KR20230099675A - Layered resin product, metal-clad laminate, circuit substrate, electronic device and electronic apparatus - Google Patents

Abstract

The present invention provides a layered resin product of polyimide resin, which has excellent heat resistance, dimensional stability represented by a coefficient of thermal expansion, flexibility, adhesiveness, and high transparency, and especially suppressed increase in HAZE, and a metal-clad laminate and a circuit board comprising the layered resin product. The layered resin product comprises a plurality of polyimide layers, satisfies the following conditions a to c: a) a thickness within a range of at least 12 μm but no more than 200 μm; b) a total light transmittance of 80% or more; and c) a HAZE of 2% or less, has a layer structure that is symmetrical in a thickness direction based on the center of the thickness direction, and comprises at least two non-thermoplastic polyimide layers formed of polyimide and at least three thermoplastic polyimide layers formed of thermoplastic polyimide, wherein the non-thermoplastic polyimide layer is stacked between two thermoplastic polyimide layers, and the outermost layer of the layered resin product is formed of a thermoplastic polyimide layer having a glass transition temperature of 250℃ or higher.

Description

Resin laminates, metal clad laminates, circuit boards, electronic devices and electronic devices

The present invention relates to a resin laminate excellent in heat resistance, adhesiveness, flexibility and high transparency, a metal clad laminate and a circuit board comprising the same, and electronic devices and electronic equipment using the same.

Polyimide (PI) is a heat-resistant resin obtained by ring-closing a polyamic acid synthesized by a condensation reaction of tetracarboxylic anhydride and diamine as raw materials. It has excellent resistance to thermal decomposition due to strong chemical bonds, high durability against chemical changes such as oxidation or hydrolysis, and excellent flexibility, mechanical properties and electrical properties. In general, polyimide is widely used in an insulating resin layer of flexible printed circuits (FPCs) used in electronic devices.

In general, the insulating resin layer in commercially available copper-clad laminates used for FPC is made of wholly aromatic polyimide resin, and exhibits a yellowish brown color due to the formation of intra- and inter-molecular charge transfer complexes. However, it is difficult to apply it to transparent FPC applications requiring colorless transparency.

Therefore, in order to make polyimide colorless and transparent, it has been proposed so far to use alicyclic diamine or alicyclic acid anhydride as a diamine component or to use fluorinated polyimide as an insulating resin layer, but along with the demand for transparency, There was a problem that it was difficult to satisfy the heat resistance of polyimide, the low thermal expansion required for FPC, or the adhesive strength with a metal layer. In particular, the metal clad laminate used for FPC is composed of a thin metal foil and an insulating resin layer containing a polyimide layer, and if the difference in coefficient of thermal expansion (CTE) between the metal foil and the insulating resin layer is greatly different, warpage or curl may occur on the board. occurs, and when mounting electronic components, a problem arises in that dimensions change and accurate mounting becomes impossible.

In response to such conventional problems, the inventors of the present application repeatedly studied intensively about a resin film and metal clad laminate for a wiring board having heat resistance, dimensional stability, flexibility, adhesiveness and high transparency, and a specific method for the insulating resin layer. In addition to using polyimide, it is proposed to make it an appropriate layer structure, and to control the thickness and specific physical properties of the polyimide layer (Patent Document 1).

International Publication No. WO2020/262450 Japanese Patent No. 5886027 Japanese Patent No. 6031396 Japanese Unexamined Patent Publication No. 2017-149128

However, in addition to the background art as described above, recently, the application of a transparent resin instead of a glass substrate has been reviewed to prevent display weight reduction and breakage, but high-speed transmission of information accompanying high performance and high functionality of electronic devices has been requested. The parts used are also required to respond to high-speed. For example, in high-frequency applications such as transparent antennas, for the reason of reducing the transmission loss of the conductor layer by increasing the thickness of the resin layer as a dielectric, as a transparent FPC, a transparent FPC having a relatively thick and metal layer on both sides Demand for resin double-sided metal clad laminates is increasing. For this new demand, a plurality of polyamic acid solutions are sequentially coated, dried, and cured on a support substrate (eg, roughened metal foil) as also adopted in Patent Document 1 above. Imidation) to form a polyimide layer (so-called cast method) as it is, there is concern about the occurrence of the following problems.

That is, according to the method in Patent Literature 1, in the single-sided metal clad laminate having a metal layer on one side of the polyimide layer, dimensional stability is excellent and the increase in HAZE (turbidity) of the polyimide layer is suppressed. Although it is easy and advantageous, when an attempt is made to manufacture a double-sided metal clad laminate obtained by further thermally pressing the roughened surface of the metal layer on the surface side of the polyimide layer, the HAZE of the polyimide layer after removal of the metal layer tends to increase (eg For example, see Table 3 of Patent Document 1, etc.).

On the other hand, in the casting method, since it is a method of applying, drying, and curing polyamic acid on a support base material as described above, a polyimide layer serving as a base (hereinafter sometimes simply referred to as “base layer”) If you want to make it thicker, the amount of shrinkage during drying increases, and curling easily occurs during the film forming and coating process. In particular, in the case of forming a long polyimide film for continuous production, the polyimide film after curing There is a possibility that the appearance may be damaged due to the generation of streaks and the like, and there is a possibility that the optical characteristics may be adversely affected. In order to avoid this, it is conceivable to manufacture the base layer by applying, drying and curing it in multiple steps, but productivity is extremely reduced. In the first place, the polyimide layer serving as the base often adopts a material that is relatively easy to crystallize as its composition in order to ensure the heat resistance and dimensional stability of the polyimide film, and as the thickness increases, the HAZE of the polyimide layer after removal of the metal layer increases. In order to avoid this, if it is desired to increase the ratio of the polyimide layer having high thermoplasticity provided on both sides of the base layer (that is, provided on the side of the contact surface with the metal layer) in order to avoid this, the polyimide layer having high thermoplasticity There is also concern about the occurrence of another problem that the linear thermal expansion coefficient of the polyimide layer deteriorates with the increase in the ratio of . Furthermore, in the manufacturing method such as Patent Document 1, in order to suppress problems such as discoloration caused by thermal compression of the metal layer, polyimide that can be thermally compressed even at a relatively low temperature is disposed on the thermal compression surface side of the metal layer, so that soldering heat resistance It is also a concern that this deterioration and occurrence of abnormalities in appearance after the reflow step are conspicuous.

Therefore, in the case of manufacturing a relatively thick double-sided metal clad laminate having a polyimide layer with high transparency, especially as a long product, in addition to the fact that there will be no curling during the film forming and coating process in the first place, It is required to prevent the HAZE from rising after the removal of the metal layer, and there is room for further examination, including viewpoints such as good appearance and soldering heat resistance.

Therefore, with respect to the resin film and metal-clad laminate previously studied, the inventors of the present application further conducted an examination from the above viewpoint, and as a result, thermoplastic polyimide surfaces in a predetermined single-sided metal-clad laminate were thermally compressed and laminated with each other, resulting in a thickness The present invention was completed by finding that the above problems can be solved by, for example, forming a layer configuration symmetrical in the thickness direction with respect to the center of the direction.

In addition, a technique for obtaining a double-sided metal-clad laminate by thermally pressing the polyimide surfaces of a single-sided metal-clad laminate is already known (for example, Patent Documents 2 to 3), but the polyimide used is colored and emits light. Since it is not transparent, development for transparent FPC is not considered. Also, it is not a consideration for HAZE or appearance. Furthermore, from the viewpoint of maintaining the heat resistance of the entire polyimide resin layer (insulation layer), since the glass transition temperature of all the polyimide layers used is as high as 300° C. or higher, discoloration due to excessive heating, for example, is a concern.

In addition, in Patent Document 4, a polyimide precursor is sequentially cast on the first copper foil layer, dried, and then subjected to heat treatment to form a composite polyimide layer having a total thickness of 40 to 60 μm, and finally a second copper foil layer. A technique for obtaining a double-sided copper clad laminate by laminating is disclosed. However, in this method, as in Patent Document 1, there is a concern about an increase in the HAZE of the polyimide resin layer after removing the copper foil, and furthermore, there is a concern that curling or streaking may occur during the film forming and coating process, which is derived from the total thickness of the polyimide layer. there is

An object of the present invention is to provide a laminate of polyimide resin having excellent heat resistance, dimensional stability represented by a coefficient of thermal expansion, flexibility, adhesiveness, and high transparency, and in particular, an increase in HAZE is suppressed, to a relatively thick one. It is to provide a resin laminate that can also be applied and a metal clad laminate or circuit board having the same.

That is, this invention is as follows.

[1] A resin laminate comprising a plurality of polyimide layers, the following a to c;

a) having a thickness within the range of 12 μm or more and 200 μm or less;

b) having a total light transmittance of 80% or more;

c) HAZE of 2% or less;

satisfies,

It has a layer configuration symmetrical in the thickness direction with respect to the center in the thickness direction, and includes at least two non-thermoplastic polyimide layers composed of non-thermoplastic polyimide and at least three thermoplastic polyimide layers composed of thermoplastic polyimide. do,

The non-thermoplastic polyimide layer is laminated between two thermoplastic polyimide layers,

The resin laminate, characterized in that the outermost layer of the resin laminate is made of a thermoplastic polyimide layer having a glass transition temperature of 250 ° C. or higher.

[2] It is described in [1] characterized in that the total thickness of the non-thermoplastic polyimide layer is within the range of 50% or more and 97% or less with respect to the total thickness of the non-thermoplastic polyimide layer and the thermoplastic polyimide layer. resin laminated body.

[3] the number of non-thermoplastic polyimide layers is two, the number of thermoplastic polyimide layers is three,

In [1] or [2], characterized in that the glass transition temperature of the thermoplastic polyimide constituting one thermoplastic polyimide layer located in the central portion in the thickness direction of the resin laminate is within the range of 150 ° C. or more and less than 250 ° C. The resin laminate described.

[4] the number of non-thermoplastic polyimide layers is two, the number of thermoplastic polyimide layers is four,

[1] or [2], characterized in that the glass transition temperature of the thermoplastic polyimide constituting the two opposing thermoplastic polyimide layers located in the central portion in the thickness direction of the resin laminate is within the range of 150 ° C. or more and less than 250 ° C. The resin laminate described in.

[5] The resin laminate described in [1] or [2] characterized in that it is long.

[6] A metal clad laminate comprising the resin laminate according to [1] or [2] and a metal layer laminated on at least one side of the resin laminate.

[7] A circuit board obtained by processing the metal layer of the metal clad laminate according to [6] into a wiring circuit.

[8] An electronic device comprising the circuit board described in [7].

[9] An electronic device comprising the circuit board described in [7].

