TW202126477A - Polyimide film and copper-clad laminate - Google Patents

Abstract

A polyimide film capable of reducing a dimensional change at the time of high-temperature processing and a copper clad laminate using the same are provided. As a polyimide film having a thermoplastic polyimide layer on at least one side of a non-thermoplastic polyimide layer, the polyimide film satisfies the following conditions: (i) a thermal expansion coefficient is in the range of 10 to 30 ppm/K; (ii) glass transition temperature of a thermoplastic polyimide is within the range of 200 to 350 DEG C; (iii) a value of in-plane retardation (RO) is in the range of 5 to 50 nm; (iv) the deviation of the RO ([Delta]RO) in the width direction (TD direction) is 10 nm or less.

Description

Polyimide film and copper clad laminate

The invention relates to a polyimide film and a copper clad laminate.

In recent years, with the development of miniaturization, weight reduction, and space saving of electronic equipment, flexible printed circuit boards (FPC) are thin, lightweight, flexible, and have excellent durability even if they are repeatedly bent. The needs of the people continue to grow. FPC can achieve three-dimensional and high-density installation even in a limited space, so its use continues to expand to electronic devices such as hard disk drives (HDD), digital versatile discs (Digital Versatile Disc, DVD), mobile phones, etc. Wiring, cables, connectors and other parts of movable parts.

FPC is manufactured by etching the copper layer of a copper-clad laminate (Copper-Clad Laminate, CCL) for wiring processing. For FPCs that are continuously bent or bent 180° in mobile phones or smart phones, rolled copper foil is mostly used as the material of the copper layer. For example, Patent Document 1 proposes that the bending resistance of a copper clad laminate produced using rolled copper foil is specified by the number of breaks resistance. In addition, Patent Document 2 proposes a copper-clad laminate using a rolled copper foil defined by glossiness and the number of folds.

In the photolithography process of the copper clad laminate or the process of mounting FPC, the alignment mark (alignment mark) provided in the copper clad laminate is used as a reference to perform various bonding, cutting, exposure, etching, etc. Processing. The processing accuracy in these steps becomes important in maintaining the reliability of the electronic device equipped with the FPC. However, the copper clad laminate has a structure in which a copper layer and a resin layer with different thermal expansion coefficients are laminated, and therefore, a stress is generated between the layers due to the difference in the thermal expansion coefficient between the copper layer and the resin layer. A part or all of this stress is relieved when the copper layer is etched to perform wiring processing, which causes expansion and contraction, resulting in a change in the size of the wiring pattern. Therefore, finally, a dimensional change occurs in the FPC stage, which causes poor contact between the wiring or the wiring and the terminal, and reduces the reliability or yield of the circuit board. Therefore, dimensional stability is a very important characteristic for the copper clad laminate as a material for a circuit board. However, in Patent Document 1 and Patent Document 2, no consideration is given to the dimensional stability of the copper clad laminate.

As a method of manufacturing a polyimide film, the following method is known: for a self-supporting gel film of polyamide acid, uniaxial stretching and thermal imidization are performed simultaneously or continuously, thereby making the polyimide The molecular chains are aligned to show in-plane birefringence. At this time, in order to control the retardation, conditions such as the uniaxial stretching operation and the heating rate during thermal imidization, the final curing temperature, and the load are controlled with high accuracy. For example, Patent Document 3 proposes a technique in which a polyimide film is heated while uniaxially stretched to control the retardation. [Prior Art Literature]

[Patent Literature] [Patent Document 1] Japanese Patent Laid-Open No. 2014-15674 (application scope, etc.) [Patent Document 2] Japanese Patent Laid-Open No. 2014-11451 (Scope of patent application, etc.) [Patent Document 3] Japanese Patent Laid-Open No. 2000-356713 (application scope, etc.)

[The problem to be solved by the invention] The first object of the present invention is to provide a polyimide film that can reduce dimensional changes during high-temperature processing and a copper-clad laminate using the polyimide film. In addition, the second object of the present invention is to provide a polyimide film that achieves high dimensional stability accuracy even under a heating environment above the glass transition temperature of the thermoplastic polyimide and can be stably produced and uses the same. Polyimide film copper clad laminate. [Technical means to solve the problem]

The inventors of the present invention conducted diligent studies, and as a result, found that the problem can be solved by controlling the in-plane retardation of the polyimide film, and completed the present invention.

That is, the polyimide film of the present invention has a thermoplastic polyimide layer containing a thermoplastic polyimide on at least one side of a non-thermoplastic polyimide layer containing a non-thermoplastic polyimide. The polyimide film of the present invention is characterized by satisfying the following conditions (i) to (iv); (I) The coefficient of thermal expansion is within the range of 10 ppm/K to 30 ppm/K; (Ii) The glass transition temperature of the thermoplastic polyimide is within the range of 200°C or more and 350°C or less; (Iii) The value of in-plane retardation (RO) is within the range of 5 nm or more and 50 nm or less; (Iv) The non-uniformity (ΔRO) of the in-plane retardation (RO) in the width direction (Transverse Direction, TD direction) is 10 nm or less.

The polyimide film of the present invention may be such that the change in the in-plane retardation (RO) before and after pressurization at a temperature of 360°C at a pressure of 340 MPa/m ^{2 and a holding time of 15 minutes is 20 nm or less.}

The polyimide film of the present invention can also make the non-thermoplastic polyimine contain tetracarboxylic acid residues and diamine residues, and the tetracarboxylic acid residues and diamine residues are aromatic groups, so The aromatic group contains biphenyltetrayl or biphenylene, and the biphenyltetrayl or biphenylene is 40 mole parts relative to the total of 100 mole parts of the tetracarboxylic acid residue and diamine residue. More than mol portion.

