KR20220136250A - Bond ply, circuit board using this, and strip line - Google Patents

Abstract

Provided is a bond ply capable of achieving both low dielectric loss tangent and dimensional stability. The bond ply includes a first adhesive layer, a polyimide layer, and a second adhesive layer, and satisfies: a) the total thickness of the bond ply is within a range of 50 μm or more and 300 μm or less, and a ratio of the thickness of the polyimide layer to the total thickness of the bond ply is within a range of 0.2 or more and 0.9 or less; b) after drying at 80 ℃ for 1 hour, a moisture absorption rate measured after 24 hours of humidity control at constant temperature and humidity of 23 ℃ and 50 %RH is 0.4 % by weight or less; and c) the storage modulus of the first adhesive layer and the second adhesive layer at 50 ℃ is each independently 1,800 MPa or less, and the maximum value of the storage modulus thereof at 180-260 ℃ is each independently 800 MPa or less. Accordingly, reliability and yield can be improved.

Description

BOND PLY, CIRCUIT BOARD USING THIS, AND STRIP LINE

The present invention relates to a bond ply useful as an electronic component material, a circuit board and a strip line using the same.

Recently, with the progress of miniaturization, weight reduction, and space saving of electronic devices, the demand for flexible printed circuit boards (FPCs) is increasing, which is thin, light, flexible, and has excellent durability even when bending is repeated. Since FPC can be mounted three-dimensionally and at high density even in a limited space, its use is expanding to wiring of movable parts of electronic devices such as HDD, DVD, and smart phone, and parts such as cables and connectors. .

In addition to increasing the density, it is also necessary to cope with the increase in the frequency of the transmission signal due to the progress of higher performance of the equipment. When a high-frequency signal is transmitted, if the transmission loss in the transmission path is large, there are disadvantages such as a loss of an electric signal or a long delay time of the signal. Therefore, as a material of a plurality of resin layers used for FPC, it is proposed to use a polyimide having a low dielectric loss tangent (for example, Patent Documents 1 and 2).

In order to cope with 5G (fifth generation mobile communication system), it is strongly required to suppress transmission loss in the GHz band even for strip lines applied as transmission paths such as RF cables, which are one aspect of FPC. is becoming In order to suppress the transmission loss of the strip line, it is effective to i) achieve a low dielectric loss tangent of the resin material, and ii) increase the thickness of the entire resin layer. Regarding ii), the approach of thickening the thickness of the layer (adhesive resin layer) by the bonding sheet built into the strip line is effective. However, since a resin material that is flexible and has a low glass transition temperature and a large coefficient of thermal expansion is used for the bonding sheet, if the thickness is increased, dimensional stability may decrease. In the step of forming the adhesive resin layer, there is a problem that damage occurs, such as cut out, or that the resin leaks due to heat in the soldering step or the like. Therefore, there is a limit to the approach of thickening the thickness of the bonding sheet.

Japanese Patent Laid-Open No. 2018-170417 Japanese Patent Laid-Open No. 2020-55186

In order to compensate for the above-mentioned drawbacks of the bonding sheet, a bond ply in which a resin layer having relatively high heat resistance is inserted between the adhesive resin layers is used. However, with respect to the resin material used for the bond ply, there have been few studies so far for achieving both low dielectric loss tangent and dimensional stability.

An object of the present invention is, first, to provide a bond ply that can achieve both low dielectric loss tangent and dimensional stability. Second, by using this bond ply, transmission loss of high-frequency signals is small, dimensional stability is excellent, and reliability is high. It is to provide a circuit board such as a high strip line.

As a result of repeated research, the present inventors have used a resin having a low storage modulus as an adhesive resin layer in the bond ply having a structure in which a polyimide layer is inserted between the adhesive resin layers, and the thickness ratio of each layer By considering the moisture absorption rate of the whole, it found that the said subject was solvable, and came to complete this invention.

That is, the bond ply of the present invention is

a polyimide layer;

a first adhesive layer laminated on one side of the polyimide layer;

A second adhesive layer laminated on the opposite side of the polyimide layer to the first adhesive layer

It is a bond ply with

And the bond ply of the present invention,

The following conditions a to c;

a) the total thickness of the bond ply is in the range of 50 μm or more and 300 μm or less, and the ratio of the thickness of the polyimide layer to the thickness of the entire bond ply is in the range of 0.2 or more and 0.9 or less;

b) After drying at 80°C for 1 hour, the moisture absorption measured after 24 hours under constant temperature and humidity at 23°C and 50%RH is 0.4% by weight or less;

c) The storage modulus of the first adhesive layer and the second adhesive layer at 50 ° C. are each independently 1800 MPa or less, and the maximum value of the storage modulus at 180 to 260 ° C. are each independently 800 MPa or less. ;

characterized in that it satisfies

The bond ply of the present invention is further subjected to the following conditions d;

d) Dielectric loss tangent at 10 GHz measured by a split post dielectric resonator (SPDR) of 0.004 or less after 24 hours of humidity control under constant temperature and humidity conditions (normal conditions) of 23°C and 50%RH:

It is good if it satisfies

In the bond ply of the present invention, each of the first adhesive layer and the second adhesive layer may have a glass transition temperature (Tg) of 180° C. or less.

In the bond ply of the present invention, the first adhesive layer and the second adhesive layer contain a polyimide as a resin component, and the polyimide is an acid anhydride residue derived from a tetracarboxylic acid anhydride component and a diamine derived from a diamine component. What is necessary is just to contain a residue, and it may contain 50 mol% or more of diamine residues derived from the dimerdiamine composition which has dimerdiamine as a main component which consists of two terminal carboxylic acid groups of a dimer acid substituted by primary aminomethyl group or an amino group.

In the bond ply of the present invention, the coefficient of thermal expansion of the polyimide layer may be within the range of 1 ppm/K or more and 30 ppm/K or less.

The bond ply of the present invention is, in the polyimide layer, the dielectric at 10 GHz measured by a split post dielectric resonator (SPDR) after 24 hours of humidity control under a constant temperature and humidity condition (normal condition) of 23° C. and 50% RH. The tangent may be 0.006 or less.

In the bond ply of the present invention, the polyimide constituting the polyimide layer may contain a tetracarboxylic acid residue and a diamine residue, and with respect to all the diamine residues, a diamine derived from a diamine compound represented by the following general formula (A1) The content of the residue may be 50 mol% or more.

[In the formula (A1), the linking group Z represents a single bond or -COO-, and Y is independently a monovalent hydrocarbon having 1 to 3 carbon atoms which may be substituted with a halogen atom or a phenyl group, or an alkoxy group having 1 to 3 carbon atoms. , or a C1-C3 perfluoroalkyl group or an alkenyl group, n represents an integer of 0-2, p and q independently represent an integer of 0-4.]

The circuit board of the present invention includes any one of the above-described bond ply.

The strip line of the present invention comprises:

a first metal layer;

a first insulating resin layer comprising a single layer or a plurality of layers laminated on one side of the first metal layer;

a wiring layer formed in contact with the first insulating resin layer;

a second metal layer;

a second insulating resin layer comprising a single layer or a plurality of layers laminated on one side of the second metal layer;

An intermediate resin layer interposed between the first insulating resin layer and the second insulating resin layer and stacked

to provide

The intermediate resin layer is made of any one of the above bond ply and the wiring layer is covered by the first adhesive layer or the second adhesive layer.

Since the bond ply of the present invention achieves both low dielectric loss tangent and dimensional stability, when applied to a circuit board such as a strip line for transmitting high-frequency signals in the GHz band (eg, 1 to 50 GHz) , it is possible to effectively reduce the transmission loss of high-frequency signals and to improve reliability and yield by excellent dimensional stability.

BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic diagram which shows the cross-sectional structure of the bond ply of one Embodiment of this invention.
Fig. 2 is a schematic cross-sectional view showing the configuration of a strip line according to a preferred embodiment of the present invention.

EMBODIMENT OF THE INVENTION Embodiment of this invention is suitably demonstrated with reference to drawings.

[bond fly]

BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic diagram which shows the structure of the cross section of the bond ply which concerns on one Embodiment of this invention.

The bond ply 100 of the present embodiment includes a polyimide layer 10 , a first adhesive layer 20A laminated on one side of the polyimide layer 10 , and a first adhesive agent of the polyimide layer 10 . A second adhesive layer 20B laminated on the opposite side to the layer 20A is provided. That is, the bond ply 100 has a structure in which the first adhesive layer 20A, the polyimide layer 10, and the second adhesive layer 20B are laminated in this order.

The bond ply 100 of the present embodiment satisfies the following conditions a to c.

Condition a) The overall thickness (T1) of the bond ply 100 is within the range of 50 μm or more and 300 μm or less, and the ratio of the thickness (T2) of the polyimide layer (10) to the thickness (T1) of the entire bond ply (100) (T2/T1) is within the range of 0.2 or more and 0.9 or less.

If the overall thickness T1 of the bond ply 100 is less than 50 μm, the overall thickness of the resin layer cannot be thickened when applied to a strip line, so the effect of lowering the transmission loss is insufficient. As such, there is a fear that the required flexibility cannot be guaranteed. From this viewpoint, the thickness T1 of the whole bond ply 100 is more preferably in the range of 50 µm or more and 300 µm or less, and more preferably in the range of 50 µm or more and 150 µm or less.

In addition, when the ratio (T2/T1) of the thickness (T2) of the polyimide layer 10 to the overall thickness (T1) of the bond ply 100 is less than 0.2, dimensional stability is reduced, and when it exceeds 0.9, the first adhesive layer ( 20A) and the second adhesive layer 20B become too thin, and it becomes difficult to ensure the adhesiveness and circuit filling properties required for the bonding sheet. From this viewpoint, the thickness ratio (T2/T1) is preferably in the range of 0.2 to 0.9.

Condition b) After drying at 80° C. for 1 hour, moisture absorption measured after 24 hours of humidity control at 23° C. and 50% RH under constant temperature and humidity is 0.4 wt% or less.

When the moisture absorption exceeds 0.4% by weight, the dielectric loss tangent of the entire bond ply 100 increases, and transmission loss increases when applied to a strip line. From such a viewpoint, it is preferable that the moisture absorption is 0.4 weight% or less. Moreover, the moisture absorption rate of the whole bond ply 100 can be adjusted by each moisture absorption rate and thickness ratio of the polyimide layer 10, the 1st adhesive agent layer 20A, and the 2nd adhesive agent layer 20B.

Condition c) The storage modulus of the first adhesive layer 20A and the second adhesive layer 20B at 50° C. are each independently 1800 MPa or less, and the maximum values of the storage modulus at 180 to 260° C. are each independently with 800 MPa or less.

