TWI814908B - Metal-clad laminates and circuit boards - Google Patents

Abstract

The present invention provides a metal-clad laminate and a circuit board that can reduce transmission loss even in high-frequency transmission and have excellent dimensional stability. A metal-clad laminate, including: a first single-sided metal-clad laminate having a first metal layer and a first insulating resin layer laminated on at least one side of the first metal layer; a second single-sided metal-clad laminate A plate having a second metal layer and a second insulating resin layer laminated on at least one side of the second metal layer; and an adhesive layer disposed in contact with the first insulating resin layer and the second insulating resin layer. , laminated between the first single-sided metal-clad laminate and the second single-sided metal-clad laminate. The adhesive layer is composed of thermoplastic resin or thermosetting resin and satisfies (i) the storage elastic coefficient at 50°C is less than 1800 MPa; (ii) the maximum storage elastic coefficient in the temperature range of 180°C to 260°C is 800 MPa below; (iii) the glass transition temperature (Tg) is below 180°C.

Description

Metal-clad laminates and circuit boards

The present invention relates to a metal-clad laminate and a circuit board useful as electronic components.

In recent years, with the advancement of miniaturization, weight reduction, and space saving of electronic equipment, flexible printed wiring boards (flexible printed wiring boards) that are thin, lightweight, flexible, and have excellent durability even if they are repeatedly bent are The demand for Flexible Printed Circuits (FPC) has increased. FPC enables three-dimensional and high-density installation even in a limited space, so it is used in electronic devices such as Hard Disk Drives (HDD), Digital Video Discs (DVD), and smartphones. Its use is gradually expanding in parts such as wiring of movable parts, cables, and connectors.

In addition to the above-mentioned high-density, the performance of equipment has been promoted, so it is also necessary to cope with the increase in frequency of transmission signals. When a high-frequency signal is transmitted, if the transmission loss in the transmission path is large, problems such as loss of the electrical signal or an increase in signal delay time may occur. Therefore, reduction of transmission loss will also become important in FPC in the future. In order to cope with high-frequency signal transmission, FPC using liquid crystal polymer with lower dielectric constant and low dielectric loss factor as the dielectric layer is used instead of the polyimide commonly used as FPC material. However, although liquid crystal polymers have excellent dielectric properties, there is room for improvement in heat resistance or adhesion to metal layers.

In addition, fluorine-based resins are also known as polymers exhibiting low dielectric constant and low dielectric dissipation factor. For example, as an FPC material that can handle high-frequency signal transmission and has excellent adhesion, it has been proposed to laminate a thermoplastic polyimide layer and a highly heat-resistant polyimide layer on both sides of a fluorine-based resin layer. An insulating film made of an adhesive film (Patent Document 1). Since the insulating film of Patent Document 1 uses a fluorine-based resin, it is excellent in dielectric properties, but has issues with dimensional stability. Especially when applied to FPC, there is concern about dimensional changes before and after circuit processing due to etching. big. Therefore, it is difficult to increase the thickness of the fluorine-based resin and increase the thickness ratio.

Furthermore, as technologies related to adhesive layers used in electronic materials, a resin composition containing an epoxy resin and a phenoxy resin or a resin composition containing a thermoplastic polyimide and a maleimide compound has been proposed. Application in adhesive sheets (Patent Document 2, Patent Document 3). The film-like adhesive sheets of Patent Document 2 and Patent Document 3 have the advantage of having a low glass transition temperature and showing high adhesion to the laminate material. However, Patent Document 2 and Patent Document 3 do not examine the possibility of application to high-frequency signal transmission or application to an adhesive layer of a metal-clad laminated board. [Prior art documents] [Patent Document]

[Patent Document 1] Japanese Patent Application Laid-Open No. 2017-24265 [Patent Document 2] Japanese Patent No. 6191800 [Patent Document 3] Japanese Patent No. 5553108

[Problem to be solved by the invention] An 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 have excellent dimensional stability.

[Technical means to solve the problem] The present inventors conducted diligent research and found that the above problems can be solved by using an adhesive layer with a low glass transition temperature and a low elastic coefficient in a metal-clad laminate, and thus completed the present invention.

The metal-clad laminated board of the present invention is the following metal-clad laminated board, including: A first single-sided metal-clad laminate having a first metal layer and a first insulating resin layer laminated on at least one side of the first metal layer; A second single-sided metal-clad laminate having a second metal layer and a second insulating resin layer laminated on at least one side of the second metal layer; and An adhesive layer is disposed in contact with the first insulating resin layer and the second insulating resin layer, and is laminated between the first single-sided metal-clad laminated board and the second single-sided metal-clad laminated board. between. In the metal-clad laminate of the present invention, the adhesive layer is composed of thermoplastic resin or thermosetting resin and satisfies the following conditions (i) to (iii): (i) The storage elastic modulus at 50°C is below 1800 MPa; (ii) The maximum value of the storage elastic coefficient in the temperature range of 180°C to 260°C is 800 MPa or less; (iii) The glass transition temperature (Tg) is 180°C or less.

In the metal-clad laminate of the present invention, the total thickness T1 of the first insulating resin layer, the adhesive layer, and the second insulating resin layer may be in the range of 70 μm to 500 μm, and the adhesive layer has The ratio of thickness T2 to the total thickness T1 (T2/T1) may be in the range of 0.5 to 0.8.

In the metal-clad laminated board of the present invention, the first insulating resin layer and the second insulating resin layer may both have a thermoplastic polyimide layer, a non-thermoplastic polyimide layer, and a thermoplastic polyimide layer laminated in sequence. The multi-layer structure formed by The adhesive layer may be disposed in contact with the two thermoplastic polyimide layers.

In the metal-clad laminate of the present invention, the non-thermoplastic polyimide constituting the non-thermoplastic polyimide layer contains a tetracarboxylic acid residue and a diamine residue, relative to 100 mole parts of all diamine residues. , the content of the diamine residue derived from the diamine compound represented by the following general formula (1) may be 80 mole parts or more.

[Chemical 1]

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

In the metal-clad laminate of the present invention, the overall thermal expansion coefficient of the first insulating resin layer, the adhesive layer, and the second insulating resin layer may be in a range of 10 ppm/K or more and 30 ppm/K or less. .

In the metal-clad laminate of the present invention, both the first metal layer and the second metal layer may include copper foil.

The circuit board of the present invention is formed by processing the first metal layer and/or the second metal layer of any of the metal-clad laminates into wiring.

[Effects of the invention] The metal-clad laminated board of the present invention adheres to the structure of two single-sided metal-clad laminated boards by interposing an adhesive layer with specific parameters, thereby increasing the thickness of the insulating resin layer and ensuring dimensional stability. In addition, when used in circuit boards that transmit high-frequency signals above 10 GHz, transmission losses can be reduced. Therefore, improvements in reliability and yield can be achieved in the circuit substrate.

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

[metal clad laminate] FIG. 1 is a schematic diagram showing the structure of a metal-clad laminated board according to an embodiment of the present invention. The metal-clad laminated board (C) of this embodiment has a structure in which a pair of single-sided metal-clad laminated boards are bonded together using an adhesive layer (B). That is, the metal-clad laminated board (C) includes a first single-sided metal-clad laminated board (C1), a second single-sided metal-clad laminated board (C2), and the first single-sided metal-clad laminated board (C1) and the third single-sided metal-clad laminated board. The adhesive layer (B) between two single-sided metal-clad laminates (C2). Here, the first single-sided metal-clad laminated board (C1) has a first metal layer (M1), and a first insulating resin layer (P1) laminated on at least one side of the first metal layer (M1). ). The second single-sided metal-clad laminated board (C2) has a second metal layer (M2) and a second insulating resin layer (P2) laminated on at least one side of the second metal layer (M2). Furthermore, the adhesive layer (B) is disposed in contact with the first insulating resin layer (P1) and the second insulating resin layer (P2). That is, the metal-clad laminate (C) has first metal layer (M1)/first insulating resin layer (P1)/adhesive layer (B)/second insulating resin layer (P2)/second metal layer (M2) in this order A layered structure. The first metal layer (M1) and the second metal layer (M2) are respectively located on the outermost side, and the first insulating resin layer (P1) and the second insulating resin layer (P2) are arranged inside them, and then the first insulating resin layer A placement adhesive layer (B) is interposed between the layer (P1) and the second insulating resin layer (P2).

＜Single-sided metal clad laminate＞ The composition of the pair of single-sided metal-clad laminated boards (C1, C2) is not particularly limited. As the FPC material, general materials can be used, and commercially available copper-clad laminated boards, etc. can also be used. Furthermore, the first single-sided metal-clad laminated board (C1) and the second single-sided metal-clad laminated board (C2) may have the same or different structures.

(metal layer) The materials of the first metal layer (M1) and the second metal layer (M2) are not particularly limited, and 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 these, copper or a copper alloy is particularly preferred. In addition, the material of the wiring layer in the circuit board of this embodiment which will be described later is also the same as that of 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 5 μm to 25 μm. within the range. From the viewpoint of production stability and handleability, the lower limit of the thickness of the metal foil is preferably 5 μm. Furthermore, when copper foil is used, it may be a rolled copper foil or an electrolytic copper foil. In addition, as the copper foil, a commercially available copper foil can be used.

In addition, the metal foil may be subjected to surface treatment using, for example, board wall, aluminum alcoholate, aluminum chelate, silane coupling agent, etc., for the purpose of anti-rust treatment or improvement of adhesion.

(Insulating resin layer) The first insulating resin layer (P1) and the second insulating resin layer (P2) are not particularly limited as long as they are made of an electrically insulating resin. Examples thereof include: polyimide, epoxy resin, Phenol resin, polyethylene, polypropylene, polytetrafluoroethylene, silicone, tetrafluoroethylene (Ethyl Tetrafluoroethylene, ETFE), etc., but is preferably composed of polyimide. In addition, the first insulating resin layer (P1) and the second insulating resin layer (P2) are not limited to single layers, and may be layers in which a plurality of resin layers are laminated. Furthermore, when polyamide imide is mentioned in the present invention, in addition to polyamide imide, it means that polyamide imide, polyether imide, polyester imine, and polysiloxane are included. Resins of polymers such as amide imine and polybenzimidazol amide imine, which have a amide imine group in the molecular structure.

