to the cured product of the present invention by a condensation reaction between polyimide siloxane and an amino compound. Here, the “cured product” of the present invention includes not only a state in which the crosslinking reaction between the ketone group of the polyimidesiloxane and the primary amino group of the amino compound does not proceed any more, but also the above-mentioned crosslinking reaction. Including a semi-cured state leaving room. In the adhesive resin composition of the present invention, the weight average molecular weight of the component (A) is preferably in the range of, for example, 30,000 to 200,000, and sufficient moisture-resistant solder heat resistance by heating at 160 ° C. for 2 hours. From the viewpoint of obtaining properties, a range of 70,000 to 140,000 is more preferable. When the weight average molecular weight of the component (A) is less than 70,000, it becomes difficult to control the fluidity when the adhesive resin composition is made into a solution, and the heat resistance of the cured product tends to decrease. . On the other hand, when the weight average molecular weight exceeds 140,000, the solubility in the solvent tends to be impaired.

  The adhesive resin composition has a total of primary amino groups of 0.004 mol to 1.5 mol, preferably 0.005 mol to 1.2 mol, more preferably 0.03 mol per mol of ketone groups. An amino compound is contained so that it may become mol-0.9 mol, Most preferably, it is 0.04 mol-0.5 mol.

  It is preferable that the adhesive resin composition of the present invention contains the inorganic filler of the component (C) as an optional component together with the polyimide siloxane of the component (A) and the amino compound of the component (B). Further, if necessary, other resin components such as an epoxy resin, a curing accelerator, a coupling agent, a filler, a pigment, a solvent, a flame retardant and the like can be appropriately blended. However, some plasticizers contain a large number of polar groups, and there is a concern that this may promote the diffusion of copper from the copper wiring. Therefore, it is preferable not to use the plasticizer as much as possible.

  When blending optional components other than the inorganic filler of component (C) in the adhesive resin composition of the present invention, for example, the blended amount of 1 to 10 parts by weight in total of the optional components with respect to 100 parts by weight of the crosslinked polyimide resin It is preferable that the blending amount is 2 to 7 parts by weight.

  The adhesive resin composition of the present invention obtained as described above has excellent flexibility and thermoplasticity when it is used to form an adhesive layer, such as FPC, rigid flex circuit board, etc. It has preferable characteristics as an adhesive for a coverlay film that protects the wiring part. When used as an adhesive layer of a cover lay film, after applying the adhesive resin composition of the present invention in a solution state (for example, a varnish containing a solvent) on one side of a cover lay film material, for example, 60 to By carrying out thermocompression bonding at a temperature of 220 ° C., the coverlay film of the present invention having a coverlay film material layer and an adhesive layer can be formed. In this case, it is possible to heat-condense the ketone group of the polyimide siloxane and the primary amino group of the amino compound using heat at the time of thermocompression bonding. Moreover, even when heat condensation at the time of thermocompression bonding is not sufficient, heat treatment can be further performed after thermocompression bonding for heat condensation. When heat treatment is performed after thermocompression bonding, the heat treatment temperature is preferably, for example, 60 to 220 ° C, and more preferably 80 to 200 ° C. Moreover, it peels, after apply | coating the adhesive resin composition of this invention in the state of a solution (for example, varnish shape containing a solvent) on arbitrary base materials, for example, drying at the temperature of 80-180 degreeC. The film having the coverlay film material layer and the adhesive layer can also be formed by thermocompression bonding the adhesive film with the coverlay film material at a temperature of 60 to 220 ° C., for example. The coverlay film of the invention can be formed. In this case as well, the ketone group of the polyimide siloxane and the primary amino group of the amino compound can be heat-condensed using the heat during thermocompression bonding. As described above, the adhesive resin composition of the present invention can be used after being processed into various forms in a state where the ketone group of polyimidesiloxane and the primary amino group of the amino compound are unreacted. Furthermore, the adhesive resin composition of the present invention can be used by forming a coating film in the form of a solution by screen printing on an arbitrary substrate and drying it at a temperature of, for example, 80 to 180 ° C. . Preferably, a cured product can be formed by further heat-treating at a temperature of 130 to 220 ° C. for a predetermined time to completely cure the coating film.

[Coverlay film / bonding sheet]
The coverlay film of the present invention includes a coverlay film material and an adhesive layer composed of the adhesive resin composition laminated on the coverlay film material. The coverlay film material in the coverlay film of the present invention is not limited, but, for example, polyimide resin films such as polyimide resin, polyetherimide resin, and polyamideimide resin, polyamide resin film, and polyester resin A film or the like can be used. Among these, it is preferable to use a polyimide resin film having excellent heat resistance. The thickness of the coverlay film material layer is not particularly limited, but is preferably 5 μm or more and 100 μm or less, for example. The thickness of the adhesive layer is not particularly limited, but is preferably 10 μm or more and 50 μm or less, for example.

  Moreover, what formed the adhesive resin composition of this invention in the film form can be utilized also as a bonding sheet of multilayer FPC, for example. When used as a bonding sheet, an adhesive film obtained by applying the adhesive resin composition of the present invention in the form of a solution on an arbitrary base film, drying at a temperature of, for example, 80 to 180 ° C., and then peeling. May be used as a bonding sheet as it is, or may be used in a state where this adhesive film is laminated with an arbitrary substrate film. Also when used as a bonding sheet, the heat of thermocompression bonding can be used to heat-condense the polyimidesiloxane ketone group and the primary amino group of the amino compound. Heat condensation can also be performed.