According to the present invention, while having excellent heat resistance, dimensional stability represented by a coefficient of thermal expansion, flexibility, adhesiveness, and high transparency, as well as having a particularly high HAZE increase, a resin laminate of polyimide resin, which is relatively thick, It is also possible to obtain a resin laminate, which can also be applied, and a metal clad laminate or circuit board having the same.

Fig. 1 is a schematic cross-sectional view illustrating the configuration of a resin laminate comprising two non-thermoplastic polyimide layers and three thermoplastic polyimide layers.
Fig. 2 is a schematic cross-sectional view illustrating the configuration of a resin laminate comprising two non-thermoplastic polyimide layers and four thermoplastic polyimide layers.
Fig. 3 is a schematic cross-sectional view illustrating the configuration of a resin laminate comprising three non-thermoplastic polyimide layers and six thermoplastic polyimide layers.
Fig. 4 is a schematic cross-sectional view illustrating the configuration of a resin laminate comprising four non-thermoplastic polyimide layers and eight thermoplastic polyimide layers.
Fig. 5 is a schematic cross-sectional view illustrating a configuration in the case where other layers are provided in a resin laminate having two non-thermoplastic polyimide layers and four thermoplastic polyimide layers.
Fig. 6 is a diagram illustrating one step of the method for manufacturing a metal clad laminate according to the present invention.
Fig. 7 is a diagram illustrating one step of the manufacturing method of another metal clad laminate according to the present invention.

EMBODIMENT OF THE INVENTION Below, embodiment of this invention is described with reference to drawings suitably.

<Resin Laminate>

The resin laminate of the present invention is constituted by including a plurality of polyimide layers, and includes at least three thermoplastic polyimide layers and at least two non-thermoplastic polyimide layers, and one non-thermoplastic polyimide layer comprises two layers. It is laminated between the thermoplastic polyimide layers. In addition, the resin laminate of the present invention has a layer configuration symmetrical in the thickness direction with respect to the center in the thickness direction while having the above layer configuration. A specific layer structure can be grasped from FIG. 1, for example.

That is, Fig. 1 is a schematic diagram showing one embodiment of the layer structure of the resin laminate of the present invention, wherein two non-thermoplastic polyimide layers 2 are interposed between two thermoplastic polyimide layers 1 and 1', respectively. It shows a laminated configuration, and has a configuration in which the thermoplastic polyimide layer 1' is laminated in the thickness center. The thermoplastic polyimide layers 1 and 1' are not necessarily limited to this arrangement. The "centre in the thickness direction" in Fig. 1 is the center of one thermoplastic polyimide layer 1' as indicated by the broken line 3. In order from the top, a thermoplastic polyimide layer 1', a non-thermoplastic polyimide layer 2, and a thermoplastic polyimide layer 1 (hereinafter, this may be simply described as "1'-2-1" or the like). ) has a layer configuration of On the other hand, since the layer configuration is 1'-2-1 in order toward the lower side with the same center as the reference (boundary), the upper and lower sides are symmetrical with respect to the thickness center. That is, the layer configuration is symmetrical in the thickness direction with respect to the center in the thickness direction. It is preferable that the resin laminate of the present invention has the embodiment shown in Fig. 1 as a basic layer configuration. In addition, "center" and "middle" in this specification may indicate not only one point but the vicinity thereof.

The resin laminate of the present invention basically has the configuration as shown in Fig. 1 above, but as illustrated in Fig. 2, for example, in the center of the thickness, two thermoplastic polyimide layers (1') ) may be provided with a mutually laminated structure, and as illustrated in FIGS. 3 to 4, for example, in addition to the layer structure of FIG. 2, for example, "1'-2-1'" layers A resin laminate having a plurality of further may be used. Here, as can be understood from FIGS. 1 and 3, as long as the layer structure is symmetrical in the thickness direction with respect to the center 3 in the thickness direction, the center 3 in the thickness direction may be in the middle of the layer (ie, layer It may not be the laminated side of the layer). Further, the embodiments illustrated in FIGS. 2 to 4 include layers in which two thermoplastic polyimide layers 1' are mutually laminated, but at least one of these layers is one thermoplastic polyimide layer not shown in the drawings. It may consist of (1'). As illustrated in Fig. 5, another layer 4 or the like may be provided at any place in the thickness direction (for example, in the center, preferably other than the outermost layer). . For such a layer 4, for example, a transparent substrate having relatively low roughness (for example, a resin film such as PET, PEN, PFA, etc.), which does not impair the object of the present invention, can be selected. can

In addition, in the resin laminate of the present invention, as illustrated above, the uppermost layer and the lowermost layer (hereinafter, the layer on one side or the layer on both sides thereof are collectively described as "outermost layer" In some cases), a thermoplastic polyimide layer is laminated. By using thermoplastic polyimide for the outermost layer, it can be suitably used as an adhesive layer with a substrate such as a metal layer or another resin layer, for example. In the resin laminate of the present invention, the outermost thermoplastic polyimide layer has a glass transition temperature (Tg) of 250°C or higher from the viewpoint of heat resistance and dimensional stability. Preferably, it is good to use a Tg of 260 ° C. or higher, more preferably 270 ° C. or higher. In a preferable upper limit of Tg, it is 350 degreeC or less.

On the other hand, the Tg of the thermoplastic polyimide layer disposed outside the outermost layer (that is, inside the outermost layer (inner layer)) is not limited to this, but since it becomes a thermal compression (lamination) surface during manufacture, it is difficult to improve adhesion. For this purpose, it is preferable to use a relatively low Tg thermoplastic polyimide. Preferably, a thermoplastic polyimide having a Tg of 150°C or more and less than 250°C, more preferably 150°C or more and 200°C or less is used. Most preferably, it is good that all of the thermoplastic polyimide layers arrange|positioned inside (inner layer) rather than the outermost layer have this Tg.

Here, thermoplastic polyimide (also referred to as “TPI”) is generally a polyimide whose Tg can be clearly confirmed, but in the present invention, the storage modulus at 30° C. measured using a dynamic viscoelasticity measuring device (DMA). is 1.0 × 10 ⁹ Pa or more and the storage modulus at 300°C is less than 1.0 × 10 ⁸ Pa. In addition, non-thermoplastic polyimide is generally a polyimide that does not soften or exhibit adhesiveness even when heated, but in the present invention, the storage modulus at 30 ° C measured using DMA is 1.0 × 10 ⁹ Pa or more And, it refers to a polyimide having a storage modulus at 360°C of 1.0×10 ⁹ Pa or more.

The resin laminate of the present invention is not limited by the above examples, nor is it limited by its manufacturing method (to be described later), but by having such a layer configuration as essential, even if the thickness is relatively increased, dimensional stability is maintained. It is possible to obtain a resin laminate in which the increase in HAZE and the occurrence of abnormalities in appearance are suppressed.

In the resin laminate of the present invention, the total thickness of the resin laminate is within the range of 12 μm or more and 200 μm or less from the viewpoint of transparency, dimensional stability or process transportability. A preferable lower limit is 15 μm, a more preferable lower limit is 20 μm, and a still more preferable lower limit is 25 μm. On the other hand, a preferable upper limit is 180 μm, and a more preferable upper limit is 100 μm. Regarding the thickness of each layer, the non-thermoplastic polyimide layer is preferably 5 µm or more and 50 µm or less, more preferably 5 µm or more and 25 µm or less, from the viewpoint of light transmittance. On the other hand, the thermoplastic polyimide layer is preferably 1 µm or more and 5 µm or less, more preferably 1 µm or more and 3 µm or less, from the viewpoint of heat resistance. From the standpoint of dimensional stability, it is preferable that the total thickness of the non-thermoplastic polyimide layer is 50% or more and 97% or less with respect to the total thickness of the non-thermoplastic polyimide layer and the thermoplastic polyimide layer in the resin laminate. and more preferably 60% or more and 90% or less.

Further, the resin laminate of the present invention has a total light transmittance of 80% or more in the visible region from the viewpoint of transparency. The light transmittance at a wavelength of 500 nm is preferably 70% or more, more preferably 75% or more. For example, in the overall thickness of 20 μm, it is preferable to satisfy the above. More preferably, the total light transmittance is 83% or more. By controlling within such a range, cloudiness due to reflection and scattering of light in the resin laminate is suppressed, and excellent transparency is obtained. When the total light transmittance is less than 80%, the turbidity increases and the transparency decreases.

Further, the resin laminate of the present invention has a HAZE (turbidity) of 2% or less. Preferably it is good that it is 1.9 % or less. When HAZE exceeds 2%, light scattering becomes easy to occur, for example. In the case of application to a display, images may be doubled or images may not be clearly visible. In addition, HAZE depends on the surface profile of the resin laminate, and since even a low-profile resin laminate has a thermoplastic polyimide layer on the outermost layer, it is possible to achieve both adhesive strength and transparency, for example, when laminating fine metal layers. It can be used suitably for bonding with a circuit board or a glass substrate.

Further, in the resin laminate of the present invention, the coefficient of thermal expansion (CTE) is preferably within the range of 10 ppm/K or more and 30 ppm/K or less. By controlling within such a range, deformation such as curling can be suppressed, and high dimensional stability can be ensured. Here, CTE is an average value of thermal expansion coefficients in the longitudinal direction (MD direction) and width direction (TD direction) of the resin laminate. In particular, it is preferable that the non-thermoplastic polyimide layer used is constituted by a polyimide layer having low thermal expansion properties, and the thermoplastic polyimide layer constitutes a polyimide layer having high thermal expansion properties. Here, the low thermal expansion non-thermoplastic polyimide layer preferably has a coefficient of thermal expansion (CTE) within the range of 1 ppm/K or more and 25 ppm/K or less, more preferably within the range of 3 ppm/K or more and 25 ppm/K or less. . Further, the high thermally expansible thermoplastic polyimide layer has a CTE of preferably 35 ppm/K or more, more preferably 35 ppm/K or more and 80 ppm/K or less, and still more preferably 35 ppm/K or more and 70 ppm/K or less. It's good to be mine. The polyimide layer can be made into a polyimide layer having a desired CTE by appropriately changing the combination of raw materials used, the thickness, and drying/curing conditions.

Further, the resin laminate of the present invention preferably has a YI (yellowing index) of 10 or less when the thickness is 10 µm. Moreover, it is preferable that YI in case thickness is 50 micrometers is 30 or less. By controlling within such a range, the resin laminate can be made almost colorless. On the other hand, when YI is out of the above range, there is a risk that yellow to yellowish brown coloration becomes strong and visibility deteriorates.

It is preferable that the resin laminate of the present invention is manufactured as a particularly elongated product. Here, the long picture (long picture) in this specification is not particularly limited, but refers to a resin laminate having a length of 30 m or more or a metal clad laminate to be described later.