＜Adhesive layer＞ The adhesive layer (B) is composed of thermoplastic resin or thermosetting resin and satisfies (i) the storage elastic coefficient at 50°C is 1800 MPa or less, (ii) the maximum storage elastic coefficient at 180°C to 260°C is 800 MPa The following, and (iii) the glass transition temperature (Tg) is 180°C or less. Examples of the resin include polyimide resin, polyamide resin, epoxy resin, phenoxy resin, acrylic resin, polyurethane resin, styrene resin, polyester resin, and phenol resin. Polystyrene resin, polyetherstyrene resin, polyphenylene sulfide resin, polyethylene resin, polypropylene resin, silicone resin, polyetherketone resin, polyvinyl alcohol resin, polyvinyl butyral resin, styrene-male Resins such as imine copolymer, maleimide-vinyl compound copolymer or (meth)acrylic acid copolymer, benzoxazine resin, bismaleimide resin and cyanate ester resin, among these resins , you can choose materials that satisfy conditions (i) to (iii) or design them in a way that satisfies conditions (i) to (iii) and use them in the adhesive layer (B).

When the adhesive layer (B) is a thermosetting resin, it may contain an organic peroxide, a hardener, a hardening accelerator, etc., and a hardener and a hardening accelerator, or a catalyst and a cocatalyst may be used in combination as necessary. As long as the conditions (i) to (iii) can be ensured, the addition amounts and presence or absence of the hardening agent, hardening accelerator, catalyst, cocatalyst, and organic peroxide may be determined.

＜Layer thickness＞ In the metal-clad laminate (C), when the total thickness of the first insulating resin layer (P1), the adhesive layer (B), and the second insulating resin layer (P2) is set to T1, the total thickness T1 is 70 μm. ~500 μm, preferably 100 μm ~ 300 μm. If the total thickness T1 is less than 70 μm, the effect of reducing transmission loss when forming a circuit board is insufficient. If the total thickness T1 exceeds 500 μm, productivity may decrease.

In addition, the thickness T2 of the adhesive layer (B) is preferably in the range of, for example, 50 μm to 450 μm, and more preferably in the range of 50 μm to 250 μm. If the thickness T2 of the adhesive layer (B) does not satisfy the lower limit, the transmission loss may increase as a high-frequency substrate. On the other hand, if the thickness of the adhesive layer (B) exceeds the upper limit, problems such as reduced dimensional stability may occur.

In addition, the ratio (T2/T1) of the thickness T2 of the adhesive layer (B) to the total thickness T1 is in the range of 0.5 to 0.8, preferably in the range of 0.5 to 0.7. If the ratio (T2/T1) is less than 0.5, it will be difficult to set T1 to 70 μm or more. If it exceeds 0.8, problems such as reduced dimensional stability may occur.

The thickness T3 of both the first insulating resin layer (P1) and the second insulating resin layer (P2) is preferably, for example, in the range of 12 μm to 100 μm, and more preferably in the range of 12 μm to 50 μm. If the thickness T3 of the first insulating resin layer (P1) and the second insulating resin layer (P2) does not satisfy the lower limit, problems such as warping of the metal-clad laminate (C) may occur. If the thickness T3 of the first insulating resin layer (P1) and the second insulating resin layer (P2) exceeds the upper limit, problems such as reduced productivity may occur. Furthermore, the first insulating resin layer (P1) and the second insulating resin layer (P2) may not necessarily have the same thickness.

＜Coefficient of thermal expansion＞ The coefficient of thermal expansion (Coefficient of Thermal Expansion, CTE) of the first insulating resin layer (P1) and the second insulating resin layer (P2) may be 10 ppm/K or more, preferably 10 ppm/K or more and 30 ppm/K or less. Within the range, more preferably within the range of 15 ppm/K or more and 25 ppm/K or less. If the CTE is less than 10 ppm/K or exceeds 30 ppm/K, warpage will occur or dimensional stability will decrease. By appropriately changing the combination of raw materials used, thickness, drying and hardening conditions, a polyimide layer having a desired CTE can be produced.

The adhesive layer (B) has high thermal expansion but low elasticity and low glass transition temperature. Therefore, even if the CTE exceeds 30 ppm/K, it can relax the internal stress generated during lamination. In addition, the overall thermal expansion coefficient (CTE) of the first insulating resin layer (P1), the adhesive layer (B) and the second insulating resin layer (P2) may be 10 ppm/K or more, preferably 10 ppm/K or more and 30 Within the range of ppm/K or less, more preferably 15 ppm/K or more and 25 ppm/K or less. If the overall CTE of these resin layers is less than 10 ppm/K or exceeds 30 ppm/K, warpage will occur or dimensional stability will decrease.

＜Glass transition temperature (Tg)＞ The glass transition temperature (Tg) of the adhesive layer (B) is 180°C or lower, preferably within the range of 160°C or lower. By setting the glass transition temperature of the adhesive layer (B) to 180°C or lower, thermocompression bonding can be performed at low temperatures, thereby relaxing the internal stress generated during lamination and suppressing dimensional changes after circuit processing. If the Tg of the adhesive layer (B) exceeds 180°C, the temperature during adhesion will increase due to the intervening between the first insulating resin layer (P1) and the second insulating resin layer (P2), which may damage the circuit after processing. dimensional stability.

＜Storage elasticity coefficient＞ The storage elastic coefficient of the adhesive layer (B) at 50°C is 1800 MPa or less, and the maximum value of the storage elastic coefficient in the temperature range of 180°C to 260°C is 800 MPa or less. The characteristics of the adhesive layer (B) are considered to be the main reason for alleviating internal stress during thermocompression bonding and maintaining dimensional stability after circuit processing. In addition, the storage elastic coefficient of the adhesive layer (B) at the upper limit temperature (260° C.) of the temperature range is preferably 800 MPa or less, and more preferably 500 MPa or less. By setting the storage elastic coefficient to the above-mentioned storage elastic coefficient, warpage is less likely to occur even after the reflow step after circuit processing.

＜Dielectric loss factor＞ When the first insulating resin layer (P1) and the second insulating resin layer (P2) are applied to a circuit board, for example, in order to suppress deterioration of dielectric loss, the dielectric loss factor (Tan δ) at 10 GHz is preferably 0.02 or less. , more preferably in the range of 0.0005 or more and 0.01 or less, and still more preferably in the range of 0.001 or more and 0.008 or less. If the dielectric loss factor at 10 GHz of the first insulating resin layer (P1) and the second insulating resin layer (P2) exceeds 0.02, when applied to a circuit board, it is easy to cause distortion of electrical signals on the transmission path of high-frequency signals. Loss and other adverse conditions. On the other hand, the lower limit value of the dielectric loss factor at 10 GHz of the first insulating resin layer (P1) and the second insulating resin layer (P2) is not particularly limited, but it is considered to be the physical property control of the insulating resin layer as a circuit board. .

For example, when the adhesive layer (B) is applied to a circuit board, in order to suppress deterioration of dielectric loss, the dielectric loss factor (Tan δ) at 10 GHz is preferably 0.015 or less, more preferably 0.01 or less, and still more preferably 0.006 or less. . If the dielectric loss factor at 10 GHz of the adhesive layer (B) exceeds 0.015, when applied to a circuit board, problems such as loss of electrical signals on the transmission path of high-frequency signals are likely to occur. On the other hand, the lower limit value of the dielectric loss factor at 10 GHz of the adhesive layer (B) is not particularly limited.

＜Dielectric constant＞ For example, when the first insulating resin layer (P1) and the second insulating resin layer (P2) are used as insulating resin layers of a circuit board, in order to ensure impedance matching, it is preferable that the entire insulating resin layer be dielectric at 10 GHz. The electrical constant is 4.0 or less. If the dielectric constant at 10 GHz of the first insulating resin layer (P1) and the second insulating resin layer (P2) exceeds 4.0, when applied to a circuit substrate, the first insulating resin layer (P1) and the second insulating resin layer (P2) will The deterioration of the dielectric loss of the resin layer (P2) easily causes problems such as loss of electrical signals on the transmission path of high-frequency signals.

When the adhesive layer (B) is applied to a circuit board, for example, in order to ensure impedance matching, the dielectric constant at 10 GHz is preferably 4.0 or less. If the dielectric constant of the adhesive layer (B) exceeds 4.0 at 10 GHz, the dielectric loss of the adhesive layer (B) will deteriorate when applied to a circuit board, and electrical signals on the transmission path of high-frequency signals will easily occur. losses and other adverse conditions.

＜Function＞ In the metal-clad laminated board (C) of this embodiment, the thickness of the adhesive layer (B) is increased in order to realize a low dielectric loss factor of the entire insulating resin layer and to cope with high-frequency transmission. However, materials with low elastic coefficients such as the adhesive layer (B) generally exhibit high thermal expansion coefficients, so increasing the layer thickness may lead to a decrease in dimensional stability. Here, it is considered that the dimensional change that occurs when the metal-clad laminate (C) is subjected to circuit processing is mainly caused by the following mechanisms a) to c), and the total amount of b) and c) becomes the dimensional change after etching. Show it. a) During the production of the metal-clad laminated board (C), internal stress is accumulated in the resin layer. b) During circuit processing, the internal stress accumulated in a) is released by etching the metal layer, and the resin layer expands or contracts. c) During circuit processing, by etching the metal layer, the exposed resin absorbs moisture and expands.

The main causes of the internal stress in a) are 1) the difference in thermal expansion coefficient between the metal layer and the resin layer, and 2) the internal strain of the resin due to film formation. Here, the magnitude of the internal stress caused by 1) affects not only the difference in thermal expansion coefficient, but also the temperature difference ΔT from the temperature at the time of adhesion (heating temperature) to the cooling and solidification temperature. That is, since the internal stress increases in proportion to the temperature difference ΔT, even if the difference in thermal expansion coefficient between the metal layer and the resin layer is small, the more high-temperature resin is required for adhesion, the greater the internal stress becomes. In the metal-clad laminated board (C) of this embodiment, a layer satisfying the above conditions (i) to (iii) is used as the adhesive layer (B) to reduce internal stress and ensure dimensional stability.