  Moreover, a coverlay film and a bonding sheet are good also as a form which has a release material layer by bonding a release material on the adhesive surface. The material of the release material is not particularly limited as long as it can be peeled without impairing the form of the coverlay film or the bonding sheet. For example, resin films such as polyethylene terephthalate, polyethylene, and polypropylene, and these resin films And the like laminated on paper can be used.

  The coverlay film or bonding sheet obtained by molding using the adhesive resin composition of the present invention and causing the heat condensation reaction by heat treatment is a cross-linked polyimide resin obtained by reaction of polyimidesiloxane and an amino compound. Therefore, it has excellent solder heat resistance. More specifically, as shown in Examples below, the solder heat resistance (drying) is 260 ° C. or higher, preferably 280 ° C. or higher, more preferably 300 ° C. or higher, and the solder heat resistance (humidity resistance) is 200 ° C. or higher. The temperature is preferably 260 ° C. or higher, more preferably 280 ° C. or higher. Thus, by having extremely excellent solder heat resistance, the occurrence of deformation or peeling in the soldering process is prevented, and it is possible to contribute to the improvement of the yield and reliability of the circuit board to be manufactured.

[Circuit board]
As long as the circuit board of this invention is provided with the coverlay film and bonding sheet which are obtained as mentioned above, there is no restriction | limiting in particular in the structure. For example, the preferred form of the circuit board of the present invention includes at least a base material, a wiring layer made of a metal such as copper formed on the base material in a predetermined pattern, and the cover lay film of the present invention covering the wiring layer. And. The base material of the circuit board is not particularly limited, but in the case of FPC, the same material as the coverlay film material is preferably used, and the base material made of polyimide resin is preferably used.

By using the cover lay film of the present invention, the circuit board of the present invention is filled with an adhesive layer having excellent flexibility and thermoplasticity between the wirings, and high adhesion between the cover lay film and the wiring layer is obtained. It is done. In addition, by forming an adhesive layer containing a cross-linked polyimide resin obtained by the reaction of polyimide siloxane and amino compound, copper diffusion from the copper wiring is suppressed, even if repeated use in a high temperature environment, Excellent adhesion can be maintained over a long period of time. More specifically, after a long-term heat resistance test at 150 ° C. and 1000 hours in the atmosphere, the measurement of the energy dispersive X-ray (EDX) analyzer (see Examples below) shows that the copper on the adhesive layer The amount of diffusion can be suppressed to 2.5% or less. As a result, it is possible to maintain the peel strength between the copper wiring layer and the coverlay film material layer after the long-term heat resistance test at 0.2 kN / m or more. In particular, by selecting the group Ar, the group R ₁ and the group R ₂ in the general formulas (1) and (2), it is possible to obtain an extremely high peel strength of 0.4 kN / m or more. Also, by setting the blending ratio of diaminosiloxane to the total diamine component of the raw material to 35 mol% or more, it is possible to obtain excellent solubility and prevent warping of the coverlay film without blending a plasticizer. it can.

  The circuit board of the present invention may be configured as a multilayer circuit board. In this case, the adhesive film obtained from the adhesive resin composition of the present invention can be used not only for the coverlay film but also for the bonding sheet.

  The production of the circuit board of the present invention is not particularly limited. For example, after the metal foil of a metal-clad laminate such as a copper-clad laminate is processed into a predetermined pattern by a method such as chemical etching, the circuit is produced. For example, a method of laminating a cover lay film on the necessary portion above and performing thermocompression bonding using, for example, a hot press apparatus can be used. In this case, the pressure bonding conditions are not particularly limited. For example, the pressure bonding temperature is preferably 130 ° C. or higher and 220 ° C. or lower, more preferably 140 ° C. or higher and 200 ° C. or lower, and the pressure is 0.1 MPa or higher and 4 MPa or lower. It is preferable. In addition, when the ketone group of polyimide siloxane and the primary amino group of the amino compound are unreacted in the state of the cover lay film, condensation is performed using heat when the cover lay film is thermocompression bonded to the circuit wiring. A reaction can be caused. That is, it arrange | positions so that the adhesive bond layer of a coverlay film may contact | connect a wiring layer, and the process of carrying out the thermocompression bonding of both members, and the ketone group of (A) component contained in an adhesive bond layer, and (B) component It is possible to carry out a condensation reaction with a primary amino group to form a C═N bond.

  EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited to these examples. In the following examples, various measurements and evaluations are as follows unless otherwise specified.

[Measurement of adhesive strength]
The adhesive strength was 10 mm in width and 100 mm in length, and the adhesive surface of the test piece was placed on a glossy surface of copper foil (thickness of 35 μm) (with rust-proof metal removed), temperature 160 ° C., pressure 2 MPa, After pressing for 2 hours, the tensile strength (strength-M1 manufactured by Toyo Seiki Co., Ltd.) is used, and the force at the time of peeling at a speed of 50 mm / min in the 180 ° direction is defined as the adhesive strength.

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

[Evaluation method of warpage]
The warpage was evaluated by the following method. A polyimide adhesive was applied onto a 25 μm thick Kapton film so that the thickness after drying was 35 μm. In this state, the Kapton film was placed on the lower surface, and the average of the heights of warping at the four corners of the film was measured.