The polyimide film of the present invention can also make the thermoplastic polyimine contain tetracarboxylic acid residues and diamine residues, and the tetracarboxylic acid residues and diamine residues are both aromatic groups. The aromatic group contains biphenyltetrayl or biphenylene, and the biphenyltetrayl or biphenylene is 30 moles relative to the total of 100 mole parts of the tetracarboxylic acid residue and diamine residue. In the range of more than ear part and less than 80 mol part.

The polyimide film of the present invention can also be 100 mole parts relative to all the tetracarboxylic acid residues contained in the non-thermoplastic polyimide, which is composed of 3,3',4,4'-biphenyltetracarboxylic acid The tetracarboxylic acid residue derived from the acid dianhydride is in the range of 20 mol parts or more and 70 mol parts or less.

The polyimide film of the present invention may also be 100 mol parts of all tetracarboxylic acid residues contained in the thermoplastic polyimide, which is composed of 3,3',4,4'-biphenyltetracarboxylic acid The tetracarboxylic acid residue derived from the dianhydride is 40 mole parts or more.

The polyimide film of the present invention may also be 100 mole parts relative to all diamine residues contained in the non-thermoplastic polyimide, and the diamine residue represented by the following general formula (1) is 20 parts. More than mol portion.

[式中，R₁ 、R₂ 獨立地表示可經鹵素原子或苯基取代的碳數1～3的烷基或碳數1～3的烷氧基或者碳數2～3的烯基][化1]

[In the formula, R ₁ and R ₂ independently represent an alkyl group having 1 to 3 carbons or an alkoxy group having 1 to 3 carbons or an alkenyl group having 2 to 3 carbons which may be substituted with a halogen atom or a phenyl group]

The polyimide film of the present invention may be 100 mole parts of all diamine residues contained in the thermoplastic polyimide, and the diamine residue represented by the following general formula (2) is 3 mole parts. In the range of more than ear part and less than 60 mol part.

[式中，R₃ 、R₄ 獨立地表示可經鹵素原子或苯基取代的碳數1～3的烷基或碳數1～3的烷氧基或者烯基][化2]

[In the formula, R ₃ and R ₄ independently represent an alkyl group having 1 to 3 carbons or an alkoxy group or alkenyl group having 1 to 3 carbons which may be substituted with a halogen atom or a phenyl group]

The copper clad laminate of the present invention includes an insulating layer and a copper layer located on at least one surface of the insulating layer. Furthermore, the copper clad laminate of the present invention is characterized in that the insulating layer has a thermoplastic polyimide layer in contact with the surface of the copper layer, and a non-thermoplastic polyimide layer laminated indirectly, The insulating layer includes any of the polyimide films.

In the copper clad laminate of the present invention, the dimensional change in the longitudinal direction (Machine Direction, MD direction) and the dimensional change in the width direction (TD direction) of the copper layer before and after the etching may both be 2% or less. [Effects of the invention]

The polyimide film of the present invention suppresses the amount of retardation change even in a high-temperature and high-pressure environment, and therefore has excellent dimensional stability even when, for example, it is thermocompression-bonded to a copper foil at a high temperature. Therefore, by using the polyimide film of the present invention, the time for the production step of the copper-clad laminate can be shortened, and the production stability is excellent. Especially when a wide-width polyimide film is processed in a roll-to-roll method, and copper foil is laminated to produce a copper-clad laminate, the overall width of the film also has a low dimensional change rate. It is stable, so the FPC obtained from the copper clad laminate can be mounted at high density. Therefore, by using the polyimide film of the present invention and the copper-clad laminate using the polyimide film as an FPC material, the reliability and yield of the circuit board can be improved.

Next, the embodiments of the present invention will be described with appropriate reference to the drawings.

<Polyimide film> The polyimide film of this embodiment has a thermoplastic polyimide layer on at least one side of the non-thermoplastic polyimide layer. That is, the thermoplastic polyimide layer is provided on one side or both sides of the non-thermoplastic polyimide layer. For example, when a copper-clad laminate composed of the polyimide film of this embodiment and a copper layer is used, the copper layer is laminated on the surface of the thermoplastic polyimide layer. The so-called non-thermoplastic polyimide here generally refers to a polyimide that does not exhibit adhesiveness even if it is softened by heating. In the present invention, it refers to the use of a dynamic viscoelasticity measuring device (Dynamic Mechanical Analysis (Dynamic Mechanical Analysis)). , DMA)) The measured storage modulus at 30°C is 1.0×10 ⁹ Pa or more, and the storage modulus at 360°C is 1.0×10 ⁸ Pa or more of polyimide. In addition, the so-called thermoplastic polyimide is usually a polyimide whose glass transition temperature (Tg) can be clearly confirmed. In the present invention, it means that the storage modulus at 30°C measured using DMA is 1.0×10. ⁹ Pa or more, and the storage modulus at 360 ℃ is less than 1.0×10 ⁸ Pa polyimide.

The polyimide film of this embodiment may be a film (sheet), or it may be laminated on a resin sheet such as copper foil, glass plate, polyimide film, polyimide film, polyester film, etc. The state of the membrane.