In addition, since the adhesive layer (B) is laminated between the first insulating resin layer (P1) and the second insulating resin layer (P2), it functions as an intermediate layer and suppresses warpage and dimensional changes. Furthermore, for example, in a heating step such as reflow when mounting a semiconductor wafer, direct heat or contact with oxygen is blocked by the first insulating resin layer (P1) or the second insulating resin layer (P2). It is less susceptible to oxidative deterioration and does not easily undergo dimensional changes. In this way, it also has the advantages brought about by the layer structure characteristics of the first insulating resin layer (P1), the adhesive layer (B) and the second insulating resin layer (P2).

[Manufacturing of metal clad laminates] The metal-clad laminated board (C) can be produced by the following method 1 or method 2, for example. [method 1] The resin composition that becomes the adhesive layer (B) is shaped into a sheet to form an adhesive sheet, and the adhesive sheet is disposed and bonded to the first insulating resin layer (P1) of the first single-sided metal-clad laminate (C1). A method of thermo-compression bonding with the second insulating resin layer (P2) of the second single-sided metal-clad laminate (C2). [Method 2] The solution of the resin composition that becomes the adhesive layer (B) is applied to the first insulating resin layer (P1) of the first single-sided metal-clad laminated board (C1) or the second single-sided metal-clad laminated board (C2) with a prescribed thickness. ) on either or both of the second insulating resin layers (P2) and drying, then bonding one side of the coating film to thermocompression bonding.

The adhesive sheet used in Method 1 can be produced, for example, by applying a solution of the resin composition to be the adhesive layer (B) on an arbitrary support base material, drying it, and then peeling it off from the support base material to prepare an adhesive sheet. . In addition, in the above description, the method of applying the solution of the resin composition that becomes the adhesive layer (B) on the supporting base material or the insulating resin layer (P1, P2) is not particularly limited. For example, a notch wheel can be used. , mold, scraper, die lip and other coating machines for coating.

The metal-clad laminated board (C) of this embodiment obtained as described above can be used to produce a single-sided FPC or Double-sided FPC and other circuit substrates.

[Preferred structural example of metal-clad laminate] Next, the first insulating resin layer (P1), the second insulating resin layer (P2), the adhesive layer (B), the first metal layer (M1) and the second metal layer in the metal-clad laminate (C) of this embodiment are Layer (M2) is explained more specifically.

FIG. 2 is a schematic cross-sectional view showing the structure of the metal-clad laminated board 100 according to this embodiment. As shown in FIG. 2 , the metal-clad laminate 100 includes: metal layers 101 and 101 as a first metal layer (M1) and a second metal layer (M2); and a first insulating resin layer (P1) and a second insulating resin. The polyimide layers 110 and 110 of the layer (P2); and the adhesive polyimide layer 120 as the adhesive layer (B). Here, the metal layer 101 and the polyimide layer 110 form the single-sided metal-clad laminate 130 as the first single-sided metal-clad laminate ( C1 ) or the second single-sided metal-clad laminate ( C2 ). In this form, the first single-sided metal-clad laminated board (C1) and the second single-sided metal-clad laminated board (C2) have the same configuration.

Each of the polyimide layers 110 and 110 may have a structure in which a plurality of polyimide layers are laminated. For example, in the form shown in FIG. 2 , non-thermoplastic polyimide layers 111 and 111 composed of non-thermoplastic polyimide as a base layer are formed, and the non-thermoplastic polyimide layers 111 and 111 are respectively provided. A three-layer structure including thermoplastic polyimide layers 112 and 112 on both sides. Furthermore, the polyimide layers 110 and 110 are not limited to three-layer structures respectively.

In the metal-clad laminate 100 shown in FIG. 2 , the outer thermoplastic polyimide layers 112 and 112 of the two single-sided metal-clad laminates 130 and 130 are respectively bonded to the adhesive polyimide layer 120. The metal-clad laminate 100 is formed. The adhesive polyimide layer 120 is an adhesive layer used to bond the two single-sided metal-clad laminates 130 and 130 in the metal-clad laminate 100, and is used to maintain the metal-clad laminate while ensuring dimensional stability. The insulating resin layer of the board 100 is a thickened layer. The adhesive polyimide layer 120 is as described for the adhesive layer (B).

Next, the non-thermoplastic polyimide layer 111 and the thermoplastic polyimide layer 112 constituting the polyimide layers 110 and 110 will be described. In addition, the so-called "non-thermoplastic polyimide" usually refers to a polyimide that does not show softening or tackiness even when heated. However, in the present invention, it refers to a polyimide that uses a dynamic viscoelasticity measuring device (Dynamic Mechanical Analyzer). Analysis, DMA)) The measured storage elastic coefficient at 30°C is 1.0×10 ⁹ Pa or more, and the storage elastic coefficient at 350°C is 1.0×10 ⁸ Pa or more. In addition, the so-called "thermoplastic polyimide" is generally a polyimide whose glass transition temperature (Tg) can be clearly confirmed, but in the present invention, it means that the storage elastic coefficient at 30°C measured using DMA is 1.0× Polyimide with a storage elasticity coefficient of 10 ⁹ Pa or above and less than 1.0×10 ⁸ Pa at 350°C.

Non-thermoplastic polyimide layer: The non-thermoplastic polyimide constituting the non-thermoplastic polyimide layer 111 contains a tetracarboxylic acid residue and a diamine residue. In addition, in the present invention, the tetracarboxylic acid residue represents a tetravalent group derived from tetracarboxylic dianhydride, and the diamine residue represents a divalent group derived from a diamine compound. 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 forming the non-thermoplastic polyimide layer 111 preferably contains 3,3',4,4'-biphenyl tetracarboxylic dianhydride (3,3',4,4'-biphenyl tetracarboxylic dianhydride). tetracarboxylic acid residue derived from at least one of dianhydride (BPDA) and 1,4-phenylene bis (trimellitic acid monoester) dianhydride (TAHQ) group and composed of at least one of pyromellitic dianhydride (PMDA) and 2,3,6,7-naphthalene tetracarboxylic dianhydride (NTCDA) Derivatized tetracarboxylic acid residues are used as tetracarboxylic acid residues.

The tetracarboxylic acid residue derived from BPDA (hereinafter, also referred to as "BPDA residue") and the tetracarboxylic acid residue derived from TAHQ (hereinafter, also referred to as "TAHQ residue") easily form polymers The ordered structure can reduce the dielectric loss factor or hygroscopicity by inhibiting the movement of molecules. The BPDA residue can impart self-supporting properties to the gel film of polyamide as a precursor of polyimide, but on the other hand, it increases the CTE after imidization and lowers the glass transition temperature. Tendency to decrease heat resistance.

From this viewpoint, the total amount of the non-thermoplastic polyimide constituting the non-thermoplastic polyimide layer 111 is preferably 30 mole parts or more and 60 mole parts per 100 mole parts of all the tetracarboxylic acid residues. It is controlled so that the BPDA residue and the TAHQ residue are included in the range of 40 molar parts or less and 50 molar parts or less. If the total amount of BPDA residues and TAHQ residues is less than 30 mole parts, the formation of the ordered structure of the polymer becomes insufficient, the moisture absorption resistance decreases, or the reduction of the dielectric loss factor becomes insufficient. If it exceeds 60 molar parts, in addition to an increase in CTE or an increase in the change in in-plane retardation (RO), there is a concern that the heat resistance will decrease.

In addition, the tetracarboxylic acid residue derived from pyromellitic dianhydride (hereinafter also referred to as "PMDA residue") and the tetracarboxylic acid residue derived from 2,3,6,7-naphthalenetetracarboxylic dianhydride The acid residue (hereinafter, also referred to as "NTCDA residue") has rigidity, so it improves in-plane orientation, suppresses CTE at a low level, and controls in-plane retardation (RO) or glass transition temperature. The acting residues. On the other hand, the PMDA residue has a small molecular weight, so if its amount becomes too large, the concentration of the acyl imine group of the polymer will increase, the polar groups will increase, and the hygroscopicity will increase, and the medium will be diluted due to the influence of moisture inside the molecular chain. The loss factor increases. In addition, the NTCDA residue tends to cause the film to become brittle due to the highly rigid naphthalene skeleton and to increase the elastic coefficient. Therefore, the total of the non-thermoplastic polyimide constituting the non-thermoplastic polyimide layer is preferably in a range of 40 mole parts or more and 70 mole parts or less based on 100 mole parts of all the tetracarboxylic acid residues. It is more preferable that the PMDA residue and the NTCDA residue are contained in the range of 50 molar parts or more and 60 molar parts or less, and still more preferably in the range of 50 molar parts to 55 molar parts. If the total of PMDA residues and NTCDA residues is less than 40 mole parts, there is a concern that CTE will increase or heat resistance will decrease. If it exceeds 70 mole parts, the concentration of the acyl imine group in the polymer will increase, resulting in polar groups. There is a concern that the low hygroscopicity will be impaired, the dielectric loss factor will increase, or the film will become brittle and the self-supporting properties of the film will 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 may be 80 mole parts or more with respect to 100 mole parts of all tetracarboxylic acid residues, Preferably it is 90 molar parts or more.

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 can be {(BPDA residue+TAHQ residue)/(PMDA residue+NTCDA residue) group)} is within the range of 0.4 or more and 1.5 or less, preferably 0.6 or more and 1.3 or less, more preferably 0.8 or more and 1.2 or less, to control the formation of the ordered structure of the CTE and the polymer.