[Method for evaluating solder heat resistance (drying)]
A circuit of polyimide copper-clad laminate (manufactured by Nippon Steel Chemical Co., Ltd., trade name: Espanex MC18-25-00FRM) was formed, and a circuit with wiring width / wiring interval (L / S) = 1 mm / 1 mm was formed. A printed circuit board is prepared, and the adhesive surface of the test piece is placed on the wiring of the printed circuit board and pressed under conditions of a temperature of 170 ° C., a pressure of 1 MPa, and an hour of 1 minute, and then an oven at 150 ° C. for 24 hours Heated at conditions. This test piece with copper foil was left at 105 ° C. and 50% relative humidity for 1 hour, then immersed in a solder bath set to each evaluation temperature for 10 seconds, and observed for adhesion, foaming, blistering and peeling. The presence or absence of such defects was confirmed. The heat resistance is expressed by an upper limit temperature at which no defect occurs. For example, “320 ° C.” means that no defect is recognized when evaluated in a solder bath at 320 ° C.

[Method for evaluating solder heat resistance (moisture resistance)]
A circuit of polyimide copper-clad laminate (manufactured by Nippon Steel Chemical Co., Ltd., trade name: Espanex MC18-25-00FRM) was formed, and a circuit with wiring width / wiring interval (L / S) = 1 mm / 1 mm was formed. A printed circuit board is prepared, and the adhesive surface of the test piece is placed on the wiring of the printed circuit board and pressed under conditions of a temperature of 170 ° C., a pressure of 1 MPa, and an hour of 1 minute, and then an oven at 150 ° C. for 24 hours Heated at conditions. The test piece with the copper foil was allowed to stand at 85 ° C. and a relative humidity of 85% for 24 hours, then immersed in a solder bath set to each evaluation temperature for 10 seconds, and observed for adhesion, foaming, blistering and peeling. The presence or absence of such defects was confirmed. The heat resistance is expressed by an upper limit temperature at which no defect occurs. For example, “270 ° C.” means that a defect is not recognized when evaluated in a solder bath at 270 ° C.

[Rheometer evaluation]
A polyimide adhesive was applied onto the release PET film so that the thickness after drying was 25 μm. The polyimide adhesive film is peeled from the release PET film, about 10 polyimide adhesive films (3 cm × 3 cm) are laminated, and thermocompression bonding is performed using a vacuum laminator under the conditions of 70 ° C./0.85 MPa / 10 sec. A sample having a thickness of about 250 μm was prepared. About the obtained sample, the viscosity change of the sample was evaluated on the conditions of the temperature increase rate of 4 degree-C / min using the rheometer (RS150 RheoStress, the product made from Haake).

The abbreviations used in the examples represent the following compounds.
BTDA: 3,3 ′, 4,4′-benzophenone tetracarboxylic dianhydride BPDA: 3,3 ′, 4,4′-diphenyltetracarboxylic dianhydride BAPP: 2,2-bis (4-aminophenoxy) Phenyl) propane BAFL: bisaniline fluorene PSX: diaminosiloxane (weight average molecular weight is 740)
N-12: dodecanedioic acid dihydrazide ADH: adipic acid dihydrazide K-1: talc (manufactured by Nippon Talc Co., Ltd., trade name; MICRO ACE K-1, shape: scaly, average major axis; 7.0 μm, average minor axis; 5.8 μm, ratio of major axis to thickness: 15 or more, average particle size: 6.6 μm, median diameter (D50); 6.9 μm, maximum particle size; 64.9 μm, minimum particle size: 0.5 μm, mode Diameter: 8.7 μm, cumulative particle amount of particle size of 10 μm or less; 77%, cumulative particle amount of particle size of 20 μm or more; 5%)

Synthesis example 1
In a 1000 ml separable flask, 71.850 g PSX (0.0971 mol), 7.474 g BAPP (0.0182 mol), 1.568 g N-12 (0.0061 mol), 39.109 g BTDA. (0.1214 mol) 168 g of N-methyl-2-pyrrolidone and 112 g of xylene were charged and mixed well at room temperature for 1 hour to obtain a polyamic acid solution. This polyamic acid solution was heated to 190 ° C., heated and stirred for 20 hours to obtain a polyimide solution a having completed imidization. The weight average molecular weight (Mw) of the polyimide resin in the obtained polyimide solution a was 90,000. At this time, the mol% of the diaminosiloxane component relative to the total diamine component is 80% (m value = 0.8).

Synthesis example 2
In a 1000 ml separable flask, 72.407 g PSX (0.0978 mol), 5.021 g BAPP (0.0122 mol), 3.160 g N-12 (0.0122 mol), 39.412 g BTDA (0.1223 mol) 168 g of N-methyl-2-pyrrolidone and 112 g of xylene were charged and mixed well at room temperature for 1 hour to obtain a polyamic acid solution. This polyamic acid solution was heated to 190 ° C. and heated and stirred for 20 hours to obtain a polyimide solution b in which imidization was completed. The weight average molecular weight (Mw) of the polyimide resin in the obtained polyimide solution b was 73,000. At this time, the mol% of the diaminosiloxane component relative to the total diamine component is 80% (m value = 0.8).

Synthesis example 3
In a 1000 ml separable flask, 73.364 g PSX (0.0991 mol), 10.175 g BAPP (0.0248 mol), 36.461 g BPDA (0.1239 mol), 168 g N-methyl-2 -Pyrrolidone and 112 g of xylene were charged and mixed well at room temperature for 1 hour to obtain a polyamic acid solution. This polyamic acid solution was heated to 190 ° C., heated and stirred for 6 hours to obtain a polyimide solution c in which imidization was completed. The weight average molecular weight (Mw) of the polyimide resin in the obtained polyimide solution c was 27,900. At this time, the mol% of the diaminosiloxane component relative to the total diamine component is 80% (m value = 0.8).

