TW202126128A - Metal-clad laminate and circuit substrate capable of reducing transmission loss even in high-frequency transmission and excellent in dimensional stability - Google Patents

Abstract

The present invention provides a metal-clad laminate and a circuit substrate capable of reducing transmission loss even in high-frequency transmission and excellent in dimensional stability. The metal-clad laminate includes: a first metal layer, a first transmission loss suppression layer in contact with one side of the first metal layer, a second metal layer, a second transmission loss suppression layer in contact with one side of the second metal layer, and a plurality of resin layers interposed between the first transmission loss suppression layer and the second transmission loss suppression layer. A resin laminate comprises the first transmission loss suppression layer, the second transmission loss suppression layer, at least two or more dimensional accuracy maintaining layers and an intermediate transmission loss suppression layer laminated between the dimensional accuracy maintaining layers. In the metal-clad laminate, when the dielectric loss tangent of the first transmission loss suppression layer and the second transmission loss suppression layer at 10 GHz is set to Df1, and the dielectric loss tangent of the dimensional accuracy maintaining layer is set to Df2, Df1 is less than Df2.

Description

Metal-clad laminated board and circuit substrate

The present invention relates to a metal-clad laminate and a circuit board that are effectively used as electronic parts.

In recent years, along with advances in the miniaturization, weight reduction, and space saving of electronic equipment, flexible printed circuit boards (FPC) are thin, lightweight, flexible, and have excellent durability even if they are repeatedly bent. The need for increased. FPC can achieve three-dimensional and high-density installation even in a limited space. Therefore, for example, in hard disk drives (Hard Disk Drive, HDD), digital video discs (Digital Video Disk, DVD), smart phones and other electronic devices The use of wiring of moving parts of equipment, cables, connectors and other parts is gradually expanding.

In addition to the above-mentioned higher density, higher performance of equipment is being promoted, so it is also necessary to cope with the higher frequency of transmission signals. When high-frequency signals are transmitted, when the transmission loss in the transmission path is large, disadvantages such as loss of electrical signals or increased delay time of signals occur. Therefore, in FPC in the future, the reduction of transmission loss will also become important.

In order to improve high-frequency transmission characteristics, it has been proposed to use a laminate in which a fluororesin-containing film is laminated on both sides of a polyimide film as an insulating resin layer (Patent Document 1). The insulating resin layer of Patent Document 1 uses a fluorine-based resin, so it is excellent in terms of dielectric properties, but there are problems with dimensional stability. Especially when applied to FPC, there is concern about dimensional changes before and after circuit processing caused by etching. The dimensional change before and after the heat treatment becomes larger.

In order to improve the high-frequency transmission characteristics, it is proposed that two single-sided metal-clad laminates are laminated and laminated by introducing an adhesive layer with specific diamine residues, and the thickness of the entire resin layer and the adhesive layer are controlled ( Patent Document 2). However, in Patent Document 2, the low dielectric loss tangent adhesive layer and the metal layer (wiring) are far away due to the insulating layer of the single-sided metal-clad laminate, so there is room for further improvement in the reduction effect of transmission loss . [Prior Art Literature]

[Patent Literature] [Patent Document 1] Japanese Patent Laid-Open No. 2004-216830 [Patent Document 2] Japanese Patent Laid-Open No. 2018-170417

[The problem to be solved by the invention] The object of the present invention is to provide a metal-clad laminate and a circuit board that can reduce transmission loss even in high-frequency transmission and are excellent in dimensional stability. [Technical means to solve the problem]

The inventors of the present invention conducted diligent studies and found that by providing low-dielectric loss tangent transmission loss suppression layers in contact with a pair of metal layers (wiring), and using intermediate transmission between the transmission loss suppression layers The loss suppression layer is a structure in which multiple dimensional accuracy maintenance layers are laminated, and the ratio of the total thickness of the dimensional accuracy maintenance layer to the thickness of the entire resin layer is set to a certain value or more. Even if the thickness of the entire resin layer is increased, wiring can be suppressed Offset of the position, and can make the reduction of transmission loss and the maintenance of dimensional accuracy coexist.

The metal-clad laminate of the present invention includes: a first metal layer, a first transmission loss suppression layer provided in contact with one side of the first metal layer, a second metal layer, and one side of the second metal layer A second transmission loss suppression layer is provided adjacent to each other, and a multilayer resin layer intervening between the first transmission loss suppression layer and the second transmission loss suppression layer. In the metal-clad laminate of the present invention, a resin laminate is formed by the first transmission loss suppression layer, the second transmission loss suppression layer, and the multilayer resin layer, and the resin laminate has at least two layers of A dimensional accuracy maintaining layer and an intermediate transmission loss suppressing layer laminated between the dimensional accuracy maintaining layers. Furthermore, the metal-clad laminate of the present invention satisfies the following condition i and condition ii; i) When the dielectric loss tangent of the first transmission loss suppression layer and the second transmission loss suppression layer is Df ₁ , and When the dielectric loss tangent of the dimensional accuracy maintaining layer is set to Df ₂ , it is in _{the relationship of Df 1} <Df ₂ , and the dielectric loss tangent is humidity control under constant temperature and humidity conditions (normal state) at 23°C and 50% RH After 24 hours, the dielectric loss tangent at 10 GHz measured by a Split Post Dielectric Resonator (SPDR); ii) The total thickness of the dimensional accuracy maintaining layer is less than the total thickness of the resin laminate Within the range of 25% to 60%. The circuit board of the present invention includes: a first wiring layer, a first transmission loss suppression layer provided in contact with a single side of the first wiring layer, a second wiring layer, and a single side contact with the second wiring layer A second transmission loss suppression layer is provided, and a multilayer resin layer interposed between the first transmission loss suppression layer and the second transmission loss suppression layer.

In the circuit board of the present invention, a resin laminate is formed by the first transmission loss suppression layer, the second transmission loss suppression layer, and the multilayer resin layer, and the resin laminate has at least two or more layers of maintaining dimensional accuracy Layer, and an intermediate transmission loss suppression layer laminated between the dimensional accuracy maintaining layers. Furthermore, the circuit board of the present invention satisfies the following condition i and condition ii; i) When the dielectric loss tangent of the first transmission loss suppression layer and the second transmission loss suppression layer is Df ₁ , the When the dielectric loss tangent of the dimensional accuracy maintaining layer is set to Df ₂ , it is in _{the relationship of Df 1} <Df ₂ , and the dielectric loss tangent is humidity control for 24 hours under the constant temperature and humidity condition (normal state) of 23°C and 50%RH After that, the dielectric loss tangent at 10 GHz measured by the separation dielectric resonator (SPDR); ii) The total thickness of the dimensional accuracy maintaining layer is in the range of 25% to 60% of the total thickness of the resin laminate Inside.

In the metal-clad laminate or circuit board of the present invention, the dimensional accuracy maintaining layer may have a storage elastic coefficient in a temperature range of 100°C to 250°C. The minimum value of the storage elasticity coefficient may be in the range of 1.0 GPa to 8.0 GPa, and the coefficient of thermal expansion It is a low thermal expansion polyimide layer in the range of 15 ppm/K to 25 ppm/K.

In the metal-clad laminate or circuit board of the present invention, the resin constituting the first transmission loss suppression layer and the second transmission loss suppression layer may be polyimide formed by reacting an acid anhydride component and a diamine component, and A dimer diamine in which two terminal carboxylic acid groups of a dimer acid containing 50 mol parts or more of dimer acid are substituted with primary aminomethyl groups or amino groups with respect to 100 mol parts of the total amount of the diamine components. [Effects of the invention]

Since the metal-clad laminate of the present invention is provided with low-dielectric loss tangent transmission loss suppression layers so as to be in contact with a pair of metal layers (wirings), it can effectively suppress transmission loss in high-frequency signal transmission. In addition, since a structure in which a plurality of dimensional accuracy maintaining layers and an intermediate transmission loss suppressing layer are laminated between the transmission loss suppression layers, and the ratio of the total thickness of the dimensional accuracy maintaining layers to the thickness of the entire resin layer is set to be constant or more , So it can ensure high dimensional stability, while achieving low dielectric. Therefore, when the metal-clad laminate of the present invention is applied to, for example, a circuit board that transmits a high-frequency signal with a frequency of 10 GHz or higher, the transmission loss can be effectively reduced.

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

[Metal Clad Laminate] FIG. 1 is a schematic diagram showing the structure of a metal-clad laminate according to an embodiment of the present invention. The metal-clad laminate 10 of this embodiment includes: The first metal layer M1, The first transmission loss suppression layer BS1 is provided in contact with one side of the first metal layer M1 The second metal layer M2, A second transmission loss suppression layer BS2 provided in contact with one side of the second metal layer M2, and A multilayer resin layer existing between the first transmission loss suppression layer BS1 and the second transmission loss suppression layer BS2 is interposed. The metal-clad laminate 10 is provided with a first transmission loss suppression layer BS1 and a second low-dielectric loss tangent at the positions closest to the pair of metal layers (the first metal layer M1 and the second metal layer M2 that become the wiring). The transmission loss suppression layer BS2 can effectively suppress transmission loss in high-frequency signal transmission. Here, the resin laminate 20 is formed by the first transmission loss suppression layer BS1, the second transmission loss suppression layer BS2, and the multilayer resin layer. In addition to the first transmission loss suppression layer BS1 and the second transmission loss suppression layer BS2, the resin laminate 20 also has at least two or more dimensional accuracy maintenance layers PL and an intermediate transmission layer laminated between the dimensional accuracy maintenance layer PL Loss suppression layer BS3. As described above, the laminated structure of the dimensional accuracy maintaining layer PL and the intermediate transmission loss suppressing layer BS3 is provided between the first transmission loss suppression layer BS1 and the second transmission loss suppression layer BS2, thereby ensuring high dimensional stability while achieving Low dielectric. In addition, the resin laminated body 20 may have any resin layer other than the above, but it is preferable to form only the resin layer which has each function mentioned above.

As shown in FIG. 1, the first metal layer M1 and the second metal layer M2 are respectively located on the outermost side, and a first transmission loss suppression layer BS1 and a second transmission loss suppression layer BS2 are arranged in contact with their inner sides. A multilayer resin layer including a multilayer dimensional accuracy maintaining layer PL and an intermediate transmission loss suppressing layer BS3 is arranged between the first transmission loss suppression layer BS1 and the second transmission loss suppression layer BS2. Here, the first transmission loss suppression layer BS1 is adjacent to a dimensional accuracy maintaining layer PL, and the second transmission loss suppression layer BS2 is adjacent to another dimensional accuracy maintaining layer PL.

The metal-clad laminate 10 shown in FIG. 1 has two dimensional accuracy maintenance layers PL and one intermediate transmission loss suppression layer BS3, but the dimensional accuracy maintenance layer PL only needs to be two or more layers. The number of layers of the intermediate transmission loss suppression layer BS3 There are no special restrictions. For example, it may be a structure having three dimensional accuracy maintaining layers PL and two intermediate transmission loss suppression layers BS3 as shown in FIG. 2, or it may be a structure having five dimensional accuracy maintaining layers PL and four layers as shown in FIG. The structure of the intermediate transmission loss suppression layer BS3.

In the metal-clad laminate 10, the structures of the first metal layer M1 and the second metal layer M2 may be the same or different, but are preferably the same material, the same physical properties, and the same thickness.

In addition, the structures of the first transmission loss suppression layer BS1 and the second transmission loss suppression layer BS2 may be the same or different, but are preferably the same material, the same physical properties, and the same thickness. For example, by making the dielectric loss tangent or thickness of the first transmission loss suppression layer BS1 and the second transmission loss suppression layer BS2 the same, design for reduction of transmission loss when manufacturing a circuit board for high-frequency transmission becomes easy.

Furthermore, the structures of the first transmission loss suppression layer BS1, the second transmission loss suppression layer BS2, and the intermediate transmission loss suppression layer BS3 may be the same or different, but in order to improve the overall dielectric properties of the resin laminate 20 and effectively suppress high frequency The signal transmission loss is preferably the same material and the same physical properties.

The structure of the multilayer dimensional accuracy maintaining layer PL may be the same or different, but in terms of easy design and manufacture of the circuit board, mechanical strength or dimensional accuracy, the same material, the same physical properties, the same thickness, and the same layer structure are preferable.

The metal-clad laminate 10 satisfies the following condition i and condition ii.

Condition i: When the dielectric loss tangent of the first transmission loss suppression layer BS1 and the second transmission loss suppression layer BS2 is Df ₁ , and the dielectric loss tangent of the dimensional accuracy maintaining layer PL is Df ₂ , it is Df ₁ ＜Df ₂ relationship. Dielectric loss tangents of the first transmission loss suppression layer BS1 and the second transmission loss suppression layer BS2 respectively connected to the first metal layer M1 and the second metal layer M2 that should be the transmission path of the high-frequency signal, that is, the circuit wiring Df _{1 is} designed to be lower than the dielectric loss tangent Df _{2 of the} dimensional accuracy maintaining layer PL, which can effectively suppress the transmission loss of high-frequency signals. Furthermore, even when the dielectric loss tangents of the first transmission loss suppression layer BS1 and the second transmission loss suppression layer BS2 are different, both of them need to satisfy the relationship of _{Df 1} <Df _2. In the present invention, unless specifically stated otherwise, the dielectric constant and the dielectric loss tangent refer to the resonant vibration of the separation medium after adjusting the humidity for 24 hours under the constant temperature and humidity condition of 23°C and 50% RH (normal state) The dielectric constant and dielectric loss tangent at 10 GHz measured by the SPDR.