PMDA and NTCDA have a rigid skeleton, so compared with other general acid anhydride components, they can control the in-plane orientation of molecules in polyimide, suppressing the coefficient of thermal expansion (CTE) and increasing the glass transition temperature (Tg) Effect. In addition, since BPDA and TAHQ have larger molecular weights than PMDA, the imine group concentration decreases as the loading ratio increases, thereby having an effect on reducing the dielectric loss factor or the moisture absorption rate. On the other hand, if the loading ratio of BPDA and TAHQ increases, the in-plane orientation of the molecules in the polyimide decreases, resulting in an increase in CTE. Furthermore, the formation of an ordered structure within the molecule is promoted, and the haze value increases. From this point of view, the total loading amount of PMDA and NTCDA can be in the range of 40 to 70 mole parts, preferably 50 to 50 mole parts based on 100 mole parts of all the acid anhydride components of the raw material. Within the range of 60 molar parts, more preferably, within the range of 50 to 55 molar parts. If the total loading amount of PMDA and NTCDA is less than 40 mole parts based on 100 mole parts of all the acid anhydride components of the raw material, the in-plane orientation of the molecules will decrease, making it difficult to achieve low CTE, and the Tg will also decrease. The resulting decrease in the heat resistance or dimensional stability of the film during heating. On the other hand, if the total loading amount of PMDA and NTCDA exceeds 70 mole parts, the moisture absorption rate will become worse due to an increase in the acyl imine group concentration, or the elasticity coefficient will tend to increase.

In addition, BPDA and TAHQ are effective in inhibiting molecular motion or lowering the dielectric loss factor and reducing the moisture absorption rate caused by the decrease in the concentration of acyl imide groups, but they will affect the quality of the polyimide film after acyl imidization. CTE increases. From this point of view, the total loading amount of BPDA and TAHQ can be in the range of 30 to 60 mole parts, preferably 40 to 40 mole parts based on 100 mole parts of all the acid anhydride components of the raw material. Within the range of 50 molar parts, more preferably, it is within the range of 40 to 45 molar parts.

Examples of the tetracarboxylic acid residues other than the BPDA residue, TAHQ residue, PMDA residue, and NTCDA residue contained in the non-thermoplastic polyimide layer 111 include 3,3',4,4'-diphenyltetracarboxylic dianhydride, 4,4'-oxydiphthalic anhydride, 2,3',3,4'-diphenyltetracarboxylic 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)tere dianhydride or bis(3,4 -Dicarboxyphenyl)teresine 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-anthracenetetracarboxylic 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-hexahydrogen 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 -Tetracarboxylic acid residues derived from aromatic tetracarboxylic dianhydrides such as dicarboxyphenoxy)diphenylmethane dianhydride and ethylene glycol bis-trimellitic anhydride.

(diamine residue) The diamine residue contained in the non-thermoplastic polyimide constituting the non-thermoplastic polyimide layer 111 is preferably a diamine residue derived from a diamine compound represented by the general formula (1).

[Chemicalization 2]

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

The diamine compound represented by the general formula (1) (hereinafter, may be expressed as "diamine (1)") is an aromatic diamine having one to three benzene rings. The diamine (1) has a rigid structure and therefore has the function of imparting an ordered structure to the entire polymer. Therefore, polyimide with low air permeability and low hygroscopicity can be obtained, which can reduce the moisture inside the molecular chain, thus reducing the dielectric loss factor. Here, the connecting group Z is preferably a single bond.

Examples of the diamine (1) include: 1,4-diaminobenzene (p-phenylenediamine (p-PDA)), 2,2'-dimethyl-4,4'-diamino Biphenyl (m-TB), 2,2'-n-propyl-4,4'-diaminobiphenyl (2,2'-n-propyl-4,4'-diamino biphenyl, m-NPB), 4 -Aminophenyl-4'-aminobenzoate (4-amino phenyl-4'-amino benzoate, APAB), etc.

The non-thermoplastic polyimide constituting the non-thermoplastic polyimide layer 111 may contain preferably 80 mole parts or more, more preferably 85 mole parts or more of diamine based on 100 mole parts of all diamine residues. (1) Derivatized diamine residues. By using the diamine (1) in an amount within the above range, it is easy to form an ordered structure to the entire polymer by utilizing the rigid structure derived from the monomer, and it is easy to obtain low air permeability, low hygroscopicity and low dielectric loss. Factor of non-thermoplastic polyimide.

In addition, the diamine residue derived from the diamine (1) is 80 or more and 85 mole parts or less based on 100 mole parts of all diamine residues in the non-thermoplastic polyimide. Within the range, it is preferable to use 1,4-diaminobenzene as the diamine (1) from the viewpoint of having a more rigid structure and excellent in-plane orientation.

Examples of other diamine residues contained in the non-thermoplastic polyimide layer 111 include a 2,2-bis-[4-(3-aminophenoxy)phenyl group. ]propane, bis[4-(3-aminophenoxy)phenyl]trine, bis[4-(3-aminophenoxy)]biphenyl, bis[1-(3-aminophenoxy)]biphenyl Benzene, bis[4-(3-aminophenoxy)phenyl]methane, bis[4-(3-aminophenoxy)phenyl]ether, bis[4-(3-aminophenoxy)]di Benzophenone, 9,9-bis[4-(3-aminophenoxy)phenyl]fluorene, 2,2-bis-[4-(4-aminophenoxy)phenyl]hexafluoropropane, 2 ,2-bis-[4-(3-aminophenoxy)phenyl]hexafluoropropane, 3,3'-dimethyl-4,4'-diaminobiphenyl, 4,4'-methylene Di-o-toluidine, 4,4'-methylenedi-2,6-dimethylaniline, 4,4'-methylene-2,6-diethylaniline, 3,3'-diaminodianiline Phenylethane, 3,3'-diaminobiphenyl, 3,3'-dimethoxybenzidine, 3,3''-diamino-p-terphenyl, 4,4'-[1,4- Phylenebis(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-tert. Butyl)toluene, 2,4-diaminotoluene, m-xylene-2,5-diamine, p-xylylene-2,5-diamine, m-xylylenediamine, p-xylylenediamine , 2,6-diaminopyridine, 2,5-diaminopyridine, 2,5-diamino-1,3,4-oxadiazole, 2'-methoxy-4,4'-bis Aminobenzamide, 4,4'-diaminobenzoaniline, 1,3-bis[2-(4-aminophenyl)-2-propyl]benzene, 6-amino-2-(4- Diamine residues derived from aromatic diamine compounds such as aminophenoxy)benzoxazole, dimer acid-type diamines in which the two terminal carboxylic acid groups of dimer acid are substituted with primary aminomethyl or amino groups Diamine residues derived from aliphatic diamine compounds.

In non-thermoplastic polyimide, it is possible to control by selecting the types of the tetracarboxylic acid residue and the diamine residue, or by using the respective molar ratios of two or more tetracarboxylic acid residues or diamine residues. Thermal expansion coefficient, storage elastic coefficient, tensile elastic coefficient, etc. In addition, in non-thermoplastic polyimide, when it has a plurality of polyimide structural units, it can exist in the form of blocks or randomly. However, in order to suppress the variation in in-plane retardation (RO) From a viewpoint, it is preferable to exist randomly.

Furthermore, by setting both the tetracarboxylic acid residues and the diamine residues contained in the non-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 reduced. The amount of change in internal retardation (RO) is therefore preferred.

The amide group concentration of the non-thermoplastic polyimide is preferably 33% or less, and more preferably 32% or less. Here, the "imide group concentration" represents a value obtained by dividing the molecular weight of the amide imine group (-(CO) ₂ -N-) in the polyimide by the molecular weight of the entire structure of the polyimide. If the acyl imine group concentration exceeds 33%, the molecular weight of the resin itself decreases, and the low hygroscopicity becomes worse due to the increase in polar groups. By selecting a combination of the acid anhydride and the diamine compound, the orientation of the molecules in the non-thermoplastic polyimide is controlled, thereby suppressing an increase in CTE accompanying a decrease in the amide group concentration and ensuring low hygroscopicity.

The weight average molecular weight of the non-thermoplastic polyimide is, for example, preferably in the range of 10,000 to 400,000, 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 will decrease and the film will tend to become brittle. On the other hand, if the weight average molecular weight exceeds 400,000, the viscosity tends to increase excessively and defects such as uneven film thickness and streaks tend to occur during coating operations.

From the viewpoint of ensuring the function as a base layer and ensuring transportability during production and application of thermoplastic polyimide, the thickness of the non-thermoplastic polyimide layer 111 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 111 is less than the lower limit, electrical insulation and operability become insufficient, and when it exceeds the upper limit, productivity decreases.

From the viewpoint of heat resistance, the glass transition temperature (Tg) of the non-thermoplastic polyimide layer 111 is preferably 280° C. or higher.

In addition, from the viewpoint of suppressing warpage, the thermal expansion coefficient of the non-thermoplastic polyimide layer 111 may be in the range of 1 ppm/K or more and 30 ppm/K or less, preferably 1 ppm/K or more and 25 ppm/K or more. K or less, more preferably 15 ppm/K or more and 25 ppm/K or less.

In addition, the non-thermoplastic polyimide constituting the non-thermoplastic polyimide layer 111 may be suitably blended with other cured resin components such as plasticizers and epoxy resins, curing agents, curing accelerators, coupling agents, and fillers. , solvents, flame retardants, etc. as optional ingredients. However, some plasticizers contain substances containing a large amount of polar groups, and these substances may promote diffusion of copper from copper wiring. Therefore, it is preferable not to use plasticizers as much as possible.

Thermoplastic polyimide layer: The thermoplastic polyimide constituting the thermoplastic polyimide layer 112 contains a tetracarboxylic acid residue and a diamine residue, and preferably contains an aromatic tetracarboxylic acid residue derived from an aromatic tetracarboxylic dianhydride. Aromatic diamine residue derived from aromatic diamine.

(tetracarboxylic acid residue) As the tetracarboxylic acid residue used in the thermoplastic polyimide constituting the thermoplastic polyimide layer 112, the same tetracarboxylic acid residue as in the non-thermoplastic polyimide constituting the non-thermoplastic polyimide layer can be used. The residues are the same as those exemplified.

(diamine residue) The diamine residue contained in the thermoplastic polyimide constituting the thermoplastic polyimide layer 112 is preferably a diamine residue derived from a diamine compound represented by general formula (B1) to general formula (B7). base.