<Composition of polyimide layer>

Although the layer structure of the polyimide used in the resin laminate of the present invention is the same as above, the composition of the thermoplastic polyimide and the non-thermoplastic polyimide used will be described below, respectively.

(thermoplastic polyimide layer)

The thermoplastic polyimide layer is provided with a diamine residue derived from a diamine compound and a tetracarboxylic acid anhydride residue derived from a tetracarboxylic acid anhydride compound, but is disposed on at least the outermost layer (hereinafter referred to simply as "P1"). may be) is a diamine residue derived from a diamine compound represented by the following general formula (A1) with respect to all diamine residues (sometimes simply referred to as "A1 residue". The same applies to the following compounds) It contains 10 mol% or more.

In the formula (A1), R is independently a halogen atom, an alkyl group or alkoxy group having 1 to 6 carbon atoms which may be substituted with a halogen atom, or a phenyl group or phenoxy group which may be substituted with a monovalent hydrocarbon group or alkoxy group having 1 to 6 carbon atoms. represents a period, Z independently represents a divalent group selected from -O-, -S-, -CH ₂ -, -CH(CH ₃ )-, -C(CH ₃ ) ₂ -, -SO ₂ -, and at least one Z is -SO ₂ -. n ₁ represents an integer of 0 to 3, and n ₂ represents an integer of 0 to 4. Here, “independently” means that the plurality of substituents R, the divalent group Z, and the constant n ₁ may be the same or different. The same applies to other chemical formulas or substituents that follow. In the above formula (A1), the hydrogen atoms in the terminal two amino groups may be substituted, for example, -NR ₃ R ₄ (where R ₃ and R ₄ are independently any alkyl group or the like means a substituent). The same applies to other diamine compounds hereinafter.

The diamine residue derived from the diamine compound represented by the above formula (A1) contains at least two benzene rings, and they are bonded by a flexible bond such as an ether bond, and at least one of the bonding sites Z is -SO Since ₂ - is included, the refractive index can be increased due to the electron-rich nature of the -SO ₂ - site, and adhesion to the metal layer is expressed due to the bending structure, and furthermore, it is one of the polymers because it contains a plurality of benzene rings. By suppressing the imide group ratio, the effect of expressing transparency can also be expected. From such a viewpoint, 10 mol% or more of A1 residues are contained with respect to 100 mol% of total diamine residues as diamine residues used for the thermoplastic polyimide layer P1 arranged at least in the outermost layer. It is preferably contained within the range of 30 to 100 mol%, more preferably within the range of 50 to 100 mol%, and even more preferably within the range of 75 to 100 mol%.

Preferred specific examples of the A1 residue are diamine residues derived from diamine compounds such as bis[4-(4-aminophenoxy)phenyl]sulfone (BAPS) and 4,4'-diaminodiphenylsulfone (DDS). can be heard Among these, diamine residues derived from bis[4-(4-aminophenoxy)phenyl]sulfone (BAPS) are particularly preferred.

As long as the effects of the present invention are not impaired, the polyimide layer may contain, as diamine residues other than the above, diamine residues derived from diamine components generally used for polyimide synthesis. As other diamine residues, for example, 2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl (TFMB), 2,2'-dimethyl-4,4'-diaminobi Phenyl (m-TB), 2,2'-divinyl-4,4'-diaminobiphenyl (VAB), 4,4'-diaminobiphenyl, p-phenylenediamine (p-PDA), m -phenylenediamine (m-PDA), 3,4'-diaminobenzophenone, (3,3'-bisamino)diphenylamine, 1,4-bis(3-aminophenoxy)benzene, 1,3 -bis(4-aminophenoxy)benzene (TPE-R), 3-[4-(4-aminophenoxy)phenoxy]benzenamine, 3-[3-(4-aminophenoxy)phenoxy]benzene Amine, 1,3-bis(3-aminophenoxy)benzene (APB), bis[4-(3-aminophenoxy)phenyl]ether, bis[4-(3-aminophenoxy)]benzophenone, bis [4-(4-aminophenoxy)phenyl]ether (BAPE), bis[4-(4-aminophenoxy)phenyl]ketone (BAPK), bis[4-(3-aminophenoxy)]biphenyl, and structural units derived from bis[4-(4-aminophenoxy)]biphenyl and the like. Among these, 1,3-bis(3-aminophenoxy)benzene (APB) and 1,3-bis(4-aminophenoxy)benzene (TPE-R) are preferable.

On the other hand, as tetracarboxylic acid anhydride residues, all tetracarboxylic acid anhydride residues (sometimes simply referred to as "acid anhydride residues" or the like. Hereinafter, the same applies) are derived from tetracarboxylic acid anhydride compounds represented by the following general formula (B1). It is preferable to contain 10 mol% or more of tetracarboxylic acid anhydride residues.

Since the tetracarboxylic acid anhydride residue derived from the tetracarboxylic acid anhydride represented by the above formula (B1) has a structure in which two phenyl groups are bonded by an ether bond, the electron-accepting property of the acid anhydride residue is reduced when an imide structure is formed with diamine. As it is suppressed, the charge transfer interaction is suppressed, and transparency can be expected. In addition, since the ether bond can impart appropriate flexibility to the polymer chain, expression of adhesiveness with the conductor layer can also be expected. From such a viewpoint, as the acid anhydride residue used in the polyimide layer P1, it is preferable to contain 10 mol% or more of the B1 residue with respect to 100 mol% in total of all acid anhydride residues, within the range of 30 to 100 mol%. It is more preferable to contain, and it is still more preferable to contain within the range of 50 to 100 mol%. It is still more preferable to contain within the range of 75-100 mol%. If it is less than 10 mol%, yellowness (YI) may deteriorate.

Specific examples of the B1 residue include 4,4'-oxydiphthalic anhydride (ODPA) and 3,4'-oxydiphthalic anhydride as more preferred acid dianhydrides.

As long as the effects of the present invention are not impaired, the polyimide layer may contain, as acid anhydride residues other than those described above, acid anhydride residues derived from acid anhydride components generally used for polyimide synthesis. As such an acid anhydride residue, an aromatic tetracarboxylic acid residue is preferable. It may also contain an alicyclic tetracarboxylic acid residue, for example, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, fluorenylidenebisanhydride phthalic acid, 1,2,4,5-cyclohexanetetracarboxylic acid Acid anhydride residues derived from alicyclic tetracarboxylic acid dianhydrides such as dianhydride and cyclopentanone bisspironorbornane tetracarboxylic acid dianhydride are preferable.

Examples of other acid anhydride residues include 3,3',4,4'-biphenyltetracarboxylic dianhydride, 3,3',4,4'-benzophenonetetracarboxylic dianhydride, 2,2',3, 3'-benzophenonetetracarboxylic dianhydride, 2,3,3',4'-benzophenonetetracarboxylic dianhydride, naphthalene-1,2,5,6-tetracarboxylic dianhydride, naphthalene-1,2,4, 5-tetracarboxylic dianhydride, naphthalene-1,4,5,8-tetracarboxylic dianhydride, naphthalene-1,2,6,7-tetracarboxylic dianhydride, 4,8-dimethyl-1,2,3,5 ,6,7-hexahydronaphthalene-1,2,5,6-tetracarboxylic dianhydride, 4,8-dimethyl-1,2,3,5,6,7-hexahydronaphthalene-2,3,6, 7-tetracarboxylic dianhydride, 2,6-dichloronaphthalene-1,4,5,8-tetracarboxylic dianhydride, 2,7-dichloronaphthalene-1,4,5,8-tetracarboxylic dianhydride, 2,3 ,6,7-tetrachloronaphthalene-1,4,5,8-tetracarboxylic dianhydride, 1,4,5,8-tetrachloronaphthalene-2,3,6,7-tetracarboxylic dianhydride, 2,2 ',3,3'-biphenyltetracarboxylic dianhydride, 2,3,3',4'-biphenyltetracarboxylic dianhydride, 3,3'',4,4''-p-terphenyltetracarboxylic acid Anhydride, 2,2'',3,3''-p-terphenyltetracarboxylic dianhydride, 2,3,3'',4''-p-terphenyltetracarboxylic dianhydride, 2,2-bis( 2,3-dicarboxyphenyl)-propane dianhydride, 2,2-bis(3,4-dicarboxyphenyl)-propane dianhydride, bis(2,3-dicarboxyphenyl)ether dianhydride, bis(2,3 -Dicarboxyphenyl)methandianhydride, bis(3,4-dicarboxyphenyl)methandianhydride, bis(2,3-dicarboxyphenyl)sulfonicdianhydride, bis(3,4-dicarboxyphenyl)sulfonicdianhydride , 1,1-bis (2,3-dicarboxyphenyl) ethanedianhydride, 1,1-bis (3,4-dicarboxyphenyl) ethanedianhydride, perylene-2,3,8,9-tetracarboxylic acid dianhydride, perylene-3,4,9,10-tetracarboxylic dianhydride, perylene-4,5,10,11-tetracarboxylic dianhydride, perylene-5,6,11,12-tetracarboxylic dianhydride , phenanthrene-1,2,7,8-tetracarboxylic dianhydride, phenanthrene-1,2,6,7-tetracarboxylic dianhydride, phenanthrene-1,2,9,10-tetracarboxylic dianhydride, cyclo Pentane-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'-oxydiphthalic dianhydride, (trifluoromethyl)pyromellitic dianhydride, di(trifluoromethyl)pyromellitic dianhydride, di (heptafluoropropyl) pyromellitic dianhydride, pentafluoroethylpyromellitic dianhydride, bis{3,5-di(trifluoromethyl)phenoxy}pyromellitic dianhydride, 2,2-bis( 3,4-dicarboxyphenyl) hexafluoropropane dianhydride, 5,5'-bis (trifluoromethyl) -3,3', 4,4'-tetracarboxybiphenyl dianhydride, 2,2', 5,5'-tetrakis(trifluoromethyl)-3,3',4,4'-tetracarboxybiphenyl dianhydride, 5,5'-bis(trifluoromethyl)-3,3',4 ,4'-tetracarboxydiphenylether dianhydride, 5,5'-bis(trifluoromethyl)-3,3',4,4'-tetracarboxybenzophenone dianhydride, bis{(trifluoromethyl)di Carboxyphenoxy} benzene dianhydride, bis{(trifluoromethyl)dicarboxyphenoxy}trifluoromethylbenzene dianhydride, bis(dicarboxyphenoxy)trifluoromethylbenzene dianhydride, bis(dicarboxyphenoxy ) Bis (trifluoromethyl) benzene dianhydride, bis (dicarboxyphenoxy) tetrakis (trifluoromethyl) benzene dianhydride, 2,2-bis {4- (3,4-dicarboxyphenoxy) phenyl }Hexafluoropropanedianhydride, bis{(trifluoromethyl)dicarboxyphenoxy}biphenyldianhydride, bis{(trifluoromethyl)dicarboxyphenoxy}bis(trifluoromethyl)biphenyldianhydride , bis{(trifluoromethyl)dicarboxyphenoxy}diphenylether dianhydride, bis(dicarboxyphenoxy)bis(trifluoromethyl)biphenyldianhydride, 1,2,3,4-cyclobutanetetracarboxylic acid acid anhydride residues derived from dianhydride, fluorenylidenebisphthalic anhydride, and 1,2,4,5-cyclohexanetetracarboxylic dianhydride; and the like. Among these, an acid anhydride residue derived from 3,3',4,4'-biphenyltetracarboxylic dianhydride capable of imparting strength and flexibility to the polyimide film is preferable.