For example, when the polyimide film of this embodiment is used as an insulating layer of a circuit board, in order to prevent warpage or decrease in dimensional stability, it is important that the coefficient of thermal expansion (CTE) is 10 Within the range of ppm/K or more and 30 ppm/K or less, preferably in the range of 10 ppm/K or more and 25 ppm/K or less. If the CTE is less than 10 ppm/K or more than 30 ppm/K, warpage occurs, or dimensional stability is reduced. In addition, in the polyimide film of the present embodiment, the CTE of the polyimide film is more preferably in the range of ±5 ppm/K or less, and most preferably ±2 ppm/ relative to the CTE of the copper layer including copper foil or the like. Within the range below K.

In the polyimide film of this embodiment, the thickness of the polyimide film can be set to a thickness within a predetermined range according to the purpose of use. The thickness of the polyimide film is, for example, preferably in the range of 8 μm to 50 μm, and more preferably in the range of 11 μm to 26 μm. If the thickness of the polyimide film is less than the lower limit, electrical insulation may not be ensured, or problems such as difficulty in handling in the manufacturing process due to reduced operability may occur. On the other hand, if the thickness of the polyimide film exceeds the upper limit, in order to control the in-plane retardation (RO), it is necessary to control the manufacturing conditions with high accuracy, which may cause problems such as decreased productivity.

In the polyimide film of this embodiment, the non-thermoplastic polyimide layer constitutes a low thermal expansion polyimide layer, and the thermoplastic polyimide layer constitutes a high thermal expansion polyimide layer. Here, the polyimide layer with low thermal expansion means that the coefficient of thermal expansion (CTE) is preferably in the range of 1 ppm/K or more and 25 ppm/K, more preferably in the range of 3 ppm/K or more and 25 ppm/K. The polyimide layer. In addition, the highly thermally expandable polyimide layer means that the CTE is 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. Polyimide layer within the following range. The polyimide layer can be made into a polyimide layer with a desired CTE by appropriately changing the combination of raw materials used, thickness, drying and curing conditions.

In addition, in the polyimide film of this embodiment, the thickness ratio of the non-thermoplastic polyimide layer to the thermoplastic polyimide layer (non-thermoplastic polyimide layer/thermoplastic polyimide layer) is 1.5 to The range of 6.0 is appropriate. If the value of this ratio is less than 1.5, the non-thermoplastic polyimide layer relative to the entire polyimide film becomes thinner, so the unevenness of the in-plane retardation (RO) tends to increase. If it exceeds 6.0, the thermoplastic polyimide layer becomes thinner. The imine layer becomes thinner, so the adhesion reliability between the polyimide film and the copper layer is likely to decrease. The control of the in-plane retardation (RO) is related to the resin composition and thickness of each polyimide layer constituting the polyimide film. For a thermoplastic polyimide layer composed of a resin that imparts adhesiveness, that is, high thermal expansion or softening, the greater the thickness, the greater the influence on the RO value of the polyimide film. Therefore, the ratio of the thickness of the non-thermoplastic polyimide layer is increased, the ratio of the thickness of the thermoplastic polyimide layer is decreased, and the value of RO of the polyimide film and its non-uniformity are decreased.

In the polyimide film of this embodiment, the polyimide constituting the thermoplastic polyimide layer can improve the adhesion to the copper layer. The glass transition temperature of such a thermoplastic polyimide is in the range of 200°C or more and 350°C or less, preferably in the range of 200°C or more and 320°C or less.

From the viewpoint of exhibiting the effect of improving the dimensional accuracy of the polyimide film of the present embodiment to a greater extent, the polyimide film of the present embodiment preferably has a film width of 490 mm or more and 1100 mm or less. , And the length of the strip is more than 20 m. In the case of continuously manufacturing the polyimide film of the present embodiment, the wider the film in the width direction (hereinafter also referred to as the TD direction), the more the effect of the invention becomes more pronounced. In addition, it also includes that after the polyimide film of the present embodiment is continuously manufactured, it is slit at a certain value in the longitudinal direction (hereinafter also referred to as the MD direction) and the TD direction of the long polyimide film. ) The resulting film.

The in-plane retardation (RO) value of the polyimide film of this embodiment is in the range of 5 nm or more and 50 nm or less, preferably in the range of 5 nm or more and 20 nm or less, more preferably 5 nm or more and 15 nm Within the following range. In addition, the RO unevenness (ΔRO) in the TD direction is 10 nm or less, preferably 5 nm or less, and more preferably 3 nm or less. Since it is controlled within this range, it is especially important for films with a thickness of 25 μm or more. The dimensional accuracy is also improved.

The polyimide film of the present embodiment preferably has a pressure of 340 MPa/m ² and a holding time of 15 minutes in an environment with a temperature of 360° C. The change in the in-plane retardation (RO) before and after pressure is 20 nm or less. It is preferably 10 nm or less, and more preferably 5 nm or less. In the polyimide film of this embodiment, even at a temperature exceeding the glass transition temperature of the polyimide constituting the thermoplastic polyimide layer, the amount of change in RO is controlled to the upper limit or less. Therefore, for example, before and after the step of bonding the polyimide film of the present embodiment and the copper foil by thermal lamination, RO is not easily changed, and therefore, it becomes a polyimide film having excellent dimensional stability.

In addition, the tensile modulus of the polyimide film of the present embodiment is preferably in the range of 3.0 GPa to 10.0 GPa, and more preferably in the range of 4.5 GPa to 8.0 GPa. If the tensile modulus of the polyimide film is less than 3.0 GPa, the strength of the polyimide itself is lowered, which may cause operational problems such as film cracking when the copper-clad laminate is processed into a circuit board. Conversely, if the tensile modulus of the polyimide film exceeds 10.0 GPa, the bending rigidity of the copper-clad laminate increases. As a result, when the copper-clad laminate is bent, the bending stress applied to the copper wiring increases. , The bending resistance is reduced. By setting the tensile modulus of the polyimide film within the above range, the strength and flexibility of the polyimide film can be ensured.