[Chemical 3]

In the formulas (B1) to (B7), R ₁ independently represents a monovalent hydrocarbon group or an alkoxy group having 1 to 6 carbon atoms, and the linking group A independently represents a group selected from -O-, -S-, -CO-, The divalent group in -SO-, -SO ₂ -, -COO-, -CH ₂ -, -C(CH ₃ ) ₂ -, -NH- or -CONH-, n ₁ independently represents an integer from 0 to 4 . Among them, the duplicates of formula (B2) are removed from formula (B3), and the duplicates of formula (B4) are removed from formula (B5). Here, "independently" means that the plurality of connecting groups A, the plurality of R ₁ or the plurality of n ₁ in one or more of the formulas (B1) to (B7) may be the same or different. . Furthermore, in the formulas (B1) to (B7), the hydrogen atoms in the two terminal amino groups may be substituted, for example, they may also be -NR ₂ R ₃ (here, R ₂ and R ₃ independently represent alkyl and other optional substituents).

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

Examples of the diamine (B1) include: 3,3'-diaminodiphenylmethane, 3,3'-diaminodiphenylpropane, 3,3'-diaminodiphenyl sulfide, 3, 3'-diaminodiphenyl ester, 3,3'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 3,4'-diaminodiphenylmethane, 3,4' - Diaminodiphenylpropane, 3,4'-diaminodiphenyl sulfide, 3,3'-diaminobenzophenone, (3,3'-diamino)diphenylamine, etc.

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

Examples of the diamine (B2) include: 1,4-bis(3-aminophenoxy)benzene, 3-[4-(4-aminophenoxy)phenoxy]aniline, 3-[3- (4-Aminophenoxy)phenoxy]aniline, etc.

The diamine represented by formula (B3) (hereinafter, may be expressed 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 two divalent linking groups A directly bonded to a benzene ring. 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, the coupling group A is preferably -O-.

Examples of the diamine (B3) include: 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)dioxy]bisaniline, 4,4'-[4-Methyl-(1,3-phenylene)dioxy]bisaniline, 4,4'-[5-methyl-(1,3-phenylene)dioxy] ] Dianiline etc.

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

Examples of the diamine (B4) include bis[4-(3-aminophenoxy)phenyl]methane, bis[4-(3-aminophenoxy)phenyl]propane, bis[4-(3 -Aminophenoxy)phenyl] ether, bis[4-(3-aminophenoxy)phenyl]terine, bis[4-(3-aminophenoxy)]benzophenone, bis[4, 4'-(3-Aminophenoxy)]benzylaniline, etc.

The diamine represented by formula (B5) (hereinafter, may be expressed 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. The polyimide molecular chain has an increased degree of freedom and high flexibility, and has Helps improve the flexibility of polyimide molecular chains. Therefore, by using diamine (B5), the thermoplasticity of polyimide is improved. Here, the coupling group A is preferably -O-.

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

The diamine represented by formula (B6) (hereinafter, may be expressed as "diamine (B6)") is an aromatic diamine having four benzene rings. It is thought 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, the coupling group A is preferably -C(CH ₃ ) ₂ -, -O-, -SO ₂ -, -CO-.

Examples of the diamine (B6) include: 2,2-bis[4-(4-aminophenoxy)phenyl]propane (BAPP) ), Bis[4-(4-aminophenoxy)phenyl]ether (BAPE), Bis[4-(4-aminophenoxy)phenyl]ether (BAPE), Bis[4-(4-aminophenoxy)phenyl]ether Bis[4-(4-aminophenoxy)phenyl]sulfone, BAPS, Bis[4-(4-aminophenoxy)phenyl]ketone, BAPK wait.

The diamine represented by formula (B7) (hereinafter, may be expressed as "diamine (B7)") is an aromatic diamine having four benzene rings. The diamine (B7) has highly flexible divalent linking groups A on both sides of the diphenyl skeleton, and therefore is considered to contribute to the improvement of the flexibility of the polyimide molecular chain. Therefore, by using diamine (B7), the thermoplasticity of polyimide is improved. Here, the coupling group A is preferably -O-.

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

The thermoplastic polyimide constituting the thermoplastic polyimide layer 112 may be in a range of 60 mole parts or more, preferably 60 mole parts or more and 99 mole parts or less based on 100 mole parts of all diamine residues. It contains a diamine residue derived from at least one diamine compound selected from diamine (B1) to diamine (B7), and more preferably 70 mole parts or more and 95 mole parts or less. Diamine (B1) to diamine (B7) contain a flexible molecular structure. Therefore, by using at least one diamine compound selected from these compounds in an amount within the above range, the polyimide molecular chain can be improved. Softness and thermoplasticity. If the total amount of diamine (B1) to diamine (B7) in the raw material is less than 60 mole parts based on 100 mole parts of all diamine components, the polyimide resin will not have sufficient flexibility and cannot be obtained. Fully thermoplastic.

In addition, the diamine residue contained in the thermoplastic polyimide constituting the thermoplastic polyimide layer 112 is also preferably a diamine residue derived from a diamine compound represented by the general formula (1). The diamine compound [diamine (1)] represented by the formula (1) is as described in the description of the non-thermoplastic polyimide. Diamine (1) has a rigid structure and has the function of imparting an ordered structure to the entire polymer. Therefore, it can reduce the dielectric loss factor or hygroscopicity by inhibiting the movement of molecules. Furthermore, by using it as a raw material for thermoplastic polyimide, a polyimide with low air permeability and excellent long-term heat-resistant adhesion can be obtained.

The thermoplastic polyimide constituting the thermoplastic polyimide layer 112 may be preferably in the range of 1 mole part or more and 40 mole parts or less, and more preferably in the range of 5 mole parts or more and 30 mole parts or less. Contains diamine residues derived from diamine (1). By using the diamine (1) in an amount within the above range, the rigid structure derived from the monomer forms an ordered structure throughout the polymer, thereby achieving thermoplasticity, low air permeability and hygroscopicity, and long-term heat-resistant adhesion. Polyimide with excellent properties.

The thermoplastic polyimide constituting the thermoplastic polyimide layer 112 may contain diamine compounds other than diamine (1) and diamine (B1) to diamine (B7) within a range that does not impair the effects of the invention. Derivatized diamine residues.

In thermoplastic polyimide, thermal expansion can be controlled by selecting the types of tetracarboxylic acid residues and diamine residues, or by using the respective molar ratios of two or more tetracarboxylic acid residues or diamine residues. coefficient, tensile elastic coefficient, glass transition temperature, etc. In addition, when the thermoplastic polyimide has a plurality of structural units of the polyimide, it may exist in the form of blocks or may exist randomly, but it is preferable to exist randomly.

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

The thermoplastic polyimide group concentration is preferably 33% or less, more preferably 32% or less. Here, the "imide group concentration" represents a value obtained by dividing the molecular weight of the amide imine group (-(CO) ₂ -N-) in the polyimide by the molecular weight of the entire structure of the polyimide. If the acyl imine group concentration exceeds 33%, the molecular weight of the resin itself decreases, and the low hygroscopicity becomes worse due to the increase in polar groups. By selecting a combination of the diamine compounds to control the orientation of molecules in the thermoplastic polyimide, the increase in CTE associated with a decrease in the amide group concentration is suppressed and low hygroscopicity is ensured.

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 will decrease and the film will tend to become brittle. On the other hand, if the weight average molecular weight exceeds 400,000, the viscosity tends to increase excessively and defects such as uneven film thickness and streaks tend to occur during coating operations.

The thermoplastic polyimide constituting the thermoplastic polyimide layer 112 serves as an adhesive layer in, for example, an insulating resin of a circuit board. Therefore, in order to suppress the diffusion of copper, it is most preferable to have a completely imidized structure. Among them, a part of polyimide can also become amide acid. The acyl imidization rate is determined by using a Fourier transform infrared spectrometer (commercially available product: FT/IR620 manufactured by Nippon ASCO) and using the Attenuated Total Reflectance (ATR) method to measure the infrared rays of the polyimide film. The absorption spectrum was calculated from the absorbance derived from the C=O stretching of the amide imine group at 1780 cm ^-1 based on the benzene ring absorber near 1015 cm ^-1 .

From the viewpoint of ensuring adhesive performance, the thickness of the thermoplastic polyimide layer 112 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. When the thickness of the thermoplastic polyimide layer 112 is less than the lower limit, the adhesion is insufficient. If the thickness 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 112 may be 30 ppm/K or more, preferably 30 ppm/K or more and 100 ppm/K or less, and more preferably 30 ppm/K. Within the range from K to 80 ppm/K.

In addition, in addition to polyimide, the resin used in the thermoplastic polyimide layer 112 may be suitably blended with other cured resin components such as plasticizers, epoxy resins, curing agents, curing accelerators, inorganic fillers, Coupling agents, fillers, solvents, flame retardants, etc. are included as optional ingredients. However, some plasticizers contain substances containing a large amount of polar groups, and these substances may promote diffusion of copper from copper wiring. Therefore, it is preferable not to use plasticizers as much as possible.

In the metal-clad laminate 100, in order to ensure dimensional stability after circuit processing, the overall thermal expansion coefficient of the two polyimide layers 110 and the adhesive polyimide layer 120 can be 10 ppm/K or more, which is preferably It is in the range of 10 ppm/K or more and 30 ppm/K or less, and it is more preferable that it is in the range of 15 ppm/K or more and 25 ppm/K or less. Furthermore, in the metal-clad laminate 100, the total thickness T1 of the two polyimide layers 110 and the adhesive polyimide layer 120, the thickness T2 of the adhesive polyimide layer 120, and the adhesive polyimide layer The ratio (T2/T1) of the thickness T2 of the imide layer 120 to the total thickness T1 is as explained in FIG. 1 .