Since the first adhesive layer 20A and the second adhesive layer 20B have such storage modulus, the internal stress when thermocompression bonding the bond ply 100 is relieved, and dimensional stability after application to the strip line can be maintained. have. When the storage modulus of the first adhesive layer 20A and the second adhesive layer 20B at 50°C exceeds 1800 MPa, dimensional stability is impaired. From such a viewpoint, it is preferable that the storage modulus in 50 degreeC of the 1st adhesive bond layer 20A and the 2nd adhesive bond layer 20B is 1800 MPa or less.

In addition, since the maximum values of the storage modulus of the first adhesive layer 20A and the second adhesive layer 20B in the temperature range of 180°C to 260°C are 800 MPa or less, respectively, even after performing the solder reflow step after circuit processing It is difficult to generate warpage. It is preferable that the maximum value of the storage modulus of the 1st adhesive agent layer 20A and the 2nd adhesive agent layer 20B in the temperature range of 180 degreeC - 260 degreeC is 800 MPa or less, respectively.

It is preferable that the bond ply 100 of this embodiment also satisfy|fills the following condition d.

Condition d) Dielectric loss tangent at 10 GHz measured by a split post dielectric resonator (SPDR) after 24 hours of humidity control under constant temperature and humidity conditions (normal condition) of 23°C and 50%RH is 0.004 or less.

When the dielectric loss tangent at 10 GHz of the entire bond ply 100 exceeds 0.004, when applied to a strip line, loss of an electric signal is likely to occur on a transmission path of a high-frequency signal. From this point of view, it is more preferable that the dielectric loss tangent at 10 GHz of the entire bond ply 100 is 0.003 or less. Moreover, the lower limit of the dielectric loss tangent in 10 GHz of the whole bond ply 100 is not restrict|limited in particular.

It is preferable that the bond ply 100 of this embodiment also satisfy|fills the following condition e.

Condition e) The tensile modulus of elasticity of the polyimide layer 10 is 5.0 GPa or more.

By having the polyimide layer 10 having such a tensile modulus of elasticity, the influence of the coefficient of thermal expansion of the first adhesive layer 20A and the second adhesive layer 20B can be suppressed, and dimensional stability after application to a strip line can be further improved. can In addition, by setting the tensile modulus of elasticity of the polyimide layer 10 within the above range, the thickness ratio of the polyimide layer 10 is relatively small, and the thickness ratio of the first adhesive layer 20A and the second adhesive layer 20B is increased. Since it is possible to do it, it becomes advantageous from a viewpoint of ensuring adhesiveness. The tensile modulus of elasticity of the polyimide layer 10 is more preferably 7.0 GPa or more.

(Polyimide layer)

The polyimide layer 10 is preferably a main component of the resin component, more preferably 70% by weight or more of the resin component, more preferably 90% by weight or more of the resin component, and most preferably all of the resin component. Contains non-thermoplastic polyimide. The main component of the resin component means a component contained in an amount exceeding 50% by weight based on the total resin component. In addition, although "non-thermoplastic polyimide" is a polyimide which generally does not show softening or adhesiveness even when heated, in the present invention, the storage modulus at 30°C measured using a dynamic viscoelasticity measuring device (DMA) is 1.0. It is x10 ⁹ Pa or more, and refers to the polyimide whose storage modulus in 350 degreeC is 1.0 x 10 ⁸ Pa or more. In addition, although "thermoplastic polyimide" is a polyimide whose glass transition temperature (Tg) can be clearly confirmed in general, in the present invention, the storage modulus at 30°C measured using DMA is 1.0×10 ⁹ Pa As mentioned above, the storage modulus in 350 degreeC says the polyimide which is less than 1.0x10< ⁸ >Pa. In the present invention, when referring to polyimide, in addition to polyimide, polyamideimide, polyetherimide, polyesterimide, polysiloxaneimide, polybenzimidazolimide, etc. are composed of a polymer having an imide group in the molecular structure. means resin.

The non-thermoplastic polyimide constituting the polyimide layer 10 contains a tetracarboxylic acid residue and a diamine residue. In the present invention, the tetracarboxylic acid residue represents a tetravalent group derived from tetracarboxylic dianhydride, and the diamine residue represents a divalent group derived from a diamine compound. When the raw material tetracarboxylic dianhydride and the diamine compound are reacted in substantially equimolar amounts, the types and molar ratios of the tetracarboxylic acid residues and diamine residues contained in the polyimide can be substantially matched to the type and molar ratio of the raw material.

(tetracarboxylic acid residue)

The non-thermoplastic polyimide constituting the polyimide layer 10 is 3,3',4,4'-biphenyltetracarboxylic dianhydride (BPDA) and 1,4-phenylenebis(trimelli) as tetracarboxylic acid residues. Triacid monoester) tetracarboxylic acid residues derived from at least one dianhydride (TAHQ), and at least one of pyromellitic dianhydride (PMDA) and 2,3,6,7-naphthalenetetracarboxylic dianhydride (NTCDA) It is preferable to contain a tetracarboxylic acid residue derived from

The tetracarboxylic acid residues derived from BPDA (hereinafter also referred to as “BPDA residues”) and tetracarboxylic acid residues derived from TAHQ (hereinafter also referred to as “TAHQ residues”) tend to form an ordered structure of the polymer, thereby inhibiting molecular motion. This may reduce the dielectric loss tangent or hygroscopicity. The BPDA residue can impart self-supporting properties of the gel film as polyamic acid, which is a polyimide precursor, but on the other hand, it increases the CTE after imidization and lowers the glass transition temperature. It tends to reduce heat resistance. From this point of view, the non-thermoplastic polyimide constituting the polyimide layer 10 is preferably within the range of 20 mol% or more and 60 mol% or less of the total of BPDA residues and TAHQ residues with respect to all tetracarboxylic acid residues, more preferably It is preferable to control so that it is contained within the range of 40 mol% or more and 50 mol% or less. If the total of the BPDA residues and TAHQ residues is less than 20 mol%, the formation of an ordered structure of the polymer becomes insufficient, the hygroscopic resistance decreases or the decrease in dielectric loss tangent becomes insufficient. In addition to the increase in the amount of change of RO), there is a possibility that the heat resistance may decrease.

In addition, a tetracarboxylic acid residue derived from pyromellitic dianhydride (hereinafter also referred to as “PMDA residue”) and a tetracarboxylic acid residue derived from 2,3,6,7-naphthalenetetracarboxylic dianhydride (hereinafter also referred to as “NTCDA residue”) ) is a residue responsible for controlling in-plane retardation (RO) and controlling glass transition temperature while suppressing low CTE by increasing in-plane orientation because it has rigidity. On the other hand, since the molecular weight of PMDA residues is small, if the amount thereof is excessively large, the imide group concentration of the polymer increases, polar groups increase, and hygroscopicity increases, and the dielectric loss tangent increases under the influence of moisture in the molecular chain. Moreover, the NTCDA residue tends to make a film brittle by a naphthalene skeleton with high rigidity, and there exists a tendency for an elasticity modulus to increase. Therefore, in the non-thermoplastic polyimide constituting the polyimide layer 10, the total of PMDA residues and NTCDA residues with respect to all tetracarboxylic acid residues is preferably within the range of 40 mol% or more and 80 mol% or less, more preferably It is preferable to contain it within the range of 50 mol% or more and 60 mol% or less, and more preferably within the range of 50-55 mol%. When the total of PMDA residues and NTCDA residues is less than 40 mol%, there is a risk that CTE increases or heat resistance may decrease. There is a fear that the tangent increases or the film becomes brittle and the self-supporting property of the film may decrease.

Moreover, it is good that the sum of at least 1 type of BPDA residue and TAHQ residue, and at least 1 type of PMDA residue and NTCDA residue is 80 mol% or more with respect to all the tetracarboxylic-acid residues, Preferably it is 90 mol% or more.

Examples of tetracarboxylic acid residues other than the BPDA residue, TAHQ residue, PMDA residue, and NTCDA residue contained in the non-thermoplastic polyimide constituting the polyimide layer 10 include 3,3',4,4'-di Phenylsulfone tetracarboxylic dianhydride, 4,4'-oxydiphthalic anhydride, 2,3',3,4'-biphenyltetracarboxylic dianhydride, 2,2',3,3'-, 2,3,3 ',4'- or 3,3',4,4'-benzophenonetetracarboxylic dianhydride, 2,3',3,4'-diphenyl ether tetracarboxylic dianhydride, bis(2,3-dicarboxyphenyl ) ether dianhydride, 3,3'',4,4''-, 2,3,3'',4''- or 2,2'',3,3''-p-terphenyltetracarboxylic dianhydride , 2,2-bis(2,3- or 3,4-dicarboxyphenyl)-propanedianhydride, bis(2,3- or 3,4-dicarboxyphenyl)methandianhydride, bis(2,3- or 3,4-dicarboxyphenyl)sulfondianhydride, 1,1-bis(2,3- or 3,4-dicarboxyphenyl)ethanedianhydride, 1,2,7,8-, 1,2,6 ,7- or 1,2,9,10-phenanthrene-tetracarboxylic dianhydride, 2,3,6,7-anthracenetetracarboxylic dianhydride, 2,2-bis(3,4-dicarboxyphenyl)tetrafluoro Ropropane dianhydride, 2,3,5,6-cyclohexane dianhydride, 1,2,5,6-naphthalenetetracarboxylic dianhydride, 1,4,5,8-naphthalenetetracarboxylic dianhydride, 4,8- Dimethyl-1,2,3,5,6,7-hexahydronaphthalene-1,2,5,6-tetracarboxylic dianhydride, 2,6- or 2,7-dichloronaphthalene-1,4,5,8 -tetracarboxylic dianhydride, 2,3,6,7- (or 1,4,5,8-) tetrachloronaphthalene-1,4,5,8- (or 2,3,6,7-) tetracarboxylic acid dianhydride, 2,3,8,9-, 3,4,9,10-, 4,5,10,11- or 5,6,11,12-perylene-tetracarboxylic dianhydride, cyclopentane-1 ,2,3,4-tetracarboxylic dianhydride, pyrazine-2,3,5,6-tetracarboxylic dianhydride, pyrrolidine-2,3,4, 5-tetracarboxylic dianhydride, thiophene-2,3,4,5-tetracarboxylic dianhydride, 4,4'-bis(2,3-dicarboxyphenoxy)diphenylmethane dianhydride, ethylene glycol bisanhydro and tetracarboxylic acid residues derived from aromatic tetracarboxylic dianhydrides such as trimellitate.

(diamine residues)

As a diamine residue contained in the non-thermoplastic polyimide which comprises the polyimide layer 10, the diamine residue derived from the diamine compound represented by General formula (A1) is preferable.