From the viewpoint of achieving suppression of transmission loss of high-frequency signals, the dielectric loss tangent Df ₁ at 10 GHz of the first transmission loss suppression layer BS1 and the second transmission loss suppression layer BS2 is preferably 0.005 or less, more preferably 0.003 or less .

Furthermore, from the viewpoint of achieving suppression of transmission loss of high-frequency signals, the dielectric loss tangent Df ₃ of the intermediate transmission loss suppression layer BS3 at 10 GHz measured in the same manner as condition i is preferably 0.005 or less, and more preferably 0.003 Hereinafter, it is most preferable to be the same as _{the dielectric loss tangent Df 1 of the} first transmission loss suppression layer BS1 and the second transmission loss suppression layer BS2.

In addition, the dielectric loss tangent Df _{2 of the} dimensional accuracy maintaining layer PL is desirably as low as possible, but since it is a layer whose main purpose is to maintain dimensional accuracy and mechanical strength, it is preferably 0.012 or less as long as the condition i is satisfied. Yes, it is more preferably 0.010 or less. The reason is that even if the dielectric loss tangent Df _{2 of the} dimensional accuracy maintaining layer PL becomes slightly higher, the first transmission loss suppression layer BS1, the second transmission loss suppression layer BS2, and the intermediate transmission loss suppression layer having a lower dielectric loss tangent The BS3 is laminated, and considering the thickness ratio to these, the low dielectric of the entire resin laminate 20 can also be ensured.

Condition ii: The total thickness T _PL of the dimensional accuracy maintaining layer PL is in the resin laminate 20 (that is, the first transmission loss suppression layer BS1 and the second transmission loss suppression layer BS2, one or more intermediate transmission loss suppression layers BS3, and the multilayer dimensional accuracy The maintenance layer PL) is in the range of 25% to 60% of the total thickness T. _{By setting the ratio of the total thickness T PL of the} multilayer dimensional accuracy maintaining layer PL to the total thickness T of the resin laminate 20 within the above range, it is possible to maintain the dimensional accuracy and mechanical strength when the metal-clad laminate 10 is subjected to circuit processing. At the same time, the transmission loss of high-frequency signals can be reduced. From the above viewpoint, _{the ratio of the thickness T PL} to the total thickness T is preferably in the range of 25% to 50%.

Here, the thickness of each layer in the resin laminate 20 can be appropriately set according to the purpose of use, and therefore is not particularly limited, but can be exemplified as follows. The thickness of one layer of the first transmission loss suppression layer BS1 and the second transmission loss suppression layer BS2 is preferably in the range of 2 μm to 100 μm, and more preferably in the range of 5 μm to 75 μm. The thickness of one layer of the dimensional accuracy maintaining layer PL is preferably in the range of 10 μm to 100 μm, and more preferably in the range of 12 μm to 50 μm. The thickness of one layer of the intermediate transmission loss suppression layer BS3 is preferably in the range of 12 μm to 150 μm, and more preferably in the range of 25 μm to 100 μm. The total thickness T of the resin laminate 20 is preferably in the range of 50 μm to 300 μm, and more preferably in the range of 75 μm to 200 μm.

Further, in order to achieve a resin laminate 20 as a whole is a low dielectric of the first transmission loss inhibiting layer BS1 and the second transmission loss inhibiting layer BS2 and the intermediate transmission loss inhibiting layer BS3 total thickness T _B relative to the total thickness of the resin laminate 20 T is preferably in the range of 40% to 75%, and more preferably in the range of 50% to 75%.

Hereinafter, each layer constituting the metal-clad laminate 10 will be described.

[Metal layer] The materials of the first metal layer M1 and the second metal layer M2 are not particularly limited. Examples include copper, stainless steel, iron, nickel, beryllium, aluminum, zinc, indium, silver, gold, tin, zirconium, tantalum, Titanium, lead, magnesium, manganese and their alloys, etc. Among them, copper or copper alloys are particularly preferred. In addition, the material of the wiring layer in the circuit board of the present embodiment described later is also the same as the first metal layer M1 and the second metal layer M2.

The thickness of the first metal layer M1 and the second metal layer M2 is not particularly limited. For example, when a metal foil such as copper foil is used, it is preferably 35 μm or less, and more preferably in the range of 5 μm to 25 μm. . From the viewpoint of production stability and handling properties, the lower limit of the thickness of the metal foil is preferably 5 μm. In addition, in the case of using copper foil, it may be rolled copper foil or electrolytic copper foil. In addition, as the copper foil, a commercially available copper foil can be used.

In addition, regarding the metal foil, for example, for the purpose of rust prevention treatment or improvement of adhesive strength, for example, surface treatment using siding, aluminum alcoholate, aluminum chelate, silane coupling agent, etc. may be performed.

[Transmission loss suppression layer] The resin constituting the first transmission loss suppression layer BS1, the second transmission loss suppression layer BS2, and the intermediate transmission loss suppression layer BS3 (hereinafter, these may be collectively referred to as "transmission loss suppression layer BS1-transmission loss suppression layer BS3") The glass transition temperature (Tg) of Tg is preferably 180°C or lower, and more preferably 160°C or lower. By setting the glass transition temperature of the transmission loss suppression layer BS1 to the transmission loss suppression layer BS3 to 180°C or less, thermocompression bonding at low temperature can be performed, so the internal stress generated during lamination can be relieved and the circuit processing can be suppressed. The size changes. If the Tg of the transmission loss suppression layer BS1 to the transmission loss suppression layer BS3 exceeds 180°C, the temperature at the time of bonding between the dimensional accuracy maintaining layers PL will increase, which will impair the dimensional stability after circuit processing. Yu.

The transmission loss suppression layer BS1-the transmission loss suppression layer BS3 are preferably such that the maximum value of the storage elastic coefficient in the temperature range of 100° C. to 250° C. is 1.0 GHz or less. If this kind of storage elastic coefficient is used, the internal stress during thermal compression bonding can be alleviated, and the dimensional stability after circuit processing can be maintained. In addition, even after the reflow soldering step after circuit processing, warping is not likely to occur.

The resin constituting the first transmission loss suppression layer BS1, the second transmission loss suppression layer BS2, and the intermediate transmission loss suppression layer BS3 is preferably polyimide, and more preferably a precursor obtained by reacting an acid anhydride component with a diamine component The thermoplastic polyimide obtained by the imidization of polyamide (hereinafter, sometimes referred to as "DDA-based polyimide") or its cross-linked and cured product, the diamine component is relative to the total amount of the diamine component A dimer diamine in which the two terminal carboxylic acid groups of a dimer acid having an amount of 100 mol parts and 50 mol parts or more are substituted with a primary aminomethyl group or an amino group. Furthermore, in the case of polyimide in the present invention, in addition to polyimide, it still refers to polyimide, polyetherimide, polyesterimide, polysiloxane A resin containing a polymer having an imine group in a molecular structure, such as imine and polybenzimidazole imine.

＜DDA series polyimide＞ DDA-based polyimide is an aliphatic thermoplastic polyimide, which is rich in flexibility. Even when a large amount of liquid crystalline polymer filler is added, it has sufficient toughness. When a resin film is formed, it maintains Its shape capability is high.

The DDA-based polyimide contains a tetracarboxylic acid residue derived from a tetracarboxylic anhydride as a raw material and a diamine residue derived from a diamine compound as a raw material. Furthermore, in the present invention, the tetracarboxylic acid residue means a tetravalent group derived from tetracarboxylic dianhydride, and the diamine residue means a divalent group derived from a diamine compound. By reacting the tetracarboxylic anhydride and diamine compound as the raw material with approximately equal molar reaction, the type and amount of the tetracarboxylic acid residue and the diamine residue contained in the DDA-based polyimide and the type of the raw material can be changed The amount roughly corresponds.

(Anhydride component) DDA-based polyimine can be used as a raw material without particular limitation, tetracarboxylic anhydride generally used in thermoplastic polyimine, but it is preferable to contain 90 mol% or more of the following general formula in total with respect to all acid anhydride components (1) and/or tetracarboxylic anhydride represented by general formula (2). In other words, the DDA-based polyimide preferably contains a total of 90 mol parts or more, represented by the following general formula (1) and/or general formula (2), based on 100 mol parts of all tetracarboxylic acid residues. Tetracarboxylic acid residue derived from tetracarboxylic anhydride. By containing a total of 90 mol parts or more of tetracarboxylic acid residues derived from tetracarboxylic anhydrides represented by the following general formula (1) and/or general formula (2) with respect to 100 mol parts of tetracarboxylic acid residues , It is easy to realize the coexistence of flexibility and heat resistance of DDA-based polyimide, which is preferable. If the total amount of tetracarboxylic acid residues derived from the tetracarboxylic anhydride represented by the following general formula (1) and/or general formula (2) is less than 90 moles, the solvent of DDA-based polyimide will dissolve Tendency to decrease sex.

[化1]

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

[化2]

In the formula, Z represents -C ₆ H ₄ -, -(CH ₂ )n- or -CH ₂ -CH(-OC(=O)-CH ₃ )-CH ₂ -, n represents 1-20 Integer.

As the tetracarboxylic anhydride represented by the general formula (1), for example, 3,3',4,4'-biphenyl tetracarboxylic dianhydride (3,3',4,4'-biphenyl tetracarboxylic dianhydride) , BPDA), 3,3',4,4'-benzophenone tetracarboxylic dianhydride (3,3',4,4'-benzophenone tetracarboxylic dianhydride, BTDA), 3,3',4,4' -Diphenylsulfone tetracarboxylic dianhydride (3,3',4,4'-diphenylsulfone tetracarboxylic dianhydride, DSDA), 4,4'-oxydiphthalic dianhydride (4,4'-oxydiphthalic dianhydride, ODPA), 4,4'-(hexafluoroisopropylidene)diphthalic anhydride (4,4'-(hexafluoroisopropylidene)diphthalic anhydride, 6FDA), 2,2-bis[4-(3,4- Dicarboxyphenoxy) phenyl] propane dianhydride (2,2-bis[4-(3,4-dicarboxyphenoxy]propane dianhydride, BPADA), p-phenylene bis(trimellitic acid monoester) anhydride (p -phenylene bis (trimellitic acid monoester) anhydride, TAHQ), ethylene glycol bistrimellitic anhydride (TMEG), etc. Among these, 3,3',4,4'-benzophenone tetracarboxylic acid is particularly preferred Acid dianhydride (BTDA). In the case of BTDA, the carbonyl group (ketone group) contributes to the adhesion, so it can improve the adhesion of the DDA-based polyimide. In addition, BTDA has some existing in the molecular skeleton When the ketone group reacts with the amino group of the amino compound formed by crosslinking described later to form a C=N bond, it is easy to exhibit the effect of improving the heat resistance. From this point of view, it is relative to 100 tetracarboxylic acid residues. It is preferable to contain a tetracarboxylic acid residue derived from BTDA in a molar amount of preferably 50 molar parts or more, more preferably 60 molar parts or more.

In addition, as the tetracarboxylic anhydride represented by the general formula (2), for example, 1,2,3,4-cyclobutane tetracarboxylic dianhydride, 1,2,3,4-cyclopentane tetracarboxylic acid can be cited Dianhydride, 1,2,4,5-cyclohexanetetracarboxylic dianhydride, 1,2,4,5-cycloheptanetetracarboxylic dianhydride, 1,2,5,6-cyclooctane tetracarboxylic acid Acid dianhydride and so on.

The DDA-based polyimide may contain a tetracarboxylic acid residue derived from an acid anhydride other than the tetracarboxylic anhydride represented by the general formula (1) and the general formula (2) within a range that does not impair the effect of the invention. The tetracarboxylic acid residue is not particularly limited, and examples include pyromellitic dianhydride, 2,3',3,4'-biphenyltetracarboxylic dianhydride, 2,2',3, 3'-benzophenone tetracarboxylic dianhydride or 2,3,3',4'-benzophenone tetracarboxylic dianhydride, 2,3',3,4'-diphenyl ether tetracarboxylic acid Dianhydride, bis(2,3-dicarboxyphenyl) ether dianhydride, 3,3``,4,4''-p-terphenyltetracarboxylic dianhydride, 2,3,3``,4'' -P-terphenyltetracarboxylic dianhydride or 2,2``,3,3''-p-terphenyltetracarboxylic dianhydride, 2,2-bis(2,3-dicarboxyphenyl)-propane dianhydride Or 2,2-bis(3,4-dicarboxyphenyl)-propane dianhydride, bis(2,3-dicarboxyphenyl)methane dianhydride or bis(3,4-dicarboxyphenyl)methane dianhydride , Bis(2,3-dicarboxyphenyl) dianhydride or bis(3,4-dicarboxyphenyl) dianhydride, 1,1-bis(2,3-dicarboxyphenyl)ethane dianhydride Or 1,1-bis(3,4-dicarboxyphenyl)ethane dianhydride, 1,2,7,8-phenanthrene-tetracarboxylic dianhydride, 1,2,6,7-phenanthrene-tetracarboxylic acid Dianhydride or 1,2,9,10-phenanthrene-tetracarboxylic dianhydride, 2,3,6,7-anthracene tetracarboxylic dianhydride, 2,2-bis(3,4-dicarboxyphenyl)tetra Fluoropropane dianhydride, 1,2,5,6-naphthalenetetracarboxylic dianhydride, 1,4,5,8-naphthalenetetracarboxylic dianhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride, 4,8-Dimethyl-1,2,3,5,6,7-hexahydronaphthalene-1,2,5,6-tetracarboxylic dianhydride, 2,6-dichloronaphthalene-1,4, 5,8-tetracarboxylic dianhydride or 2,7-dichloronaphthalene-1,4,5,8-tetracarboxylic dianhydride, 2,3,6,7-(or 1,4,5,8- ) Tetrachloronaphthalene-1,4,5,8-(or 2,3,6,7-)tetracarboxylic dianhydride, 2,3,8,9-perylene-tetracarboxylic dianhydride, 3,4, 9,10-perylene-tetracarboxylic dianhydride, 4,5,10,11-perylene-tetracarboxylic dianhydride or 5,6,11,12-perylene-tetracarboxylic dianhydride, pyrazine-2,3 ,5,6-tetracarboxylic dianhydride, pyrrolidine-2,3,4,5-tetracarboxylic dianhydride, thiophene-2,3,4,5-tetracarboxylic dianhydride, 4,4'-bis (2,3-Dicarboxyphenoxy) tetracarboxylic acid residue derived from aromatic tetracarboxylic dianhydride such as diphenylmethane dianhydride.