The embodiment of the method of manufacturing the polyimide film of this embodiment includes, for example: [1] A solution of polyimide acid is coated on a support substrate, dried, and then imidized to produce a polyimide film. Method; and [2] After coating the polyamide acid solution on the supporting substrate and drying, the polyamide acid gel film is peeled from the supporting substrate, and then imidized to produce polyimide Membrane method. In addition, the polyimide film of the present embodiment is a polyimide film including multiple polyimide layers. Therefore, the embodiment of the manufacturing method thereof may, for example, include: [3] Repeating the polyimide film on the supporting substrate After coating and drying the solution of amino acid, the method of imidization (hereinafter referred to as the casting method); and [4] After coating and drying the polyamic acid in a multilayered state by multi-layer extrusion at the same time , The method of carrying out imidization (hereinafter referred to as the multilayer extrusion method), etc.

The method [1] may include the following steps 1a to 1c, for example; (1a) A step of coating a polyamic acid solution on a supporting substrate and drying it; (1b) a step of heat-treating polyamide acid on a supporting substrate to form a polyimide layer; and (1c) A step of separating the supporting substrate from the polyimide layer, thereby obtaining a polyimide film.

The method [2] may include the following steps 2a to 2c, for example; (2a) The step of coating a polyamic acid solution on the supporting substrate and drying it; (2b) The step of separating the support substrate from the gel membrane of polyamide acid; and (2c) A step of heat-treating the gel film of polyimide to obtain a polyimide film.

The method [3] is to repeat step 1a or step 2a multiple times in the method [1] or [2] to form a laminated structure of polyamide acid on the supporting substrate. Otherwise, It is implemented in the same manner as the method [1] or the method [2] described above.

In the method [4], in step 1a of the method [1] or step 2a of the method [2], the laminated structure of polyamide acid is simultaneously coated by multi-layer extrusion and dried. Otherwise, It is implemented in the same manner as the method [1] or the method [2] described above.

The polyimide film produced in the present invention preferably completes the imidization of polyimide on a supporting substrate. Since the polyimide resin layer is fixed on the supporting substrate, the imidization is carried out, so that the expansion and contraction of the polyimide layer during the imidization process can be suppressed, and the polyimide film can be maintained The thickness or dimensional accuracy.

However, for the polyimide film in which the imidization of polyimide is completed on the supporting substrate, due to the impact on the polyimide film applied when the polyimide film is separated from the supporting substrate Tension, or stress to the polyimide film generated when peeling using a knife edge or the like, for example, stretches the polyimide film. Therefore, the inhomogeneity of the in-plane retardation (RO) of the polyimide film is likely to occur, and in particular, the more the film width of the polyimide film is 490 mm or more, the more the RO unevenness becomes more obvious. For the polyimide film of this embodiment, it is set so that the polyimide constituting the non-thermoplastic polyimide layer and the thermoplastic polyimide layer can easily form an ordered structure, thereby making peeling necessary The stress is dispersed in the layers of the polyimide film, thereby controlling RO.

In addition, the in-plane retardation (RO) can also be controlled by the following methods: separating the polyamic acid gel film on the support substrate, uniaxially or biaxially extending the polyamic acid gel film, and simultaneously Or continuously carry out the imidization. At this time, in order to control RO more precisely and highly, it is preferable to appropriately adjust conditions such as the stretching operation and the temperature increase rate during the imidization, the completion temperature of the imidization, and the load.

(Non-thermoplastic polyimide) In the polyimide film of this embodiment, it is preferable that the non-thermoplastic polyimide contains tetracarboxylic acid residues and diamine residues, and these residues are aromatic groups and contain biphenyltetrayl or biphenylene base. Here, the biphenyltetrayl or biphenylene has the same meaning as the diphenyl skeleton. For example, a substituent such as a halogen atom, an alkyl group, an alkoxy group, and an alkenyl group may be bonded to the biphenyltetrayl or biphenylene group. In particular, from the viewpoint of reducing the amount of change in in-plane retardation (RO) in a high-temperature environment, for example, it is more preferable to set the carbon number of substituents such as alkyl, alkoxy, and alkenyl groups to 1 to Within the range of 3. In the present invention, the term “tetracarboxylic acid residue” means a tetravalent group derived from tetracarboxylic dianhydride, and the term “diamine residue” means a divalent group derived from a diamine compound. In addition, the diamine compound is a compound having two amine groups, but the hydrogen atom in each amine group may be substituted with any substituent.

The tetracarboxylic acid residues and diamine residues contained in the non-thermoplastic polyimide are both aromatic groups. By setting them as aromatic groups, the in-plane retardation (RO ) The amount of change. Furthermore, relative to the total of 100 mole parts of the tetracarboxylic acid residue and the diamine residue, the biphenyltetrayl or biphenylene group is preferably 40 mole parts or more, and more preferably 50 mole parts. It is easy to form an ordered structure derived from biphenyltetrayl or biphenylene, which can reduce the amount of change of RO in the high-temperature environment of the polyimide film, and suppress the non-uniformity of RO.