(Synthesis of polyimide) The polyimide constituting the polyimide layer 110 can be produced by reacting the acid anhydride and the diamine in a solvent, generating a precursor resin, and then performing heating and loop closure. For example, a polymer can be obtained by dissolving approximately equimolar amounts of an acid anhydride component and a diamine component in an organic solvent, stirring at a temperature in the range of 0°C to 100°C for 30 minutes to 24 hours, and performing a polymerization reaction. Polyamide precursor of amide imine. During the reaction, the reaction components are dissolved in the organic solvent so that the resulting precursor is in the range of 5% to 30% by weight, preferably in the range of 10% to 20% by weight. Examples of the organic solvent used in the polymerization reaction include N,N-dimethylformamide, N,N-dimethylacetamide (DMAc), N-methyl- 2-Pyrrolidone, 2-butanone, dimethyl styrene, dimethyl sulfate, cyclohexanone, dioxane, tetrahydrofuran, diglyme, triglyme, etc. Two or more of these solvents may be used in combination, and aromatic hydrocarbons such as xylene and toluene may be used in combination. In addition, the usage amount of the organic solvent is not particularly limited, but it is preferably adjusted so that the concentration of the polyamide solution (polyimide precursor solution) obtained by the polymerization reaction becomes 5% by weight to 30% by weight. Use it at about % usage.

In the synthesis of polyimide, only one type of the acid anhydride and the diamine may be used, or two or more types may be used in combination. Thermal expansion, adhesion, glass transition temperature, etc. can be controlled by selecting the types of acid anhydrides and diamines, or the respective molar ratios when using two or more acid anhydrides or diamines.

The synthesized precursor is usually advantageously used as a reaction solvent solution, but can be concentrated, diluted or replaced with other organic solvents as necessary. In addition, the precursor generally has excellent solvent solubility and can therefore be used advantageously. The method of imidizing the precursor is not particularly limited. For example, a heat treatment of heating in the solvent at a temperature in the range of 80° C. to 400° C. for 1 hour to 24 hours is preferably used.

[Circuit board] The metal-clad laminated board 100 is mainly useful as a circuit substrate material such as FPC, rigid and flexible circuit substrates. That is, by processing one or both of the two metal layers 101 of the metal-clad laminate 100 into a pattern using a conventional method to form a wiring layer, a circuit board such as an FPC as an embodiment of the present invention can be manufactured. Although not shown in the figure, the circuit board includes a resin laminate in which a first insulating resin layer (P1), an adhesive layer (B), and a second insulating resin layer (P2) are sequentially laminated, and a resin layer provided on the resin layer. A wiring layer on one or both sides of a laminated body. [Example]

The present invention will be specifically described below through examples, but the present invention is not limited to these examples in any way. In addition, in the following Examples, unless otherwise stated, various measurements and evaluations are as follows.

[Measurement of dielectric constant and dielectric loss factor] Using a vector network analyzer (manufactured by Agilent, trade name E8363C) and a split post dielectric resonator (SPDR), the dielectric constant (Dk) and the dielectric constant (Dk) of the polyimide film at 10 GHz were measured. Dielectric loss factor (Df). 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 of 45% to 55%RH.

[Measurement of storage elastic coefficient and glass transition temperature (Tg)] Regarding the storage elastic coefficient of the adhesive layer, the adhesive layer (thickness 50 m) was peeled and removed from the base film, cut into 5 mm × 20 mm, heated in an oven at 120°C for 2 hours, and heated at 170°C for 3 hours. The obtained sample was heated step by step at a heating rate of 4°C/min from 30°C to 400°C using a dynamic viscoelasticity measuring device (DMA: manufactured by UBM Co., Ltd., trade name: E4000F), with a frequency of 1 Measured at Hz. In addition, the maximum temperature at which the Tanδ value during measurement is the largest is defined as Tg.

[Measurement of dimensional change rate] The dimensional change rate was measured according to the following procedure. First, a 150 mm square test piece was used to expose and develop the dry film resist at intervals of 100 mm to form a target for position measurement. After measuring the dimensions before etching (normal) in an atmosphere with a temperature of 23±2°C and a relative humidity of 50±5%, remove the copper other than the target of the test piece by etching (liquid temperature 40°C or lower, time within 10 minutes). After leaving for 24±4 hours in an atmosphere with a temperature of 23±2°C and a relative humidity of 50±5%, measure the etched dimensions. The dimensional change rate from the normal state was calculated at three locations each in the MD direction (long side direction) and the TD direction (width direction), and the average value was used as the dimensional change rate after etching. The dimensional change rate after etching is calculated by the following equation.

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 an oven at 250° C. for 1 hour, and the distance between the subsequent targets was measured. The dimensional change rate after etching was calculated at three locations each in the MD direction (long side direction) and the TD direction (width direction), and the average value was used as the dimensional change rate after heat treatment. The dimensional change rate after heating is calculated by the following equation.

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

The abbreviations used in this example represent the following compounds: BPDA: 3,3',4,4'-biphenyltetracarboxylic dianhydride PMDA: Pyromellitic dianhydride BTDA: 3,3',4,4'-benzophenone tetracarboxylic dianhydride m-TB: 2,2'-dimethyl-4,4'-diaminobiphenyl TPE-R: 1,3-bis(4-aminophenoxy)benzene Bisaniline-M: 1,3-bis[2-(4-aminophenyl)-2-propyl]benzene DDA: manufactured by Croda Japan Co., Ltd. (trade name: PRIAMINE 1075) N-12: Dodecanedioic acid dihydrazine DMAc: N,N-dimethylacetamide R710: (trade name, manufactured by Printec Co., Ltd., bisphenol type epoxy resin, epoxy equivalent: 170, liquid at room temperature, weight average molecular weight: about 340) VG3101L: (trade name, manufactured by Printec Co., Ltd., multifunctional epoxy resin, epoxy equivalent: 210, softening point: 39°C to 46°C) SR35K: (trade name, manufactured by Printec Co., Ltd., epoxy resin, epoxy equivalent: 930 to 940, softening point: 86°C to 98°C) YDCN-700-10: (trade name, manufactured by Nippon Steel & Sumitomo Metal Chemical Co., Ltd., cresol novolak type epoxy resin, epoxy equivalent 210, softening point 75°C to 85°C) Milex (milex) ) HE200C-10: (trade name, manufactured by Air Water Co., Ltd., phenolic resin, hydroxyl equivalent: 200, softening point: 65°C to 76°C, water absorption: 1% by mass, heating mass reduction rate: 4% by mass) HE910-10: (trade name, manufactured by Air Water Co., Ltd., phenolic resin, hydroxyl equivalent: 101, softening point: 83°C, water absorption: 1 mass%, heating mass reduction rate: 3 mass%) SC1030-HJA: (trade name, manufactured by Admatechs Co., Ltd., silica filler dispersion, average particle size: 0.25 μm) Aerosil R972: (trade name, manufactured by Nippon Aerosil Co., Ltd., silica, average particle size: 0.016 μm) Acrylic rubber HTR-860P-30B-CHN: (Sample name, manufactured by Teikoku Chemical Industry Co., Ltd., weight average molecular weight: 230,000, glycidyl functional group monomer ratio: 8%, Tg: -7℃) Acrylic rubber HTR-860P-3CSP: (Sample name, manufactured by Teikoku Chemical Industry Co., Ltd., weight average molecular weight: 800,000, glycidyl functional group monomer ratio: 3%, Tg: -7℃) A-1160: (trade name, manufactured by GE Toshiba Corporation, γ-ureidopropyltriethoxysilane) A-189: (trade name, manufactured by GE Toshiba Corporation, γ-mercaptopropyltrimethoxysilane) Curezol 2PZ-CN: (trade name, manufactured by Shikoku Chemical Industry Co., Ltd., 1-cyanoethyl-2-phenylimidazole) RE-810NM: (trade name, manufactured by Nippon Chemical Co., Ltd., diallyl bisphenol A diglycidyl ether, properties: liquid) PHORET SCS: (trade name, manufactured by Soken Chemical Co., Ltd., styrene-based acrylic polymer, Tg: 70°C, weight average molecular weight: 15000) BMI-1: (trade name, manufactured by Tokyo Chemical Industry Co., Ltd., 4,4'-bismaleimide diphenylmethane) TPPK: (trade name, manufactured by Tokyo Chemical Industry Co., Ltd., tetraphenylphosphonium tetraphenylborate) HP-P1: (trade name, manufactured by Mizushima Alloy Iron Co., Ltd., boron nitride filler) NMP: (manufactured by Kanto Chemical Co., Ltd., N-methyl-2-pyrrolidone).

(Synthesis example 1) <Preparation of resin solution A for adhesive layer> Cyclohexanone was added to a composition containing (a) epoxy resin and phenol resin as thermosetting resins and (c) inorganic filler with the product names and composition ratios (unit: parts by mass) shown in Table 1, and stirred and mixed. . Add the acrylic rubber as the high molecular weight component (b) shown in Table 1 and stir, further add the (e) coupling agent and (d) hardening accelerator shown in Table 1, and stir until the components are uniform to obtain adhesion. Layer with resin solution A.

[Table 1]

(Synthesis example 2) ＜Synthesis of polyimide resin (PI-1) and preparation of resin solution B for adhesive layer＞ In a 300 mL flask equipped with a thermometer, stirrer, cooling tube, and nitrogen inflow tube, 1,3-bis(3-aminopropyl)tetramethyldisiloxane (manufactured by Shin-Etsu Chemical Industry Co., Ltd., commercial product) was placed Name: LP-7100) 15.53 g, polyoxypropylene diamine (manufactured by BASF Co., Ltd., trade name: D400, molecular weight: 450) 28.13 g and NMP 100.0 g were stirred to prepare a reaction liquid. After the diamine was dissolved, 4,4'-oxydiphthalic anhydride, which had been previously purified by recrystallization from acetic anhydride, was added little by little to the reaction solution while cooling the flask in an ice bath. 32.30g. After reacting at normal temperature (25°C) for 8 hours, 67.0 g of xylene was added, and the mixture was heated at 180°C while blowing nitrogen gas, thereby azeotropically removing the xylene with water. The reaction solution was poured into a large amount of water, and the precipitated resin was filtered out and dried to obtain polyimide resin (PI-1). The molecular weight of the obtained polyimide resin (PI-1) was measured using gel permeation chromatography (GPC). The result was that the number average molecular weight Mn=22400 and the weight average molecular weight Mw=70200 in terms of polystyrene conversion. Using the polyimide resin (PI-1) obtained as described above, each component was prepared at a composition ratio (unit: parts by mass) shown in Table 2 to obtain a resin solution B for an adhesive layer.