In the formula (A1), the linking group Z represents a single bond or -COO-, and Y is independently a monovalent hydrocarbon having 1 to 3 carbon atoms which may be substituted with a halogen atom or a phenyl group, or a monovalent hydrocarbon having 1 to 3 carbon atoms. represents an alkoxy group, a C1-C3 perfluoroalkyl group, or an alkenyl group, n represents an integer of 0-2, p and q independently represent an integer of 0-4. Here, "independently" means that a plurality of substituents Y and integers p and q in the formula (A1) may be the same or different. Further, in the formula (A1), the hydrogen atoms in the two amino groups at the terminals may be substituted, for example, -NR ₂ R ₃ (wherein R ₂ and R ₃ are independently arbitrary substituents such as an alkyl group) means) may be

The diamine compound represented by the general formula (A1) (hereinafter, may be described as "diamine (A1)") is an aromatic diamine having 1 to 3 benzene rings. Since the diamine (A1) has a rigid structure, it is acting to impart an ordered structure to the entire polymer. Therefore, a polyimide having low gas permeability and low hygroscopicity can be obtained, and since moisture in the molecular chain can be reduced, the dielectric loss tangent can be lowered. Here, as the linking group Z, a single bond is preferable.

Examples of the diamine (A1) include 1,4-diaminobenzene (p-PDA; paraphenylenediamine), 2,2'-dimethyl-4,4'-diaminobiphenyl (m-TB), 2 and 2'-n-propyl-4,4'-diaminobiphenyl (m-NPB) and 4-aminophenyl-4'-aminobenzoate (APAB). Among these, 2,2'-dimethyl-4,4'-diaminobiphenyl (m-TB) is the most preferable.

The non-thermoplastic polyimide constituting the polyimide layer 10 contains the diamine residues derived from the diamine (A1) with respect to the total diamine residues, preferably 50 mol% or more, more preferably 80 mol% or more, further Preferably, it is good to contain 85 mol% or more. By using the diamine (A1) in an amount within the above range, an ordered structure is easily formed throughout the polymer due to the rigid structure derived from the monomer, and a non-thermoplastic polyimide having low gas permeability, low hygroscopicity and low dielectric loss tangent can be obtained. easy. From this point of view, it is most preferable to contain the residues derived from 2,2'-dimethyl-4,4'-diaminobiphenyl (m-TB) within the range of 90 to 100 mol% with respect to the total diamine residues. .

The other diamine residues contained in the non-thermoplastic polyimide constituting the polyimide layer 10 are not particularly limited as long as they are residues derived from the diamine compound used as a raw material of the polyimide. For example, 1,3-bis ( 4-Aminophenoxy)benzene (TPE-R), 1,3-bis(3-aminophenoxy)benzene (APB), 4,4'-[2-methyl-(1,3-phenylene)bisoxy ]bisaniline, 4,4'-[4-methyl-(1,3-phenylene)bisoxy]bisaniline, 4,4'-[5-methyl-(1,3-phenylene)bisoxy]bis Aniline, 2,2-bis-[4-(3-aminophenoxy)phenyl]propane, bis[4-(3-aminophenoxy)phenyl]sulfone, bis[4-(3-aminophenoxy)]bi Phenyl, bis[1-(3-aminophenoxy)]biphenyl, bis[4-(3-aminophenoxy)phenyl]methane, bis[4-(3-aminophenoxy)phenyl]ether, bis[4 -(3-aminophenoxy)]benzophenone, 9,9-bis[4-(3-aminophenoxy)phenyl]fluorene, 2,2-bis-[4-(4-aminophenoxy)phenyl] Hexafluoropropane, 2,2-bis-[4-(3-aminophenoxy)phenyl]hexafluoropropane, 3,3'-dimethyl-4,4'-diaminobiphenyl, 4,4'- Methylenedi-o-toluidine, 4,4'-methylenedi-2,6-xylidine, 4,4'-methylene-2,6-diethylaniline, 3,3'-diaminodiphenylethane, 3 , 3'-diaminobiphenyl, 3,3'-dimethoxybenzidine, 3,3''-diamino-p-terphenyl, 4,4'-[1,4-phenylenebis (1-methyl to thylidene)]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-aminophen) tyl)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-diamine, m-xylylenediamine, p-xylylenedia Min, 2,6-diaminopyridine, 2,5-diaminopyridine, 2,5-diamino-1,3,4-oxadiazole, piperazine, 2'-methoxy-4,4'-dia Minobenzanilide, 4,4'-diaminobenzanilide, 1,3-bis[2-(4-aminophenyl)-2-propyl]benzene, 6-amino-2-(4-aminophenoxy)benzoxa Diamine residues derived from aromatic diamine compounds such as sol, diamine residues derived from aliphatic diamine compounds such as dimer acid-type diamine in which two terminal carboxylic acid groups of dimer acid are substituted with primary aminomethyl groups or amino groups.

In the non-thermoplastic polyimide, the thermal expansion coefficient, storage modulus of elasticity, tensile modulus of elasticity, etc. can be controlled by selecting the types of the tetracarboxylic acid residues and diamine residues, or the molar ratios in the case of applying two or more types of tetracarboxylic acid residues or diamine residues. can Moreover, nonthermoplastic polyimide WHEREIN: When providing two or more structural units of polyimide, it may exist as a block and may exist at random, but it is preferable to exist randomly.

When both the tetracarboxylic acid residue and the diamine residue contained in the non-thermoplastic polyimide are aromatic groups, it is preferable because the dimensional accuracy of the polyimide film can be improved in a high-temperature environment.

(Synthesis of polyimide)

The non-thermoplastic polyimide can be produced by reacting the acid anhydride and diamine in a solvent to produce a precursor resin, followed by heating and ring closure. For example, by dissolving an acid anhydride component and a diamine component in an organic solvent in approximately equimolar amounts, stirring at a temperature within the range of 0 to 100° C. for 30 minutes to 24 hours, followed by polymerization to obtain polyamic acid, a precursor of polyimide lose In the reaction, the reactant components are dissolved in the organic solvent so that the resulting precursor is in the range of 5 to 30% by weight, preferably in the range of 10 to 20% by weight. Examples of the organic solvent used in the polymerization reaction include N,N-dimethylformamide, N,N-dimethylacetamide (DMAc), N-methyl-2-pyrrolidone, 2-butanone, dimethylsulfoxide, Dimethyl sulfate, cyclohexanone, dioxane, tetrahydrofuran, diglyme, triglyme, etc. are mentioned. Two or more of these solvents can be used in combination, and also can be used in combination with an aromatic hydrocarbon such as xylene or toluene. In addition, the amount of the organic solvent used is not particularly limited, but it is preferable to adjust the amount so that the concentration of the polyamic acid solution (polyimide precursor solution) obtained by the polymerization reaction is about 5 to 30% by weight.

In the synthesis|combination of a polyimide, the said acid anhydride and diamine may use only 1 type, respectively, and may use 2 or more types together. Dielectric properties, thermal expansibility, glass transition temperature, etc. can be controlled by selecting the types of acid anhydrides and diamines or molar ratios of two or more types of acid anhydrides or diamines.

The synthesized precursor is usually advantageously used as a reaction solvent, but may be concentrated, diluted, or substituted with another organic solvent if necessary. In addition, the precursor is generally used advantageously because it has excellent solvent solubility. The method for imidizing the precursor is not particularly limited, and for example, a heat treatment in which the precursor is heated in the solvent at a temperature within the range of 80 to 400° C. over 1 to 24 hours is preferably employed.

It is preferable that it is 37 weight% or less, and, as for the imide group density|concentration of a non-thermoplastic polyimide, it is more preferable that it is 33 weight% or less, It is more preferable that it is 32 weight% or less. Here, "imide group concentration" means the value obtained by dividing the molecular weight of the imide group moiety (-(CO) ₂ -N-) in the polyimide by the molecular weight of the entire structure of the polyimide. When the imide group concentration exceeds 37% by weight, the molecular weight of the resin itself decreases and the low hygroscopicity also deteriorates due to an increase in polar groups. By selecting the combination of the acid anhydride and the diamine compound, the molecular orientation in the non-thermoplastic polyimide is controlled, thereby suppressing an increase in CTE accompanying a decrease in the imide group concentration and ensuring low hygroscopicity.

The weight average molecular weight of the non-thermoplastic polyimide is, for example, preferably in the range of 10,000 to 400,000, more preferably in the range of 50,000 to 350,000. When the weight average molecular weight is less than 10,000, the strength of the bond ply 100 tends to decrease. On the other hand, when the weight average molecular weight exceeds 400,000, the viscosity is excessively increased, and defects such as unevenness of film thickness and streaks tend to occur during coating operation.

The thickness of the polyimide layer 10, as a base layer in the bond ply 100, guarantees functions such as insulation and mechanical strength maintenance, and has transportability when manufacturing the bond ply 100. From the viewpoint of When the thickness of the polyimide layer 10 is less than the above lower limit, electrical insulation and handling properties become insufficient, and when the thickness exceeds the upper limit, productivity decreases.

From the viewpoint of heat resistance, the polyimide layer 10 preferably has a glass transition temperature (Tg) of 280°C or higher. When the glass transition temperature (Tg) of the polyimide layer 10 is 280° C. or higher, dimensional stability can be maintained during heating in a soldering process or the like.

The coefficient of thermal expansion of the polyimide layer 10 is preferably within the range of 1 ppm/K or more and 30 ppm/K or less, more preferably 1 ppm from the viewpoint of improving the dimensional stability of the bond ply 100 and suppressing warpage. It is good to be in the range of /K or more and 25 ppm/K or less, and more preferably, it is in the range of 15 ppm/K or more and 25 ppm/K or less.

The polyimide layer 10 preferably has a dielectric loss tangent of 0.006 or less at 10 GHz as measured by a split post dielectric resonator (SPDR) after 24 hours of humidity control under a constant temperature and humidity condition (normal condition) of 23° C. and 50% RH. do. When the polyimide layer 10 has a dielectric loss tangent at 10 GHz of 0.006 or less, it is possible to lower the dielectric loss tangent of the entire bond ply 100 . When the dielectric loss tangent at 10 GHz of the polyimide layer 10 exceeds 0.006, it becomes difficult to suppress the dielectric loss tangent of the entire bond ply 100 low.

In the polyimide layer 10, as an optional component, for example, a plasticizer, another cured resin component such as an epoxy resin, a curing agent, a curing accelerator, a coupling agent, a filler, a flame retardant, etc. can be appropriately blended.