In addition, the tetracarboxylic acid residue contained in the non-thermoplastic polyimide can preferably be exemplified by 3,3',4,4'-biphenyltetracarboxylic dianhydride (BPDA), 2,2 ',3,3'-Biphenyltetracarboxylic dianhydride and other derived tetracarboxylic acid residues. Among these tetracarboxylic acid residues, especially tetracarboxylic acid residues derived from BPDA (hereinafter also referred to as BPDA residues) easily form an ordered structure, which can reduce the amount of change in in-plane retardation (RO) in a high-temperature environment. Therefore, it is particularly preferred. In addition, although the BPDA residue can impart self-supporting properties to the polyimide precursor of the polyimide gel film, it tends to increase the CTE after imidization. From this point of view, with respect to 100 mole parts of all tetracarboxylic acid residues contained in the non-thermoplastic polyimide, the BPDA residue is preferably in the range of 20 mole parts to 70 mole parts, more preferably 20 mole parts. It is suitable to be in the range of mol parts to 60 mol parts.

The tetracarboxylic acid residues other than the BPDA residue contained in the non-thermoplastic polyimide may preferably be tetracarboxylic acid residues derived from pyromellitic dianhydride (PMDA) (hereinafter also Referred to as PMDA residues). Relative to 100 mol parts of all tetracarboxylic acid residues contained in the non-thermoplastic polyimide, PMDA residues are preferably in the range of 0 mol parts to 60 mol parts, more preferably 0 mol parts to 50 mol parts Within the range of parts is appropriate. The PMDA residue is arbitrary, but it is a residue that functions to control the thermal expansion coefficient and control the glass transition temperature.

Examples of other tetracarboxylic acid residues include tetracarboxylic acid residues derived from the following aromatic tetracarboxylic dianhydrides: 3,3',4,4'-diphenyl tetracarboxylic dianhydride, 4 ,4'-oxydiphthalic anhydride, 2,3',3,4'-biphenyltetracarboxylic dianhydride, 2,2',3,3'-benzophenonetetracarboxylic 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-di Carboxyphenyl)-propane dianhydride or 2,2-bis(3,4-dicarboxyphenyl)-propane dianhydride, bis(2,3-dicarboxyphenyl)methane dianhydride or bis(3,4- Dicarboxyphenyl) methane dianhydride, bis(2,3-dicarboxyphenyl) dianhydride or bis(3,4-dicarboxyphenyl) dianhydride, 1,1-bis(2,3-di Carboxyphenyl)ethane dianhydride or 1,1-bis(3,4-dicarboxyphenyl)ethane dianhydride, 1,2,7,8-phenanthrene-tetracarboxylic dianhydride, 1,2,6 ,7-phenanthrene-tetracarboxylic dianhydride or 1,2,9,10-phenanthrene-tetracarboxylic dianhydride, 2,3,6,7-anthracene tetracarboxylic dianhydride, 2,2-bis(3, 4-Dicarboxyphenyl)tetrafluoropropane dianhydride, 2,3,5,6-cyclohexane dianhydride, 1,2,5,6-naphthalenetetracarboxylic dianhydride, 1,4,5,8- Naphthalenetetracarboxylic dianhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride, 4,8-dimethyl-1,2,3,5,6,7-hexahydronaphthalene-1,2, 5,6-tetracarboxylic dianhydride, 2,6- or 2,7-dichloronaphthalene-1,4,5,8-tetracarboxylic dianhydride, 2,3,6,7-tetrachloronaphthalene-1 ,4,5,8-tetracarboxylic dianhydride or 1,4,5,8-tetrachloronaphthalene-2,3,6,7-tetracarboxylic dianhydride, 2,3,8,9-perylene-tetra Carboxylic dianhydride, 3,4,9,10-perylene-tetracarboxylic dianhydride, 4,5,10,11-perylene-tetracarboxylic dianhydride or 5,6,11,12-perylene-tetracarboxylic acid Dianhydride, cyclopentane-1,2,3,4-tetracarboxylic dianhydride, pyrazine-2,3,5,6-tetracarboxylic dianhydride, pyrrolidine-2,3,4,5-tetra Carboxylic dianhydride, thiophene-2,3,4,5-tetracarboxylic dianhydride, 4,4'-bis(2,3-dicarboxyphenoxy)diphenylmethane dianhydride, etc.

Among the tetracarboxylic acid residues contained in non-thermoplastic polyimine, 100 mole parts relative to all the tetracarboxylic acid residues contained in non-thermoplastic polyimide is composed of 2,3',3,4'-two Phenyl ether tetracarboxylic dianhydride, 3,3',4,4'-diphenyl tetracarboxylic dianhydride, 4,4'-oxydiphthalic anhydride and 2,3',3, The tetracarboxylic acid residue derived from the tetracarboxylic dianhydride of 4'-diphenyltetracarboxylic dianhydride is preferably 20 mol parts or less, more preferably 15 mol parts or less. If these tetracarboxylic acid residues exceed 20 mol parts with respect to all the tetracarboxylic acid residues contained in the non-thermoplastic polyimide, the orientation of the molecule decreases and the control of in-plane retardation (RO) becomes difficult.

In the polyimide film of this embodiment, the diamine residue contained in the non-thermoplastic polyimide preferably includes, for example, a diamine residue represented by the following general formula (1).

[化3]

In the formula (1), R ₁ and R ₂ independently represent an alkyl group having 1 to 3 carbon atoms, or an alkoxy group having 1 to 3 carbon atoms, or an alkoxy group having 2 to 3 carbon atoms, which may be substituted with a halogen atom or a phenyl group.的alkenyl.

The diamine residue represented by the general formula (1) easily forms an ordered structure, and can particularly advantageously suppress the amount of change in the in-plane retardation (RO) in a high-temperature environment. From this point of view, the diamine residue represented by the general formula (1) is preferably 20 mol parts or more, more preferably 100 mol parts of all diamine residues contained in the non-thermoplastic polyimide It is preferably 50 mol parts or more, more preferably in the range of 60 mol parts to 90 mol parts.