(Thermoplastic polyimide layer other than the outermost layer)

There is no particular restriction on the thermoplastic polyimide layer other than the thermoplastic polyimide layer P1 arranged on the outermost layer here, and one having the same composition as the thermoplastic polyimide layer P1 described above may be applied. When applying a thing of a different composition, it is preferable to contain 50 mol% or more of the diamine residue derived from the aromatic diamine compound represented by General formula (A3). Here, about the thermoplastic polyimide layer different from the thermoplastic polyimide layer P1 arrange|positioned as the outermost layer, this may simply be described as "P2". P2 may be used for all (inner) thermoplastic polyimide layers other than the outermost layer, or P2 may be used only for the thermoplastic polyimide layer near the "centre" portion as described above.

In Formula (A3), Z is independently 2 selected from -O-, -S-, -CH ₂ -, -CH(CH ₃ )-, -C(CH ₃ ) ₂ - or -SO ₂ - represents a valent group, preferably -O-. n ₂ represents an integer of 0 to 4, and is preferably 0 or 1. R is, as a substituent, independently a halogen atom, an alkyl group or alkoxy group having 1 to 6 carbon atoms which may be substituted with a halogen atom, or a phenyl group or phenoxy group which may be substituted with a monovalent hydrocarbon group or alkoxy group having 1 to 6 carbon atoms. n ₁ independently represents an integer of 0 to 3, and is preferably 0 or 1.

The aromatic diamine compound represented by the above formula (A3) has two or more benzene rings, and has an amino group directly connected to at least two benzene rings and a divalent linking group Z, thereby increasing the degree of freedom of the polyimide molecular chain and providing high flexibility. It is thought that it contributes to improving the flexibility of the polyimide molecular chain and promotes adhesion and high toughness.

In addition, if the thermoplastic polyimide layer P2 different from the thermoplastic polyimide layer P1 disposed in the outermost layer in this way is used as a thermoplastic polyimide layer other than the outermost layer, it is derived from an aromatic tetracarboxylic acid anhydride represented by the following general formula (B2) containing 50 mol% or more of acid anhydride residues based on all acid anhydride residues, and 50 moles of diamine residues derived from the aromatic diamine compound represented by the general formula (A3) with respect to all diamine residues contained in the polyimide. It is good to contain more than %.

Examples of the aromatic diamine compound represented by the formula (A3) include 3,3'-diaminodiphenylmethane, 3,3'-diaminodiphenylpropane, 3,3'-diaminodiphenylsulfide, and 3 ,3'-diaminodiphenylsulfone, 3,3-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 3,4'-diaminodiphenylmethane, 3,4'-diaminodi Phenylpropane, 3,4'-diaminodiphenylsulfide, 3,4'-diaminobenzophenone, (3,3'-bisamino)diphenylamine, 1,4-bis(3-aminophenoxy) Benzene, 1,3-bis(3-aminophenoxy)benzene (APB), 1,3-bis(4-aminophenoxy)benzene (TPE-R), 3-[4-(4-aminophenoxy) Phenoxy]benzenamine, 3-[3-(4-aminophenoxy)phenoxy]benzenamine, 4,4'-[2-methyl-(1,3-phenylene)bisoxy]bisaniline, 4, 4'-[4-methyl-(1,3-phenylene)bisoxy]bisaniline, 4,4'-[5-methyl-(1,3-phenylene)bisoxy]bisaniline, bis[4- (3-aminophenoxy)phenyl]methane, bis[4-(3-aminophenoxy)phenyl]propane, bis[4-(3-aminophenoxy)phenyl]ether, bis[4-(3-aminophenoxy) cy)phenyl]sulfone, bis[4-(3-aminophenoxy)]benzophenone, bis[4,4'-(3-aminophenoxy)]benzanilide, 4-[3-[4-(4- Aminophenoxy)phenoxy]phenoxy]aniline, 4,4'-[oxybis(3,1-phenyleneoxy)]bisaniline, bis[4-(4-aminophenoxy)phenyl]ether (BAPE) , bis[4-(4-aminophenoxy)phenyl]ketone (BAPK), bis[4-(3-aminophenoxy)]biphenyl, bis[4-(4-aminophenoxy)]biphenyl, 2 ,2-bis(4-aminophenoxyphenyl)propane (BAPP), 4,4'-diaminodiphenyl ether, etc. are mentioned. Among these, 1,3-bis(3-aminophenoxy)benzene (APB) and 1,3-bis(4-aminophenoxy)benzene (TPE-R) are preferable.

Examples of other diamine residues include 9,9-bis[4-(3-aminophenoxy)phenyl]fluorene and 4,4'-bis(2-(trifluoromethyl)-4-aminophenoxy). Biphenyl, 2,2-bis(4-(2-(trifluoromethyl)-4-aminophenoxy)phenyl)hexafluoropropane, 4,4'-bis(3-(trifluoromethyl)- 4-aminophenoxy)biphenyl, p-bis[(2-trifluoromethyl)-4-aminophenoxy]benzene, 2,2'-bis(trifluoromethyl)-4,4'-diamino Biphenyl (TFMB), bis[4-(aminophenoxy)phenyl]sulfone (BAPS), 4,6-dimethyl-m-phenylenediamine, 2,5-dimethyl-p-phenylenediamine, 2,4- Diaminomesitylene, 3,3'-dimethyl-4,4'-diaminodiphenylmethane, 3,5,3',5'-tetramethyl-4,4'-diaminodiphenylmethane, 2,4 -Toluene diamine, m-phenylenediamine, p-phenylenediamine, 4,4'-diaminodiphenylpropane, 3,3'-diaminodiphenylpropane, 4,4'-diaminodiphenylethane, 3 ,3'-diaminodiphenylethane, 4,4'-diaminodiphenylmethane, 3,3'-diaminodiphenylmethane, 2,2-bis(4-aminophenoxyphenyl)propane, 2,2 -bis[4-(4-aminophenoxy)phenyl]propane, 4,4'-diaminodiphenylsulfide, 3,3'-diaminodiphenylsulfide, 4,4'-diaminodiphenylsulfone , 3,3'-diaminodiphenylsulfone, 4,4'-diaminodiphenyl ether, 3,3'-diaminodiphenyl ether, 1,3-bis (3-aminophenoxy) benzene, 1, 3-bis(4-aminophenoxy)benzene, 1,4-bis(4-aminophenoxy)benzene, benzidine, 3,3'-diaminobiphenyl, 3,3'-dimethyl-4,4'- Diaminobiphenyl, 3,3'-dimethoxybenzidine, 4,4''-diamino-p-terphenyl, 3,3''-diamino-p-terphenyl, bis(p-aminocyclohexyl) Methane, bis(p-β-amino-t-butylphenyl)ether, bis(p-β-methyl-δ-aminopentyl)benzene, p-bis(2-methyl-4-aminopentyl)benzene, p-bis (1,1-dimethyl-5-aminopentyl)benzene, 1,5-diaminonaphthalene, 2,6-diaminonaphthalene, 2,4-bis(β-amino-t-butyl)toluene, 2,4- Diaminotoluene, m-xylene-2,5-diamine, p-xylene-2,5-diamine, m-xylylenediamine, p-xylylenediamine, 2,6-diaminopyridine, 2,5- Diaminopyridine, 2,5-diamino-1,3,4-oxadiazole, piperazine, 4-(1H,1H,11H-eicosafluoroundecanoxy)-1,3-diaminobenzene, 4 -(1H,1H-perfluoro-1-butanoxy)-1,3-diaminobenzene, 4-(1H,1H-perfluoro-1-heptanoxy)-1,3-diaminobenzene, 4 -(1H,1H-perfluoro-1-octaneoxy)-1,3-diaminobenzene, 4-pentafluorophenoxy-1,3-diaminobenzene, 4-(2,3,5,6 -Tetrafluorophenoxy)-1,3-diaminobenzene, 4-(4-fluorophenoxy)-1,3-diaminobenzene, 4-(1H,1H,2H,2H-perfluoro- 1-hexanoxy)-1,3-diaminobenzene, 4-(1H,1H,2H,2H-perfluoro-1-dodecaneoxy)-1,3-diaminobenzene, (2,5) -Diaminobenzotrifluoride, diaminotetra (trifluoromethyl) benzene, diamino (pentafluoroethyl) benzene, 2,5-diamino (perfluorohexyl) benzene, 2,5-diamino ( Perfluorobutyl) benzene, 2,2'-bis (trifluoromethyl) -4,4'-diaminobiphenyl, 3,3'-bis (trifluoromethyl) -4,4'-diamino Biphenyl, octafluorobenzidine, 4,4'-diaminodiphenyl ether, 2,2-bis (4-aminophenyl) hexafluoropropane, 1,3-bis (anilino) hexafluoropropane, 1 4-bis (anilino) octafluorobutane, 1,5-bis (anilino) decafluoropentane, 1,7-bis (anilino) tetradecafluoroheptane, 2,2'-bis (tri Fluoromethyl) -4,4'-diaminodiphenyl ether, 3,3'-bis (trifluoromethyl) -4,4'-diaminodiphenyl ether, 3,3',5,5'- Tetrakis(trifluoromethyl)-4,4'-diaminodiphenyl ether, 3,3'-bis(trifluoromethyl)-4,4'-diaminobenzophenone, 4,4'-diamino -p-terphenyl, 1,4-bis(p-aminophenyl)benzene, p-(4-amino-2-trifluoromethylphenoxy)benzene, bis(aminophenoxy)bis(trifluoromethyl) Benzene, bis(aminophenoxy)tetrakis(trifluoromethyl)benzene, 2,2-bis{4-(4-aminophenoxy)phenyl}hexafluoropropane, 2,2-bis{4-(3) -Aminophenoxy)phenyl}hexafluoropropane, 2,2-bis{4-(2-aminophenoxy)phenyl}hexafluoropropane, 2,2-bis{4-(4-aminophenoxy)- 3,5-dimethylphenyl} hexafluoropropane, 2,2-bis {4- (4-aminophenoxy) -3,5-ditrifluoromethylphenyl} hexafluoropropane, 4,4'-bis ( 4-amino-2-trifluoromethylphenoxy) biphenyl, 4,4'-bis (4-amino-3-trifluoromethylphenoxy) biphenyl, 4,4'-bis (4-amino- 2-trifluoromethylphenoxy)diphenylsulfone, 4,4'-bis(3-amino-5-trifluoromethylphenoxy)diphenylsulfone, 2,2-bis{4-(4-amino- 3-trifluoromethylphenoxy)phenyl}hexafluoropropane, bis{(trifluoromethyl)aminophenoxy}biphenyl, bis[{(trifluoromethyl)aminophenoxy}phenyl]hexafluoropropane , bis{2-[(aminophenoxy)phenyl]hexafluoroisopropyl}benzene, and diamine residues derived from 4,4'-bis(4-aminophenoxy)octafluorobiphenyl. Among these, 2,2-bis{4-(4-aminophenoxy)phenyl}hexafluoropropane, 9,9-bis[4- (3-aminophenoxy) phenyl] fluorene, 2,2'-bis (trifluoromethyl) -4,4'-diaminobiphenyl, 4,4'-bis (2- (trifluoromethyl) -4-aminophenoxy) biphenyl, 2,2-bis (4- (2- (trifluoromethyl) -4-aminophenoxy) phenyl) hexafluoropropane, 4,4'-bis (3- Diamine residues derived from diamine compounds such as (trifluoromethyl)-4-aminophenoxy)biphenyl and p-bis[(2-trifluoromethyl)-4-aminophenoxy]benzene are preferred.