(1st adhesive layer, 2nd adhesive layer)

The material of the first adhesive layer 20A and the second adhesive layer 20B is not particularly limited as long as the condition c is satisfied, and they may each independently be composed of a thermoplastic resin or a thermosetting resin. Examples of such resins include polyimide resins, polyamide resins, epoxy resins, phenoxy resins, acrylic resins, polyurethane resins, styrene resins, polyester resins (including liquid crystalline polyester resins), phenol resins, and polysulfone resins. Resin, polyether sulfone resin, polyphenylene sulfide resin, polyethylene resin, polypropylene resin, silicone resin, polyether ketone resin, polyvinyl alcohol resin, polyvinyl butyral resin, styrene-maleimide copolymer, maleimide-vinyl Resin, such as a compound copolymer or a (meth)acrylic copolymer, benzoxazine resin, bismaleimide resin, and cyanate ester resin, is mentioned. It can be used as the 1st adhesive agent layer 20A and the 2nd adhesive agent layer 20B by selecting the thing which satisfies the condition c from among these, or designing so that it may satisfy the condition c. When the first adhesive layer 20A and the second adhesive layer 20B are thermosetting resins, an organic peroxide, a curing agent, a curing accelerator, etc. may be contained, and if necessary, a curing agent and a curing accelerator, or a catalyst and a cocatalyst You may use it together. Within the range that can satisfy condition c, the amount of the curing agent, the curing accelerator, the catalyst, the co-catalyst and the organic peroxide added and the presence or absence of the addition may be determined.

As the resin constituting the first adhesive layer 20A and the second adhesive layer 20B, a resin containing polyimide as a main component of the resin component is preferable, more preferably 70% by weight or more of the resin component, still more preferably Preferably, it is preferable to contain polyimide as 90% by weight or more of the resin component, and most preferably as the whole of the resin component. In addition, the main component of the resin component means a component contained in excess of 50% by weight with respect to the total resin component. As a preferable polyimide used for the formation of the first adhesive layer 20A and the second adhesive layer 20B while satisfying the condition c, an acid anhydride residue derived from a tetracarboxylic acid anhydride component and a diamine residue derived from a diamine component Containing 50 mol% or more of diamine residues derived from a dimer diamine composition containing as a main component dimer diamine in which two terminal carboxylic acid groups of dimer acid are substituted with primary aminomethyl groups or amino groups with respect to the total diamine residues Polyimide (hereinafter, sometimes referred to as "adhesive polyimide") is preferable. In other words, the adhesive polyimide is a raw material containing 50 mol% or more of a dimer diamine composition mainly containing dimer diamine in which two terminal carboxylic acid groups of dimer acid are substituted with primary aminomethyl groups or amino groups with respect to the total diamine component. is obtained by using With respect to the total diamine residues, the content of the diamine residues derived from the dimer diamine composition is preferably 50 mol% or more, more preferably 70 mol% or more, and still more preferably 80 to 99 mol%, so that condition c In addition to satisfying the , the relative permittivity and dielectric loss tangent can be reduced. That is, by containing the diamine residue derived from the dimerdiamine composition in the above amount, the improvement of thermocompression bonding properties by lowering the glass transition temperature (lower Tg) of the polyimide and the relaxation of internal stress by lowering the modulus of elasticity becomes possible Further, when the content of the diamine residue derived from the dimerdiamine composition is less than 50 mol%, the relative permittivity and dielectric loss tangent are likely to rise because the polar groups contained in the polyimide relatively increase.

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

(a) dimerdiamine;

(a) The dimer diamine of component means the diamine formed by replacing two terminal carboxylic acid groups (-COOH) of a dimer acid with a primary aminomethyl group (-CH ₂ -NH ₂ ) or an amino group (-NH ₂ ). Dimer acid is a known dibasic acid obtained by intermolecular polymerization of unsaturated fatty acids, and its industrial production process is almost standardized in the industry. lose The industrially obtained dimer acid is mainly composed of a dibasic acid having 36 carbon atoms obtained by dimerizing an unsaturated fatty acid having 18 carbon atoms, such as oleic acid, linoleic acid, and linolenic acid. Polymeric fatty acids other than acid (C54) and C20-54 are contained. Although double bonds remain after the dimerization reaction, in the present invention, the dimer acid also includes those whose unsaturation is reduced by hydrogenation reaction. The dimer diamine of component (a) is defined as a diamine compound obtained by substituting a primary aminomethyl group or an amino group for the terminal carboxylic acid group of a dibasic acid compound having 18 to 54 carbon atoms, preferably 22 to 44 carbon atoms. can

As a characteristic of dimerdiamine, the characteristic derived from the backbone of a dimer acid can be provided. That is, since dimerdiamine is an aliphatic macromolecule having a molecular weight of about 560 to 620, the polar group of the polyimide can be relatively reduced by increasing the molar volume of the molecule. The characteristics of such dimer acid type diamine are considered to contribute to improving dielectric properties by reducing the relative permittivity and dielectric loss tangent while suppressing a decrease in the heat resistance of the polyimide. In addition, since it has two freely moving minor chains having 7 to 9 carbon atoms and two chain aliphatic amino groups having a length close to 18 carbon atoms, it not only gives flexibility to the polyimide but also makes the polyimide asymmetrical. It can be set as a chemical structure or a non-planar chemical structure, and it is thought that low dielectric constant of a polyimide can be aimed at.

As the dimer diamine composition, the dimer diamine content of component (a) is increased to 96% by weight or more, preferably 97% by weight or more, more preferably 98% by weight or more by a purification method such as molecular distillation. . (a) Dimerdiamine content of a component shall be 96 weight% or more, and the diffusion of molecular weight distribution of a polyimide can be suppressed. In addition, if technically possible, it is best that all (100% by weight) of the dimerdiamine composition is composed of the dimerdiamine of component (a).

(b) a monoamine compound obtained by substituting a terminal carboxylic acid group of a monobasic acid compound having 10 to 40 carbon atoms with a primary aminomethyl group or an amino group;

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

(b) The monoamine compound of a component is a component which suppresses the molecular weight increase of a polyimide. During polymerization of polyamic acid or polyimide, the monofunctional amino group of the monoamine compound reacts with the terminal acid anhydride group of the polyamic acid or polyimide to seal the terminal acid anhydride group, increasing the molecular weight of the polyamic acid or polyimide suppress

(c) an amine compound obtained by substituting a terminal carboxylic acid group of a polybasic acid compound having a hydrocarbon group within the range of 41 to 80 carbon atoms with a primary aminomethyl group or an amino group (provided that the dimerdiamine is excluded);

The polybasic acid compound having a hydrocarbon group in the range of 41 to 80 carbon atoms is a polybasic acid compound mainly comprising a tribasic acid compound in the range of 41 to 80 carbon atoms, which is a by-product in the production of dimer acid. Moreover, you may contain polymeric fatty acids other than a C41-C80 dimer acid. The amine compound is obtained by substituting a terminal carboxylic acid group of these polybasic acid compounds with a primary aminomethyl group or an amino group.

(c) The amine compound of a component is a component which promotes the molecular weight increase of a polyimide. A trifunctional or higher amino group containing a triamine derived from trimer acid as a main component reacts with a terminal acid anhydride group of a polyamic acid or polyimide to rapidly increase the molecular weight of the polyimide. In addition, amine compounds derived from polymerized fatty acids other than dimer acids having 41 to 80 carbon atoms also increase the molecular weight of the polyimide, causing gelation of the polyamic acid or polyimide.

When each component is quantified by measurement using gel permeation chromatography (GPC), in order to facilitate identification of the peak start, peak top and peak end of each component of the dimerdiamine composition, the dimerdiamine composition is dried A sample treated with acetic acid and pyridine is used, and cyclohexanone is used as an internal standard. Using the thus prepared sample, each component is quantified by area percent of the chromatogram of GPC. The peak start and peak end of each component are taken as the minimum value of each peak curve, and the area percent of the chromatogram can be calculated based on this.

Further, in the dimerdiamine composition, the sum of the components (b) and (c) is 4% or less, preferably less than 4%, in the area percent of the chromatogram obtained by GPC measurement. Diffusion of molecular weight distribution of a polyimide can be suppressed by making the sum total of components (b) and (c) 4 % or less.

Moreover, as for the area percent of the chromatogram of (b) component, Preferably it is 3 % or less, More preferably, it is 2 % or less, More preferably, 1 % or less is good. By setting it as such a range, the fall of the molecular weight of a polyimide can be suppressed and the range of the molar ratio of preparation of a tetracarboxylic anhydride component and a diamine component can be expanded. Moreover, (b) component does not need to be contained in the dimer diamine composition.

Moreover, the area percent of the chromatogram of (c) component is 2 % or less, Preferably it is 1.8 % or less, More preferably, 1.5 % or less is good. By setting it as such a range, the rapid increase of the molecular weight of a polyimide can be suppressed and also the raise of the dielectric loss tangent in the frequency range of a resin film can be suppressed. Moreover, (c) component does not need to be contained in the dimer diamine composition.

Further, when the ratio (b/c) of the area percent of the chromatograms of the components (b) and (c) is 1 or more, the molar ratio of the tetracarboxylic acid anhydride component and the diamine component (tetracarboxylic acid anhydride component/diamine component) is preferably It is good to set it as 0.97 or more and less than 1.0, and control of the molecular weight of a polyimide becomes easier by setting it as such a molar ratio.

Further, when the ratio (b/c) of the area percent in the chromatogram of the components (b) and (c) is less than 1, the molar ratio of the tetracarboxylic anhydride component and the diamine component (tetracarboxylic acid anhydride component/diamine component) is preferably Preferably, it is good to set it as 0.97 or more and 1.1 or less, and control of the molecular weight of a polyimide becomes easier by setting it as such a molar ratio.

The dimerdiamine composition can use a commercial item, and it is preferable to refine|purify for the purpose of reducing components other than dimerdiamine of (a) component, For example, it is preferable to make (a) component 96 area% or more. . Although it does not restrict|limit especially as a purification method, Well-known methods, such as a distillation method and precipitation purification, are preferable. As a commercial item of a dimerdiamine composition, Croda Japan (Croda Japan) PRIAMINE 1073 (brand name), the same PRIAMINE 1074 (brand name), the same PRIAMINE 1075 (brand name), etc. are mentioned, for example. .

Synthesis of the adhesive polyimide can be carried out according to the method described for the non-thermoplastic polyimide.