Preferable specific examples of the diamine residue represented by the general formula (1) include diamine residues derived from the following diamine compounds: 2,2'-dimethyl-4,4'-diamino group Biphenyl (m-TB), 2,2'-diethyl-4,4'-diaminobiphenyl (m-EB), 2,2'-diethoxy-4,4'-diamine Biphenyl (m-EOB), 2,2'-dipropoxy-4,4'-diaminobiphenyl (m-POB), 2,2'-n-propyl-4,4'-di Amino biphenyl (m-NPB), 2,2'-divinyl-4,4'-diamino biphenyl (VAB), 4,4'-diamino biphenyl, 4,4'-di Amino-2,2'-bis(trifluoromethyl)biphenyl (TFMB), etc. Among these diamine compounds, especially 2,2'-dimethyl-4,4'-diaminobiphenyl (m-TB) is easy to form an ordered structure, which can reduce the in-plane retardation (RO) under high temperature environment. The amount of change is therefore particularly preferred.

The diamine residues other than the diamine residue represented by the general formula (1) may preferably include diamine residues derived from p-phenylenediamine (p-PDA), m-phenylenediamine (m-PDA), etc. The group is more preferably a diamine residue derived from p-PDA (hereinafter also referred to as a PDA residue). Relative to 100 mole parts of all the tetracarboxylic acid residues contained in the non-thermoplastic polyimide, the PDA residue is preferably in the range of 0 mole parts to 80 mole parts, more preferably 0 mole parts to 50 mole parts Within the range of parts is appropriate. The PDA residue is arbitrary, but it is a residue that plays the role of controlling the thermal expansion coefficient and controlling the glass transition temperature.

In addition, in order to improve the elongation and bending resistance when the polyimide film is made, it is preferable that the non-thermoplastic polyimide contains those represented by the following general formulas (3) to (5) At least one diamine residue in the group consisting of diamine residues.

[化4]

In the above formula (3), R ₅ and R ₆ each independently represent a hydrogen atom, or a halogen atom, or an alkyl group, alkoxy group, or alkenyl group having 1 to 4 carbon atoms which may be substituted with a halogen atom, and X is independently Represents selected from -O-, -S-, -CH ₂ -, -CH(CH ₃ )-, -C(CH ₃ ) ₂ -, -CO-, -COO-, -SO ₂ -, -NH- or In the divalent group in -NHCO-, m and n independently represent an integer of 1-4.

[化5]

In the formula (4), R ₅ , R ₆ and R ₇ each independently represent a hydrogen atom, or a halogen atom, or an alkyl group, alkoxy group, or alkenyl group having 1 to 4 carbon atoms that may be substituted with a halogen atom, X independently represents selected from -O-, -S-, -CH ₂ -, -CH(CH ₃ )-, -C(CH ₃ ) ₂ -, -CO-, -COO-, -SO ₂ -,- In the divalent group in NH- or -NHCO-, m, n, and o independently represent an integer of 1-4.

[化6]

In the formula (5), R ₅ , R ₆ , R ₇ and R ₈ each independently represent a hydrogen atom, or a halogen atom, or an alkyl group or alkoxy group having 1 to 4 carbon atoms which may be substituted with a halogen atom or Alkenyl, X ₁ and X ₂ each independently represent a single bond or are selected from -O-, -S-, -CH ₂ -, -CH(CH ₃ )-, -C(CH ₃ ) ₂ -, -CO- The divalent group in, -COO-, -SO ₂ -, -NH- or -NHCO-, _{except when both X 1} and X ₂ are single bonds, m, n, o and p independently represent 1 An integer of ~4.

The diamine residue represented by the general formula (3) to the general formula (5) has a flexible portion, and therefore can impart flexibility to the polyimide film. Here, the diamine residues represented by general formula (4) and general formula (5) have three or four benzene rings. Therefore, in order to suppress the increase in the coefficient of thermal expansion (CTE), it is preferable to bond to benzene The end group of the ring is set to the para position. In addition, from the viewpoint of imparting flexibility to the polyimide film and suppressing the increase in the coefficient of thermal expansion (CTE), the general formula ( 3) The diamine residue represented by the general formula (5) is preferably in the range of 10 mol parts to 40 mol parts, more preferably in the range of 10 mol parts to 30 mol parts. If the diamine residue represented by the general formula (3) to the general formula (5) is less than 10 mole parts, the elongation in the case of forming a film is reduced, and the bending resistance and the like are reduced. On the other hand, if it exceeds 40 mole parts, the orientation of the molecule decreases, and it becomes difficult to achieve low CTE.

In the general formula (3), _{preferred examples of the group R 5} and the group R ₆ include: a hydrogen atom or an alkyl group having 1 to 4 carbon atoms which may be substituted by a halogen atom, or an alkoxy group having 1 to 3 carbon atoms基 or alkenyl. In addition, in the general formula (3), preferred examples of the linking group X include -O-, -S-, -CH ₂ -, -CH(CH ₃ )-, -SO ₂ -, or -CO-. Preferred specific examples of the diamine residue represented by the general formula (3) include diamine residues derived from the following diamine compounds: 4,4'-diaminodiphenyl ether (4,4' -DAPE), 3,3'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 4,4'-diaminodiphenylmethane, 3,3'-diamine Diphenylmethane, 3,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylpropane, 3,3'-diaminodiphenylpropane, 3,4'- Diaminodiphenylpropane, 4,4'-diaminodiphenyl sulfide, 3,3'-diaminodiphenyl sulfide, 3,4'-diaminodiphenyl sulfide, 4,4'-diaminodiphenyl benzene, 3,3'-diaminodiphenyl benzene, 4,4'-diamino benzophenone, 3,4'-diamino benzophenone Ketones, 3,3'-diaminobenzophenone, etc.