(Diamine component) The DDA-based polyimide uses the following diamine component as a raw material, the diamine component contains 50 mol parts or more, more preferably 70 mol parts or more of dimerization relative to 100 mol parts of the total amount of diamine components A dimer diamine in which the two terminal carboxylic acid groups of an acid are substituted by a primary aminomethyl group or an amino group. By containing the dimer diamine in this amount, the dielectric properties of the polyimine can be improved, and the thermocompression bonding properties can be improved by lowering the glass transition temperature of the polyimine (lower Tg) and The internal stress is alleviated by lowering the coefficient of elasticity.

The so-called dimer diamine refers to a diamine in which the two terminal carboxylic acid groups (-COOH) of the dimer acid are replaced by 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. Its industrial manufacturing process has been roughly standardized in the industry, and clay catalysts and other unsaturated fatty acids with carbon numbers of 11-22 can be used. Obtained by dimerization. Regarding the industrially obtained dimer acid, the main component is the 36 carbon dibasic acid obtained by dimerizing oleic acid, linoleic acid, linolenic acid, and other unsaturated fatty acids with carbon number 18, depending on the degree of purification It contains any amount of monomeric acid (18 carbon atoms), trimer acid (54 carbon atoms), and other polymerized fatty acids with 20 to 54 carbon atoms. In addition, the double bond remains after the dimerization reaction. However, in the present invention, the dimer acid also includes a compound that further undergoes a hydrogenation reaction to reduce the degree of unsaturation. Dimer diamine can be defined as a diamine obtained by substituting a terminal carboxylic acid group of a dibasic acid compound having a carbon number in the range of 18-54, preferably in the range of 22-44, with a primary aminomethyl group or an amino group Compound.

As a characteristic of the dimer diamine, the characteristic derived from the skeleton of the dimer acid can be imparted. That is, the dimer diamine is an aliphatic macromolecule with a molecular weight of about 560 to 620, so the molar volume of the molecule can be increased, and the polar group of the DDA-based polyimide can be relatively reduced. It is believed that the characteristics of such dimer acid-type diamines contribute to suppressing the decrease in the heat resistance of the DDA-based polyimide, and reducing the dielectric constant and the dielectric loss tangent to improve the dielectric properties. In addition, since it contains two freely movable hydrophobic chains with 7-9 carbons and two chain aliphatic amino groups with a length close to 18 carbons, it can not only impart flexibility to the DDA-based polyimide, but also The DDA-based polyimide can also be made into an asymmetric chemical structure or a non-planar chemical structure, so it is considered that a low dielectric constant can be achieved.

The dimer diamine used in the present invention is preferably purified for the purpose of reducing components other than the dimer diamine. The purification method is not particularly limited, but well-known methods such as distillation and precipitation purification are suitable. The dimer diamine before refining can be obtained as a commercially available product. Examples include: PRIAMINE 1073 (trade name) manufactured by Croda Japan, and Croda Japan. PRIAMINE 1074 (trade name) manufactured by the company, PRIAMINE 1075 (trade name) manufactured by Croda Japan, etc.

Examples of diamine compounds other than the dimer diamine used in the DDA-based polyimide include aromatic diamine compounds and aliphatic diamine compounds. Specific examples of these include: 1,4-diaminobenzene (p-PDA (p-phenylenediamine); p-phenylenediamine), 2,2'-dimethyl-4,4'-diaminobiphenyl (2,2'-dimethyl-4,4'-diamino biphenyl, m-TB), 2,2'-n-propyl-4,4'-diamino biphenyl (2,2'-n-propyl-4 ,4'-diamino biphenyl, m-NPB), 4-amino phenyl-4'-amino benzoate (APAB), 2,2-bis-[4- (3-Aminophenoxy)phenyl]propane, bis[4-(3-aminophenoxy)phenyl]sulfonate, bis[4-(3-aminophenoxy)]biphenyl, 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]sulfuron, 2,2-bis-[4-(4-aminophenoxy) Yl)phenyl]hexafluoropropane, 2,2-bis-[4-(3-aminophenoxy)phenyl]hexafluoropropane, 3,3'-dimethyl-4,4'-diamino Benzene, 4,4'-methylenebis-o-toluidine, 4,4'-methylenebis-2,6-xylidine, 4,4'-methylene-2,6-diethyl Aniline, 3,3'-diaminodiphenylethane, 3,3'-diaminodiphenyl, 3,3'-dimethoxybenzidine, 3,3''-diamino-p-terphenyl, 4,4'-[1,4-phenylenebis(1-methylethylene)]bisaniline, 4,4'-[1,3-phenylenebis(1-methylethylene) ]Bisaniline, bis(p-aminocyclohexyl)methane, bis(p-β-amino-tert-butylphenyl) ether, bis(p-β-methyl-δ-aminopentyl)benzene, p-bis( 2-Methyl-4-aminopentyl)benzene, p-bis(1,1-dimethyl-5-aminopentyl)benzene, 1,5-diaminonaphthalene, 2,6-diaminonaphthalene, 2, 4-bis(β-amino-tertiary butyl) toluene, 2,4-diaminotoluene, meta-xylene-2,5-diamine, para-xylene-2,5-diamine, meta-xylylenediamine , P-xylylenediamine, 2,6-diaminopyridine, 2,5-diaminopyridine, 2,5-diamino-1,3,4-oxadiazole, piperazine, 2'-methoxy- 4,4'-diaminobenzaniline, 4,4'-diaminobenzaniline, 1,3-bis[2-(4-aminophenyl)-2-propyl]benzene, 6-amino Diamine compounds such as -2-(4-aminophenoxy)benzoxazole and 1,3-bis(3-aminophenoxy)benzene.

The DDA-based polyimide can be produced by reacting the acid anhydride component and the diamine component in a solvent to produce polyamide acid and then heating the ring to close it. For example, the acid anhydride component and the diamine component are dissolved in an organic solvent at approximately equal moles and stirred at a temperature in the range of 0°C to 100°C for 30 minutes to 24 hours to carry out the polymerization reaction, thereby obtaining a polyamide Polyamide acid which is the precursor of imine. At the time of the reaction, the reaction component is dissolved so that the produced precursor is in the range of 5% by weight to 50% by weight, preferably in the range of 10% by weight to 40% by weight, in the organic solvent. As the organic solvent used in the polymerization reaction, for example, N,N-dimethylformamide (N,N-dimethylformamide, DMF), N,N-dimethylformamide (N,N-dimethylformamide, acetamide, DMAc), N,N-diethyl acetamide, N-methyl-2-pyrrolidone (N-methyl-2-pyrrolidone, NMP), 2-butanone, dimethylsulfoxide (dimethylsulfoxide) , DMSO), hexamethylphosphamide, N-methylcaprolactam, dimethyl sulfate, cyclohexanone, methylcyclohexane, dioxane, tetrahydrofuran, diethylene glycol dimethyl ether (diglyme ), triethylene glycol dimethyl ether (triglyme), methanol, ethanol, benzyl alcohol, cresol, etc. These solvents may be used in combination of two or more types, and aromatic hydrocarbons such as xylene and toluene may also be used in combination. In addition, the amount of such an organic solvent used is not particularly limited, but it is preferably adjusted so that the concentration of the polyamide acid solution obtained by the polymerization reaction becomes about 5% by weight to 50% by weight.

The synthesized polyamide acid is advantageously generally used as a reaction solvent solution, and can be concentrated, diluted or replaced with other organic solvents as necessary. In addition, polyamide acid is generally excellent in solvent solubility, and therefore is advantageously used. The viscosity of the polyamide acid solution is preferably in the range of 500 mPa·s to 100,000 mPa·s. If it deviates from the above range, defects such as thickness unevenness and streaks are likely to occur in the film during coating work using a coater or the like.

There is no particular limitation on the method of imidizing polyamide acid to form polyimide. For example, a temperature condition in the range of 80°C to 400°C in the solvent can be suitably used for 1 hour to 24 hours. Heat treatment such as heating for hours. In addition, regarding the temperature, heating may be performed under a fixed temperature condition, or the temperature may be changed in the middle of the step.

By selecting the type of the acid anhydride component and diamine component in the DDA-based polyimide, or using the respective molar ratios of two or more acid anhydride components or diamine components, it is possible to control the dielectric properties, the coefficient of thermal expansion, Tensile coefficient of elasticity, glass transition temperature, etc. In addition, when there are a plurality of polyimine structural units in the DDA-based polyimine, it may exist in the form of a block or may exist randomly, but it is preferably present randomly.

The weight average molecular weight of the DDA-based polyimine is, for example, preferably in the range of 10,000 to 200,000, and if it is within such a range, the weight average molecular weight of the polyimide can be easily controlled. In addition, when used as an adhesive for FPC, for example, the weight average molecular weight of the DDA-based polyimide is more preferably in the range of 20,000 to 150,000, and still more preferably in the range of 40,000 to 150,000. When used as an adhesive for FPC, when the weight average molecular weight of the DDA-based polyimide is less than 20,000, the flow resistance tends to deteriorate. On the other hand, if the weight average molecular weight of the DDA-based polyimide exceeds 150,000, the viscosity increases excessively and becomes insoluble in solvents, and defects such as uneven thickness of the adhesive layer and streaks tend to occur during the coating operation.

The concentration of the imine group of the DDA-based polyimide is preferably 22% by weight or less, and more preferably 20% by weight or less. Here, the "imine group concentration" refers to _{the value obtained by dividing the molecular weight of the polyimine group (-(CO) 2} -N-) by the molecular weight of the entire structure of the polyimide . If the concentration of the imine group exceeds 22% by weight, the molecular weight of the resin itself becomes small, and the low hygroscopicity is also deteriorated due to the increase of the polar group, and the Tg and elastic coefficient increase.

The DDA-based polyimide is most preferably a structure that is completely imidized. However, a part of polyimide may also become amide acid. The imidization rate can be measured by using a Fourier transform infrared spectrophotometer (commercially available product: FT/IR620 manufactured by JASCO Corporation), and using the Attenuated Total Reflection (ATR) method to measure polyimide The infrared absorption spectrum of the film was measured, and it was calculated based on the absorbance of C=O stretched and stretched at ^{1780 cm -1} derived from the amide group based on the benzene ring absorber in the vicinity of ^{1015 cm -1.}

In the DDA-based polyimide, other hardening resin components such as plasticizers, epoxy resins, hardeners, hardening accelerators, inorganic fillers, coupling agents, fillers, solvents, flame retardants, etc. can be suitably formulated as optional components. .

[Crosslink formation of DDA series polyimine] When the DDA-based polyimide has a ketone group, the ketone group is combined with an amino compound having at least two primary amino groups as functional groups (hereinafter, sometimes referred to as "amino compound for crosslinking formation") The amino group reacts to form a C=N bond, thereby forming a cross-linked structure. By forming a cross-linked structure, the heat resistance of the DDA-based polyimide can be improved. As a tetracarboxylic anhydride that is preferable for forming a DDA-based polyimide having a ketone group, for example, 3,3',4,4'-benzophenone tetracarboxylic dianhydride (BTDA) can be cited as a diamine compound For example, 4,4'-bis(3-aminophenoxy)benzophenone (4,4'-bis(3-aminophenoxy)benzophenone, BABP), 1,3-bis[4-(3- Aromatic diamines such as 1,3-bis[4-(3-aminophenoxy)benzoyl]benzene (BABB), etc.

For the purpose of forming a cross-linked structure, it is particularly preferable to include the DDA-based polyimine and an amino compound for cross-linking formation, and the DDA-based polyimine contains preferably 50% relative to all tetracarboxylic acid residues. Mole% or more, more preferably 60 mole% or more of BTDA residues derived from BTDA. Furthermore, in the present invention, the so-called "BTDA residue" refers to a tetravalent group derived from BTDA.