Synthesis example 4
In a 1000 ml separable flask, 71.301 g PSX (0.0964 mol), 9.889 g BAPP (0.0241 mol), 38.810 g BTDA (0.1204 mol), 168 g N-methyl-2 -Pyrrolidone and 112 g of xylene were charged and mixed well at room temperature for 1 hour to obtain a polyamic acid solution. This polyamic acid solution was heated to 190 ° C., heated and stirred for 6 hours to obtain a polyimide solution d having completed imidization. The weight average molecular weight (Mw) of the polyimide resin in the obtained polyimide solution d was 107,000. At this time, the mol% of the diaminosiloxane component relative to the total diamine component is 80% (m value = 0.8).

  Synthesis Examples 1 to 4 are summarized in Table 1.

Reference example 1
The polyimide solution a obtained in Synthesis Example 1 is applied to one side of a polyimide film (manufactured by DuPont, trade name: Kapton ENS, length × width × thickness = 200 mm × 300 mm × 25 μm), and dried at 80 ° C. for 15 minutes. A coverlay film having an adhesive layer thickness of 35 μm was obtained. Next, the obtained coverlay film was placed on a copper foil from which the surface antirust metal layer was removed, and pressed under conditions of a temperature of 160 ° C., a pressure of 2 MPa, and a time of 2 hours to obtain an evaluation sample.

[Example 1]
To the polyimide solution a obtained in Synthesis Example 1, 5.78 g of N-12 (0.0224 mol) and 57.81 g of K-1 were blended and further stirred for 1 hour to obtain a polyimide solution 1.

  The obtained polyimide solution 1 was applied to one side of a polyimide film (manufactured by DuPont, trade name: Kapton ENS, length × width × thickness = 200 mm × 300 mm × 25 μm), dried at 80 ° C. for 15 minutes, and adhesive A coverlay film 1 having a layer thickness of 35 μm was obtained. This cover lay film 1 was placed on a copper foil from which the rust-proof metal layer on the surface was removed, and pressed under the conditions of a temperature of 160 ° C., a pressure of 2 MPa, and a time of 2 hours to obtain Evaluation Sample 1. The adhesive strength with the copper foil after curing was 0.65 kN / m. Moreover, the warp of the coverlay film was no problem. Moreover, the polyimide solution 1 was apply | coated to the single side | surface of a base material, and it dried for 15 minutes at 80 degreeC, and produced the 25-micrometer-thick polyimide adhesive film. About 10 sheets of this polyimide adhesive film were thermocompression-bonded with a vacuum laminator under conditions of a temperature of 70 ° C., a pressure of 0.85 MPa, and a time of 10 sec, and a sample having a thickness of about 250 μm was prepared. The viscosity at 11 ° C. was 118,000 Pa · s.

  Next, the evaluation sample 1 was heat-treated in an oven at 150 ° C. for 1000 hours in an oven. It was 0.45 kN / m when the copper foil after a process and the adhesive strength of a coverlay film were measured. The peeling surface at this time was an interface between copper and the adhesive layer.

  Further, a printed board having a circuit {wiring width / wiring interval (L / S) = 25 μm / 25 μm} formed of copper on both sides of the polyimide film is prepared. The coverlay film 1 obtained in Example 1 is printed board. The circuit board was placed under pressure and pressed under the conditions of a temperature of 160 ° C., a pressure of 2 MPa, and a time of 2 hours to obtain a wiring board 1 provided with a coverlay film.

[Example 2]
Instead of blending 57.81 g of K-1 in Example 1, a polyimide solution 2 was obtained in the same manner as in Example 1 except that K-1 was not blended. 2 was obtained and an evaluation sample 2 was obtained. When the Raman spectrum of the adhesive layer in the evaluation sample was measured, a peak due to the formation of an imino group was confirmed in the vicinity of 1567 cm ⁻¹ . From this measurement result, in the evaluation sample, it is presumed that the condensation reaction between the ketone group in the polyimide resin and the amino compound (N-12) occurred simultaneously with the thermocompression bonding of the coverlay film and the copper foil. The adhesive strength with the copper foil after curing was 1.08 kN / m. Moreover, the warp of the coverlay film was no problem. In addition, when the rheometer evaluation of the polyimide adhesive film produced similarly to Example 1 using the polyimide solution 2 was performed, the viscosity in 260 degreeC was 113,000 Pa.s.

  Next, heat treatment was performed on the evaluation sample 2 in an oven in the air at 150 ° C. for 1000 hours. It was 0.41 kN / m when the copper foil after a process and the adhesive strength of a coverlay film were measured. The peeling surface at this time was an interface between copper and the adhesive layer.

  Further, in the same manner as in Example 1, a printed circuit board on which a circuit {wiring width / wiring interval (L / S) = 25 μm / 25 μm} is prepared, and the coverlay film 2 obtained in Example 2 is printed. It was placed on the circuit surface of the substrate and thermocompression bonded to obtain a wiring substrate 2 provided with a coverlay film.