[Table 2]

(Synthesis example 3) <Preparation of polyamide solution for insulating resin layer> Under nitrogen flow, 64.20 g of m-TB (0.302 mole), 5.48 g of bisaniline-M (0.016 mole) and DMAc in an amount such that the post-polymerization solid content concentration was 15% by weight were put into the reaction tank. Stir at room temperature to dissolve. Secondly, after adding 34.20 g of PMDA (0.157 mol) and 46.13 g of BPDA (0.157 mol), the polymerization reaction was continued at room temperature for 3 hours to prepare polyamide solution 1 (viscosity: 26,500 cps) .

(Synthesis example 4) <Preparation of polyamide solution for insulating resin layer> In addition to 69.56 g of m-TB (0.328 mol), 542.75 g of TPE-R (1.857 mol), DMAc in an amount with a post-polymerization solid content concentration of 12% by weight, and 194.39 g of PMDA (0.891 mol). Polyamide solution 2 (viscosity: 2,650 cps) was prepared in the same manner as in Synthesis Example 3 except that 393.31 g of BPDA (1.337 mol) was used as the raw material composition.

(Production example 1) <Preparation of resin sheet A for adhesive layer> After the resin solution A for the adhesive layer is coated on the silicone-treated surface of the release base material (length × width × thickness = 320 mm × 240 mm × 25 μm) to a thickness of 50 μm after drying, heat it at 80°C The resin sheet A was prepared by heating and drying at 120° C. for 15 minutes, further drying at 120° C. for 15 minutes, and then peeling it off from the release base material. In addition, in order to evaluate the physical properties after curing, the resin sheet A was heated in an oven at 120°C for 2 hours and at 170°C for 3 hours. After that, the Tg of the hardened resin sheet A was 95°C, the storage elasticity coefficient at 50°C was 960 MPa, and the maximum value of the storage elasticity coefficient at 180°C to 260°C was 7 MPa.

(Production example 2) <Preparation of resin sheet B for adhesive layer> After the resin solution B for the adhesive layer is applied to the silicone-treated surface of the release base material (length × width × thickness = 320 mm × 240 mm × 25 μm) to a thickness of 50 μm after drying, heat it at 80°C. The resin sheet B was prepared by heating and drying at 120° C. for 15 minutes, further drying at 120° C. for 15 minutes, and then peeling it off from the release base material. In addition, in order to evaluate the physical properties after curing, the resin sheet B was heated in an oven at 120° C. for 2 hours and at 170° C. for 3 hours. Thereafter, the Tg of the hardened resin sheet B is 100°C or less, the storage elastic coefficient at 50°C is 1800 MPa or less, and the maximum value of the storage elasticity coefficient at 180°C to 260°C is 70 MPa.

(Production example 3) ＜Preparation of single-sided metal-clad laminate＞ The polyamide solution 2 is evenly applied on the copper foil 1 (electrolytic copper foil, thickness: 12 μm, surface roughness Rz on the resin layer side: 0.6 μm) so that the thickness after hardening becomes about 2 μm to 3 μm. , and then heated and dried at 120°C to remove the solvent. Next, the polyamide solution 1 was uniformly coated on it so that the thickness after hardening would be about 21 μm, and the solution was heated and dried at 120° C. to remove the solvent. Furthermore, the polyamide solution 2 is uniformly applied thereon so that the thickness after hardening becomes about 2 μm to 3 μm, and then heated and dried at 120° C. to remove the solvent. Furthermore, stepwise heat treatment is performed from 120°C to 360°C to complete the imidization, and the single-sided metal-clad laminate 1 is produced. The dimensional change rate of the single-sided metal-clad laminate 1 is as follows. Dimensional change rate in MD direction (long side direction) after etching: 0.01% Dimensional change rate in TD direction (width direction) after etching: -0.04% Dimensional change rate after heating in MD direction (long side direction): -0.03% Dimensional change rate after heating in TD direction (width direction): -0.01%

＜Preparation of polyimide membrane＞ The copper foil 1 of the single-sided metal-clad laminate 1 is etched away using an aqueous ferric chloride solution to prepare a polyimide film 1 (thickness: 25 μm, CTE: 20 ppm/K, Dk: 3.40, Df: 00029).

[Example 1] Two single-sided metal-clad laminated boards 1 were prepared, and the surfaces on the insulating resin layer side of each sheet were overlapped with both surfaces of the resin sheet A, and pressure-bonding was performed at 180° C. for 2 hours with a pressure of 3.5 MPa. Thus, a metal-clad laminated board 1 was prepared. The evaluation results of the metal-clad laminated board 1 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 after heating in MD direction: -0.02% Dimensional change rate after heating in TD direction: -0.02% The metal-clad laminated board 1 has no warpage and no dimensional changes. In addition, the CTE of the resin laminate 1 (thickness: 100 μm) prepared by etching and removing the copper foil 1 in the metal-clad laminate 1 was 24.1 ppm/K.

[Example 2] Two single-sided metal-clad laminated boards 1 were prepared, and the surfaces on the insulating resin layer side of each sheet were overlapped with both surfaces of the resin sheet B, and pressure bonding was performed at 180° C. for 2 hours by applying a pressure of 3.5 MPa to prepare a metal-clad laminated board 2 . The evaluation results of the metal-clad laminated board 2 are as follows. Dimensional change rate after etching in MD direction: -0.05% Dimensional change rate after etching in TD direction: -0.05% Dimensional change rate after heating in MD direction: -0.03% Dimensional change rate after heating in TD direction: -0.04% The metal-clad laminated board 2 has no warping or dimensional changes. In addition, the CTE of the resin laminate 2 (thickness: 100 μm) prepared by etching and removing the copper foil 1 in the metal-clad laminate 2 was 23.3 ppm/K.

(Comparative example 1) In addition to using a fluororesin sheet (manufactured by Asahi Glass Co., Ltd., trade name: adhesive perfluororesin EA-2000, thickness: 50 μm, Tm: 303°C, Tg: none) instead of resin sheet A, apply 3.5 MPa at 320°C for 5 minutes. A metal-clad laminated board 3 was prepared in the same manner as in Example 1, except that pressure was applied for crimping. The evaluation results of the metal-clad laminated board 3 are as follows. Dimensional change rate after etching in MD direction: -0.11% Dimensional change rate after etching in TD direction: -0.13% Dimensional change rate after heating in MD direction: -0.19% Dimensional change rate after heating in TD direction: -0.20% The metal-clad laminated board 3 has no warping or dimensional changes. In addition, the CTE of the resin laminate 3 (thickness: 100 μm) prepared by etching and removing the copper foil 1 in the metal-clad laminate 3 was 27.6 ppm/K.

(Reference example 1) The copper foil 1, the resin sheet A, the polyimide film 1, the resin sheet A, and the copper foil 1 were stacked in this order, and pressure-bonded at 180° C. for 2 hours with a pressure of 3.5 MPa to prepare a metal-clad laminate 4. The evaluation results of the metal-clad laminated board 4 are as follows. Dimensional change rate after etching in MD direction: -0.04% Dimensional change rate after etching in TD direction: -0.05% Dimensional change rate after heating in MD direction: -0.12% Dimensional change rate after heating in TD direction: -0.14% The metal-clad laminated board 4 has no warpage and no dimensional changes. In addition, the CTE of the resin laminate 4 (thickness: 100 μm) prepared by etching away the copper foil 1 in the metal-clad laminate 4 was 23.9 ppm/K.

It can be seen that even when Examples 1 and 2 are compared with Comparative Example 1 and Reference Example 1 respectively, the dimensional change rate after etching and the dimensional change rate after heating are low. Furthermore, in Comparative Example 1, lamination by thermocompression bonding at 320°C was performed, and there was no problem with adhesion. However, the same thermocompression bonding conditions as those in Examples 1 and 2 were used (temperature: 180°C, time: 2 hours, pressure: 3.5 MPa) cannot obtain sufficient adhesive force. In addition, Reference Example 1 was performed for the purpose of verifying the positional configuration of the resin sheet A.

[Example 3] Prepare the single-sided metal-clad laminate 1. Apply the resin solution A for the adhesive layer to the surface on the insulating resin layer side so that the thickness after drying is 50 μm, heat and dry it at 80°C for 15 minutes, and further dry it at 120°C. Dry for 15 minutes at ℃ to prepare a single-sided metal-clad laminate 1 with an adhesive layer. Secondly, after the adhesive layer of the single-sided metal-clad laminate 1 with the adhesive layer is overlapped with the surface on the insulating resin layer side of the other single-sided metal-clad laminate 1, a pressure of 3.5 MPa is applied for 2 hours at 180°C for crimping. , prepare the metal-clad laminated board 1'. The evaluation results of the metal-clad laminated board 1' are as follows. Dimensional change rate after etching in MD direction: -0.03% Dimensional change rate after etching in TD direction: -0.03% Dimensional change rate after heating in MD direction: -0.02% Dimensional change rate after heating in TD direction: -0.02% The metal-clad laminated board 1' has no warping or dimensional changes. In addition, the CTE of the resin laminate 1' (thickness: 100 μm) prepared by etching and removing the copper foil 1 in the metal-clad laminate 1' was 23.1 ppm/K.

[Example 4] Prepare two single-sided metal-clad laminates 1 with adhesive layers. After overlapping the adhesive layers, apply a pressure of 3.5 MPa at 180°C for 2 hours for crimping to prepare a metal-clad laminate 5. The evaluation results of the metal-clad laminated board 5 are as follows. Dimensional change rate after etching in MD direction: -0.03% Dimensional change rate after etching in TD direction: -0.03% Dimensional change rate after heating in MD direction: -0.03% Dimensional change rate after heating in TD direction: -0.03% The metal-clad laminated board 5 has no warping or dimensional changes. In addition, the CTE of the resin laminate 5 (thickness: 150 μm) prepared by etching away the copper foil 1 in the metal-clad laminate 5 was 23.8 ppm/K.