As an amino compound for crosslinking formation, (I) a dihydrazine compound, (II) aromatic diamine, (III) aliphatic amine, etc. can be illustrated. Among these, dihydrazine compounds are preferred. Aliphatic amines other than the dihydrazine compound tend to form a crosslinked structure even at room temperature, and there is a concern about the storage stability of the varnish. On the other hand, the aromatic diamine needs to be set to a high temperature in order to form a crosslinked structure. As described above, when the dihydrazine compound is used, the storage stability of the varnish and the shortening of the curing time can be coexisted. As the dihydrazine compound, for example, dihydrazine oxalate, dihydrazine malonate, dihydrazine succinate, dihydrazine glutarate, dihydrazine adipate, dihydrazine pimelate, Dihydrazine suberate, dihydrazine azelate, dihydrazine sebacate, dihydrazine dodecanedioate, dihydrazine maleate, dihydrazine fumarate, diglycolic acid dihydrazide Hydrazine, dihydrazine tartrate, dihydrazine malate, dihydrazine phthalate, dihydrazine isophthalate, dihydrazine terephthalate, dihydrazine 2,6-naphthoate, 4,4 -Diphenyldihydrazine, 1,4-naphthoic acid dihydrazine, 2,6-pyridine diacid dihydrazine, itaconic acid dihydrazine and other dihydrazine compounds. The above dihydrazine compounds may be used alone, or two or more of them may be mixed and used.

In addition, the amino compounds such as (I) dihydrazine compounds, (II) aromatic diamines, (III) aliphatic amines, etc. may also be, for example, combinations of (I) and (II), (I) and (III) The combination of (I), (II) and (III), the super category uses two or more combinations.

In addition, from the viewpoint of making the network structure formed by crosslinking with the crosslinking amino compound denser, the molecular weight of the crosslinking amino compound used in the present invention (in the crosslinking amino compound In the case of an oligomer, the weight average molecular weight) is preferably 5,000 or less, and more preferably 90 to 2,000, and still more preferably 100 to 1,500. Among them, particularly preferred is an amino compound for crosslinking formation having a molecular weight of 100 to 1,000. If the molecular weight of the cross-linking amino compound is less than 90, one amino group of the cross-linking amino compound is limited to forming a C=N bond with the ketone group of the DDA-based polyimide, and the surrounding area of the remaining amino group becomes three-dimensionally bulky , So there is a tendency that the remaining amino groups are not easy to form C=N bonds.

In the case of cross-linking the ketone group in the DDA-based polyimide with the cross-linking amino compound, the cross-linking-forming amino compound is added to the resin solution containing the DDA-based polyimide to make The ketone group in the DDA-based polyimide undergoes a condensation reaction with the primary amino group of the crosslinking amino compound. Through the condensation reaction, the resin solution is cured to become a cured product. In this case, the addition amount of the amino compound for crosslinking can be set to a total of 0.004 mol to 1.5 mol, preferably 0.005 mol to 1.2 mol, based on 1 mol of the ketone group. It is more preferably 0.03 mol to 0.9 mol, most preferably 0.04 mol to 0.6 mol. Regarding the addition amount of the cross-linking amino compound such as 1 mol of the ketone group and less than 0.004 mol in total, the cross-linking by the cross-linking amino compound is insufficient, so it is difficult to exhibit hardening. After the tendency of heat resistance, if the addition amount of the amino compound for crosslinking exceeds 1.5 mol, the unreacted amino compound for crosslinking acts as a thermoplastic agent, which may reduce the heat resistance of the adhesive layer. Propensity.

The conditions for the condensation reaction for cross-linking formation are the conditions that the ketone group in the DDA-based polyimide reacts with the primary amino group of the amino compound for cross-linking formation to form an imine bond (C=N bond) , There are no special restrictions. Regarding the heating condensation temperature, it is preferable to release the water produced by condensation to the outside of the system, or to simplify the condensation step when the heating condensation reaction is performed after the synthesis of the DDA-based polyimide. For example, it is preferable It is within the range of 120°C to 220°C, more preferably within the range of 140°C to 200°C. The reaction time is preferably about 30 minutes to 24 hours. The end point of the reaction can be measured, for example, by using a Fourier transform infrared spectrophotometer (commercial product: FT/IR620 manufactured by JASCO Corporation) to measure the infrared absorption spectrum, and using the polyimide resin in the vicinity of ^{1670 cm -1} It was confirmed that the absorption peak of the ketone group decreased or disappeared, and the absorption peak derived from the imine group near ^{1635 cm -1 appeared.}

The heating condensation of the ketone group of the DDA-based polyimide and the primary amino group of the amino compound for crosslinking can be carried out, for example, by the following method: (1) Immediately after the synthesis of the DDA-based polyimide (imination), an amino compound for crosslinking is added and heated; (2) Preliminarily put an excessive amount of amino compound as the diamine component, followed by the synthesis of DDA-based polyimid (imidation), and use the remaining amino compound that does not participate in imidization or amidation as A method of forming an amino compound for cross-linking and heating together with DDA-based polyimide; or (3) After processing the DDA-based polyimide composition to which the amino compound for crosslinking is added into a predetermined shape (for example, after coating on any substrate or after forming into a film) Method of heating.

In order to impart heat resistance to the DDA-based polyimide, the formation of the imine bond is described in the formation of the cross-linked structure, but it is not limited to this. As a curing method of the polyimide, for example, epoxy resin can also be formulated , Epoxy resin curing agent, maleimide, activated ester resin, or resin with styrene skeleton, and other compounds having unsaturated bonds.

[Dimensional accuracy maintenance layer] Regarding the dimensional accuracy maintaining layer PL, in order to maintain the mechanical strength of the metal-clad laminate 10, the minimum value of the storage elastic coefficient in the temperature range of 100°C to 250°C is preferably in the range of 1.0 GPa to 8.0 GPa, more preferably 2.0 GPa ～6.0 GPa. If the minimum value of the storage elastic coefficient of the dimensional accuracy maintaining layer PL is less than 1.0 GPa, sufficient mechanical strength and dimensional accuracy after circuit processing cannot be obtained. When the minimum value of the storage elasticity coefficient exceeds 8.0 GPa, warping is likely to occur during lamination pressing.

In addition, regarding the dimensional accuracy maintaining layer PL, in order to maintain the dimensional accuracy during circuit processing of the metal-clad laminate 10, the coefficient of thermal expansion (CTE) is preferably in the range of 15 ppm/K to 25 ppm/K. It is more preferably in the range of 16 ppm/K to 23 ppm/K. If the CTE of the dimensional accuracy maintaining layer PL is less than 15 ppm/K, the metal-clad laminate 10 is likely to warp, and if it exceeds 25 ppm/K, the dimensional accuracy after circuit processing cannot be obtained.

The dimensional accuracy maintaining layer PL is not particularly limited as long as it contains a resin with electrical insulation. Examples include polyimide, epoxy resin, phenol resin, polyethylene, polypropylene, polytetrafluoroethylene, silicone, and vinyl. It is preferable that tetrafluoroethylene (Ethylene tetrafluoroethylene, ETFE) etc. contain polyimide. That is, the dimensional accuracy maintaining layer PL is preferably a single layer or a low thermal expansion polyimide layer composed of multiple layers.

When the dimensional accuracy maintaining layer PL is a single-layer polyimide layer, it can have the same structure as the non-thermoplastic polyimide layer 31 described later. As a single-layer polyimide layer, for example, Kapton EN (trade name; manufactured by Toray dupont), Apical NPI (trade name; KANEKA ) Company system) and other commercially available products.

In the case where the dimensional accuracy maintaining layer PL includes multiple polyimide layers, as shown in FIG. 4, the dimensional accuracy maintaining layer PL may be, for example, a non-thermoplastic polyimide layer containing non-thermoplastic polyimide as a resin component. A structure in which a thermoplastic polyimide layer 33 containing a thermoplastic polyimide as a resin component is laminated on both sides of 31. Furthermore, the so-called "non-thermoplastic polyimide" is usually a polyimide that does not show softening and adhesiveness even when heated, but in the present invention, it refers to the use of a dynamic viscoelasticity measuring device (dynamic thermomechanical analyzer). (Dynamic thermomechanical analyzer, DMA)) measured, the storage modulus at 30 deg.] C is 1.0 × 10 ⁹ Pa or more and a storage modulus at 350 deg.] C less than 1.0 × 10 ⁸ Pa is polyimide. In addition, the so-called "thermoplastic polyimide" is usually a polyimide whose glass transition temperature (Tg) can be clearly confirmed, but in the present invention, it refers to the storage elasticity coefficient at 30°C measured using DMA It is a polyimide with 1.0×10 ⁹ Pa or more and a storage elastic modulus at 350°C of less than 1.0×10 ^{8 Pa.}

Next, a preferable structure example of the non-thermoplastic polyimide layer 31 and the thermoplastic polyimide layer 33 for constituting the dimensional accuracy maintaining layer PL will be described.

Non-thermoplastic polyimide layer: The non-thermoplastic polyimide constituting the non-thermoplastic polyimide layer 31 includes a tetracarboxylic acid residue and a diamine residue. The polyimide preferably contains an aromatic tetracarboxylic acid residue derived from an aromatic tetracarboxylic dianhydride and an aromatic diamine residue derived from an aromatic diamine.

(Tetracarboxylic acid residue) The non-thermoplastic polyimide constituting the non-thermoplastic polyimide layer 31 preferably contains 3,3',4,4'-biphenyltetracarboxylic dianhydride (BPDA) and 1,4-phenylene bis( Trimellitic acid monoester) dianhydride (1,4-phenylene bis (trimellitic acid monoester) dianhydride, TAHQ) derived from at least one tetracarboxylic acid residue and from pyromellitic dianhydride (Pyromellitic dianhydride, PMDA) and At least one tetracarboxylic acid residue derived from 2,3,6,7-naphthalene tetracarboxylic dianhydride (NTCDA) is used as the tetracarboxylic acid residue.

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") easily form the order of the polymer The structure can reduce the dielectric loss tangent or hygroscopicity by inhibiting the movement of molecules. BPDA residues can impart self-supporting properties to the gel film of polyimide, which is the precursor of polyimide. On the other hand, the CTE after imidization is increased, and the glass transition temperature is lowered. The tendency to reduce heat resistance.

From this viewpoint, the non-thermoplastic polyimide constituting the non-thermoplastic polyimide layer 31 is preferably 30 mol parts or more and 60 mol parts in total with respect to 100 mol parts of all tetracarboxylic acid residues. The manner in which the BPDA residue and the TAHQ residue are contained within the following range, more preferably within the range of 40 mol parts or more and 50 mol parts or less, is controlled. If the total of BPDA residues and TAHQ residues is less than 30 moles, the formation of the ordered structure of the polymer will become insufficient, the moisture resistance will decrease, or the reduction of the dielectric loss tangent will become insufficient. 60 mole parts, in addition to the increase in CTE or the increase in the amount of change in the in-plane retardation (RO), there is also a risk of a decrease in heat resistance.

In addition, tetracarboxylic acid residues derived from pyromellitic dianhydride (hereinafter also referred to as "PMDA residues") and tetracarboxylic acid residues derived from 2,3,6,7-naphthalenetetracarboxylic dianhydride The radical (hereinafter, also referred to as "NTCDA residue") has rigidity, so it is a residue that improves in-plane alignment, suppresses CTE to a low level, and controls in-plane retardation (RO) or glass transition temperature. base. On the other hand, PMDA residues have a small molecular weight, so if the amount becomes too large, the concentration of the polymer's imine groups will increase, the polar groups will increase, and the hygroscopicity will increase. This is due to the influence of the moisture inside the molecular chain. The electrical loss tangent increases. In addition, NTCDA residues tend to become brittle and increase the elastic modulus due to the naphthalene skeleton with high rigidity. Therefore, the non-thermoplastic polyimide constituting the non-thermoplastic polyimide layer is preferably within the range of 40 mol parts or more and 70 mol parts in total with respect to 100 mol parts of all tetracarboxylic acid residues. It is more preferable that the PMDA residue and the NTCDA residue are contained in the range of 50 mol parts or more and 60 mol parts or less, and still more preferably in the range of 50 mol parts to 55 mol parts. If the total of PMDA residues and NTCDA residues is less than 40 mol parts, the CTE may increase or the heat resistance may decrease. If it exceeds 70 mol parts, the concentration of the polymer's imine groups may increase and the polar groups may increase. Increased and low hygroscopicity is impaired, and the dielectric loss tangent may increase; or the film may become brittle and the self-supporting property of the film may decrease.

In addition, the total of at least one of BPDA residues and TAHQ residues and at least one of PMDA residues and NTCDA residues is 80 mol parts or more, preferably 90 mol parts relative to 100 mol parts of all tetracarboxylic acid residues. More than mol portion is suitable.

In addition, the molar ratio of at least one of BPDA residues and TAHQ residues to at least one of PMDA residues and NTCDA residues {(BPDA residues + TAHQ residues)/(PMDA residues + NTCDA residues) } It is preferably in the range of 0.4 or more and 1.5 or less, preferably in the range of 0.6 or more and 1.3 or less, more preferably in the range of 0.8 or more and 1.2 or less, to control the formation of an ordered structure of CTE and the polymer.

PMDA and NTCDA have a rigid skeleton, so compared with other common acid anhydride components, it can control the in-plane orientation of the molecules in polyimine, and has the suppression of the coefficient of thermal expansion (CTE) and the glass transition temperature (Tg) The improvement effect. In addition, compared with PMDA, BPDA and TAHQ have a larger molecular weight, so the increase in the input ratio reduces the concentration of the imine group, thereby having an effect on the reduction of the dielectric loss tangent or the reduction of the moisture absorption rate. On the other hand, if the input ratio of BPDA and TAHQ increases, the in-plane orientation of the molecules in the polyimide decreases, leading to an increase in CTE. Furthermore, the formation of an ordered structure within the molecule advances, and the haze value increases. From this point of view, the total input amount of PMDA and NTCDA is in the range of 40 mol parts to 70 mol parts relative to 100 mol parts of the total acid anhydride components of the raw materials, preferably 50 mol parts to 60 mol parts. It is more preferable to be in the range of ear parts, more preferably in the range of 50 mol parts to 55 mol parts. If the total input amount of PMDA and NTCDA is less than 40 mol parts relative to 100 mol parts of the total acid anhydride components of the raw materials, the in-plane alignment of the molecules will decrease, and it will be difficult to achieve low CTE. The heat resistance or dimensional stability of the film at the time of heating caused by the decrease is decreased. On the other hand, if the total input amount of PMDA and NTCDA exceeds 70 mole parts, the moisture absorption rate will deteriorate due to the increase in the imidine group concentration, or the elastic modulus will tend to increase.