(Non-thermoplastic polyimide layer)

In the resin laminate of the present invention, the non-thermoplastic polyimide layer disposed between the thermoplastic polyimide layers has the largest thickness in the resin laminate as described above, but in particular, the total light transmittance In order to satisfy the properties, it is preferable to contain a diamine residue derived from an aromatic diamine compound containing a fluorine atom and/or an acid anhydride residue derived from an aromatic tetracarboxylic acid anhydride containing a fluorine atom.

Since the diamine residue containing a fluorine atom has a group containing a bulky fluorine atom, it reduces interactions such as π-π stacking between polymer chains, thereby reducing charge transfer between the aromatic tetracarboxylic acid residue and the aromatic diamine residue. (CT) is difficult to occur. Therefore, it is thought that polyimide can be made close to colorless and transparent.

Among the diamine residues containing a fluorine atom, it is more preferable to contain a diamine residue derived from a diamine compound represented by the general formula (A2).

In the formula (A2), R ² independently represents a fluorine atom or an alkyl group or alkoxy group having 1 to 3 carbon atoms which may be substituted with a fluorine atom, and p and q independently represent integers of 0 to 4.

The diamine represented by the above formula (A2) is composed mainly of an aromatic skeleton and is excellent in heat resistance, and also excellent in transparency due to a fluorine-containing structure. In addition, an effect of lowering the coefficient of thermal expansion (CTE) can be expected from the action of orienting the molecules. From the viewpoint of heat resistance, R ² is preferably a fluorine atom or a methyl group substituted with a fluorine atom. From such a viewpoint, as the diamine residue used as the non-thermoplastic polyimide layer, it is preferable to contain 20 mol% or more of the A2 residue with respect to 100 mol% in total of all diamine residues, within the range of 50 to 100 mol%. It is more preferable to contain, and it is more preferable to contain within the range of 75-100 mol%. By making residue A2 into the said range, it can prevent that the CTE of the whole polyimide layer increases, and it can suppress that warp arises.

Specifically, structural units derived from the following formulas (A2-1) to (A2-4) are exemplified.

Among the above formulas (A2-1) to (A2-4), more preferably a structural unit derived from 2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl (TFMB). Formula (A2-1).

The said polyimide layer may contain the diamine residue derived from the diamine component generally used for the synthesis|combination of polyimide as a diamine residue other than the above. As such a diamine component, 3,3'-diaminodiphenyl methane, 3,3'-diaminodiphenyl propane, 3,3'-diaminodiphenyl sulfide, 3,3'-diaminodiphenyl Sulfone, 3,3-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 3,4'-diaminodiphenylmethane, 3,4'-diaminodiphenylpropane, 3,4'- Diaminodiphenylsulfide, 3,4'-diaminobenzophenone, (3,3'-bisamino)diphenylamine, 1,4-bis(3-aminophenoxy)benzene, 1,3-bis( 3-aminophenoxy)benzene (APB), 1,3-bis(4-aminophenoxy)benzene (TPE-R), 3-[4-(4-aminophenoxy)phenoxy]benzenamine, 3- [3-(4-aminophenoxy)phenoxy]benzenamine, 4,4'-[2-methyl-(1,3-phenylene)bisoxy]bisaniline, 4,4'-[4-methyl- (1,3-phenylene)bisoxy]bisaniline, 4,4'-[5-methyl-(1,3-phenylene)bisoxy]bisaniline, bis[4-(3-aminophenoxy)phenyl ]methane, bis[4-(3-aminophenoxy)phenyl]propane, bis[4-(3-aminophenoxy)phenyl]ether, bis[4-(3-aminophenoxy)phenyl]sulfone, bis[ 4-(3-aminophenoxy)]benzophenone, bis[4,4'-(3-aminophenoxy)]benzanilide, 4-[3-[4-(4-aminophenoxy)phenoxy]phenoxy cy]aniline, 4,4'-[oxybis(3,1-phenyleneoxy)]bisaniline, bis[4-(4-aminophenoxy)phenyl]ether (BAPE), bis[4-(4- Aminophenoxy)phenyl]ketone (BAPK), bis[4-(3-aminophenoxy)]biphenyl, bis[4-(4-aminophenoxy)]biphenyl, 2,2-bis(4-amino Phenoxyphenyl) propane (BAPP), 4,4'-diaminodiphenyl ether, etc. are mentioned. Among these, 1,3-bis(3-aminophenoxy)benzene (APB) and 1,3-bis(4-aminophenoxy)benzene (TPE-R) are preferable.

On the other hand, as the acid anhydride residues used in the non-thermoplastic polyimide layer, it is preferable to contain 10 mol% or more of acid anhydride residues derived from the acid anhydride compound represented by the general formula (B2) with respect to all acid anhydride residues.

In the formula (B2), X represents a divalent group selected from a single bond, -O- or -C(CF ₃ ) ₂ -.

The aromatic tetracarboxylic acid anhydride represented by the formula (B2) imparts flexibility to the polyimide and improves the tensile strength of the insulating resin layer by providing X groups contributing to bending, as well as π-π stacking between polymer chains. It is thought that the obtained polyimide can be made close to colorless and transparent, since the occurrence of charge transfer (CT) between the aromatic tetracarboxylic acid residue and the aromatic diamine residue is reduced.

Examples of the aromatic tetracarboxylic acid anhydride represented by the formula (B2) include 4,4'-oxydiphthalic dianhydride (ODPA), 3,3',4,4'-biphenyltetracarboxylic acid dianhydride (BPDA), 2,2-bis(3,4-dicarboxyphenyl)-hexafluoropropanedianhydride (6FDA). These aromatic tetracarboxylic anhydrides are preferable because they can impart strength and flexibility to the polyimide film, have excellent heat resistance and transparency, and can control the CTE within an appropriate range. Among these, ODPA and 6FDA are particularly preferable.

Further, the non-thermoplastic polyimide layer preferably contains a fluorine-containing acid anhydride residue. The fluorine-containing acid anhydride residue reduces interactions such as π-π stacking between polymer chains by providing a group containing a bulky fluorine atom, thereby reducing charge transfer (CT) between the aromatic tetracarboxylic acid residue and the aromatic diamine residue. It is thought that it is possible to make the polyimide close to colorless and transparent because it makes the generation of difficult.

In addition, in order to control the CTE of the polyimide layer within the above range, the non-thermoplastic polyimide layer contains tetravalent acid anhydride residues derived from pyromellitic dianhydride (PMDA) represented by the following formula (B3) (hereinafter referred to as " PMDA residue”) is preferably contained. The PMDA residue is preferably contained in an amount of 50 parts by mole or more, more preferably within a range of 60 to 100 parts by mole, based on 100 parts by mole in total of all acid anhydride residues. When the PMDA residue is within the above range, it is possible to prevent an increase in the CTE of the polyimide layer and suppress a decrease in dimensional stability.

In addition, the non-thermoplastic polyimide layer may contain an acid anhydride residue derived from an acid anhydride component generally used for polyimide synthesis as an acid anhydride residue other than the above. As such an acid anhydride residue, an aromatic tetracarboxylic acid residue is preferable. It may also contain an alicyclic tetracarboxylic acid residue, for example, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, fluorenylidenebisanhydride phthalic acid, 1,2,4,5-cyclohexanetetracarboxylic acid Acid anhydride residues derived from alicyclic tetracarboxylic acid dianhydrides such as dianhydride and cyclopentanone bisspironorbornane tetracarboxylic acid dianhydride are preferable.