In the general formula (4), _{preferred examples of the group R 5} , the group R ₆ and the group R ₇ include a hydrogen atom or an alkyl group having 1 to 4 carbon atoms which may be substituted with a halogen atom, or a carbon number of 1 ~3 alkoxy or alkenyl. In addition, in the general formula (4), preferred examples of the linking group X include -O-, -S-, -CH ₂ -, -CH(CH ₃ )-, -SO ₂ -, or -CO-. Preferred specific examples of the diamine residue represented by the general formula (4) include diamine residues derived from the following diamine compounds: 1,3-bis(4-aminophenoxy)benzene (TPE -R), 1,4-bis(4-aminophenoxy)benzene (TPE-Q), bis(4-aminophenoxy)-2,5-di-tert-butylbenzene (DTBAB), 4,4-bis(4-aminophenoxy)benzophenone (BAPK), 1,3-bis[2-(4-aminophenyl)-2-propyl]benzene, 1,4- Bis[2-(4-aminophenyl)-2-propyl]benzene and the like.

In the general formula (5), _{preferred examples of the group R 5} , the group R ₆ , the group R ₇ and the group R ₈ include: a hydrogen atom or an alkyl group having 1 to 4 carbon atoms which may be substituted by a halogen atom , Or alkoxy or alkenyl having 1 to 3 carbons. In addition, in the general formula (5), _{preferred examples of the linking group X 1} and the linking group X ₂ include a single bond, -O-, -S-, -CH ₂ -, -CH(CH ₃ )-, -SO ₂ -or -CO-. However, from the viewpoint of providing a bent portion, _{the case where both the linking group X 1} and the linking group X ₂ are single bonds is excluded. Preferable specific examples of the diamine residue represented by the general formula (5) include a diamine residue derived from the following diamine compound: 4,4'-bis(4-aminophenoxy)biphenyl (BAPB), 2,2'-bis[4-(4-aminophenoxy)phenyl]propane (BAPP), 2,2'-bis[4-(4-aminophenoxy)phenyl ] Ether (BAPE), bis[4-(4-aminophenoxy)phenyl] chrysene, etc.

Examples of other diamine residues include diamine residues derived from the following aromatic diamine compounds: 2,2-bis-[4-(3-aminophenoxy)phenyl]propane, bis[ 4-(3-aminophenoxy)phenyl] sulfide, bis[4-(3-aminophenoxy)biphenyl, bis[1-(3-aminophenoxy)]biphenyl, double [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'-methylene bis-2,6-dimethylaniline, 4,4'-methylene-2,6-diethyl aniline, 3,3'- Diaminodiphenylethane, 3,3'-diaminobiphenyl, 3,3'-dimethoxybenzidine, 3,3''-diaminop-terphenyl, 4,4'- [1,4-Phenylenebis(1-methylethylene)]bisaniline, 4,4'-[1,3-phenylenebis(1-methylethylene)]bisaniline, bisaniline (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, meta-xylene-2,5-diamine, para-xylene-2,5-diamine, meta-xylenediamine , P-xylene diamine, 2,6-diaminopyridine, 2,5-diaminopyridine, 2,5-diamino-1,3,4-oxadiazole, piperazine, etc.

In the non-thermoplastic polyimide, by selecting the types of the tetracarboxylic acid residues and diamine residues, or using two or more kinds of tetracarboxylic acid residues or diamine residues, the respective moles Ratio, can control thermal expansion coefficient, storage modulus, tensile modulus, etc. In addition, in the case of non-thermoplastic polyimine having a variety of polyimine structural units, it can exist in the form of blocks, or it can exist randomly, so as to suppress the in-plane retardation (RO) non-uniformity From the viewpoint of, it is preferable to exist randomly.

(Thermoplastic polyimide) In the polyimide film of this embodiment, it is preferable that the thermoplastic polyimide contains tetracarboxylic acid residues and diamine residues, and these residues are aromatic groups and contain biphenyltetrayl or biphenylene base. Here, regarding the biphenyltetrayl or biphenylene group, for example, substituents such as halogen atoms, alkyl groups, alkoxy groups, and alkenyl groups may be bonded to the biphenyltetrayl group or biphenylene group, especially to suppress high-temperature environments. From the viewpoint of the amount of change in the in-plane retardation (RO) below, for example, the carbon number of substituents such as an alkyl group, an alkoxy group, and an alkenyl group is preferably set within the range of 1 to 3.

The tetracarboxylic acid residues and diamine residues contained in the thermoplastic polyimide are both aromatic groups. By setting them as aromatic groups, the in-plane retardation (RO) of the polyimide film in a high temperature environment can be suppressed. The amount of change. Furthermore, the biphenyltetrayl group or biphenylene group is made into the range of 30 mol parts or more and 80 mol parts or less with respect to the total of 100 mol parts of a tetracarboxylic acid residue and a diamine residue. If the biphenyltetrayl or biphenylene group is less than 30 moles, it is difficult to form an ordered structure derived from the biphenyltetrayl or biphenylene group, and the amount of change in RO of the polyimide film in a high-temperature environment increases . On the other hand, if the biphenyltetrayl or biphenylene group exceeds 80 mole parts, the thermoplasticity is impaired.