In addition, BPDA and TAHQ are effective in reducing the dielectric loss tangent and lowering the moisture absorption rate caused by the suppression of molecular motion or the decrease in the concentration of amide groups. The CTE increases. From this point of view, the total input amount of BPDA and TAHQ is in the range of 30 mol parts to 60 mol parts relative to 100 mol parts of all acid anhydride components of the raw materials, preferably 40 mol parts to 50 mol parts Appropriate within the range of ears.

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 non-thermoplastic polyimide layer 31 include 3,3',4,4'-diphenyl tetracarboxylic dianhydride, 4,4'-oxydiphthalic anhydride, 2,3',3,4'-biphenyl tetracarboxylic dianhydride Anhydride, 2,2',3,3'-benzophenone tetracarboxylic dianhydride, 2,3,3',4'-benzophenone tetracarboxylic dianhydride or 3,3',4,4 '-Benzophenone tetracarboxylic dianhydride, 2,3',3,4'-diphenyl ether tetracarboxylic dianhydride, bis(2,3-dicarboxyphenyl) ether dianhydride, 3,3 '',4,4''-p-terphenyltetracarboxylic dianhydride, 2,3,3'',4''-p-terphenyltetracarboxylic dianhydride or 2,2'',3,3'' -P-terphenyltetracarboxylic dianhydride, 2,2-bis(2,3-dicarboxyphenyl)-propane dianhydride or 2,2-bis(3,4-dicarboxyphenyl)-propane dianhydride, Bis(2,3-dicarboxyphenyl)methane dianhydride or bis(3,4-dicarboxyphenyl)methane dianhydride, bis(2,3-dicarboxyphenyl)methane dianhydride or bis(3,4 -Dicarboxyphenyl) dianhydride, 1,1-bis(2,3-dicarboxyphenyl)ethane dianhydride or 1,1-bis(3,4-dicarboxyphenyl)ethane dianhydride, 1,2,7,8-phenanthrene-tetracarboxylic dianhydride, 1,2,6,7-phenanthrene-tetracarboxylic dianhydride or 1,2,9,10-phenanthrene-tetracarboxylic dianhydride, 2, 3,6,7-anthracene tetracarboxylic dianhydride, 2,2-bis(3,4-dicarboxyphenyl)tetrafluoropropane 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-hexahydro Naphthalene-1,2,5,6-tetracarboxylic dianhydride, 2,6-dichloronaphthalene-1,4,5,8-tetracarboxylic dianhydride or 2,7-dichloronaphthalene-1,4, 5,8-tetracarboxylic dianhydride, 2,3,6,7-(or 1,4,5,8-)tetrachloronaphthalene-1,4,5,8-(or 2,3,6,7 -) Tetracarboxylic dianhydride, 2,3,8,9-perylene-tetracarboxylic dianhydride, 3,4,9,10-perylene-tetracarboxylic dianhydride, 4,5,10,11-perylene- Tetracarboxylic dianhydride 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 bistrimellitic anhydride, and other aromatic tetracarboxylic dianhydrides derived from tetracarboxylic acid residues.

(Diamine residue) The diamine residue contained in the non-thermoplastic polyimide constituting the non-thermoplastic polyimide layer 31 is preferably a diamine residue derived from a diamine compound represented by the general formula (A1).

[化3]

In the formula (A1), the linking group Z represents a single bond or -COO-, and Y independently represents a monovalent hydrocarbon group having 1 to 3 carbons, or an alkoxy group having 1 to 3 carbons, which may be substituted by a halogen atom or a phenyl group. A group or a perfluoroalkyl or alkenyl group having 1 to 3 carbon atoms, n represents an integer of 0 to 2, and p and q independently represent an integer of 0 to 4. Here, "independently" means that in the formula (A1), the plurality of substituents Y, the integer p, and the integer q may be the same or different. Furthermore, in the formula (A1), the hydrogen atoms in the two terminal amino groups may be substituted, for example, -NR ₂ R ₃ (here, R ₂ and R ₃ independently refer to an alkyl group, etc.) Optional substituents).

The diamine compound represented by the general formula (A1) (hereinafter, sometimes referred to as "diamine (A1)") is an aromatic diamine having one or three benzene rings. Since the diamine (A1) has a rigid structure, it has the effect of imparting an ordered structure to the entire polymer. Therefore, a polyimide with low air permeability and low hygroscopicity can be obtained, and the moisture inside the molecular chain can be reduced, so the dielectric loss tangent can be reduced. Here, as the linking group Z, a single bond is preferable.

As the diamine (A1), for example, 1,4-diaminobenzene (p-PDA; p-phenylenediamine), 2,2'-dimethyl-4,4'-diaminobiphenyl (m- TB), 2,2'-n-propyl-4,4'-diaminobiphenyl (m-NPB), 4-aminophenyl-4'-aminobenzoate (APAB), etc.

The non-thermoplastic polyimide constituting the non-thermoplastic polyimide layer 31 contains preferably 80 mol parts or more, more preferably 85 mol parts or more with respect to 100 mol parts of all diamine residues. Diamine residues derived from amine (A1) are preferred. By using the diamine (A1) in an amount within the above range, and using the rigid structure derived from the monomer, it is easy to form an ordered structure in the entire polymer, and it is easy to obtain low air permeability, low hygroscopicity, and low dielectric. Loss tangent non-thermoplastic polyimide.

In addition, the diamine residue derived from the diamine (A1) is in the range of 80 mol parts to 85 mol parts relative to 100 mol parts of all diamine residues in the non-thermoplastic polyimide In the case of internal, it is preferable to use 1,4-diaminobenzene as the diamine (A1) from the viewpoint of a more rigid structure and excellent in-plane alignment.

Examples of other diamine residues contained in the non-thermoplastic polyimide constituting the non-thermoplastic polyimide layer 31 include 2,2-bis-[4-(3-aminophenoxy)phenyl ] Propane, bis[4-(3-aminophenoxy)phenyl] sulfide, bis[4-(3-aminophenoxy)]biphenyl, bis[1-(3-aminophenoxy)] Benzene, bis[4-(3-aminophenoxy)phenyl]methane, bis[4-(3-aminophenoxy)phenyl]ether, bis[4-(3-aminophenoxy)]bis Benzophenone, 9,9-bis[4-(3-aminophenoxy)phenyl] sulfone, 2,2-bis-[4-(4-aminophenoxy)phenyl]hexafluoropropane, 2 ,2-Bis-[4-(3-Aminophenoxy)phenyl]hexafluoropropane, 3,3'-dimethyl-4,4'-diaminobiphenyl, 4,4'-methylene Di-o-toluidine, 4,4'-methylenebis-2,6-dimethylaniline, 4,4'-methylene-2,6-diethylaniline, 3,3'-diaminodi Phenylethane, 3,3'-diaminobiphenyl, 3,3'-dimethoxybenzidine, 3,3''-diamino-p-terphenyl, 4,4'-[1,4- Phenylenebis(1-methylethylene)]bisaniline, 4,4'-[1,3-phenylenebis(1-methylethylene)]bisaniline, bis(p-aminocyclohexyl) )Methane, bis(p-β-amino-tert-butylphenyl) ether, bis(p-β-methyl-δ-aminopentyl)benzene, p-bis(2-methyl-4-aminopentyl) Yl)benzene, p-bis(1,1-dimethyl-5-aminopentyl)benzene, 1,5-diaminonaphthalene, 2,6-diaminonaphthalene, 2,4-bis(β-amino- Tertiary butyl) toluene, 2,4-diaminotoluene, m-xylene-2,5-diamine, p-xylene-2,5-diamine, m-xylene diamine, p-xylene diamine, 2 ,6-Diaminopyridine, 2,5-diaminopyridine, 2,5-diamino-1,3,4-oxadiazole, piperazine, 2'-methoxy-4,4'-diaminobenzene Carboxamide, 4,4'-diaminobenzamide, 1,3-bis[2-(4-aminophenyl)-2-propyl]benzene, 6-amino-2-(4-aminobenzene (Oxy) diamine residues derived from aromatic diamine compounds such as benzoxazole, dimer acid type diamines and other fats in which two terminal carboxylic acid groups of dimer acid are substituted by primary aminomethyl or amino groups Diamine residues derived from a group of diamine compounds.

By selecting the types of the tetracarboxylic acid residues and diamine residues in the non-thermoplastic polyimide, or applying the respective molar ratios of two or more tetracarboxylic acid residues or diamine residues, Control thermal expansion coefficient, storage elastic coefficient, tensile elastic coefficient, etc. In addition, when there are a plurality of polyimine structural units in the non-thermoplastic polyimine, they may exist in the form of blocks or randomly, but from the viewpoint of suppressing the deviation of the in-plane retardation (RO) In other words, it is preferable to exist randomly.

Furthermore, by setting the tetracarboxylic acid residues and diamine residues contained in the non-thermoplastic polyimide as aromatic groups, the dimensional accuracy of the polyimide film under a high temperature environment can be improved, and the dimensional accuracy can be reduced. The amount of change in the in-face retardation (RO) is therefore preferable.

The concentration of the non-thermoplastic polyimine group is preferably 33% or less, and more preferably 32% or more. Here, the "imine group concentration" refers to _{the value obtained by dividing the molecular weight of the polyimine group (-(CO) 2} -N-) by the molecular weight of the entire structure of the polyimide . If the concentration of the imine group exceeds 33%, the molecular weight of the resin itself becomes small, and the low hygroscopicity also deteriorates due to the increase of the polar group. By selecting the combination of the acid anhydride and the diamine compound, the orientation of the molecules in the non-thermoplastic polyimine is controlled, thereby suppressing the increase in CTE accompanying the decrease in the concentration of the imine group, 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, and more preferably in the range of 50,000 to 350,000. If the weight average molecular weight is less than 10,000, the strength of the film decreases and it tends to become brittle. On the other hand, if the weight average molecular weight exceeds 400,000, the viscosity increases excessively, and defects such as film thickness unevenness and streaks tend to occur during the coating operation.

From the viewpoint of ensuring the function as a base layer and the transportability at the time of manufacture and at the time of thermoplastic polyimide coating, the thickness of the non-thermoplastic polyimide layer 31 is preferably in the range of 6 μm or more and 100 μm or less. More preferably, it is in the range of 9 μm or more and 50 μm or less. When the thickness of the non-thermoplastic polyimide layer 31 is less than the above-mentioned lower limit value, electrical insulation or handling properties become insufficient, and when the thickness exceeds the upper limit value, productivity decreases.

From the viewpoint of heat resistance, the glass transition temperature (Tg) of the non-thermoplastic polyimide layer 31 is preferably 280° C. or higher.

In addition, from the viewpoint of suppressing warpage, the thermal expansion coefficient of the non-thermoplastic polyimide layer 31 is in the range of 1 ppm/K or more and 30 ppm/K, preferably 1 ppm/K or more and 25 ppm/K. It is preferable to be in the range of K or less, more preferably in the range of 15 ppm/K or more and 25 ppm/K or less.

In addition, in the non-thermoplastic polyimide constituting the non-thermoplastic polyimide layer 31, other hardening resin components such as plasticizers, epoxy resins, hardeners, hardening accelerators, coupling agents, fillers, Solvents, flame retardants, etc. are used as optional components. However, there is a plasticizer containing a large amount of polar groups in the plasticizer, and there is a concern that it promotes the diffusion of copper from the copper wiring. Therefore, it is preferable not to use a plasticizer as much as possible.

Thermoplastic polyimide layer: The thermoplastic polyimide constituting the thermoplastic polyimide layer 33 contains a tetracarboxylic acid residue and a diamine residue, and preferably contains an aromatic tetracarboxylic acid residue derived from an aromatic tetracarboxylic dianhydride and an aromatic tetracarboxylic acid residue derived from an aromatic tetracarboxylic dianhydride. Aromatic diamine residue derived from diamine.

(Tetracarboxylic acid residue) As the tetracarboxylic acid residue used in the thermoplastic polyimide constituting the thermoplastic polyimide layer 33, the same as the tetracarboxylic acid residue in the non-thermoplastic polyimide constituting the non-thermoplastic polyimide layer can be used. The acid residue is the same as the exemplified group.

(Diamine residue) The diamine residue contained in the thermoplastic polyimide constituting the thermoplastic polyimide layer 33 is preferably a diamine residue derived from a diamine compound represented by the general formula (B1) to (B7) .

[化4]

In formulas (B1) to (B7), R ₁ independently represents a monovalent hydrocarbon group or alkoxy group having 1 to 6 carbon atoms, and the linking group A independently represents a group selected from -O-, -S-, -CO- , -SO-, -SO ₂ -, -COO-, -CH ₂ -, -C(CH ₃ ) ₂ -, -NH- or -CONH- in the divalent group, n ₁ independently represents 0～4 Integer. However, the part that overlaps with the formula (B2) is removed from the formula (B3), and the part that overlaps with the formula (B4) is removed from the formula (B5). Here, "independently" means that one or two or more of the above formulas (B1) to (B7), in which multiple linking groups A, multiple R ₁ or multiple n ₁ may be the same It can also be different. Furthermore, in the formulas (B1) to (B7), the hydrogen atoms in the two terminal amino groups may be substituted, for example, -NR ₂ R ₃ (here, R ₂ and R _{3 are} independently It means an optional substituent such as an alkyl group).