Examples of other acid anhydride residues include 3,3',4,4'-biphenyltetracarboxylic dianhydride, 3,3',4,4'-benzophenonetetracarboxylic dianhydride, 2,2',3, 3'-benzophenonetetracarboxylic dianhydride, 2,3,3',4'-benzophenonetetracarboxylic dianhydride, naphthalene-1,2,5,6-tetracarboxylic dianhydride, naphthalene-1,2,4, 5-tetracarboxylic dianhydride, naphthalene-1,4,5,8-tetracarboxylic dianhydride, naphthalene-1,2,6,7-tetracarboxylic dianhydride, 4,8-dimethyl-1,2,3,5 ,6,7-hexahydronaphthalene-1,2,5,6-tetracarboxylic dianhydride, 4,8-dimethyl-1,2,3,5,6,7-hexahydronaphthalene-2,3,6, 7-tetracarboxylic dianhydride, 2,6-dichloronaphthalene-1,4,5,8-tetracarboxylic dianhydride, 2,7-dichloronaphthalene-1,4,5,8-tetracarboxylic dianhydride, 2,3 ,6,7-tetrachloronaphthalene-1,4,5,8-tetracarboxylic dianhydride, 1,4,5,8-tetrachloronaphthalene-2,3,6,7-tetracarboxylic dianhydride, 2,2 ',3,3'-biphenyltetracarboxylic dianhydride, 2,3,3',4'-biphenyltetracarboxylic dianhydride, 3,3'',4,4''-p-terphenyltetracarboxylic acid Anhydride, 2,2'',3,3''-p-terphenyltetracarboxylic dianhydride, 2,3,3'',4''-p-terphenyltetracarboxylic dianhydride, 2,2-bis( 2,3-dicarboxyphenyl)-propane dianhydride, 2,2-bis(3,4-dicarboxyphenyl)-propane dianhydride, bis(2,3-dicarboxyphenyl)ether dianhydride, bis(2,3 -Dicarboxyphenyl)methandianhydride, bis(3,4-dicarboxyphenyl)methandianhydride, bis(2,3-dicarboxyphenyl)sulfonicdianhydride, bis(3,4-dicarboxyphenyl)sulfonicdianhydride , 1,1-bis (2,3-dicarboxyphenyl) ethanedianhydride, 1,1-bis (3,4-dicarboxyphenyl) ethanedianhydride, perylene-2,3,8,9-tetracarboxylic acid dianhydride, perylene-3,4,9,10-tetracarboxylic dianhydride, perylene-4,5,10,11-tetracarboxylic dianhydride, perylene-5,6,11,12-tetracarboxylic dianhydride , phenanthrene-1,2,7,8-tetracarboxylic dianhydride, phenanthrene-1,2,6,7-tetracarboxylic dianhydride, phenanthrene-1,2,9,10-tetracarboxylic dianhydride, cyclo Pentane-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'-oxydiphthalic dianhydride, (trifluoromethyl)pyromellitic dianhydride, di(trifluoromethyl)pyromellitic dianhydride, di (heptafluoropropyl) pyromellitic dianhydride, pentafluoroethylpyromellitic dianhydride, bis{3,5-di(trifluoromethyl)phenoxy}pyromellitic dianhydride, 2,2-bis( 3,4-dicarboxyphenyl) hexafluoropropane dianhydride, 5,5'-bis (trifluoromethyl) -3,3', 4,4'-tetracarboxybiphenyl dianhydride, 2,2', 5,5'-tetrakis(trifluoromethyl)-3,3',4,4'-tetracarboxybiphenyl dianhydride, 5,5'-bis(trifluoromethyl)-3,3',4 ,4'-tetracarboxydiphenylether dianhydride, 5,5'-bis(trifluoromethyl)-3,3',4,4'-tetracarboxybenzophenone dianhydride, bis{(trifluoromethyl)di Carboxyphenoxy} benzene dianhydride, bis{(trifluoromethyl)dicarboxyphenoxy}trifluoromethylbenzene dianhydride, bis(dicarboxyphenoxy)trifluoromethylbenzene dianhydride, bis(dicarboxyphenoxy ) Bis (trifluoromethyl) benzene dianhydride, bis (dicarboxyphenoxy) tetrakis (trifluoromethyl) benzene dianhydride, 2,2-bis {4- (3,4-dicarboxyphenoxy) phenyl }Hexafluoropropanedianhydride, bis{(trifluoromethyl)dicarboxyphenoxy}biphenyldianhydride, bis{(trifluoromethyl)dicarboxyphenoxy}bis(trifluoromethyl)biphenyldianhydride , bis{(trifluoromethyl)dicarboxyphenoxy}diphenylether dianhydride, bis(dicarboxyphenoxy)bis(trifluoromethyl)biphenyldianhydride, 1,2,3,4-cyclobutanetetracarboxylic acid acid anhydride residues derived from dianhydride, fluorenylidenebisphthalic anhydride, and 1,2,4,5-cyclohexanetetracarboxylic dianhydride; and the like. Among these, since it is possible to impart strength and flexibility to the polyimide film, and the coefficient of thermal expansion (CTE) of the polyimide film does not rise excessively and can be controlled within an appropriate range, 3,3',4,4'- Acid anhydride residues derived from biphenyltetracarboxylic dianhydride are preferred.

Toughness, thermal expansion, adhesiveness, glass transition temperature (Tg), etc. can be controlled by selecting the types of acid anhydride residues and diamine residues or the molar ratios of two or more kinds of acid anhydride residues or diamine residues. there is.

<Method of synthesizing polyimide>

Next, a method for synthesizing the polyimide constituting the polyimide layer will be described.

The polyimide of the present embodiment can be produced by reacting the acid anhydride and diamine in a solvent to produce a polyamic acid, followed by heating and cyclization. For example, polyamic acid as a precursor of polyimide is obtained by dissolving an acid anhydride component and a diamine component in substantially equal molar amounts in an organic solvent and stirring them at a temperature within the range of 0 to 100°C for 30 minutes to 24 hours to cause a polymerization reaction. In the reaction, the reaction components are dissolved so that the precursor to be produced is within the range of 5 to 30% by weight, preferably within the range of 10 to 20% by weight, in the organic solvent. Examples of the organic solvent used in the polymerization reaction include N,N-dimethylformamide, N,N-dimethylacetamide (DMAC), N-methyl-2-pyrrolidone, 2-butanone, dimethylsulfoxide, Dimethyl sulfate, cyclohexanone, dioxane, tetrahydrofuran, diglyme, triglyme, γ-butyrolactone, etc. are mentioned. Two or more of these solvents may be used in combination, and aromatic hydrocarbons such as xylene and toluene may also be used in combination. The amount of the organic solvent used is not particularly limited, but it is preferable to adjust the amount so that the concentration of the polyamide acid solution (polyimide precursor solution) obtained by the polymerization reaction is about 5 to 30% by weight.

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

In addition, the polyimide of the present embodiment may use an end capping agent. As the terminal blocker, monoamines or dicarboxylic acids are preferable. The amount of the terminal blocker to be introduced is preferably 0.0001 to 0.18 mol, particularly preferably 0.001 to 0.15 mol, per 1 mol of the acid anhydride component. Examples of monoamine terminal blockers include methylamine, ethylamine, propylamine, butylamine, benzylamine, 4-methylbenzylamine, 4-ethylbenzylamine, 4-dodecylbenzylamine, 3-methylbenzylamine, Aniline, 4-methylaniline and the like are recommended. Among these, benzylamine and aniline can be used suitably. As the dicarboxylic acid end capping agent, dicarboxylic acids are preferable, and a part thereof may be ring-closed. For example, phthalic acid, phthalic anhydride, 4-chlorophthalic acid, tetrafluorophthalic acid, cyclopentane-1,2-dicarboxylic acid, 4-cyclohexene-1,2-dicarboxylic acid and the like are recommended. Among these, phthalic acid and phthalic anhydride can be suitably used.

Although it is usually advantageous to use the synthesized polyamic acid as a reaction solvent solution, it can be concentrated, diluted, or substituted with another organic solvent if necessary. Polyamic acids are also advantageously used because they are generally excellent in solvent solubility. The method of imidizing the polyamic acid is not particularly limited, and, for example, heat treatment in which the polyamic acid is heated for 1 to 24 hours under a temperature condition in the range of 80 to 400° C. in the solvent is suitably employed.

The weight average molecular weight of the polyamic acid is, for example, preferably in the range of 50,000 to 500,000, and more preferably in the range of 80,000 to 400,000. If the weight average molecular weight is less than 50,000, the strength of the film decreases and tends to become brittle. On the other hand, when the weight average molecular weight exceeds 500,000, the viscosity is excessively increased, and thus defects such as unevenness in film thickness and streaks tend to occur easily during the coating operation.

The polyamic acid and the polyimide layer obtained therefrom may contain an inorganic filler as needed, as long as the object of the present invention is not impaired. Specifically, silicon dioxide, aluminum oxide, magnesium oxide, beryllium oxide, boron nitride, aluminum nitride, silicon nitride, aluminum fluoride, calcium fluoride, etc. are mentioned, for example. These can be used 1 type or in mixture of 2 or more types.

<Metal clad laminate>

The metal clad laminate of the present invention includes a metal layer laminated on at least one side of the above-mentioned resin laminate, that is, one side or both sides. The metal layer may be formed directly on the outermost polyimide layer of the resin laminate or, if necessary, with an adhesive layer or the like not impairing the object of the present invention interposed therebetween.

The material of the metal layer is not particularly limited, but examples thereof include copper, stainless steel, iron, nickel, beryllium, aluminum, zinc, indium, silver, gold, tin, zirconium, tantalum, titanium, lead, magnesium, manganese, and alloys thereof. etc. can be mentioned. Among these, a metal element such as copper, iron or nickel, or indium tin oxide (ITO) is preferable. In the selection of these metal layers, they are selected so as to exhibit characteristics necessary for the purpose of use, such as conductivity of the metal layer, light transmittance of the polyimide layer, and adhesion to the polyimide layer. There is no particular restriction on the shape of the metal layer, but processing or the like may be performed as appropriate depending on the intended use. In this invention, the thing of the roll shape formed especially in the shape of a long picture is used suitably.

The thickness of the metal layer is not particularly limited, but is preferably 100 μm or less, more preferably within the range of 0.1 to 35 μm, still more preferably within the range of 1 to 25 μm.

From the viewpoint of light transmittance, the arithmetic mean roughness Ra of the surface of the metal layer is preferably 0.005 to 0.1 μm, more preferably 0.005 to 0.07, still more preferably 0.005 to 0.05. The maximum height Rz is preferably 0.05 to 0.5 μm, more preferably 0.05 to 0.3 μm, still more preferably 0.05 to 0.2 μm. Further, the 10-point average roughness Rzjis is preferably 0.5 μm or less, more preferably within a range of 0.01 to 0.3 μm or less, still more preferably within a range of 0.01 to 0.2 μm. By adjusting the surface roughness of the metal layer within the above range, the HAZE value of the resin laminate can be lowered, which is a more suitable embodiment.

In the metal clad laminate of the present invention, the heat resistance (solder heat resistance) according to the soldering heat resistance test is preferably 230°C or higher, more preferably 250°C or higher. Soldering heat resistance is evaluated by the method described in Examples.

The 180° peel strength of the resin laminate and the metal layer in the metal clad laminate of the present invention is preferably 0.3 kN/m or more, more preferably 0.5 kN/m.

In this specification, the evaluation of physical properties and characteristic values is measured under the conditions described in the examples, and values measured at room temperature (23 ° C.) are not specifically described.

<circuit board>

The metal clad laminate of the present invention is mainly useful as a circuit board such as FPC. The circuit board can be manufactured by forming a wiring layer by processing the metal layer of the metal clad laminate according to the present invention into a pattern by a conventional method. Patterning can be performed by any method using, for example, photolithography technology and etching. In addition, as processes normally performed when manufacturing circuit boards, for example, processes such as through-hole processing in the previous process and terminal plating and external processing in the subsequent process can be carried out in accordance with conventional methods. there is.