When the adhesive polyimide has a ketone group in its molecule, it is an amino compound having the ketone group and at least two primary amino groups as functional groups (hereinafter referred to as “amino compound for crosslinking” in some cases). ), by reacting the amino group to form a C=N bond, a crosslinked structure can be formed. A polyimide having such a crosslinked structure (hereinafter, may be referred to as "crosslinked polyimide") is an application example of an adhesive polyimide and is a preferred form. By forming a cross-linked structure, the heat resistance of the adhesive polyimide can be improved. As a preferable tetracarboxylic dianhydride for forming an adhesive polyimide having a ketone group, for example, 3,3',4,4'-benzophenonetetracarboxylic dianhydride (BTDA), and as a diamine compound, for example, and aromatic diamines such as 4,4'-bis(3-aminophenoxy)benzophenone (BABP) and 1,3-bis[4-(3-aminophenoxy)benzoyl]benzene (BABB). For the purpose of forming a crosslinked structure, in particular, the above-described adhesive polyimide containing BTDA residues derived from BTDA, preferably 50 mol% or more, more preferably 60 mol% or more, based on the total tetracarboxylic acid residues. In contrast, it is preferable to act with an amino compound for crosslinking. In the present invention, "BTDA residue" means a tetravalent group derived from BTDA.

Examples of the amino compound for crosslinking include (I) dihydrazide compounds, (II) aromatic diamines, (III) aliphatic amines, and the like. Among these, a dihydrazide compound is preferable. Aliphatic amines other than the dihydrazide compound easily form a crosslinked structure even at room temperature, and there is a concern about storage stability of the varnish. When the dihydrazide compound is used in this way, it is possible to achieve both storage stability of the varnish and shortening of the curing time. As the dihydrazide compound, for example, oxalic acid dihydrazide, malonic acid dihydrazide, succinic acid dihydrazide, glutaric acid dihydrazide, adipic acid dihydrazide, pimelic acid dihydrazide, suberic acid dihydrazide, and azelaic acid dihydrazide. hydrazide, sebacic acid dihydrazide, dodecane diacid dihydrazide, maleic acid dihydrazide, fumaric acid dihydrazide, diglycolic acid dihydrazide, tartrate dihydrazide, malic acid dihydrazide, phthalic acid dihydrazide, isophthalic acid dihydrazide hydrazide, terephthalic acid dihydrazide, 2,6-naphthoic acid dihydrazide, 4,4-bisbenzene dihydrazide, 1,4-naphthoeic acid dihydrazide, 2,6-pyridine diacid dihydrazide, Dihydrazide compounds, such as itaconic acid dihydrazide, are preferable. The above dihydrazide compounds may be used independently and may be used in mixture of 2 or more types.

In addition, amino compounds such as (I) dihydrazide compound, (II) aromatic diamine, and (III) aliphatic amine are, for example, a combination of (I) and (II), and a combination of (I) and (III). , like a combination of (I) and (II) and (III), it can also be used in combination of two or more types beyond categories.

In addition, from the viewpoint of making the structure of the network formed by crosslinking with the amino compound for crosslinking more dense, the amino compound for crosslinking used in the present invention has a molecular weight (amino for crosslinking) When the compound is an oligomer, the weight average molecular weight) is preferably 5,000 or less, more preferably 90 to 2,000, still more preferably 100 to 1,500. Among these, amino compounds for crosslinking having a molecular weight of 100 to 1,000 are particularly preferable. When the molecular weight of the amino compound for crosslinking is less than 90, one amino group of the amino compound for crosslinking only forms a C=N bond with the ketone group of the adhesive polyimide, and the periphery of the remaining amino group becomes sterically bulky. Since it becomes large, the remaining amino group tends to be difficult to form a C=N bond.

When the ketone group in the adhesive polyimide is crosslinked with the amino compound for crosslinking, the amino compound for crosslinking is added to the resin solution containing the adhesive polyimide, and the ketone group in the adhesive polyimide is crosslinked with the amino compound for crosslinking. Condensation reaction of the primary amino group of By this condensation reaction, the resin solution hardens and becomes a cured product. In this case, the addition amount of the amino compound for crosslinking is 0.004 to 1.5 moles, preferably 0.005 to 1.2 moles, more preferably 0.03 to 0.9 moles of primary amino groups in total with respect to 1 mole of the ketone group. mole, most preferably 0.04 mole to 0.6 mole. When the amount of the amino compound for crosslinking is added so that the total of the primary amino groups is less than 0.004 moles per mole of the ketone group, the crosslinking by the amino compound for crosslinking is insufficient, so that heat resistance after curing is difficult to develop. When the amount of the amino compound for crosslinking exceeds 1.5 mol, the unreacted amino compound for crosslinking acts as a thermoplastic and tends to decrease the heat resistance as an adhesive layer.

The conditions of the condensation reaction for crosslinking are not particularly limited as long as the ketone group in the adhesive polyimide reacts with the primary amino group of the amino compound for crosslinking to form an imine bond (C=N bond). does not The temperature of heat condensation is set to simplify the condensation process in order to release water generated by condensation to the outside, or in the case of continuously carrying out heat condensation reaction after synthesis of the adhesive polyimide. For this reason, for example, in the range of 120-220 degreeC is preferable, and the inside of the range of 140-200 degreeC is more preferable. The reaction time is preferably about 30 minutes to 24 hours. The end point of the reaction is, for example, by measuring an infrared absorption spectrum using a Fourier transform infrared spectrophotometer (commercial product: FT/IR620 manufactured by JASCO Corporation), a ketone group in the polyimide resin in the vicinity of 1670 cm ^-1 . It can be confirmed by the decrease or disappearance of the absorption peak derived from , and the appearance of the absorption peak derived from the imine group in the vicinity of 1635 cm ^-1 .

Heat condensation between the ketone group of the adhesive polyimide and the primary amino group of the amino compound for crosslinking is, for example,

(1) A method of heating by adding an amino compound for crosslinking after synthesis (imidization) of the adhesive polyimide;

(2) Put an excess amount of amino compound as a diamine component in advance and use the remaining amino compound not involved in imidation or amidation as an amino compound for crosslinking following synthesis (imidization) of the adhesive polyimide. heating with adhesive polyimide, or

(3) A method of heating the adhesive polyimide composition to which the amino compound for crosslinking has been added after processing it into a predetermined shape (for example, after coating on an arbitrary substrate or after forming into a film shape)

etc. can be carried out.

In order to impart heat resistance to the adhesive polyimide, an example of a crosslinked polyimide having a crosslinked structure by the formation of an imine bond was given and described, but it is not limited thereto. A compound having an unsaturated bond such as a resin curing agent, maleimide, an activated ester resin, or a resin having a styrene skeleton may be blended and cured.

Each of the first adhesive layer 20A and the second adhesive layer 20B has a glass transition temperature (Tg) of 180° C. or less, preferably 160° C. or less. By setting the Tg of the first adhesive layer 20A and the second adhesive layer 20B to 180° C. or less, thermocompression bonding at low temperature is possible, so internal stress generated during lamination is relieved and dimensional change after circuit processing is reduced. can be suppressed When the Tg of the first adhesive layer 20A and the second adhesive layer 20B exceeds 180° C., the temperature at the time of bonding by inserting between the insulating resin layers for application to the strip line increases, and the dimensional stability of the strip line may be damaged.

The first adhesive layer 20A and the second adhesive layer 20B were heated to 10 GHz measured by a split post dielectric resonator (SPDR) after 24 hours of humidity control under constant temperature and humidity conditions (normal conditions) of 23° C. and 50% RH. It is preferable that the dielectric loss tangent in this is 0.004 or less. When the dielectric loss tangent of the first adhesive layer 20A and the second adhesive layer 20B at 10 GHz is 0.004 or less, it is possible to lower the dielectric loss tangent of the entire bond ply 100 . When the dielectric loss tangent at 10 GHz of the polyimide layer 10 exceeds 0.004, it becomes difficult to suppress the dielectric loss tangent of the entire bond ply 100 low.

In the first adhesive layer 20A and the second adhesive layer 20B, as an optional component, for example, a plasticizer, another cured resin component such as an epoxy resin, a curing agent, a curing accelerator, a coupling agent, a filler, a flame retardant, etc. can be combined.

The bond ply 100 can be manufactured by the following method 1 or method 2, for example.

[Method 1]

A polyimide film corresponding to the polyimide layer 10 constituting the bond ply 100 and an adhesive film corresponding to the first adhesive layer 20A and the second adhesive layer 20B are separately prepared. Next, the polyimide film is disposed so that the polyimide film is inserted between the two adhesive films, for example, heated to a temperature exceeding the glass transition temperature of the resin constituting the first adhesive layer 20A and the second adhesive layer 20B. By pressing, it is possible to manufacture the bond ply 100 having a structure in which three layers are stacked.

[Method 2]

First, a polyimide film corresponding to the polyimide layer 10 is prepared by a normal method, and a resin solution constituting the first adhesive layer 20A is applied to one surface to a predetermined thickness, The first adhesive layer 20A is formed by heating the coating film. Next, a resin solution constituting the second adhesive layer 20B is applied to the other side of the polyimide film to a predetermined thickness, and then the coating film is dried by heating to form a second adhesive layer 20B, whereby three layers are laminated. It is possible to manufacture the bond ply 100 of the structure.

The polyimide film or adhesive film used in Methods 1 and 2 can be produced, for example, by coating and drying a resin solution on an arbitrary supporting substrate, then peeling it off the supporting substrate to form a film. In addition, the method of applying the resin solution on the supporting substrate or the polyimide film is not particularly limited, but may be applied by a coater such as a comma, die, knife, or lip, for example.

[circuit board]

The bond ply 100 is mainly useful as a material for circuit boards such as FPC and rigid/flex circuit boards. For example, a metal clad laminate having an insulating resin layer and a metal layer, or a circuit board on which a wiring layer is formed by processing the metal layer of the metal clad laminate by a normal method into a pattern shape is prepared, and two or more metal clad laminates and/or A circuit board having a multi-layer structure can be manufactured by inserting the bond ply 100 between the circuit boards and integrating them by thermocompression bonding. An example of such a circuit board is a strip line used as a high-frequency transmission path.

(strip line)

Fig. 2 is a schematic diagram for explaining the cross-sectional structure of a strip line as a preferred form of the circuit board of the present invention. The strip line 200 shown in Fig. 2 includes a first metal layer 30A and a first insulating resin layer 40A formed of a single layer or a plurality of layers laminated on one side of the first metal layer 30A; A wiring layer (50) formed in contact with the first insulating resin layer (40A) is provided. Here, the first metal layer 30A, the first insulating resin layer 40A, and the wiring layer 50 form a first laminate 60A.

Further, the strip line 200 includes a second metal layer 30B and a second insulating resin layer 40B formed of a single layer or a plurality of layers laminated on one side of the second metal layer 30B. Here, the second metal layer 30B and the second insulating resin layer 40B form a second laminate 60B.