[Example 3]
Polyimide solution 3 in the same manner as in Example 1 except that 3.78 g of N-12 (0.0134 mol) was added instead of 5.78 g of N-12 in Example 1. After that, a coverlay film 3 was obtained, and an evaluation sample 3 was obtained. The adhesive strength with the copper foil after curing was 0.70 kN / m. Moreover, the warp of the coverlay film was no problem. In addition, when the rheometer evaluation of the polyimide adhesive film produced like Example 1 using the polyimide solution 3 was performed, the viscosity in 260 degreeC was 35,000 Pa * s.

  Next, the evaluation sample 3 was heat-treated in an oven at 150 ° C. for 1000 hours in the atmosphere. It was 0.39 kN / m when the copper foil after a process and the adhesive strength of a coverlay film were measured. The peeling surface at this time was an interface between copper and the adhesive layer.

  Further, in the same manner as in Example 1, a printed circuit board on which a circuit {wiring width / wiring interval (L / S) = 25 μm / 25 μm} is prepared, and the coverlay film 3 obtained in Example 3 is printed. Placed on the circuit surface of the substrate and thermocompression bonded, a wiring substrate 3 provided with a coverlay film was obtained.

[Example 4]
A cover lay film 4 is obtained after obtaining a polyimide solution 4 in the same manner as in Example 1 except that the polyimide solution b obtained in Synthesis Example 2 is used instead of the polyimide solution a in Example 1. Evaluation sample 4 was obtained. The adhesive strength with the cured copper foil was 0.72 kN / m. Moreover, the warp of the coverlay film was no problem. In addition, when the rheometer evaluation of the polyimide adhesive film produced like Example 1 using the polyimide solution 4 was performed, the viscosity in 260 degreeC was 110,000 Pa.s.

  Next, the evaluation sample 4 was heat-treated in an oven in the atmosphere at 150 ° C. for 1000 hours. It was 0.58 kN / m when the copper foil after a process and the adhesive strength of the coverlay film were measured. The peeling surface at this time was an interface between copper and the adhesive layer.

  Further, similarly to Example 1, a printed circuit board on which a circuit {wiring width / wiring interval (L / S) = 25 μm / 25 μm} is prepared, and the coverlay film 4 obtained in Example 4 is printed. Placed on the circuit surface of the substrate and thermocompression bonded, a wiring substrate 4 provided with a coverlay film was obtained.

[Example 5]
Instead of the polyimide solution a in Example 1, the polyimide solution b obtained in Synthesis Example 2 was used, and instead of blending 5.78 g of N-12, 3.47 g of N-12 ( Except for blending 0.0134 mol), a polyimide solution 5 was obtained in the same manner as in Example 1, and then a coverlay film 5 was obtained and an evaluation sample 5 was obtained. The adhesive strength with the cured copper foil was 0.80 kN / m. Moreover, the warp of the coverlay film was no problem. In addition, when the rheometer evaluation of the polyimide adhesive film produced similarly to Example 1 using the polyimide solution 5 was performed, the viscosity in 260 degreeC was 108,000 Pa.s.

  Next, heat treatment was performed on the evaluation sample 5 in an oven in the air at 150 ° C. for 1000 hours. It was 0.48 kN / m when the copper foil after a process and the adhesive strength of a coverlay film were measured. The peeling surface at this time was an interface between copper and the adhesive layer.

  Further, a printed circuit board on which a circuit {wiring width / wiring interval (L / S) = 25 μm / 25 μm} is prepared in the same manner as in Example 1, and the coverlay film 5 obtained in Example 5 is printed. Placed on the circuit surface of the substrate and thermocompression bonded, a wiring substrate 5 provided with a coverlay film was obtained.

[Example 6]
A polyimide solution 6 was obtained in the same manner as in Example 1 except that 5.78 g of BAPP (0.0141 mol) was added instead of 5.78 g of N-12 in Example 1. After that, a coverlay film 6 was obtained, and an evaluation sample 6 was obtained. The adhesive strength with the cured copper foil was 0.72 kN / m. Moreover, the warp of the coverlay film was no problem. In addition, when the rheometer evaluation of the polyimide adhesive film produced similarly to Example 1 using the polyimide solution 6 was performed, the viscosity in 260 degreeC was 36,000 Pa.s.

  Next, the evaluation sample 6 was heat-treated in the atmosphere at 150 ° C. for 1000 hours in an oven. It was 0.51 kN / m when the copper foil after a process and the adhesive strength of a coverlay film were measured. The peeling surface at this time was an interface between copper and the adhesive layer.

  Further, similarly to Example 1, a printed circuit board on which a circuit {wiring width / wiring interval (L / S) = 25 μm / 25 μm} is prepared, and the coverlay film 6 obtained in Example 6 is printed. Placed on the circuit surface of the substrate and thermocompression bonded, a wiring substrate 6 provided with a coverlay film was obtained.

[Example 7]
A polyimide solution 7 was obtained in the same manner as in Example 1 except that 5.78 g of BAFL (0.0166 mol) was added instead of 5.78 g of N-12 in Example 1. After that, a coverlay film 7 was obtained, and an evaluation sample 7 was obtained. The adhesive strength with the copper foil after curing was 0.65 kN / m. Moreover, the warp of the coverlay film was no problem. In addition, when the rheometer evaluation of the polyimide adhesive film produced similarly to Example 1 using the polyimide solution 7 was performed, the viscosity in 260 degreeC was 28,000 Pa.s.