<Method of manufacturing resin laminate, manufacturing method of metal clad laminate>

First, the method for producing the resin laminate of the present invention is not particularly limited. For example, [1] a method in which applying and drying a solution of polyamic acid to a supporting base material is repeated multiple times, followed by imidation ( Hereinafter, cast method/sequential coating method), [2] a method of applying and drying a laminated structure of polyamic acid simultaneously to a support substrate by multi-layer extrusion, followed by imidization (hereinafter, multi-layer extrusion method), [ 3] After repeating application and drying of a polyamic acid solution on a metal layer as a supporting base material a plurality of times, imidization is performed to obtain a single-sided metal clad laminate in which a plurality of polyimide layers are formed on one side of the metal layer. , Method obtained by removing the metal layer by etching, [4] Two single-sided metal-clad laminates according to [3] are prepared, and each outermost polyimide layer is heat-pressed to obtain a double-sided metal-clad laminate in which a metal layer is formed on both sides. After obtaining, the metal layer is removed by etching, [5] In [4], when obtaining a double-sided metal clad laminate, a procedure of heat-pressing a resin laminate obtained by another method is sandwiched between two single-sided metal clad laminates. [6] a method of forming a resin laminate by heat-pressing a plurality of polyimide films composed of a single layer or a plurality of polyimide layers to each other; and the like. The method of applying the polyimide solution (or polyamic acid solution) onto the substrate is not particularly limited, and it is possible to apply, for example, with a coater such as a comma, die, knife, lip, or spin.

In addition, the manufacturing method of the metal clad laminate is not particularly limited either, but is a method in which a metal layer and several resin laminates are thermally compressed once or several times, or a metal foil having a metal layer formed on one or both surfaces by the above [3] to [5]. A method of obtaining a laminated board, a method of laminating a plurality of polyimide films composed of a single layer or a plurality of polyimide layers between two metal layers and heat-pressing them to obtain a double-sided metal clad laminate in which metal layers are formed on both sides; In the present invention, from the viewpoints of both the dimensional stability of the obtained resin laminate and suppression of the increase in HAZE, it is preferable to adopt the method of [3] to [5] based on the casting method, more preferably [ 4] to [5], it is preferable to employ a method of thermally compressing the polyimide layers of each outermost layer of the single-sided metal clad laminate. Most preferably, it is the method of [4] illustrated in FIG.

That is, as illustrated in FIG. 6, a single-sided metal clad laminate 6 in which a polyimide layer 1, a polyimide layer 2, and a polyimide layer 1' are formed on a metal layer 5 is manufactured, and the polyimide layer 6 is manufactured. It is preferable that the mid-layers 1' are laminated with the lamination surface 7 so that the middle layers 1' are mutually centered, and heat-compressed, for example, at a temperature equal to or higher than the Tg of the polyimide layer 1' to obtain a double-sided metal clad laminate. Thereafter, the metal layers 5 on both sides are etched away, and as shown in FIG. 2, two non-thermoplastic polyimide layers 2 are laminated resin laminated between the two thermoplastic polyimide layers 1 and 1', respectively. It is desirable to obtain a sieve. At that time, it is a more preferable embodiment that the thermoplastic polyimide layers 1 and 1' each have a Tg as described above, that is, the Tg of the thermoplastic polyimide layer 1 of the outermost layer is 250 ° C. or higher, and the outermost layer It is more preferable that the Tg of the thermoplastic polyimide layer 1' of the other inner layers is 150°C or more and less than 250°C.

In addition, the single-sided metal clad laminate 6 can be obtained, for example, by the following method. That is, using the metal layer 5 as a supporting base material, applying and drying a solution of polyamic acid for forming the thermoplastic polyimide layer 1 thereon, and subsequently forming the non-thermoplastic polyimide layer 2 thereon Poly A solution of amic acid is applied and dried, and a solution of polyamic acid for forming the thermoplastic polyimide layer 1' is further applied and dried thereon to form a three-layer polyamic acid layer, then 80 ° C. It can be obtained by imidizing the polyamic acid layer by performing stepwise heat treatment for 1 to 24 hours at a temperature condition of -400°C.

In addition, instead of using the two single-sided metal-clad laminates 6 as shown in Fig. 6, one of the two single-sided metal-clad laminates 6 is used in the embodiment in which the thermoplastic polyimide layer 1' does not exist. Replace with the metal clad laminate 6' so that the polyimide layer 2 of the single-sided metal clad laminate 6' and the polyimide layer 1' of the single-sided metal clad laminate 6 are directly laminated, for example, polyimide A double-sided metal clad laminate can also be obtained by thermal compression bonding at a temperature equal to or higher than the Tg of the layer (1'). Thereafter, the metal layers 5 on both sides are removed by etching, and as shown in FIG. 1, two non-thermoplastic polyimide layers 2 are formed by one thermoplastic polyimide layer 1' and two thermoplastic polyimide layers ), a resin laminate laminated between them can be obtained.

As another preferable method, as shown in FIG. 7, in the method of FIG. 6, the resin laminate 8 in which the non-thermoplastic polyimide layer 2 is sandwiched between two thermoplastic polyimide layers 1' is It may be further prepared and heat-compressed together with the two single-sided metal-clad laminates 6 to obtain a double-sided metal-clad laminate. After that, similarly, the metal layers 5 on both sides are etched away to obtain a resin laminate.

In addition, in the manufacturing method exemplified above, other configurations that may be provided to the above-described resin laminate and metal clad laminate may also be included, for example, at the time of thermal compression bonding of the polyimide layer 1', other than that. It may be formed by arranging layers (eg, layer 4 in Fig. 5). In addition, any known manufacturing method can be employed.

<Electronic devices/electronic devices>

The electronic device and electronic equipment of this embodiment are equipped with the said circuit board. Examples of the electronic device of the present embodiment include display devices such as liquid crystal displays, organic EL displays, and electronic paper, organic EL lights, solar cells, touch panels, camera modules, inverters, converters, and constituent members thereof. . Examples of electronic devices include HDDs, DVDs, mobile phones, smart phones, tablet terminals, automotive electronic control units (ECUs), power control units (PCUs), and the like. Circuit boards are preferably used as components such as wires of movable parts, cables, and connectors in these electronic devices and electronic equipment.

(Example)

The contents of the present invention will be specifically described below based on examples, but the present invention is not limited by the scope of these examples. In addition, in the following examples, unless otherwise specified, various measurements and evaluations are based on the following.

[Calculation of light transmittance and YI (yellowness)]

The light transmittance and (YI) of a polyimide film (also called a resin laminate. Hereinafter, the same) (50 mm × 50 mm) were measured with a UV-3600 spectrophotometer manufactured by SHIMADZU CORPORATION. .

1) Light transmittance

In accordance with JIS Z 8722, light transmittances (T400, T430, and T450) for light having a wavelength of 400 nm, 430 nm, and 450 nm were calculated.

2) YI

Based on JIS Z 8722, it calculated based on the calculation formula represented by following formula (1).

YI = 100 × (1.2879X - 1.0592Z) / Y … (One)

X, Y and Z: tristimulus values of the test piece

YI _(T10) of the polyimide film at a thickness of 10 μm was calculated by substituting the value of YI calculated by the above formula (1) into the following formula (2).

YI _(T10) ＝YI/T×10 … (2)

T: Thickness of polyimide film (μm)

[Measurement of Coefficient of Thermal Expansion (CTE)]

The polyimide film (3 mm × 15 mm) was heated from 30 ° C to 280 ° C at a heating rate of 10 ° C / min while applying a load of 5.0 g with a thermomechanical analysis (TMA) device, and then at 250 ° C. The temperature was lowered to 100°C, and the thermal expansion coefficient was measured from the amount of elongation (linear expansion) of the polyimide film at the time of temperature lowering.

[Calculation of total light transmittance (T.T.) and HAZE (turbidity)]

For polyimide film (50 mm × 50 mm), total light transmittance (T.T.) and HAZE (turbidity) were measured according to JIS K 7136 with HAZE METER NDH500 manufactured by NIPPON DENSHOKU INDUSTRIES CO., LTD. It was measured based on.

[Measurement of viscosity]

The viscosity was measured at 25°C for the polyamic acid solution obtained in Synthesis Example using a cone plate viscometer (manufactured by TOKIMEC INC.) equipped with a constant temperature water bath.

[Measurement of Glass Transition Temperature (Tg)]

Regarding the polyimide film (10 mm × 22.6 mm), the dynamic viscoelasticity was measured when the temperature was raised from 20 ° C to 400 ° C at 5 ° C / min with a dynamic thermomechanical analyzer, and the glass transition temperature (Tan δ maximum value: ° C) was determined. saved

[Measurement of Peel Strength]

Using a tension tester, the resin side of a test sample having a circuit with a width of 1 mm obtained from a laminate was fixed to an aluminum plate with double-sided tape, and the copper was peeled in a 180° direction at a rate of 50 mm/min, peeling rescued the robber.

[Measurement of Surface Roughness of Copper Foil]

The sample was cut into a size of about 10 mm × 10 mm, fixed to the sample table with double-sided tape, and soft X-rays were irradiated to remove static electricity on the surface of the copper foil, and then the surface roughness was measured. The arithmetic average roughness Ra and maximum height Rz of the copper foil surface were measured under the following measurement conditions using a scanning probe microscope (AFM, manufactured by Bruker AXS, product name: Dimension Icon type SPM). Measurement conditions are as follows.

measurement mode; tapping mode

measurement area; 1㎛×1㎛

scan speed; 1Hz

probe ; Bruker product, RTESP-300

analysis software; NanoScope Analysis

[Measurement of soldering heat resistance]

A commercially available photoresist film was laminated to each single-sided metal clad laminate according to reference examples described later and each double-sided metal clad laminate according to Examples and Comparative Examples, and exposed to a predetermined pattern forming mask (365 nm, exposure amount 500 J). /m2), the metal (copper foil) layer forms a circular pattern with a diameter of 20 mm, 15 mm, 10 mm, 5 mm, 3 mm, 1 mm and 0.5 mm integrally on the front and back. Resist layer was formed by curing.

Next, the cured resist layer is developed (developer is 1% NaOH aqueous solution), the copper foil layer unnecessary for forming a predetermined pattern is etched away using an aqueous ferric chloride solution, and the cured resist layer is further peeled off with an alkali solution. , A patterned sample for evaluating heat resistance corresponding to lead-free solder (a laminate in which a circular pattern with a diameter of 1 mm is formed on one or both surfaces of the metal layer of each single-sided metal-clad laminate or each double-sided metal-clad laminate) was obtained.

The sample was immersed in molten solder baths at different temperatures for 10 sec, and the presence or absence of deformation and swelling in the copper foil layer was observed. The highest temperature of the solder bath at which deformation, swelling, or peeling did not occur at the location of the copper foil layer was defined as the soldering heat resistance temperature.

[evaluate line]

In a width of 50 cm × length of 20 m, 5 or less lines in the longitudinal direction were set as ○, and 5 or more lines were set as ×.