The diamine represented by the formula (B1) (hereinafter, sometimes referred to as "diamine (B1)") is an aromatic diamine having two benzene rings. It is believed that the diamine (B1) is in the meta position with the divalent linking group A through the amino group directly bonded to at least one benzene ring, and the polyimide molecular chain has an increased degree of freedom and high flexibility, which helps To improve the flexibility of the polyimide molecular chain. Therefore, by using diamine (B1), the thermoplasticity of polyimide improves. Here, the linking group A is preferably -O-, -CH ₂ -, -C(CH ₃ ) ₂ -, -CO-, -SO ₂ -, -S-.

As diamine (B1), for example, 3,3'-diaminodiphenylmethane, 3,3'-diaminodiphenylpropane, 3,3'-diaminodiphenyl sulfide, 3, 3'-Diaminodiphenyl sulfide, 3,3'-Diaminodiphenyl ether, 3,4'-Diaminodiphenyl ether, 3,4'-Diaminodiphenylmethane, 3,4' -Diaminodiphenylpropane, 3,4'-diaminodiphenyl sulfide, 3,3'-diaminobenzophenone, (3,3'-bisamino)diphenylamine, etc.

The diamine represented by the formula (B2) (hereinafter, sometimes referred to as "diamine (B2)") is an aromatic diamine having three benzene rings. It is believed that the diamine (B2) is in the meta position with the divalent linking group A through the amino group directly bonded to at least one benzene ring, and the polyimide molecular chain has an increased degree of freedom and high flexibility, which helps To improve the flexibility of the polyimide molecular chain. Therefore, by using diamine (B2), the thermoplasticity of polyimide is improved. Here, as the linking group A, -O- is preferable.

As the diamine (B2), for example, 1,4-bis(3-aminophenoxy)benzene, 3-[4-(4-aminophenoxy)phenoxy]aniline, 3-[3- (4-Aminophenoxy)phenoxy]aniline and the like.

The diamine represented by the formula (B3) (hereinafter, sometimes referred to as "diamine (B3)") is an aromatic diamine having three benzene rings. It is believed that the diamine (B3) is in the meta position with each other through the two divalent linking groups A directly bonded to a benzene ring, and the polyimide molecular chain has an increased degree of freedom and high flexibility, which helps To improve the flexibility of the polyimide molecular chain. Therefore, by using diamine (B3), the thermoplasticity of polyimide is improved. Here, as the linking group A, -O- is preferable.

As the diamine (B3), for example, 1,3-bis(4-aminophenoxy)benzene (1,3-bis(4-aminophenoxy)benzene, TPE-R), 1,3-bis(3 -Aminophenoxy)benzene (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 ] Dianiline and so on.

The diamine represented by the formula (B4) (hereinafter, sometimes referred to as "diamine (B4)") is an aromatic diamine having four benzene rings. It is believed that the diamine (B4) is in meta position with the divalent linking group A through the amino group directly bonded to at least one benzene ring, and has high flexibility, which contributes to the improvement of the flexibility of the polyimide molecular chain. . Therefore, by using diamine (B4), the thermoplasticity of polyimide is improved. Here, as the linking group A, -O-, -CH ₂ -, -C(CH ₃ ) ₂ -, -SO ₂ -, -CO-, -CONH- are preferable.

Examples of the diamine (B4) include bis[4-(3-aminophenoxy)phenyl]methane, bis[4-(3-aminophenoxy)phenyl]propane, and bis[4-(3 -Aminophenoxy)phenyl]ether, bis[4-(3-aminophenoxy)phenyl]sulfonate, bis[4-(3-aminophenoxy)]benzophenone, bis[4, 4'-(3-aminophenoxy)]benzaniline and the like.

The diamine represented by the formula (B5) (hereinafter, sometimes referred to as "diamine (B5)") is an aromatic diamine having four benzene rings. It is believed that the diamine (B5) is in the meta position with each other through the two divalent linking groups A directly bonded to at least one benzene ring, and the polyimide molecular chain has an increased degree of freedom and high flexibility. Helps improve the flexibility of the polyimide molecular chain. Therefore, by using diamine (B5), the thermoplasticity of polyimide is improved. Here, as the linking group A, -O- is preferable.

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

The diamine represented by the formula (B6) (hereinafter, sometimes referred to as "diamine (B6)") is an aromatic diamine having four benzene rings. It is considered that the diamine (B6) has high flexibility by having at least two ether bonds and contributes to the improvement of the flexibility of the polyimide molecular chain. Therefore, by using diamine (B6), the thermoplasticity of polyimide is improved. Here, as the linking group A, -C(CH ₃ ) ₂ -, -O-, -SO ₂ -, -CO- are preferable.

As the diamine (B6), for example, 2,2-bis[4-(4-aminophenoxy)phenyl]propane (2,2-bis[4-(4-aminophenoxy)phenyl]propane, BAPP ), bis[4-(4-aminophenoxy)phenyl]ether (BAPE), bis[4-(4-aminophenoxy)phenyl] Bis[4-(4-aminophenoxy)phenyl]sulfone, BAPS), bis[4-(4-aminophenoxy)phenyl]ketone (BAPK) Wait.

The diamine represented by the formula (B7) (hereinafter, sometimes referred to as "diamine (B7)") is an aromatic diamine having four benzene rings. The diamine (B7) has a divalent linking group A with high flexibility on both sides of the diphenyl skeleton, and therefore it is considered that it contributes to the improvement of the flexibility of the polyimide molecular chain. Therefore, by using diamine (B7), the thermoplasticity of polyimide is improved. Here, as the linking group A, -O- is preferable.

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

The thermoplastic polyimide constituting the thermoplastic polyimide layer 33 is in the range of 60 mol parts or more, preferably 60 mol parts or more and 99 mol parts relative to 100 mol parts of all diamine residues It is more preferable to contain a diamine residue derived from at least one diamine compound selected from diamine (B1) to diamine (B7) in the range of 70 mol parts or more and 95 mol parts or less. Since diamine (B1) to diamine (B7) contain a flexible molecular structure, by using at least one diamine compound selected from these in an amount within the above-mentioned range, the polyimide molecular chain can be increased Softness, and can impart thermoplasticity. If the total amount of diamine (B1) to diamine (B7) in the raw material is less than 60 mol parts with respect to 100 mol parts of all diamine components, the polyimide resin is not sufficiently flexible due to insufficient flexibility. Obtain sufficient thermoplasticity.

In addition, the diamine residue contained in the thermoplastic polyimide constituting the thermoplastic polyimide layer 33 is also preferably a diamine residue derived from a diamine compound represented by the general formula (A1). The diamine compound [diamine (A1)] represented by the formula (A1) is as described in the description of the non-thermoplastic polyimide. Diamine (A1) has a rigid structure and has the effect of imparting an ordered structure to the entire polymer. Therefore, it can reduce the dielectric loss tangent or hygroscopicity by inhibiting the movement of molecules. Furthermore, by being used as a raw material of thermoplastic polyimide, a polyimide having low air permeability and excellent long-term heat-resistant adhesiveness can be obtained.

The thermoplastic polyimide constituting the thermoplastic polyimide layer 33 may preferably be in the range of 1 mol part or more and 40 mol part or less, more preferably in the range of 5 mol part or more and 30 mol part or less. Contains diamine residues derived from diamine (A1). By using the diamine (A1) in the amount within the above range and using the rigid structure derived from the monomer to form an ordered structure in the entire polymer, it is possible to obtain thermoplasticity with low air permeability and hygroscopicity and long-term Polyimide with excellent heat resistance.

The thermoplastic polyimide constituting the thermoplastic polyimide layer 33 may be derived from diamine compounds other than diamine (A1), diamine (B1) to diamine (B7), within a range that does not impair the effects of the invention.的diamine residues.

By selecting the types of the tetracarboxylic acid residues and diamine residues in the thermoplastic polyimide, or using two or more tetracarboxylic acid residues or diamine residues, the respective molar ratios can be controlled Thermal expansion coefficient, tensile elasticity coefficient, glass transition temperature, etc. In addition, when there are a plurality of polyimine structural units in the thermoplastic polyimine, they may exist in the form of blocks or may exist randomly, but they are preferably present randomly.

Furthermore, by setting both the tetracarboxylic acid residue and the diamine residue contained in the thermoplastic polyimide as aromatic groups, the dimensional accuracy of the polyimide film in a high-temperature environment can be improved, and the surface area can be suppressed. The amount of change in the internal delay (RO).

The concentration of the imine group of the thermoplastic polyimide is preferably 33% or less, and more preferably 32% or more. Here, the "imine group concentration" refers to _{the value obtained by dividing the molecular weight of the polyimine group (-(CO) 2} -N-) by the molecular weight of the entire structure of the polyimide . If the concentration of the imine group exceeds 33%, the molecular weight of the resin itself becomes small, and the low hygroscopicity also deteriorates due to the increase of the polar group. By selecting the combination of the diamine compounds to control the orientation of the molecules in the thermoplastic polyimine, thereby suppressing the increase in CTE accompanying the decrease in the concentration of the imine group, and ensuring low hygroscopicity.

The weight average molecular weight of the thermoplastic polyimide is, for example, preferably in the range of 10,000 to 400,000, and more preferably in the range of 50,000 to 350,000. If the weight average molecular weight is less than 10,000, the strength of the film decreases and it tends to become brittle. On the other hand, if the weight average molecular weight exceeds 400,000, the viscosity increases excessively, and defects such as film thickness unevenness and streaks tend to occur during the coating operation.

The thermoplastic polyimide constituting the thermoplastic polyimide layer 33 becomes, for example, an adhesive layer in the insulating resin of the circuit board. Therefore, in order to suppress the diffusion of copper, it is most preferable to have a structure that is completely imidized. However, a part of polyimide may also become amide acid. The imidization rate can be measured by using a Fourier transform infrared spectrophotometer (commercial product: FT/IR620 manufactured by JASCO Corporation) and using the primary reflection ATR method to measure the infrared absorption spectrum of the polyimide film to The benzene ring absorber in the vicinity of 1015 cm ^{-1 was} used as a reference, and it was calculated from the absorbance of the C=O stretch and contraction derived from the amide group at ^{1780 cm -1.}

From the viewpoint of ensuring the adhesion function, the thickness of the thermoplastic polyimide layer 33 is preferably in the range of 1 μm or more and 10 μm or less, and more preferably in the range of 1 μm or more and 5 μm or less. If the thickness of the thermoplastic polyimide layer 33 is less than the lower limit, the adhesiveness becomes insufficient, and if it exceeds the upper limit, the dimensional stability tends to deteriorate.

From the viewpoint of suppressing warpage, the thermal expansion coefficient of the thermoplastic polyimide layer 33 is in the range of 30 ppm/K or more, preferably 30 ppm/K or more and 100 ppm/K or less, more preferably 30 ppm/K. It is suitable to be in the range of K or more and 80 ppm/K or less.

In addition, in the resin used in the thermoplastic polyimide layer 33, in addition to polyimide, other hardening resin components such as plasticizers, epoxy resins, hardeners, hardening accelerators, and inorganic Fillers, coupling agents, fillers, solvents, flame retardants, etc. are used as optional components.

The non-thermoplastic polyimide and thermoplastic polyimide used to form the non-thermoplastic polyimide layer 31 and the thermoplastic polyimide layer 33 can be manufactured in the same manner as the DDA-based polyimide in the following manner: The acid anhydride component and the diamine component are reacted in a solvent to generate polyamide acid, and then the ring is closed by heating. In the synthesis of non-thermoplastic polyimine and thermoplastic polyimide, each of the acid anhydrides and diamines may be used alone, or two or more of them may be used in combination. By selecting the types of acid anhydrides and diamines, or the respective molar ratios when two or more acid anhydrides or diamines are used, thermal expansion, adhesiveness, glass transition temperature, etc. can be controlled.

＜Coefficient of Thermal Expansion＞ In the metal-clad laminate 10, the thermal expansion coefficient (CTE) of the entire resin laminate 20 is preferably 10 ppm/K or more, preferably in the range of 10 ppm/K or more and 30 ppm/K or less, and more preferably 15 ppm /K or more and 25 ppm/K or less. If the CTE is less than 10 ppm/K or more than 30 ppm/K, warpage occurs or dimensional stability decreases. By appropriately changing the combination of the raw materials used, the thickness, and the drying/curing conditions, a polyimide layer having a desired CTE can be produced.

＜Dielectric loss tangent＞ In the metal-clad laminate 10, the dielectric loss tangent (Tanδ) at 10 GHz of the entire resin laminate 20 is preferably within a range of 0.02 or less, more preferably 0.0005 or more and 0.01 or less, and still more preferably 0.001 or more and 0.008 The following ranges are appropriate. If the dielectric loss tangent at 10 GHz of the entire resin laminate 20 exceeds 0.02, when it is applied to a circuit board, defects such as electrical signal loss are likely to occur in the transmission path of high-frequency signals. On the other hand, the lower limit of the dielectric loss tangent at 10 GHz of the entire resin laminate 20 is not particularly limited, but the control of the physical properties of the insulating resin layer as a circuit board should be considered.