In addition, the strip line 200 is provided with an intermediate resin layer 101 interposed between the first insulating resin layer 40A and the second insulating resin layer 40B and laminated therebetween.

The strip line 200 is one in which the intermediate resin layer 101 is formed by the bond ply 100 . That is, the intermediate resin layer 101 made of the bond ply 100 is inserted between the first laminate 60A and the second laminate 60B, and the first adhesive layer ( 20A) is in contact with the first insulating resin layer 40A and the wiring layer 50 of the first laminate 60A, and the second adhesive layer 20B of the bond ply 100 is the second laminate 60B. It is laminated|stacked in contact with the 2 insulating resin layer 40B. The first adhesive layer 20A of the bond ply 100 covers the wiring layer 50 . That is, the wiring layer 50 protruding on the first insulating resin layer 40A is formed by being inserted into the first adhesive layer 20A.

In the strip line 200, the first metal layer 30A and the second metal layer 30B function as a ground layer or a shield layer. Further, in the strip line 200, the wiring layer 50 is patterned and functions as a signal line. The material of the first metal layer 30A, the second metal layer 30B, and the wiring layer 50 is not particularly limited, but for example, copper, stainless steel, iron, nickel, beryllium, aluminum, zinc, indium, silver, gold, and tin, zirconium, tantalum, titanium, lead, magnesium, manganese, and alloys thereof. Among these, copper or copper alloy is especially preferable. Moreover, when using copper foil, a rolled copper foil may be sufficient and an electrodeposited copper foil may be sufficient.

In the strip line 200, the first insulating resin layer 40A and the second insulating resin layer 40B are not particularly limited as long as they are made of a resin having electrical insulation, and each independently a thermoplastic resin or It may be comprised from a thermosetting resin. As such resin, for example, polyimide resin, polyamide resin, epoxy resin, phenoxy resin, acrylic resin, polyurethane resin, styrene resin, polyester resin (including liquid crystalline polyester resin), phenol resin, poly Sulfone resin, polyether sulfone resin, polyphenylene sulfide resin, polyethylene resin, polypropylene resin, silicone resin, polyether ketone resin, polyvinyl alcohol resin, polyvinyl butyral resin, styrene-maleimide copolymer, maleimide- Resin, such as a vinyl compound copolymer or a (meth)acrylic copolymer, benzoxazine resin, bismaleimide resin, and cyanate ester resin, is mentioned.

The first insulating resin layer 40A and the second insulating resin layer 40B are not limited to a single layer, and a plurality of resin layers may be laminated.

The thickness or thickness ratio of each layer constituting the strip line 200 can be appropriately set according to the purpose. It becomes possible to suppress transmission loss of high-frequency signals along with improved reliability based on the In particular, in the strip line 200, the first adhesive layer 20A is filled to cover the periphery of the wiring layer 50. Due to this characteristic structure, a resin material having a low dielectric loss tangent as the first adhesive layer 20A ( For example, in the case of using the adhesive polyimide, etc.), an excellent effect of reducing transmission loss can be expected. In addition, the strip line 200, by including the bond ply 100, is different from the case of using a bonding sheet, damage such as being cut and cut out during laser processing, or leakage of resin in the soldering process, etc. The problem can be avoided.

The strip line 200 can be manufactured by bonding the first laminated body 60A and the second laminated body 60B to each other using a separately prepared bond ply 100 manufactured by a normal method. That is, the first insulating resin layer 40A and the wiring layer 50 of the first laminate 60A face the first adhesive layer 20A of the bond ply 100, and the second laminate 60B The second insulating resin layer 40B is disposed to face the second adhesive layer 20B of the bond ply 100, for example, the first adhesive layer 20A and the second adhesive layer of the bond ply 100 It can be manufactured by thermocompression bonding at a temperature exceeding the glass transition temperature of the resin constituting (20B).

(Example)

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited in any way by these Examples. In addition, in the following examples, various measurements and evaluations are based on the following unless otherwise stated.

[Method for measuring amine value]

About 2 g of dimerdiamine composition is weighed into a 200-250 mL Erlenmeyer flask, and using phenolphthalein as an indicator, 0.1 mol/L ethanolic potassium hydroxide solution is added dropwise until the solution takes on a pale pink color, and neutralized butanol Dissolve in about 100 mL. Add 3 to 7 drops of a phenolphthalein solution thereto, and titrate with stirring with 0.1 mol/L ethanolic potassium hydroxide solution until the sample solution turns pale pink. Add 5 drops of bromophenol blue solution thereto and titrate with stirring with 0.2 mol/L hydrochloric acid/isopropanol solution until the sample solution turns yellow.

The amine titer is calculated by the following formula (1).

Amine value = {(V ₂ ×C ₂ ) - (V ₁ ×C ₁ )} × M _KOH /m ㆍㆍㆍ (1)

Here, the amine value is a value expressed in mg-KOH/g, and M _KOH is the molecular weight of potassium hydroxide 56.1. In addition, V and C are the volume and concentration of the solution used for titration, respectively, and the subscripts 1 and 2 represent 0.1 mol/L ethanolic potassium hydroxide solution and 0.2 mol/L hydrochloric acid/isopropanol solution, respectively. In addition, m is a sample weight expressed in grams.

[Calculation of area percent of GPC and chromatogram]

(a) dimerdiamine

(b) a monoamine compound obtained by substituting a terminal carboxylic acid group of a monobasic acid compound having 10 to 40 carbon atoms with a primary aminomethyl group or an amino group

(c) an amine compound obtained by substituting a primary aminomethyl group or an amino group for the terminal carboxylic acid group of a polybasic acid compound having a hydrocarbon group within the range of 41 to 80 carbon atoms (however, the dimerdiamine is excluded)

GPC is a 20 mg dimerdiamine composition pretreated with 200 µL of acetic anhydride, 200 µL of pyridine, and 2 mL of THF, 100 mg of a solution is diluted with 10 mL of THF (containing 1000 ppm of cyclohexanone), and the sample was prepared. The prepared sample is a product of Tosoh Corporation, a trade name; Measurements were made using HLC-8220GPC under the following conditions: column: TSK-gel G2000HXL, G1000HXL, flow rate: 1 mL/min, column (oven) temperature: 40°C, injection amount: 50 µL. In addition, cyclohexanone was treated as a standard material for the correction of the runoff time.

At this time, the peak top of the main peak of cyclohexanone is adjusted so that the retention time is 27 minutes to 31 minutes, and the peak end is 2 minutes from the peak start of the main peak of cyclohexanone, and the peak of cyclohexanone is Each component (a ) to (c),

(a) a component represented by a main peak;

(b) a component represented by a GPC peak detected at a time slower than the local minimum on the time side of the slow retention time in the main peak as a reference;

(c) a component represented by a GPC peak detected at a time earlier than the local minimum on the time side of the earlier retention time in the main peak as a reference;

was detected.

[Measurement of weight average molecular weight (Mw)]

The weight average molecular weight was measured by gel permeation chromatography (HLC-8220GPC manufactured by Tosoh Corporation). Polystyrene was used as a standard material, and tetrahydrofuran (THF) was used as a developing solvent.

[Measurement of viscosity]

The viscosity in 25 degreeC was measured using the E-type viscometer (The Brookfield company make, brand name; DV-II+Pro). The rotation speed was set so that the torque might be 10% to 90%, and the value when the viscosity was stable 2 minutes after starting the measurement was read.

[Measurement of coefficient of thermal expansion (CTE)]

Using a thermomechanical analyzer (manufactured by Bruker, trade name; 4000SA), a polyimide film having a size of 3 mm × 20 mm was applied with a load of 5.0 g and a constant temperature increase rate from 30° C. to 265° C. at a rate of 20° C./min. After the temperature was raised to a furnace and held at that temperature for 10 minutes, it was cooled at a rate of 5°C/min to obtain an average coefficient of thermal expansion (coefficient of thermal expansion) from 250°C to 100°C.

[Measurement of dielectric constant (Dk) and dielectric loss tangent (Df)]

Using a vector network analyzer (manufactured by Agilent, trade name; E8363C) and an SPDR resonator, the dielectric constant and dielectric loss tangent of the resin sheet (adhesive film, resin laminate) at 10 GHz were measured. In addition, the material used for the measurement was temperature; It was left to stand for 24 hours under the conditions of 20-26 degreeC, and a humidity of 45-55%RH.

[Measurement of storage modulus and glass transition temperature (Tg)]

Cut the sample to 5mm × 20mm, and using a dynamic viscoelasticity device (DMA: UBM (UBM), trade name; E4000F), heated stepwise from 30°C to 400°C at a temperature increase rate of 4°C/min, and , was measured at a frequency of 11 Hz. In addition, the maximum temperature at which the value of Tanδ during the measurement becomes the maximum was defined as Tg.

[Measurement of moisture absorption]

A sample (polyimide film or bond ply) of A4 size (TD: 210 mm x MD: 297 mm) was dried in a hot air oven at 80 ° C. for 1 hour, and the weight after drying was measured, and this was set as the dry weight (W1). After the sample whose dry weight was measured was made to absorb moisture for 24 hours under constant temperature and humidity of 23 degreeC and 50%RH, the weight was measured and it was set as the weight after moisture absorption (W2). Based on the measured weight, the moisture absorption rate was calculated by substituting the following formula.

Moisture absorption (wt%) = [(W2-W1)/W1] × 100

[Measurement of dimensional change rate]

Electrolytic copper foil (product of Fukuda Metal Foil & Powder Co., Ltd., trade name; T49A-DS-HD2, thickness; 12μm) is superimposed on both sides of the bond ply, and the glass transition temperature is less than 160℃. For an adhesive film with a glass transition temperature of 300°C or higher, heat press for 40 minutes under the conditions of temperature; 160°C, pressure; 4 MPa, temperature; 390° C., pressure; 4 MPa, for 40 minutes After obtaining, a target for position measurement is formed by exposing and developing a dry film resist at intervals of 100 mm using a test piece cut to 150 mm × 150 mm. After measuring the dimensions before etching (normal state) in an atmosphere with a temperature of 23±2°C and a relative humidity of 50±5%, the copper other than the target of the test piece is etched by etching (liquid temperature of 40°C or less, time within 10 minutes). Remove. After standing still for 24±4 hours in an atmosphere with a temperature of 23±2°C and a relative humidity of 50±5%, the dimensions after etching are measured. The dimensional change rate for each of three normal states in the MD direction (longitudinal direction) and TD direction (width direction) is calculated, and the average value of each is taken as the dimensional change rate after etching. The dimensional change rate after etching was calculated by the following formula.

Dimensional change after etching (%) = [(B-A)/A] × 100

A; Distance between targets before etching

B; Distance between targets after etching

The abbreviations used in this Example represent the following compounds.