[Evaluation of application curl of long products]

In the edge part at both ends in the width direction at the time of application of a 30 m roll, when it was rolled inward, it was set as x, and when it was not, it was set as o.

Abbreviations used in Examples and the like represent the following compounds.

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

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

TFMB: 2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl

BAPS: bis[4-(aminophenoxy)phenyl]sulfone

PMDA: pyromellitic dianhydride

6FDA: 2,2-bis(3,4-dicarboxyphenyl)-hexafluoropropanedianhydride

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

ODPA: 4,4'-oxydiphthalic dianhydride

DMAc: N,N-dimethylacetamide

m-TB: 4,4'-diamino-2,2'-dimethylbiphenyl

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

(Synthesis Example 1)

To synthesize polyamic acid solution A, DMAc as a solvent was added to a solid content concentration shown in Table 1 in a 200 ml separable flask under a nitrogen stream, and the diamine component and acid anhydride component shown in Table 1 were added while stirring at room temperature was dissolved. Then, solution A of the viscous polyamic acid was prepared by carrying out polymerization reaction by continuing to stir the solution at room temperature for 6 hours. The viscosity was 3000 cP.

(Synthesis Example 2)

To synthesize polyamic acid solution B, DMAc as a solvent was added to a solid content concentration shown in Table 1 in a 200 ml separable flask under a nitrogen stream, and the diamine component and acid anhydride component shown in Table 1 were stirred at 45 ° C. It was dissolved by heating for 2 hours. Thereafter, a viscous polyamic acid solution B was prepared by continuously stirring the solution at room temperature for 2 days to carry out a polymerization reaction. The viscosity was 27000 cP.

(Synthesis Examples 3 to 5)

For the polyamic acid solutions C to E, polymerization was carried out in the same manner as in Synthesis Example 1, with the type of monomer changed as shown in Table 1. Solutions C to E of viscous polyamic acid were prepared. Viscosity is shown in Table 1.

(Reference Example 1)

On copper foil 1 (electrolytic copper foil, product of FUKUDA METAL FOIL & POWDER CO., LTD., trade name: CF-T9DA-SV, thickness: 10 μm, long shape), polyamide acid solution A After uniformly applying the solution to a thickness of 1.1 μm after curing, the solvent was removed by stepwise heating and drying in a temperature range of up to 120 ° C. Next, a solution of polyamic acid solution B was uniformly applied thereon so that the thickness after curing was 7.8 μm, and then the solvent was removed by heating and drying stepwise in a temperature range up to 120° C. On top of that, a solution of polyamic acid solution C was uniformly applied so that the thickness after curing was 1.2 μm, followed by stepwise heating and drying in a temperature range up to 120° C. to remove the solvent. After forming three polyamic acid layers in this way, stepwise heat treatment is performed from 125°C to 360°C to complete imidation, resulting in a thickness of 10.1 µm composed of polyimide layer A/polyimide layer B/polyimide layer C. was formed to prepare a single-sided metal clad laminate 1 (indicated as "metal laminate" in the tables).

Polyimide film 1 was prepared by etching away the copper foil from the obtained single-sided metal clad laminate 1 using an aqueous ferric chloride solution. For polyimide film 1, HAZE, TT, T400, T430, T450, YI _(T10) and CTE were obtained. Table 2 shows these measurement results. Here, YI _(T10) represents the yellowness obtained by converting the thickness of the polyimide film to 10 µm.

The peeling strength of the polyamic acid-coated surface of the obtained single-sided metal clad laminate 1 was 0.5 kN/m. Moreover, the soldering heat resistance was 360 degreeC.

(Reference Examples 2 to 4)

Except for using the polyamide acid solution shown in Table 1, polyimide films 2 to 4 were prepared in the same manner as in Reference Example 1. In the preparation of a long picture, each treatment was performed on 30 m of copper foil, and in the preparation of a batch, each treatment was performed on copper foil cut into 30 cm in length x 20 cm in width. In addition, it was impossible to create a laminate having a film thickness of about 50 µm by long coating. For the polyimide films 2 to 4, HAZE, T.T., T400, T430, T450, YI and CTE were obtained. Table 2 shows these measurement results.

(Reference example 5)

On copper foil 1 (electrolytic copper foil, manufactured by Fukuda Metal Foil Co., Ltd., trade name: CF-T9DA-SV, thickness: 10 μm, elongated shape), a solution of polyamic acid solution A was applied uniformly so that the thickness after curing was 10 μm. After application, a polyamic acid layer was formed by removing the solvent by heating and drying stepwise at a temperature range of up to 120 ° C. Thereafter, stepwise heat treatment was performed from 125°C to 360°C to complete imidation, thereby forming a resin layer made of the polyimide layer A, thereby preparing a single-sided metal-clad laminate 5.

With respect to the obtained single-sided metal-clad laminate 5, the copper foil was removed by etching using an aqueous ferric chloride solution, thereby preparing a polyimide film 5. For polyimide film 5, Tg was measured. This is shown in Table 3.

(Reference Examples 6 to 7)

Polyimide films 6 to 7 were prepared in the same manner as in Reference Example 5, except that the polyamic acid solution shown in Table 1 was used. For the polyimide films 6 to 7, Tg was measured. Table 3 shows these measurement results.

(Example 1)

Two single-sided metal-clad laminates 1 obtained in Reference Example 1 were used, the polyimide layers C were bonded to each other, and heat-pressed for 30 minutes under conditions of 240°C and 6.8 MPa to obtain a double-sided metal-clad laminate 8.

A polyimide film 8 was prepared by etching away the copper foil of the double-sided metal clad laminate 8 using an aqueous ferric chloride solution. For the polyimide film 8, HAZE, TT, T400, T430, T450, YI _(T10) , CTE and Tg were obtained. Table 4 shows these measurement results. Here, YI _(T10) represents the yellowness obtained by converting the thickness of the polyimide film to 10 µm.

The peeling strength of the polyamic acid-coated surface of the obtained double-sided metal clad laminate 8 was 0.5 kN/m. Moreover, the soldering heat resistance was 290 degreeC.

(Example 2)

In the same manner as in Example 1, two single-sided metal-clad laminates 2 were used, and hot pressing was performed in the same manner as in Example 1 to prepare a double-sided metal-clad laminate 9.

The double-sided metal clad laminate 9 was etched in the same manner as in Example 1 to obtain a polyimide film 9. Various physical properties were measured, and the results are shown in Table 4.

The physical properties of the metal laminate are also shown in Table 4.

(Comparative Example 1)

The single-sided metal clad laminate 1 of Reference Example 1 was cut into 15 cm x 15 cm, the copper foil of the same type as the copper foil used in Reference Example 1 was superimposed on the opposite side of the resin layer (laminated surface), and pressed at 240°C/30 min by a press machine. was carried out to prepare a double-sided metal clad laminate 10.

Similarly to Example 1, polyimide film 10 was prepared by etching away the copper foil using an aqueous ferric chloride solution. For the polyimide film 10, HAZE, TT, T400, T430, T450, YI _(T10) , CTE and Tg were obtained. Table 5 shows these measurement results. Here, YI _(T10) represents the yellowness obtained by converting the thickness of the polyimide film to 10 µm.

The peeling strength of the polyamic acid-coated surface of the obtained double-sided metal clad laminate 10 was 0.5 kN/m. Moreover, the soldering heat resistance was 230 degreeC.

(Comparative Examples 2 to 4)

Metal clad laminates 11 to 13 were prepared by using a single-sided metal clad laminate 2 in the same manner as in Comparative Example 1 and performing a hot press in the same manner as in Comparative Example 1. Polyimide films 11 to 13 were obtained in the same manner as in Comparative Example 1, and various physical properties are shown in Table 5.

(Comparative Example 5)

On the same copper foil 1 as in Reference Example 1 (electrolytic copper foil, manufactured by Fukuda Metal Foil Co., Ltd., trade name: CF-T9DA-SV, thickness: 10 μm, elongated shape), a solution of polyamic acid solution A is applied to the thickness after curing. After uniformly applying to a thickness of 1.1 μm, it was heated and dried in stages in a temperature range up to 120° C., and the solvent was removed. Next, a solution of polyamic acid solution B was uniformly applied thereon so that the thickness after curing was 47 μm, and then the solvent was removed by heating and drying in stages in a temperature range of up to 120 ° C. As a result, application curl was generated, and the roll I couldn't write a sample for . The application curl was ×.

1, 1': Thermoplastic polyimide (layer)
2: non-thermoplastic polyimide (layer)
3: Center in thickness direction
4: layers other than the polyimide layer
5: metal layer
6: single-sided metal clad laminate
7: laminated surface
8: resin laminate

Claims (9)

A resin laminate comprising a plurality of polyimide layers, the following a to c;
a) having a thickness within the range of 12 μm or more and 200 μm or less;
b) having a total light transmittance of 80% or more;
c) HAZE of 2% or less;
satisfies,
It has a layer configuration symmetrical in the thickness direction with respect to the center in the thickness direction, and includes at least two non-thermoplastic polyimide layers composed of non-thermoplastic polyimide and at least three thermoplastic polyimide layers composed of thermoplastic polyimide. do,
The non-thermoplastic polyimide layer is laminated between two thermoplastic polyimide layers,
The resin laminate, characterized in that the outermost layer of the resin laminate is made of a thermoplastic polyimide layer having a glass transition temperature of 250 ° C. or higher.
According to claim 1,
The resin laminate characterized in that the total thickness of the non-thermoplastic polyimide layer is within a range of 50% or more and 97% or less with respect to the total thickness of the non-thermoplastic polyimide layer and the thermoplastic polyimide layer.
According to claim 1 or 2,
The non-thermoplastic polyimide layer is two, the thermoplastic polyimide layer is three,
The resin laminate characterized in that the glass transition temperature of the thermoplastic polyimide constituting one thermoplastic polyimide layer located in the central portion in the thickness direction of the resin laminate is within a range of 150 ° C. or more and less than 250 ° C.
According to claim 1 or 2,
The non-thermoplastic polyimide layer is two, the thermoplastic polyimide layer is four,
The resin laminate, characterized in that the glass transition temperature of the thermoplastic polyimide constituting the two opposing thermoplastic polyimide layers located in the central portion in the thickness direction of the resin laminate is within the range of 150 ° C. or more and less than 250 ° C. .
According to claim 1 or 2,
A resin laminate characterized in that it has a long shape.
A metal clad laminate comprising the resin laminate according to claim 1 or 2 and a metal layer laminated on at least one side of the resin laminate.
A circuit board obtained by processing the metal layer of the metal clad laminate according to claim 6 into a wiring circuit.
An electronic device comprising the circuit board according to claim 7.
An electronic device comprising the circuit board of claim 7.

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