＜Dielectric constant＞ In the metal-clad laminate 10, when the resin laminate 20 is used as an insulating resin layer of a circuit board, for example, in order to ensure impedance matching, the resin laminate 20 as a whole has a dielectric constant at 10 GHz. Below 4.0. If the dielectric constant at 10 GHz of the entire resin laminate 20 exceeds 4.0, when it is applied to a circuit board, the dielectric loss increases, and defects such as electrical signal loss are likely to occur in the transmission path of high-frequency signals.

[Manufacturing of metal-clad laminates] The metal-clad laminate 10 can be manufactured, for example, by preparing a resin corresponding to the first transmission loss suppression layer BS1, the second transmission loss suppression layer BS2, the multilayer dimensional accuracy maintaining layer PL, and one or more intermediate transmission loss suppression layers BS3 Sheets, these resin sheets are arranged between the first metal layer M1 and the second metal layer M2 and bonded together to perform thermocompression bonding.

The metal-clad laminate 10 of the present embodiment obtained in the manner described above is processed by etching the first metal layer M1 and/or the second metal layer M2 to process wiring circuits, so that circuits such as single-sided FPC or double-sided FPC can be manufactured. Substrate.

[Circuit Board] The metal-clad laminate 10 is mainly effectively used as a circuit board material such as FPC and rigid-flex circuit board. By using a conventional method to process one or both of the first metal layer M1 and the second metal layer M2 of the metal-clad laminate 10 into a pattern to form a wiring layer, the FPC as an embodiment of the present invention can be manufactured And other circuit boards. Regarding the circuit board, although illustration is omitted, the resin laminate 20 and wiring layers provided on one or both sides of the resin laminate 20 can reduce transmission loss even in high-frequency transmission. , And excellent dimensional stability.

[Example] Hereinafter, the present invention will be specifically explained through examples, but the present invention is not limited by these examples at all. In addition, in the following examples, unless otherwise specified, various measurements and evaluations are based on the following.

[Determination of Viscosity] For the measurement of viscosity, the viscosity at 25° C. was measured using an E-type viscometer (manufactured by Brookfield, trade name: DV-II+Pro). Set the rotation speed so that the torque becomes 10% to 90%. After 2 minutes have passed since the start of the measurement, read the value when the viscosity is stable.

[Measurement of Storage Elasticity Coefficient] For a resin sheet with a size of 5 mm×20 mm, a dynamic viscoelasticity measuring device (DMA: manufactured by UBM, trade name: E4000F) is used to measure from 30°C to 400°C at a heating rate of 4°C/min and a frequency of 11 Hz. .

[Determination of Coefficient of Thermal Expansion (CTE)] For the 3 mm×20 mm polyimide film, using a thermomechanical analyzer (manufactured by Bruker, trade name: 4000SA), the temperature was raised from 30°C at a constant temperature rise rate while applying a load of 5.0 g After maintaining the temperature at 265°C for 10 minutes, it was cooled at a rate of 5°C/min, and the average thermal expansion coefficient (thermal expansion coefficient) from 250°C to 100°C was obtained.

[Measurement of dielectric constant and dielectric loss tangent] Using Vector Network Analyzer (manufactured by Agilent, trade name: E8363C) and SPDR resonator, the dielectric constant (Dk) and dielectric loss tangent (Df) of the resin sheet at 10 GHz were measured ). In addition, the material used in the measurement is a material left for 24 hours under the conditions of temperature: 24°C to 26°C and humidity: 45% to 55% RH.

[Measurement of dimensional change rate] The measurement of the dimensional change rate is performed by the following procedure. First, a 150 mm square sample was used to expose and develop the dry film resist at 100 mm intervals to form a target for position measurement. Measure the size before etching (normal) in an environment with a temperature of 23±2°C and a relative humidity of 50±5%, and then remove the copper other than the target of the test piece by etching (liquid temperature below 40°C, time within 10 minutes). Let it stand for 24±4 hours in an environment with a temperature of 23±2°C and a relative humidity of 50±5%, and then measure the size after etching. The dimensional change rate from the normal state of each of the three positions in the vertical direction and the horizontal direction was calculated, and the average value of each was used as the dimensional change rate after etching. The dimensional change rate after etching is calculated by the following formula.

Dimensional change rate after etching (%)=(B-A)/A×100 A: Distance between targets before etching B: Distance between targets after etching

Next, this test piece was heat-processed in the oven of 250 degreeC for 1 hour, and the distance between the position targets after that was measured. The dimensional change rates of the three locations in the vertical direction and the horizontal direction with respect to the dimensional change after etching were calculated, and the average value of each was used as the dimensional change rate after the heat treatment. The dimensional change rate after heating is calculated by the following formula.

Dimensional change rate after heating (%)=(C-B)/B×100 B: Distance between targets after etching C: Distance between targets after heating

[Measurement of surface roughness (Rz; ten-point average roughness) of copper foil] Use stylus type surface roughness meter (manufactured by Kosaka Research Institute Co., Ltd., trade name: Surfcorder ET-3000) and according to force (Force): 100 μN, speed (Speed): 20 μm, range (Range): Calculated under the measurement conditions of 800 μm. In addition, the surface roughness is calculated by a method based on Japanese Industrial Standards (JIS)-B0601:1994.

The abbreviations used in the synthesis examples indicate the following compounds. BTDA: 3,3',4,4'-benzophenone tetracarboxylic dianhydride PMDA: Pyromellitic dianhydride BPDA: 3,3',4,4'-biphenyltetracarboxylic dianhydride BPADA: 2,2-bis[4-(3,4-dicarboxyphenoxy)phenyl]propane dianhydride DAPE: 4,4'-diaminodiphenyl ether p-PDA: p-phenylenediamine BAPP: 2,2-bis[4-(4-aminophenoxy)phenyl]propane m-TB: 2,2'-dimethyl-4,4'-diaminobiphenyl TPE-R: 1,3-bis(4-aminophenoxy)benzene DDA: aliphatic diamine with 36 carbon atoms (manufactured by Croda Japan Co., Ltd., trade name: PRIAMINE 1074, amine value: 205 mgKOH/g, cyclic structure and chain structure The dimer diamine mixture, the content of the dimer component: 95% by weight or more) OP935: Organic phosphonate aluminum salt (manufactured by Clariant Japan, trade name: Exolit OP935) N-12: Dihydrazine dodecanedioic acid DMAc: N,N-Dimethylacetamide NMP: N-methyl-2-pyrrolidone

(Synthesis example 1) Put 312 g of DMAc in a reaction vessel that includes a thermocouple and a stirrer and can introduce nitrogen. In the reaction vessel, 14.67 g of DAPE (0.073 mol) was dissolved while stirring in the vessel. Then, 23.13 g of BTDA (0.072 mol) was added. Thereafter, stirring was continued for 3 hours, thereby preparing a resin solution a of polyamide acid having a solution viscosity of 2,960 mPa·s.

(Synthesis example 2) Put 200 g of DMAc in a reaction vessel including a thermocouple and a stirrer and capable of introducing nitrogen. In the reaction vessel, 1.335 g of m-TB (0.0063 mol) and 10.414 g of TPE-R (0.0356 mol) were dissolved while stirring in the vessel. Then, 0.932 g of PMDA (0.0043 mol) and 11.319 g of BPDA (0.0385 mol) were added. Thereafter, stirring was continued for 2 hours to prepare a polyamide resin solution b with a solution viscosity of 1,420 mPa·s.

(Synthesis example 3) Put 250 g of DMAc in a reaction vessel that includes a thermocouple and a stirrer and can introduce nitrogen. In the reaction vessel, 2.561 g of p-PDA (0.0237 mol) and 16.813 g of DAPE (0.0840 mol) were dissolved while stirring in the vessel. Then, 18.501 g of PMDA (0.0848 mol) and 6.239 g of BPDA (0.0212 mol) were added. Thereafter, stirring was continued for 3 hours, thereby preparing a resin solution c of polyamide acid having a solution viscosity of 29,500 mPa·s.

(Synthesis example 4) Put 250 g of DMAc in a reaction vessel that includes a thermocouple and a stirrer and can introduce nitrogen. In the reaction vessel, 12.323 g of m-TB (0.0580 mol) and 1.886 g of TPE-R (0.0064 mol) were dissolved while stirring in the vessel. Then, 8.314 g of PMDA (0.0381 mol) and 7.477 g of BPDA (0.0254 mol) were added. Thereafter, stirring was continued for 3 hours to prepare a polyamide resin solution d with a solution viscosity of 31,500 mPa·s.

(Synthesis example 5) <Preparation of Resin Solution e for Adhesive Layer> Put 44.92 g of BTDA (0.139 mol), 75.08 into a 500 mL four-necked flask equipped with nitrogen introduction tube, stirrer, thermocouple, Dean-Stark trap and cooling tube g DDA (0.141 mol), 168 g of NMP, and 112 g of xylene were mixed at 40° C. for 30 minutes to prepare a polyamide acid solution. The polyamide acid solution was heated to 190°C, heated and stirred for 4 hours, and the distilled water and xylene were removed to the outside of the system. Thereafter, it was cooled to 100°C, 112 g of xylene was added and stirred, and then cooled to 30°C to complete the imidization, thereby obtaining a resin solution e for the adhesive layer (solid content: 29.5 wt%) .

(Synthesis example 6) <Preparation of resin solution f for adhesive layer> Except that 42.51 g of BPADA (0.082 mol), 34.30 g of DDA (0.066 mol), 6.56 g of BAPP (0.016 mol), 208 g of NMP and 112 g of xylene were used as the raw material composition, it was combined with the synthesis In Example 5, a polyamide acid solution was prepared in the same manner. The polyamide acid solution was processed in the same manner as in Synthesis Example 5 to obtain a resin solution f (solid content: 30.0% by weight) for the adhesive layer.

(Production example 1) ＜Preparation of polyimide film＞ Coat resin solution c of polyamide acid uniformly on one surface of electrolytic copper foil 1 (thickness 12 μm, Rz: 2.1 μm) so that the thickness after curing becomes about 25 μm, and then heat it at 120°C Dry and remove solvent. Furthermore, the stepwise heat treatment is performed from 120°C to 360°C within 30 minutes to complete the imidization. Use ferric chloride aqueous solution to etch and remove copper foil to prepare polyimide film 1 (thickness: 25 μm, Dk: 3.4, Df: 0.0085, CTE: 16 ppm/K, minimum storage elasticity coefficient (100℃～250℃) ) 2.9 GHz).

(Production example 2) ＜Preparation of polyimide film＞ Except for using resin solution d, a polyimide film 2 (thickness: 25 μm, Dk: 3.3, Df: 0.0034, CTE: 17 ppm/K, minimum storage elasticity coefficient (100°C ~ 250°C) 3.0 GHz).

(Production example 3) ＜Preparation of polyimide film＞ Coat resin solution a uniformly on the surface of electrolytic copper foil 1 (thickness 12 μm, Rz: 2.1 μm) so that the thickness after curing becomes approximately 2 μm to 3 μm, and then heat and dry it at 120°C. Remove solvent. Then, the resin solution d was uniformly applied thereon so that the thickness after curing became about 21 μm, and then heated and dried at 120° C. to remove the solvent. Furthermore, the resin solution a is uniformly applied thereon so that the thickness after curing becomes approximately 2 μm to 3 μm, and then heated and dried at 120° C. to remove the solvent. A three-layer polyamide layer is formed in the manner described above, and then a stepwise heat treatment is performed from 120° C. to 360° C. to complete the imidization. Use ferric chloride aqueous solution to etch and remove the copper foil layer to prepare polyimide film 3 (thickness: 25 μm, Dk: 3.4, Df: 0.0052, CTE: 21 ppm/K, minimum storage elasticity coefficient (100℃～250 ℃) 2.8 GHz).

(Production example 4) ＜Preparation of polyimide film＞ Coat resin solution b uniformly on the surface of one side of electrolytic copper foil 1 (thickness 12 μm, Rz: 2.1 μm) so that the thickness after curing becomes about 2 μm to 3 μm, and then heat and dry it at 120°C. Remove solvent. Then, the resin solution d was uniformly applied thereon so that the thickness after curing became about 21 μm, and then heated and dried at 120° C. to remove the solvent. Furthermore, the resin solution b is uniformly applied thereon so that the thickness after curing becomes approximately 2 μm to 3 μm, and then heated and dried at 120° C. to remove the solvent. A three-layer polyamide layer is formed in the manner described above, and then a stepwise heat treatment is performed from 120° C. to 360° C. to complete the imidization. Use ferric chloride aqueous solution to etch and remove the copper foil layer to prepare polyimide film 4 (thickness: 25 μm, Dk: 3.3, Df: 0.0032, CTE: 23 ppm/K, minimum storage elasticity coefficient (100℃～250 ℃) 2.7 GHz).

(Production example 5) ＜Preparation of resin sheet＞ Mix 1.8 g of N-12 (0.0036 mol) and 12.5 g of OP935 in 169.49 g of resin solution e (50 g of solid content), and add 6.485 g of NMP and 19.345 g of xylene for dilution to prepare Polyimide varnish 1.

Polyimide varnish 1 is applied to the silicone-treated surface of the release substrate so that the thickness after drying becomes 25 μm, and then it is heated and dried at 80°C and peeled from the release substrate. Thus, the resin sheet 1 was prepared. The dielectric constant (Dk) and dielectric loss tangent (Df) of the resin sheet 1 were 2.7 and 0.0023, respectively.

(Production example 6) ＜Preparation of resin sheet＞ A resin sheet 2 was prepared in the same manner as in Preparation Example 6 except that the thickness after drying was 50 μm. The dielectric constant (Dk) and dielectric loss tangent (Df) of the resin sheet 2 were 2.7 and 0.0023, respectively.