  Next, the evaluation sample 7 was heat-treated in an oven in the atmosphere at 150 ° C. for 1000 hours. It was 0.41 kN / m when the copper foil after a process and the adhesive strength of a coverlay film were measured. The peeling surface at this time was an interface between copper and the adhesive layer.

  Further, in the same manner as in Example 1, a printed circuit board on which a circuit {wiring width / wiring interval (L / S) = 25 μm / 25 μm} is prepared, and the coverlay film 7 obtained in Example 7 is printed. Placed on the circuit surface of the substrate and thermocompression bonded, a wiring substrate 7 provided with a coverlay film was obtained.

Reference example 2
A polyimide solution was obtained in the same manner as in Example 1 except that the polyimide solution d obtained in Synthesis Example 4 was used instead of the polyimide solution a in Example 1. This polyimide solution is applied to one side of a polyimide film (DuPont, trade name: Kapton ENS, length x width x thickness = 200 mm x 300 mm x 25 µm), dried at 80 ° C for 15 minutes, and the thickness of the adhesive layer A 35 μm coverlay film was obtained. The coverlay film was evaluated in the same manner as in Example 1.

  The results of Examples 1 to 7 and Reference Examples 1 and 2 are summarized in Tables 2 and 3. In Table 2 and Table 3, adhesive strength 1 indicates the adhesive strength between the cured copper foil and coverlay film, and adhesive strength 2 indicates the copper foil and coverlay film after heat treatment in air at 150 ° C. for 1000 hours. The adhesive strength is shown. In addition, the molar ratio in Table 2 and Table 3 means the molar ratio of the sum total of the primary amino group in an amino compound with respect to 1 mol of ketone groups in a polyimidesiloxane.

[Verification of the effect of shortening the time for imine bridge formation by introducing hydrogen bond-forming groups]
The shortening of the imine crosslink formation time of the adhesive resin composition according to the present invention was verified as follows.

[Example 8]
To the polyimide solution a obtained in Synthesis Example 1, 5.78 g of N-12 (0.224 mol) and 11.56 g of K-1 were blended, and further stirred for 1 hour to obtain a polyimide solution 8.

  The obtained polyimide solution 8 was applied to one side of a polyimide film (manufactured by DuPont, trade name: Kapton ENS, length × width × thickness = 200 mm × 300 mm × 25 μm), dried at 80 ° C. for 15 minutes, and adhesive A coverlay film 8 having a layer thickness of 35 μm was obtained. This cover lay film 8 was placed on a copper foil from which the surface rust-proof metal layer was removed, and pressed under the conditions of a temperature of 200 ° C., a pressure of 2 MPa, and a time of 1 hour to obtain an evaluation sample 8. The evaluation results are shown in Table 4.

[Example 9]
After obtaining the polyimide solution 8 like Example 8, the coverlay film 8 was obtained.

  In the same manner as in Example 8, except that heating was performed under the conditions of a temperature of 200 ° C., a pressure of 2 MPa, and a time of 1 hour in Example 8, except that heating was performed under conditions of a temperature of 150 ° C., a pressure of 2 MPa, and a time of 1 hour. Evaluation sample 9 was obtained. The evaluation results are shown in Table 4.

[Example 10]
Similar to Example 8 except that heating was performed under conditions of a temperature of 200 ° C., a pressure of 2 MPa, and a time of 0.5 hours instead of heating under the conditions of a temperature of 200 ° C., a pressure of 2 MPa, and a time of 1 hour in Example 8. Thus, an evaluation sample 10 was obtained. The evaluation results are shown in Table 4.

[Example 11]
Similar to Example 8 except that heating was performed under conditions of a temperature of 160 ° C., a pressure of 2 MPa, and a time of 0.5 hours instead of heating under the conditions of a temperature of 200 ° C., a pressure of 2 MPa, and a time of 1 hour in Example 8. Thus, an evaluation sample 11 was obtained. The evaluation results are shown in Table 4.

[Example 12]
In the same manner as in Example 8, except that heating was performed under the conditions of a temperature of 200 ° C., a pressure of 2 MPa, and a time of 1 hour instead of heating under the conditions of a temperature of 130 ° C., a pressure of 2 MPa, and a time of 1 hour. Evaluation sample 12 was obtained. The evaluation results are shown in Table 4.

  The results of Examples 8 to 12 are summarized in Table 4.

  From Table 4, by introducing a hydrogen bond-forming group into polyimide siloxane, practically sufficient solder heat resistance (particularly moisture solder heat resistance) is obtained by heating at a temperature of 150 ° C. to 200 ° C. for 0.5 to 1 hour. It was confirmed that

[Test Example 1]
The polyimide solution 1 prepared in Example 1 was applied to one side of a substrate and dried at 80 ° C. for 15 minutes to produce a polyimide adhesive film having a thickness of 25 μm. About 10 sheets of this polyimide adhesive film (3 cm × 3 cm) were laminated and thermocompression bonded under the conditions of 70 ° C./0.85 MPa / 10 sec using a vacuum laminator to obtain an evaluation sample A having a thickness of about 250 μm. . On the other hand, the polyimide solution prepared in Reference Example 2 was treated in the same manner to obtain Evaluation Sample B. These samples A and B were subjected to rheometer evaluation. The results are shown in FIG. The viscosity of sample A rapidly increased from around 160 ° C., and the viscosity around 260 ° C. was 118,000 Pa · s. On the other hand, the increase in viscosity of sample B was slower than that of sample A, and the viscosity at around 260 ° C. was 45,000 Pa · s. The difference in the rate of increase in viscosity between these samples A and B is that polyimide siloxane containing -NHCO- groups is different from sample B using polyimide siloxane that does not contain -NHCO- groups that are hydrogen bonding functional groups. It was thought that this was because the cross-linking reaction proceeded more rapidly in the sample A used. Here, in the comparison of solder heat resistance between Example 1 and Reference Example 2 shown in Tables 2 and 3, it can be seen that Example 1 is significantly superior in terms of moisture solder resistance. Moreover, from FIG. 1, the viscosity of the sample A is almost flat at 1 × 10 ⁵ Pa · s or more at 200 ° C. or more. From these facts, the viscosity in the vicinity of 260 ° C. being 1 × 10 ⁵ Pa · s or more is a practically sufficient moisture-resistant solder heat resistance, that is, the ratio of crosslinking to obtain a solder heat resistance temperature of 260 ° C. or more. It was thought that it was effective as a threshold value indicating