[Example 5] Prepare the single-sided metal-clad laminate 1. Apply the resin solution A for the adhesive layer to the surface on the insulating resin layer side so that the thickness after drying is 75 μm, heat and dry it at 80°C for 15 minutes, and further dry it at 120°C. Dry for 25 minutes at ℃ to prepare a single-sided metal-clad laminate 2 with an adhesive layer. Prepare two single-sided metal-clad laminates 2 with adhesive layers. After overlapping the adhesive layers, apply a pressure of 3.5 MPa at 180°C for 2 hours for crimping to prepare a metal-clad laminate 6. The evaluation results of the metal-clad laminated board 6 are as follows. Dimensional change rate after etching in MD direction: -0.01% Dimensional change rate after etching in TD direction: -0.01% Dimensional change rate after heating in MD direction: 0.01% Dimensional change rate after heating in TD direction: 0.02% The metal-clad laminated board 6 has no warping or dimensional changes. In addition, the CTE of the resin laminate 6 (thickness: 200 μm) prepared by etching and removing the copper foil 1 in the metal-clad laminate 6 was 22.8 ppm/K.

(Synthesis example 5) Under nitrogen flow, put 44.98 g of BTDA (0.139 mole), 75.02 g of DDA (0.140 mole), 168 g of NMP and 112 g of xylene into a 500 ml detachable flask at 40°C. Mix thoroughly for 30 minutes to prepare the polyamide solution. The polyimide solution was heated to 190°C, heated and stirred for 4.5 hours, and 112 g of xylene was added to prepare a polyimide adhesive solution 1 that has completed imidization. The solid content in the obtained polyimide adhesive solution 1 was 29.1% by weight, and the viscosity was 7,800 cps. In addition, the weight average molecular weight (Mw) of polyimide is 87,700.

(Synthesis example 6) To the polyimide adhesive solution 1 obtained in Synthesis Example 5, 34.4 g (solid content: 10 g), 1.25 g of N-12 and 2.5 g of Exolit OP935 (Clariant, Japan) were prepared. Japan) Co., Ltd.), add 1.297 g of NMP and 3.869 g of xylene to dilute it to prepare resin solution C for the adhesive layer.

<Preparation of resin sheet C for adhesive layer> After the adhesive layer resin solution C is applied to the silicone-treated surface of the release base material (length × width × thickness = 320 mm × 240 mm × 25 μm) to a thickness of 50 μm after drying, it is heated at 80°C The resin sheet C was prepared by heating and drying at 120° C. for 15 minutes, further drying at 120° C. for 15 minutes, and then peeling it off from the release base material. In addition, in order to evaluate the physical properties of the resin sheet C after curing, it was heated in an oven at 120° C. for 2 hours and at 170° C. for 3 hours to prepare a cured resin sheet D. The Tg of the hardened resin sheet D is 95°C, the storage elasticity coefficient at 50°C is 1220 MPa, and the maximum value of the storage elasticity coefficient at 180°C to 260°C is 26 MPa.

[Example 6] Prepare the single-sided metal-clad laminate 1. Apply the resin solution C for the adhesive layer to the surface on the insulating resin layer side so that the thickness after drying is 50 μm, heat and dry it at 80°C for 15 minutes, and further dry it at 120°C. Dry for 15 minutes at ℃ to prepare a single-sided metal-clad laminate 3 with an adhesive layer. Secondly, after the adhesive layer of the single-sided metal-clad laminate 3 with an adhesive layer is overlapped with the surface on the insulating resin layer side of the single-sided metal-clad laminate 1, a pressure of 3.5 MPa is applied for 2 hours at 180°C for crimping. A metal-clad laminated board 7 is prepared. The evaluation results of the metal-clad laminated board 7 are as follows. Dimensional change rate after etching in MD direction: -0.02% Dimensional change rate after etching in TD direction: -0.02% Dimensional change rate after heating in MD direction: -0.03% Dimensional change rate after heating in TD direction: -0.03% The metal-clad laminated board 7 has no warping or dimensional changes. In addition, the CTE of the resin laminate 7 (thickness: 100 μm) prepared by etching and removing the copper foil 1 in the metal-clad laminate 7 was 23.4 ppm/K.

In addition, any single-sided metal-clad laminate with an adhesive layer described in the embodiments can also be applied to the manufacture of multi-layer circuit substrates. In addition, it is considered that the thickness of the adhesive layer in this case is preferably 100 μm or less, and the thickness ratio of the adhesive layer in the insulating resin layer is preferably 80% or less.

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

100:Metal clad laminate 101:Metal layer 110:Polyimide layer 111: Non-thermoplastic polyimide layer 112: Thermoplastic polyimide layer 120: Adhesive polyimide layer 130:Single-sided metal clad laminate B: Adhesive layer C:Metal clad laminate C1: The first single-sided metal clad laminate (single-sided metal clad laminate) C2: The second single-sided metal clad laminate (single-sided metal clad laminate) M1: first metal layer M2: Second metal layer P1: first insulating resin layer P2: Second insulating resin layer T1:Total thickness T2, T3: thickness

FIG. 1 is a schematic diagram showing the structure of a metal-clad laminated board according to an embodiment of the present invention. FIG. 2 is a schematic cross-sectional view showing the structure of a metal-clad laminated board according to a preferred embodiment of the present invention.

B: Adhesive layer

C:Metal clad laminate

C1: The first single-sided metal clad laminate (single-sided metal clad laminate)

C2: The second single-sided metal clad laminate (single-sided metal clad laminate)

M1: first metal layer

M2: Second metal layer

P1: first insulating resin layer

P2: Second insulating resin layer

T1:Total thickness

T2, T3: thickness

Claims (9)

A metal-clad laminated board includes: a first single-sided metal-clad laminated board having a first metal layer and a first insulating resin layer laminated on at least one side of the first metal layer; a second single-sided metal-clad laminated board; A metal laminated board has a second metal layer and a second insulating resin layer laminated on at least one side of the second metal layer; and an adhesive layer to contact the first insulating resin layer and the A second insulating resin layer is disposed between the first single-sided metal-clad laminated board and the second single-sided metal-clad laminated board, and the metal-clad laminated board is characterized by: the first The total thickness T1 of the insulating resin layer, the adhesive layer and the second insulating resin layer is in the range of 70 μm ~ 500 μm, and the ratio of the thickness T2 of the adhesive layer to the total thickness T1 (T2/T1) is in the range of 0.5~0.8, and the adhesive layer is composed of thermoplastic resin or thermosetting resin and meets the following conditions (i)~(iii): (i) The storage elastic coefficient at 50°C is below 1800MPa; (ii) The maximum value of the storage elastic coefficient in the temperature range of 180°C to 260°C is 800MPa or less; (iii) The glass transition temperature (Tg) is 180°C or less. The metal-clad laminated board as claimed in item 1 of the patent application, wherein both the first insulating resin layer and the second insulating resin layer have thermoplastic polyimide. The adhesive layer is in contact with the two thermoplastic polyimide layers. The metal-clad laminate according to claim 2, wherein the non-thermoplastic polyimide constituting the non-thermoplastic polyimide layer contains a tetracarboxylic acid residue and a diamine residue. The content of the diamine residue derived from the diamine compound represented by the following general formula (1) is 80 mole parts or more based on 100 mole parts of all diamine residues:

In formula (1), the linking group Z represents a single bond or -COO-, and Y independently represents a halogen atom or a monovalent hydrocarbon with 1 to 3 carbon atoms that may be substituted by a phenyl group, or an alkoxy group with 1 to 3 carbon atoms. , or a perfluoroalkyl group having 1 to 3 carbon atoms, or an alkenyl group, n represents an integer of 0 to 2, and p and q independently represent an integer of 0 to 4. A metal-clad laminated board includes: a first single-sided metal-clad laminated board having a first metal layer and a first insulating resin layer laminated on at least one side of the first metal layer; a second single-sided metal-clad laminated board; A metal laminated board having a second metal layer and a metal layer laminated on the second a second insulating resin layer on at least one side of the metal layer; and an adhesive layer disposed in contact with the first insulating resin layer and the second insulating resin layer, and laminated on the first unit Between the surface-clad metal laminated board and the second single-sided metal clad laminated board, and the metal-clad laminated board is characterized in that: both the first insulating resin layer and the second insulating resin layer have thermoplastic polyester. An imine layer, a non-thermoplastic polyimide layer and a thermoplastic polyimide layer are laminated in sequence to form a multi-layer structure. The adhesive layer is arranged in contact with the two thermoplastic polyimide layers, and the adhesive layer is It is composed of thermoplastic resin or thermosetting resin and satisfies the following conditions (i)~(iii): (i) the storage elasticity coefficient at 50℃ is 1800MPa or less; (ii) the storage elasticity in the temperature range of 180℃~260℃ The maximum value of the coefficient is 800MPa or less; (iii) the glass transition temperature (Tg) is 180°C or less. The metal-clad laminate according to claim 4, wherein the non-thermoplastic polyimide constituting the non-thermoplastic polyimide layer contains a tetracarboxylic acid residue and a diamine residue. The content of the diamine residue derived from the diamine compound represented by the following general formula (1) is 80 mole parts or more based on 100 mole parts of all diamine residues:

In formula (1), the linking group Z represents a single bond or -COO-, and Y independently represents a halogen atom or a monovalent hydrocarbon with 1 to 3 carbon atoms that may be substituted by a phenyl group, or an alkoxy group with 1 to 3 carbon atoms. , or a perfluoroalkyl group having 1 to 3 carbon atoms, or an alkenyl group, n represents an integer of 0 to 2, and p and q independently represent an integer of 0 to 4. The metal-clad laminated board as described in any one of items 1 to 5 of the patent application, wherein the overall thermal expansion coefficient of the first insulating resin layer, the adhesive layer and the second insulating resin layer is Within the range of 10ppm/K or more and 30ppm/K or less. The metal-clad laminated board as described in any one of items 1 to 5 of the patent application, wherein both the first metal layer and the second metal layer include copper foil. The metal-clad laminate as claimed in claim 6, wherein both the first metal layer and the second metal layer include copper foil. A circuit substrate is obtained by processing the first metal layer and/or the second metal layer of the metal-clad laminate according to any one of items 1 to 8 of the patent application into wiring.