(Production example 7) ＜Preparation of resin sheet＞ A resin sheet 3 was prepared in the same manner as in Preparation Example 6 except that the thickness after drying was 75 μm. The dielectric constant (Dk) and dielectric loss tangent (Df) of the resin sheet 3 are 2.7 and 0.0023, respectively.

(Production example 8) ＜Preparation of resin sheet＞ A resin sheet 4 was prepared in the same manner as in Preparation Example 6 except that the thickness after drying was 5 μm. The dielectric constant (Dk) and dielectric loss tangent (Df) of the resin sheet 4 are 2.7 and 0.0023, respectively.

(Production example 9) ＜Preparation of resin sheet＞ The resin solution f for the adhesive layer is applied to the silicone-treated surface of the release substrate so that the thickness after drying becomes 25 μm, and then heated and dried at 80°C, and then it is self-dried on the release substrate By peeling, a resin sheet 5 is prepared. The dielectric constant (Dk) and dielectric loss tangent (Df) of the resin sheet 5 are 2.8 and 0.0028, respectively.

(Production example 10) ＜Preparation of resin sheet＞ A resin sheet 6 was prepared in the same manner as in Preparation Example 9 except that the thickness after drying was 50 μm. The dielectric constant (Dk) and dielectric loss tangent (Df) of the resin sheet 6 are 2.8 and 0.0028, respectively.

[Example 1] Prepare two electrolytic copper foil 1, two resin sheets 1, one resin sheet 2, two polyimide films 4, and use electrolytic copper foil 1 / resin sheet 1 / polyimide film 4 / resin sheet 2 / polyimide film The imide film 4/resin sheet 1/electrolytic copper foil 1 was laminated in this order, and then thermocompression-bonded under the conditions of 160° C. and 4 MPa for 60 minutes, thereby preparing a double-sided metal-clad laminate 1. The evaluation results of the double-sided metal-clad laminate 1 are as follows. The dimensional change rate after etching in the machine direction (MD) direction: -0.05% The dimensional change rate after etching in the Transverse Direction (TD) direction: -0.04% Dimensional change rate in MD direction after heating: -0.03% Dimensional change rate in the TD direction after heating: 0.03% In addition, the dielectric constant (Dk) and dielectric loss tangent (Df) of the resin laminate 1 (thickness: 150 μm) prepared by etching and removing the electrolytic copper foil 1 in the double-sided metal-clad laminate 1 were 2.9 and 0.0026, respectively. The total thickness of the dimensional accuracy maintaining layers is 33% of the entire thickness of the resin laminate 1.

[Example 2] Prepare two pieces of electrolytic copper foil 1, two pieces of resin sheet 1, one piece of resin sheet 3, and two pieces of polyimide film 4. The imide film 4/resin sheet 1/electrolytic copper foil 1 was laminated in this order, and then thermocompression-bonded under the conditions of 160° C. and 4 MPa for 60 minutes, thereby preparing a double-sided metal-clad laminate 2. The evaluation results of the double-sided metal-clad laminate 2 are as follows. Dimensional change rate after etching in MD direction: -0.06% Dimensional change rate after etching in TD direction: -0.04% Dimensional change rate in MD direction after heating: -0.04% Dimensional change rate in the TD direction after heating: 0.04% In addition, the dielectric constant (Dk) and dielectric loss tangent (Df) of the resin laminate 2 (thickness: 175 μm) prepared by etching away the electrolytic copper foil 1 in the double-sided metal-clad laminate 2 were 2.92 and 0.0026, respectively. The total thickness of the dimensional accuracy maintaining layers is 29% of the entire thickness of the resin laminate 2.

[Example 3] Prepare two pieces of electrolytic copper foil 1, one resin sheet 1, two resin sheets 2, two polyimide films 4, and use electrolytic copper foil 1/resin sheet 2/polyimide film 4/resin sheet 1 and polyimide film. The imine film 4/resin sheet 2/electrolytic copper foil 1 was laminated in this order, and then thermocompression-bonded under the conditions of 160° C. and 4 MPa for 60 minutes, thereby preparing a double-sided metal-clad laminate 3. The evaluation results of the double-sided metal-clad laminate 3 are as follows. Dimensional change rate after etching in MD direction: -0.02% Dimensional change rate after etching in TD direction: 0.03% Dimensional change rate in MD direction after heating: -0.06% The dimensional change rate in the TD direction after heating: -0.02% In addition, the dielectric constant (Dk) and dielectric loss tangent (Df) of the resin laminate 3 (thickness: 175 μm) prepared by etching and removing the electrolytic copper foil 1 in the double-sided metal-clad laminate 3 were 2.9 and 0.0026, respectively. The total thickness of the dimensional accuracy maintaining layers is 29% of the entire thickness of the resin laminate 3.

[Example 4] Except that the polyimide film 1 was used instead of the polyimide film 4, a double-sided metal-clad laminate 4 was prepared in the same manner as in Example 1. Evaluation of the double-sided metal-clad laminate 4 showed that there was no problem with dimensional changes. In addition, the dielectric constant (Dk) and dielectric loss tangent (Df) of the resin laminate 4 (thickness: 150 μm) prepared by etching away the electrolytic copper foil 1 in the double-sided metal-clad laminate 4 were 2.9 and 0.0044, respectively. The total thickness of the dimensional accuracy maintaining layers is 33% of the entire thickness of the resin laminate 4.

[Example 5] Except that the polyimide film 2 was used instead of the polyimide film 4, a double-sided metal-clad laminate 5 was prepared in the same manner as in Example 1. Evaluation of the double-sided metal-clad laminate 5 showed that there was no problem with dimensional changes. In addition, the dielectric constant (Dk) and dielectric loss tangent (Df) of the resin laminate 5 (thickness: 150 μm) prepared by etching away the electrolytic copper foil 1 in the double-sided metal-clad laminate 5 were 2.9 and 0.0027, respectively. The total thickness of the dimensional accuracy maintaining layers is 33% of the entire thickness of the resin laminate 5.

[Example 6] Except that the polyimide film 3 was used instead of the polyimide film 4, a double-sided metal-clad laminate 6 was prepared in the same manner as in Example 1. Evaluation of the double-sided metal-clad laminate 6 showed that there was no problem with dimensional changes. In addition, the dielectric constant (Dk) and dielectric loss tangent (Df) of the resin laminate 6 (thickness: 150 μm) prepared by etching away the electrolytic copper foil 1 in the double-sided metal-clad laminate 6 were 2.9 and 0.0033, respectively. The total thickness of the dimensional accuracy maintaining layers is 33% of the entire thickness of the resin laminate 6.

[Example 7] Except that the resin sheet 5 was used instead of the resin sheet 1 and the resin sheet 6 was used instead of the resin sheet 2, the double-sided metal-clad laminate 7 was prepared in the same manner as in Example 1. Evaluation of the double-sided metal-clad laminate 7 showed that there was no problem with dimensional changes. In addition, the dielectric constant (Dk) and dielectric loss tangent (Df) of the resin laminate 7 (thickness: 150 μm) prepared by etching away the electrolytic copper foil 1 in the double-sided metal-clad laminate 7 were 3.0 and 0.0029, respectively. The total thickness of the dimensional accuracy maintaining layers is 33% of the entire thickness of the resin laminate 7.

[Example 8] A double-sided metal-clad laminate 8 was prepared in the same manner as in Example 1, except that the resin sheet 4 was used instead of the resin sheet 1. Evaluation of the double-sided metal-clad laminate 8 showed that there was no problem with dimensional changes. In addition, the dielectric constant (Dk) and dielectric loss tangent (Df) of the resin laminate 8 (thickness: 110 μm) prepared by etching away the electrolytic copper foil 1 in the double-sided metal-clad laminate 8 were 3.0 and 0.0027, respectively. The total thickness of the dimensional accuracy maintaining layers is 45% of the entire thickness of the resin laminate 8.

[Comparative Example 1] Prepare two sheets of electrolytic copper foil 1, two sheets of resin sheet 2, and one sheet of polyimide film 1, which are laminated in the order of electrolytic copper foil 1 / resin sheet 2 / polyimide film 1 / resin sheet 2 / electrolytic copper foil 1 , And then thermocompression bonding under the conditions of 160° C. and 4 MPa for 60 minutes, thereby preparing a metal-clad laminate 9 on both sides. The evaluation results of the double-sided metal-clad laminate 9 are as follows. Dimensional change rate after etching in MD direction: 0.02% Dimensional change rate after etching in TD direction: 0.08% Dimensional change rate in MD direction after heating: -0.10% Dimensional change rate in the TD direction after heating: -0.05% In addition, the dielectric constant (Dk) and dielectric loss tangent (Df) of the resin laminate 9 (thickness: 125 μm) prepared by etching and removing the electrolytic copper foil 1 in the double-sided metal-clad laminate 9 were 2.8 and 0.0035, respectively. The total thickness of the dimensional accuracy maintaining layers is 20% of the entire thickness of the resin laminate 9.

As mentioned above, the embodiment of the present invention has been described in detail for the purpose of illustration, but the present invention is not restricted by the above-mentioned embodiment and can be variously modified.

10: Metal clad laminate 20: Resin laminate M1: The first metal layer M2: second metal layer BS1: The first transmission loss suppression layer BS2: The second transmission loss suppression layer BS3: Intermediate transmission loss suppression layer PL: Dimensional accuracy maintenance layer 31: Non-thermoplastic polyimide layer 33: Thermoplastic polyimide layer

FIG. 1 is a schematic diagram showing the structure of a metal-clad laminate according to an embodiment of the present invention. Fig. 2 is a schematic cross-sectional view showing the structure of a metal-clad laminate according to another embodiment of the present invention. Fig. 3 is a schematic cross-sectional view showing the structure of a metal-clad laminate according to another embodiment of the present invention. Fig. 4 is a schematic cross-sectional view showing a configuration example of a dimensional accuracy maintaining layer.

10: Metal clad laminate

20: Resin laminate

M1: The first metal layer

M2: second metal layer

BS1: The first transmission loss suppression layer

BS2: The second transmission loss suppression layer

BS3: Intermediate transmission loss suppression layer

PL: Dimensional accuracy maintenance layer

Claims (4)

A metal-clad laminate, comprising: a first metal layer, a first transmission loss suppression layer arranged in contact with a single side of the first metal layer, a second metal layer, and a single side phase with the second metal layer A second transmission loss suppression layer, and a multilayer resin layer interposed between the first transmission loss suppression layer and the second transmission loss suppression layer, and are composed of the first transmission loss suppression layer, The second transmission loss suppression layer and the multilayer resin layer form a resin laminate, the resin laminate having at least two or more dimensional accuracy maintaining layers, and an intermediate transmission loss laminated between the dimensional accuracy maintaining layers A suppression layer, and satisfy the following condition i and condition ii; condition i: set the dielectric loss tangent of the first transmission loss suppression layer and the second transmission loss suppression layer as Df ₁ , and set the dimensional accuracy When the dielectric loss tangent of the sustaining layer is set to Df ₂ , it is in _{the relationship of Df 1} <Df ₂ , and the dielectric loss tangent is that after humidity is adjusted at 23° C. and 50% RH for 24 hours, it passes through the separation medium Dielectric loss tangent at 10 GHz measured with a resonator; Condition ii: The total thickness of the dimensional accuracy maintaining layer is within a range of 25% to 60% of the total thickness of the resin laminate. The metal-clad laminate according to claim 1, wherein the minimum value of the storage elastic coefficient in the temperature range of 100°C to 250°C of the dimensional accuracy maintaining layer is in the range of 1.0 GPa to 8.0 GPa, and the thermal expansion coefficient is Low thermal expansion polyimide layer in the range of 15 ppm/K to 25 ppm/K. The metal-clad laminate according to claim 1 or claim 2, wherein the resin constituting the first transmission loss suppression layer and the second transmission loss suppression layer is a polyamide formed by reacting an acid anhydride component and a diamine component Imine, and containing 50 mol parts or more of dimer diamine relative to 100 mol parts of the total amount of the diamine component, the two terminal carboxylic acid groups of the dimer acid of the dimer diamine It is substituted by a primary aminomethyl or amino group. A circuit substrate, comprising: a first wiring layer, a first transmission loss suppression layer provided in contact with a single side of the first wiring layer, a second wiring layer, and a first wiring layer provided in contact with a single side of the second wiring layer The second transmission loss suppression layer, and the multilayer resin layer interposed between the first transmission loss suppression layer and the second transmission loss suppression layer, and are composed of the first transmission loss suppression layer, the The second transmission loss suppression layer and the multilayer resin layer form a resin laminate, the resin laminate having at least two dimensional accuracy maintaining layers, and an intermediate transmission loss suppressing layer laminated between the dimensional accuracy maintaining layers , And satisfy the following conditions i and ii; condition i: set the dielectric loss tangent of the first transmission loss suppression layer and the second transmission loss suppression layer to Df ₁ , and set the dimensional accuracy maintaining layer When the dielectric loss tangent of is set to Df ₂ , it is in _{the relationship of Df 1} <Df ₂ , and the dielectric loss tangent is 24 hours after adjusting the humidity at 23° C. and 50% RH under constant temperature and humidity conditions, and then passing through the separation dielectric resonator The measured dielectric loss tangent at 10 GHz; condition ii: the total thickness of the dimensional accuracy maintaining layer is within the range of 25% to 60% of the total thickness of the resin laminate.

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