[Test Example 2]
The polyimide siloxane used in Example 1 was tested for moisture resistance heat resistance while changing the molecular weight. A coverlay film was prepared in the same manner as in Example 1 except that polyimidesiloxane having a different weight average molecular weight was used, and the moisture-resistant solder heat resistance was evaluated. The evaluation results are shown in Table 5. When a polyimidesiloxane having a weight average molecular weight of about 88,000 to 130,000 was used, the moisture-resistant solder heat resistance was 260 ° C. or higher.

  Next, rheometer evaluation was performed by changing the molecular weight of the polyimidesiloxane used in Example 1, and the behavior of viscosity increase was tested. A polyimide solution was obtained in the same manner as in Example 1 except that polyimidesiloxane having a weight average molecular weight of 130,000 was used. This polyimide solution was applied to one side of the substrate and dried at 80 ° C. for 15 minutes to prepare a polyimide adhesive film having a thickness of 25 μm. About 10 sheets of this polyimide adhesive film (3 cm × 3 cm) were laminated and thermocompression bonded under the conditions of 70 ° C./0.85 MPa / 10 sec using a vacuum laminator to obtain an evaluation sample C having a thickness of about 250 μm. . Sample D was prepared in the same manner as described above from a polyimide solution obtained in the same manner as in Example 1 except that polyimidesiloxane having a weight average molecular weight of 67,000 was used.

The results of rheometer evaluation for these samples C and D are shown in FIG. As shown in FIG. 2, the sample C having a weight average molecular weight of 130,000 has a temperature at which the viscosity starts to increase (curing start temperature) slightly higher than that of the sample D having a weight average molecular weight of 67,000 and exceeds 200 ° C. and whereas the viscosity is almost 1 × 10 5 ^Pa · s or more, the sample D, a low temperature at which the viscosity begins to rise, and was not to exceed 1 × 10 5 ^Pa · s.

  From the results shown in FIG. 2 and Table 2 above, it is necessary to consider the weight average molecular weight of polyimidesiloxane in order to obtain practically sufficient moisture-resistant soldering heat resistance, and in order to express moisture solder resistance at 260 ° C. or higher. It was strongly suggested that an appropriate molecular weight range exists. Furthermore, considering the threshold value obtained in Test Example 1, it was considered that the weight average molecular weight of the polyimidesiloxane is preferably in the range of 70,000 to 140,000. Although the reason why such a molecular weight range is preferable for obtaining practically sufficient moisture-resistant soldering heat resistance has not yet been elucidated, a rational explanation can be made by considering the following. That is, the lower the molecular weight of polyimide siloxane, the higher the crosslinking reactivity, but at an excessively low molecular weight below 70,000, the viscosity at 260 ° C. does not reach the threshold value and the resistance to moisture solder resistance Is considered to decrease. Conversely, if the molecular weight of the polyimide siloxane is higher than 140,000, the mobility of the polyimide molecular chain is lowered and the crosslinking reactivity is lowered. In this case, too, the viscosity at 260 ° C. does not reach the threshold value. Conceivable.

As mentioned above, although embodiment of this invention was described in detail for the purpose of illustration, this invention is not restrict | limited to the said embodiment. For example, in the above embodiment, the polyimide resin of the present invention has been exemplified by adhesives for circuit board coverlay films and bonding sheets such as FPC, but other uses such as tape automated bonding. (TAB), chip size package (CSP) and the like can be used for forming an adhesive resin.

Claims (19)

The following components (A) and (B),
(A) a polyimidesiloxane having —NHCO— as a ketone group and a hydrogen bond-forming group, and
(B) an amino compound having at least two primary amino groups as functional groups,
A cross-linked polyimide resin obtained by reacting
The amino group of the amino compound of the component (B) reacts with at least a part of the ketone group in the polyimide siloxane of the component (A) to form a C═N bond, so that the polyimide siloxane is formed by the amino compound. A crosslinked polyimide resin, characterized by having a crosslinked structure. The following components (A) and (B),
(A) a polyimidesiloxane having a ketone group and a hydrogen bond-forming group, synthesized from a dihydrazide compound as a raw material, and
(B) an amino compound having at least two primary amino groups as functional groups,
A cross-linked polyimide resin obtained by reacting
  The amino group of the amino compound of the component (B) reacts with at least a part of the ketone group in the polyimide siloxane of the component (A) to form a C═N bond, so that the polyimide siloxane is formed by the amino compound. A crosslinked polyimide resin, characterized by having a crosslinked structure. The polyimidesiloxane is a structural unit represented by the following general formulas (1) and (2):