PMDA: pyromellitic dianhydride

BPDA: 3,3',4,4'-biphenyltetracarboxylic dianhydride

BTDA: 3,3',4,4'-benzophenonetetracarboxylic dianhydride

m-TB: 2,2'-dimethyl-4,4'-diaminobiphenyl

TPE-R: 1,3-bis(4-aminophenoxy)benzene

p-PDA: paraphenylenediamine

BAPP: 2,2-bis[4-(4-aminophenoxy)phenyl]propane

APB: 1,3-bis(3-aminophenoxy)benzene

NMP: N-methyl-2-pyrrolidone

DMAc: N,N-dimethylacetamide

DDA: C36 aliphatic diamine (Croda Japan Co., Ltd. product, trade name; PRIAMINE 1074 distilled and purified, amine value; 210 mgKOH/g, mixture of cyclic and chain dimer diamines, component (a); 97.9% , component (b); 0.3%, component (c); 1.8%)

N-12: dodecane diacid dihydrazide

OP935: organic phosphinic acid aluminum salt (Clariant Japan, brand name; Exolit OP935)

Moreover, in the said DDA, "%" of component (a), component (b), and component (c) means the area percent of the chromatogram in GPC measurement. In addition, the molecular weight of the said DDA was computed by the following formula.

Molecular weight = 56.1 × 2 × 1000 / amine number

(Synthesis Example 1)

Under a nitrogen stream, 12.745 g of m-TB (0.0599 mol) and 1.947 g of TPE-R (0.0066 mol) and DMAc in an amount such that the solid content concentration after polymerization is 15% by weight were added to the reaction layer and stirred at room temperature. so it was dissolved. Next, 11.447 g of PMDA (0.0525 mol) and 3.86 g of BPDA (0.0131 mol) were added, stirring was continued at room temperature for 3 hours, polymerization was carried out, and polyamic acid solution 1 (viscosity; 16,500 cps) was obtained. prepared.

(Synthesis Example 2)

Under a nitrogen stream, 13.780 g of m-TB (0.0643 mol) and DMAc in an amount such that the solid content concentration after polymerization was 15% by weight were added to the reaction layer, and the reaction layer was dissolved by stirring at room temperature. Next, 6.903 g of PMDA (0.0317 mol) and 9.317 g of BPDA (0.0317 mol) were added, followed by polymerization at room temperature for 3 hours, followed by polyamic acid solution 2 (viscosity; 12,500 cps). prepared.

(Synthesis Example 3)

In the reaction layer under a nitrogen stream, 7.715 g of m-TB (0.0363 mol), 3.694 g of p-PDA (0.0363 mol), DMAc in an amount such that the solid content concentration after polymerization is 15% by weight, 7.797 g of PMDA (0.0375) mol) and 10.524 g of BPDA (0.0375 mol), stirring was continued for 3 hours at room temperature, polymerization was carried out, and polyamic acid solution 3 (viscosity; 9,600 cps) was prepared.

(Synthesis Example 4)

Under a nitrogen stream, 9.061 g of p-PDA (0.0830 mol) and DMAc in an amount such that the solid content concentration after polymerization was 15% by weight were added to the reaction layer, and the reaction layer was dissolved by stirring at room temperature. Next, 8.9112 g of PMDA (0.0409 mol) and 12.0275 g of BPDA (0.0409 mol) were added, stirring was continued at room temperature for 3 hours, polymerization was carried out, and polyamic acid solution 4 (viscosity; 11,000 cps) was obtained. prepared.

(Synthesis Example 5)

In a 500 mL four-neck flask equipped with a nitrogen inlet tube, stirrer, thermocouple, Dean-Stark Trap, and cooling tube, 44.92 g of BTDA (0.139 mol), 75.08 g of DDA (0.141 mol), 168 g of NMP and 112 g of xylene were charged and mixed at 40°C for 30 minutes to prepare a polyamic acid solution. The polyamic acid solution was heated to 190°C, heated and stirred for 4 hours, and water and xylene flowing out were removed from the system. Thereafter, the mixture was cooled to 100° C., stirred with 112 g of xylene, and further cooled to 30° C. to prepare polyimide solution 5 (solid content: 29.5 wt%, weight average molecular weight; 75,700) in which imidization was completed.

(Synthesis Example 6)

In a 500 mL four-neck flask equipped with a nitrogen inlet tube, stirrer, thermocouple, Dean Stark trap, and cooling tube, 47.67 g BTDA (0.148 mole), 46.3969 g DDA (0.085 mole), 16.601 g APB (0.05679 mole) , 155 g of NMP and 103 g of xylene were charged and mixed at 40°C for 30 minutes to prepare a polyamic acid solution. This polyamic acid solution was heated up to 190 degreeC, heated and stirred for 4 hours, and flowing-out water and xylene were removed out of the system. After that, it was cooled to 100 ° C., 112 g of xylene was added, stirred, and further cooled to 30 ° C. to prepare polyimide solution 6 (solid content; 29.5 wt %, weight average molecular weight; 85,200) in which imidization was completed.

(Synthesis Example 7)

Under a nitrogen stream, 18.574 g of BAPP (0.0453 mol), DMAc in an amount such that the solid content concentration after polymerization is 15% by weight, and 9.7354 g of PMDA (0.0446 mol) were added to the reaction layer, followed by stirring at room temperature for 3 hours. The polymerization reaction was continued and polyamic acid solution 7 (viscosity; 5,300 cps) was prepared.

(Production Example 1)

On copper foil 1 (electrolytic copper foil, thickness; 12 μm, surface roughness Rz on the resin layer side; 0.6 μm), the polyamic acid solution 1 is uniformly coated so that the thickness after curing becomes about 50 μm, and then heated and dried at 120° C. to obtain a solvent. was removed. Thereafter, stepwise heat treatment was performed from 120° C. to 360° C. to complete imidization, and a single-sided metal clad laminate 1 was prepared. Copper foil 1 of single-sided metal clad laminate 1 was removed by etching using a ferric chloride solution, and polyimide film 1 (thickness; 50 μm, CTE; 12 ppm/K, Dk; 3.3, Df; 0.0056, moisture absorption; 0.77 wt %; Tg; 378° C.) was prepared.

(Production Example 2)

Polyimide film 2 (thickness; 50 µm, CTE; 16.4 ppm/K, Dk; 3.4, Df; 0.0036, moisture absorption rate; 0.63 wt%, Tg; 332° C.) was prepared.

(Production Example 3)

Polyimide film 3 (thickness; 50 µm, CTE; 22.4 ppm/K, Dk; 3.6, Df; 0.0051, moisture absorption rate; 0.65 wt%) was prepared in the same manner as in Production Example 1 except that polyamic acid solution 3 was used. did.

(Production Example 4)

Polyimide film 4 (thickness; 50 µm, CTE; 15.8 ppm/K, Dk; 3.8, Df; 0.0122, moisture absorption rate; 1.66 wt%, Tg> 400° C.) was prepared.

(Production Example 5)

Polyimide film 5 (thickness; 25 µm, CTE; 11.4 ppm/K, Dk; 3.4, Df; 0.0038) was carried out in the same manner as in Production Example 1, except that polyamic acid solution 2 was used and the thickness after curing was about 25 µm. , moisture absorption rate; 0.64 wt%) was prepared.

(Production Example 6)

To 169.49 g (50 g as solid content) of polyimide solution 5, 1.8 g of N-12 (0.0036 mol) and 12.5 g of OP935 were blended, 6.485 g of NMP and 19.345 g of xylene were added and diluted, and polyimide varnish 1 was prepared.

After applying polyimide varnish 1 to the silicone-treated surface of release substrate 1 (length × width × thickness = 320 mm × 240 mm × 25 μm) so that the thickness after drying becomes 50 μm, heat and dry at 80° C. for 15 minutes, and release substrate 1 phase By peeling from the adhesive film 1 (thickness; 50 µm, CTE; 113 ppm/K, Dk; 2.7, Df; 0.0024) was prepared. In addition, the maximum values of the storage modulus at 50° C. and the storage modulus at a rapid gradient temperature range of 180° C. to 260° C. after curing of the adhesive film 1 were 5.0×10 ² MPa and 3.0 MPa, respectively. In addition, the glass transition temperature of the adhesive film 1 was 54°C.

(Production Example 7)

169.49 g (50 g as solid content) of polyimide solution 6 was mixed with 1.8 g of N-12 (0.0036 mol) and 12.5 g of OP935, 6.485 g of NMP and 19.345 g of xylene were added and diluted, and polyimide varnish 2 was prepared

Adhesive film 2 (thickness; 50 µm, CTE; 78 ppm/K, Dk; 2.7, Df; 0.0028) was prepared in the same manner as in Production Example 6 except that the polyimide varnish 2 was used. In addition, the maximum values of the storage modulus at 50° C. and the storage modulus at a rapid gradient temperature range of 180° C. to 260° C. after curing of the adhesive film 2 were 15.0×10 ² MPa and 12.0 MPa, respectively. In addition, the glass transition temperature of the adhesive film 2 was 120 °C.

(Production Example 8)

On the copper foil 1, the polyamic acid solution 7 was uniformly applied to a thickness of about 50 µm after curing, and then the solvent was removed by heating and drying at 120°C. After that, stepwise heat treatment was performed from 120°C to 360°C to complete imidization, and a single-sided metal clad laminate 2 was prepared. An adhesive film 3 (thickness; 50 µm, CTE; 58 ppm/K, Dk; 3.4, Df; 0.0059) was prepared by etching off the copper foil 1 of the single-sided metal clad laminate 2 using a ferric chloride aqueous solution. In addition, the maximum values of the storage modulus at 50° C. and the storage modulus at a rapid gradient temperature range of 180° C. to 260° C. after curing of the adhesive film 3 were 29.0×10 ² MPa and 21.0×10 ² MPa, respectively. In addition, the glass transition temperature of the adhesive film 3 was 326°C.

(Production Example 9)

Polyimide film 6 (thickness; 12 μm, CTE; 28.6 ppm/K, Dk; 3.4, Df; 0.0038) was carried out in the same manner as in Production Example 1, except that the polyamic acid solution 2 was used so that the thickness after curing was about 12 μm. , moisture absorption rate; 0.6 wt%) was prepared.

[Example 1]

After applying the polyimide varnish 1 on the polyimide film 2 so that the thickness after drying might become 25 micrometers, it heat-dried at 80 degreeC for 15 minutes. Subsequently, the polyimide varnish 1 was similarly applied to the opposite side of the coating so that the thickness after drying was 25 µm, and then dried by heating at 80° C. for 15 minutes to obtain a bond ply 1. Table 1 shows the evaluation results of the bond ply 1.