[Wherein Ar is a tetravalent aromatic group derived from an aromatic tetracarboxylic anhydride, R ₁ is a divalent diaminosiloxane residue derived from diaminosiloxane, and R ₂ is derived from a diamine compound. Each represents a divalent diamine residue, and Ar and / or R ₂ contains a ketone group and a hydrogen bond-forming group, m and n represent the molar ratio of each constituent unit, and m is 0.35 to 1 Within the range of 0.0, n is within the range of 0 to 0.65]
The cross-linked polyimide resin according to claim 1, which is a polyimide siloxane having the following. The cross-linked polyimide resin according to claim 3 , wherein the molar ratio m of the structural unit is in the range of 0.75 to 1.0, and n is in the range of 0 to 0.25. The polyimidesiloxane is a structural unit represented by the following general formulas (1) and (2):

[Wherein Ar is a tetravalent aromatic group derived from an aromatic tetracarboxylic anhydride, R ₁ is a divalent diaminosiloxane residue derived from diaminosiloxane, and R ₂ is derived from a diamine compound. Each represents a divalent diamine residue, Ar contains a ketone group, R ₂ contains a hydrogen bond-forming group, m and n represent the molar ratio of each constituent unit, and m is 0.35 or more and 1 Within the range of less than 0, n is in the range of more than 0 and not more than 0.65]
Crosslinked polyimide resin according to claim 1 or 2 is a polyimide siloxane having a.   The cross-linked polyimide resin according to claim 5, wherein the molar ratio m of the structural unit is in the range of 0.75 or more and less than 1.0, and n is in the range of more than 0 and 0.25 or less. The amino compound is crosslinked polyimide resin according to any one of claims 1 to 6, which is a dihydrazide compound. Furthermore, the plate-shaped inorganic filler in the range whose average particle diameter is 2-25 micrometers is contained within the range of 5-200 weight part with respect to a total of 100 weight part of said (A) component and (B) component. Item 8. The crosslinked polyimide resin according to any one of Items 1 to 7 . The following (A) component and (B) component,
(A) Polyimidesiloxane having a weight average molecular weight of 20,000 to 150,000 having —NHCO— as a ketone group and a hydrogen bond-forming group, and (B) amino having at least two primary amino groups as functional groups Compound,
Including
Adhesive resin containing the component (B) such that the total amount of the primary amino groups is within the range of 0.004 mol to 1.5 mol with respect to 1 mol of the ketone group in the component (A). Composition.   The following (A) component and (B) component,
(A) a polyimidesiloxane having a ketone group and a hydrogen bond-forming group and synthesized from a dihydrazide compound as a raw material and having a weight average molecular weight of 20,000 to 150,000, and
(B) an amino compound having at least two primary amino groups as functional groups,
Including
  Adhesive resin containing the component (B) such that the total amount of the primary amino groups is within the range of 0.004 mol to 1.5 mol with respect to 1 mol of the ketone group in the component (A). Composition. The structural unit in which the component (A) is represented by the following general formulas (1) and (2):

[Wherein Ar is a tetravalent aromatic group derived from an aromatic tetracarboxylic anhydride, R ₁ is a divalent diaminosiloxane residue derived from diaminosiloxane, and R ₂ is derived from a diamine compound. Each represents a divalent diamine residue, and Ar and / or R ₂ contains a ketone group and a hydrogen bond-forming group, m and n represent the molar ratio of each constituent unit, and m is 0.35 to 1 Within the range of 0.0, n is within the range of 0 to 0.65]
The adhesive resin composition according to claim 9 , wherein the adhesive resin composition is polyimide siloxane.   The adhesive resin composition according to claim 11, wherein the existence molar ratio m of the structural units is in the range of 0.75 to 1.0, and n is in the range of 0 to 0.25. The structural unit in which the component (A) is represented by the following general formulas (1) and (2):

[Wherein Ar is a tetravalent aromatic group derived from an aromatic tetracarboxylic anhydride, R ₁ is a divalent diaminosiloxane residue derived from diaminosiloxane, and R ₂ is derived from a diamine compound. Each represents a divalent diamine residue, Ar contains a ketone group, R ₂ contains a hydrogen bond-forming group, m and n represent the molar ratio of each constituent unit, and m is 0.35 or more and 1 Within the range of less than 0, n is in the range of more than 0 and not more than 0.65]
The adhesive resin composition according to claim 9 or 10 , which is a polyimidesiloxane containing   14. The adhesive according to claim 13, wherein the molar ratio m of the structural unit is in a range of 0.75 or more and less than 1.0, and n is in a range of more than 0 and 0.25 or less. Resin composition. The adhesive resin composition according to claim 9 , wherein the component (B) is a dihydrazide compound. Component (A) and (B) per 100 parts by weight of the component, further (C) according to claim average particle diameter contains 5 to 200 parts by weight of plate-like inorganic filler in the range of 2 to 25 .mu.m 9 The adhesive resin composition according to any one of -15 . Hardened | cured material obtained by hardening | curing the adhesive agent resin composition of any one of Claims 9-16 . A cover lay film in which an adhesive layer and a cover lay film material layer are laminated,
The coverlay film in which the said adhesive bond layer is formed using the adhesive agent resin composition of any one of Claims 9-16 . The circuit board provided with the base material, the wiring layer formed on this base material, and the coverlay film of Claim 18 which coat | covers this wiring layer.

Images