[Example 2]

A bond ply 2 was obtained in the same manner as in Example 1 except that the thickness of the polyimide varnish 1 after drying was set to 50 μm. Table 1 shows the evaluation results of Bond Ply 2.

[Example 3]

A bond ply 3 was obtained in the same manner as in Example 2 except that the polyimide film 5 was used instead of the polyimide film 2. Table 1 shows the evaluation results of Bond Ply 3.

[Example 4]

A bond ply 4 was obtained in the same manner as in Example 2 except that the polyimide film 1 was used instead of the polyimide film 2. Table 1 shows the evaluation results of Bond Ply 4.

[Example 5]

A bond ply 5 was obtained in the same manner as in Example 2 except that the polyimide film 3 was used instead of the polyimide film 2. Table 1 shows the evaluation results of Bond Ply 5.

Comparative Example 1

A bond ply 6 was obtained in the same manner as in Example 2 except that the polyimide film 4 was used instead of the polyimide film 2. Table 1 shows the evaluation results of Bond Ply 6.

[Example 6]

A bond ply 7 was obtained in the same manner as in Example 4 except that the polyimide varnish 2 was used instead of the polyimide varnish 1. Table 1 shows the evaluation results of Bond Ply 7.

Comparative Example 2

On the polyimide film 2, the polyamic acid solution 7 was uniformly applied to a thickness of about 50 µm after curing, and then the solvent was removed by heating and drying at 120°C. After that, the polyamic acid solution 7 was uniformly applied to the opposite side of the polyimide film 2 so that the thickness after curing was about 50 µm, and then the solvent was removed by heating and drying at 120°C. Stepwise heat treatment was performed from 120° C. to 360° C. to complete imidization, thereby obtaining Bond Ply 8. Table 1 shows the evaluation results of Bond Ply 8.

Comparative Example 3

A bond ply 9 was obtained in the same manner as in Example 2 except that the polyimide film 6 was used instead of the polyimide film 2. Table 1 shows the evaluation results of Bond Ply 9.

[Example 7]

An adhesive sheet (manufactured by Nikkan Industries, trade name; NIKAFLEX SAFY, thickness; 50 µm) was superposed on both surfaces of the polyimide film 2, and the temperature was adjusted; 160°C, pressure; It hot-pressed under the conditions of 4 MPa for 40 minutes, and the bond ply 10 was obtained. Table 1 shows the evaluation results of the bond ply 10.

Table 1 summarizes the above results.

bond fly type thickness
[μm] thickness ratio dimensional change rate
[%] moisture absorption
[weight%] dielectric properties MDD TDD Dｆ Example 1 1 100 0.5 0.03 0.02 0.35 0.0029 Example 2 2 150 0.3 0.04 0.02 0.30 0.0028 Example 3 3 125 0.2 0.05 0.04 0.20 0.0026 Example 4 ４ 150 0.3 0.09 0.07 0.26 0.0035 Example 5 5 150 0.3 -0.03 -0.05 0.25 0.0033 Comparative Example 1 ６ 150 0.3 0.06 0.03 0.42 0.0057 Example 6 7 150 0.3 -0.08 -0.09 0.33 0.0038 Comparative Example 2 ８ 150 0.3 0.24 0.20 0.56 0.0052 Comparative Example 3 9 112 0.1 0.14 0.11 0.11 0.0025 Example 7 10 150 0.3 0.05 0.02 0.27 0.0039

As shown in Table 1, the bond plies of Examples 1 to 7 achieve both low dielectric loss tangent and dimensional stability. Therefore, when applied to a circuit board such as a strip line that transmits a high-frequency signal in the GHz band (for example, 1 to 50 GHz), the transmission loss of the high-frequency signal can be effectively reduced, and reliability and improved dimensional stability are achieved. It is expected to improve the yield.

[Example 8]

A plurality of straight conductor patterns (circuit conductor width/space width) by etching processing by subtractive method on copper foil of single-sided copper clad laminate (Nippon Steel, product name; ESPANEX M series) = 100 µm/100 µm), and a wiring board 1 was produced.

Two of this wiring board 1 were prepared. The bond ply 2 is arranged on the circuit processing surface of the wiring board 1, and arranged so that the circuit processing surface of the wiring board 1 is on the outside, and the temperature; 160°C, pressure; Multilayer circuit board 1 {laminated configuration; Wiring board 1 (circuit side inside)/bond ply 2/wiring board 1 (circuit side outside)} was obtained.

[Example 9]

In the same manner as in Example 8, except that the circuit processing surfaces of the two wiring boards 1 were arranged so as to be outside, and the bonding ply 2 was inserted between the two wiring boards 1, in the same manner as in Example 8, the multilayer circuit board 2 {laminated composition; Wiring board 1 (circuit side outside)/bond ply 2/wiring board 1 (circuit side outside)} was obtained.

[Example 10]

A plurality of straight conductor patterns (circuit conductor width/space width = 100 μm) by etching processing by a subtractive method on one copper foil of a double-sided copper clad laminate (Nittetsu Chemical & Materials, trade name; ESPANEX M series) /100 µm), and a wiring board 2 was produced.

In the same manner as in Example 8, except that the bond ply 2 was disposed on the circuit processing surface of the wiring board 2, and the copper foil side of the single-sided copper clad laminate was disposed thereon, the multilayer circuit board 3 {laminated configuration; Wiring board 2 (copper foil side outside, circuit side inside)/bond ply 2/single-sided copper clad laminate (copper foil side outside)} was obtained.

[Example 11]

A plurality of straight conductor patterns (circuit conductor width/space width = 100 µm/100 µm) were formed on the copper foils on both sides of the double-sided copper clad laminate by subtractive etching, and a wiring board 3 was produced.

In the same manner as in Example 10 except that the wiring board 3 was used instead of the wiring board 2, the multilayer circuit board 4 {laminated configuration; Wiring board 3/bond ply 2/single-sided copper clad laminate (copper foil side is the outer side)} was obtained.

[Example 12]

Multilayer circuit board 5 {laminated configuration; Wiring board 2 (the copper foil side is outside, the circuit side is inside)/bond ply 2/wiring board 1 (the circuit side is outside)} was obtained.

[Example 13]

In the same manner as in Example 12, except that the wiring board 3 was used instead of the wiring board 2, the multilayer circuit board 6 {laminated configuration; Wiring board 3/bond ply 2/wiring board 1 (circuit surface outside)} was obtained.

[Example 14]

Prepare 2 single-sided copper clad laminates, 2 bond ply 2 sheets, and wiring board 1, with a single-sided copper clad laminate (copper side facing out)/bond ply 2/wiring board 1 (the direction of the circuit side is not specified) /bond ply 2/single-sided copper clad laminate (copper foil side is the outer side), laminated so that the temperature; 160°C, pressure; A multilayer circuit board 7 was obtained by hot pressing under the conditions of 4 MPa for 40 minutes.

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, and various deformation|transformation is possible.

10… polyimide layer
20A… first adhesive layer
20B… second adhesive layer
30A… first metal layer
30B… second metal layer
40A… 1st insulating resin layer
40B… 2nd insulating resin layer
50… wiring layer
60A… first laminate
100… bond fly
101… middle resin layer
200… strip line

Claims (9)

a polyimide layer;
a first adhesive layer laminated on one side of the polyimide layer;
A second adhesive layer laminated on the opposite side of the polyimide layer to the first adhesive layer
As a bond ply having a,
The following conditions a to c;
a) the total thickness of the bond ply is in the range of 50 μm or more and 300 μm or less, and the ratio of the thickness of the polyimide layer to the thickness of the entire bond ply is in the range of 0.2 or more and 0.9 or less;
b) After drying at 80°C for 1 hour, the moisture absorption measured after 24 hours under constant temperature and humidity at 23°C and 50%RH is 0.4% by weight or less;
c) The storage modulus of the first adhesive layer and the second adhesive layer at 50 ° C. are each independently 1800 MPa or less, and the maximum value of the storage modulus at 180 to 260 ° C. are each independently 800 MPa or less. ;
Bond ply characterized in that it satisfies.
According to claim 1,
the following conditions d;
d) Dielectric loss tangent at 10 GHz measured by a split post dielectric resonator (SPDR) of 0.004 or less after 24 hours of humidity control under constant temperature and humidity conditions (normal conditions) of 23°C and 50%RH:
Bond fly that meets more.
3. The method of claim 1 or 2,
The first adhesive layer and the second adhesive layer is a bond ply having a glass transition temperature (Tg) of 180° C. or less, respectively.
3. The method of claim 1 or 2,
The first adhesive layer and the second adhesive layer contain polyimide as a resin component,
The polyimide contains an acid anhydride residue derived from a tetracarboxylic acid anhydride component and a diamine residue derived from a diamine component, and two terminal carboxylic acid groups of the dimer acid are substituted with a primary aminomethyl group or an amino group. A bond ply that contains 50 mol% or more of diamine residues derived from the dimerdiamine composition.
3. The method of claim 1 or 2,
A bond ply in which the coefficient of thermal expansion of the polyimide layer is within the range of 1 ppm/K or more and 30 ppm/K or less.
3. The method of claim 1 or 2,
In the polyimide layer, the dielectric loss tangent at 10 GHz measured by a split post dielectric resonator (SPDR) after 24 hours of humidity control under a constant temperature and humidity condition (normal condition) of 23° C. and 50% RH is 0.006 or less.
3. The method of claim 1 or 2,
The polyimide constituting the polyimide layer contains a tetracarboxylic acid residue and a diamine residue, and the content of the diamine residue derived from the diamine compound represented by the following general formula (A1) with respect to all the diamine residues is 50 mol% or more Characterized by Bond Fly.

[In the formula (A1), the linking group Z represents a single bond or -COO-, and Y is independently a monovalent hydrocarbon having 1 to 3 carbon atoms which may be substituted with a halogen atom or a phenyl group, or an alkoxy group having 1 to 3 carbon atoms. , or a C1-C3 perfluoroalkyl group or an alkenyl group, n represents an integer of 0-2, p and q independently represent an integer of 0-4.]
A circuit board comprising the bond ply of claim 1 or 2.
a first metal layer;
a first insulating resin layer comprising a single layer or a plurality of layers laminated on one side of the first metal layer;
a wiring layer formed in contact with the first insulating resin layer;
a second metal layer;
a second insulating resin layer comprising a single layer or a plurality of layers laminated on one side of the second metal layer;
An intermediate resin layer inserted and stacked between the first insulating resin layer and the second insulating resin layer
to provide
A strip line in which the intermediate resin layer is made of the bond ply of claim 1 or 2 and the wiring layer is covered by the first or second adhesive layer.

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