In addition, the tetracarboxylic acid residue contained in the thermoplastic polyimide can preferably be exemplified by BPDA, 2,3',3,4'-biphenyltetracarboxylic dianhydride, 2,2',3,3 '-Biphenyltetracarboxylic dianhydride and other derived tetracarboxylic acid residues. Among these tetracarboxylic acid residues, BPDA residues are particularly preferred because they tend to form an ordered structure and can suppress the amount of change in in-plane retardation (RO) in a high-temperature environment. Therefore, the BPDA residue is preferably 40 mol parts or more, more preferably 50 mol parts or more relative to 100 mol parts of all tetracarboxylic acid residues contained in the thermoplastic polyimide.

The tetracarboxylic acid residue other than the BPDA residue contained in the thermoplastic polyimide preferably includes a PMDA residue. Relative to 100 mol parts of all tetracarboxylic acid residues contained in the thermoplastic polyimide, PMDA residues are preferably in the range of 0 mol parts to 60 mol parts, more preferably 0 mol parts to 50 mol parts Within the range is appropriate. The PMDA residue is arbitrary, but it is a residue that functions to control the thermal expansion coefficient and control the glass transition temperature.

Examples of other tetracarboxylic acid residues include tetracarboxylic acid residues derived from the following aromatic tetracarboxylic dianhydrides: 3,3',4,4'-diphenyl tetracarboxylic dianhydride, 4 ,4'-oxydiphthalic anhydride, 2,2',3,3'-benzophenone tetracarboxylic dianhydride, 2,3,3',4'-benzophenone tetracarboxylic acid Dianhydride or 3,3',4,4'-benzophenone tetracarboxylic dianhydride, 2,3',3,4'-diphenyl ether tetracarboxylic dianhydride, bis(2,3-di Carboxyphenyl) 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-dicarboxybenzene) Group) bis(3,4-dicarboxyphenyl) dianhydride, 1,1-bis(2,3-dicarboxyphenyl)ethane dianhydride or 1,1-bis(3,4 -Dicarboxyphenyl)ethane dianhydride, 1,2,7,8-phenanthrene-tetracarboxylic dianhydride, 1,2,6,7-phenanthrene-tetracarboxylic dianhydride or 1,2,9,10 -Phenanthrene-tetracarboxylic dianhydride, 2,3,6,7-anthracene tetracarboxylic dianhydride, 2,2-bis(3,4-dicarboxyphenyl)tetrafluoropropane dianhydride, 2,3,5 ,6-Cyclohexane dianhydride, 1,2,5,6-naphthalenetetracarboxylic dianhydride, 1,4,5,8-naphthalenetetracarboxylic dianhydride, 2,3,6,7-naphthalenetetracarboxylic acid Acid dianhydride, 4,8-dimethyl-1,2,3,5,6,7-hexahydronaphthalene-1,2,5,6-tetracarboxylic dianhydride, 2,6-or 2,7 -Dichloronaphthalene-1,4,5,8-tetracarboxylic dianhydride, 2,3,6,7-tetrachloronaphthalene-1,4,5,8-tetracarboxylic dianhydride or 1,4,5 ,8-Tetrachloronaphthalene-2,3,6,7-tetracarboxylic dianhydride, 2,3,8,9-perylene-tetracarboxylic dianhydride, 3,4,9,10-perylene-tetracarboxylic acid Dianhydride, 4,5,10,11-perylene-tetracarboxylic dianhydride or 5,6,11,12-perylene-tetracarboxylic dianhydride, cyclopentane-1,2,3,4-tetracarboxylic acid Dianhydride, pyrazine-2,3,5,6-tetracarboxylic dianhydride, pyrrolidine-2,3,4,5-tetracarboxylic dianhydride, thiophene-2,3,4,5-tetracarboxylic acid Dianhydride, 4,4'-bis(2,3-dicarboxyphenoxy)diphenylmethane dianhydride, 2,2-bis[4-(3,4-dicarboxyphenoxy)phenyl]propane Dianhydride and so on.

In the polyimide film of the present embodiment, the diamine residue contained in the thermoplastic polyimide preferably includes, for example, a diamine residue represented by the following general formula (2).

[化7]

In the formula (2), R ₃ and R ₄ independently represent an alkyl group having 1 to 3 carbons or an alkoxy group or alkenyl group having 1 to 3 carbons which may be substituted with a halogen atom or a phenyl group.

The diamine residue represented by the general formula (2) easily forms an ordered structure, and can particularly advantageously suppress the amount of change in in-plane retardation (RO) in a high-temperature environment. From this point of view, the diamine residue represented by the general formula (2) is preferably 3 mol parts to 60 mol parts relative to 100 mol parts of all diamine residues contained in the thermoplastic polyimide It is more preferably within the range of 5 mol parts to 40 mol parts. If the diamine residue represented by the general formula (2) is less than 3 moles, it is difficult to form an ordered structure, and the amount of change in the in-plane retardation (RO) of the polyimide film under a high temperature environment increases. If it exceeds 60 Moer parts, the thermoplasticity is impaired.

Preferable specific examples of the diamine residue represented by the general formula (2) include a diamine residue derived from the following diamine compound: 2,2'-dimethyl-4,4'-diamino group Biphenyl (m-TB), 2,2'-diethyl-4,4'-diaminobiphenyl (m-EB), 2,2'-diethoxy-4,4'-diamine Biphenyl (m-EOB), 2,2'-dipropoxy-4,4'-diaminobiphenyl (m-POB), 2,2'-n-propyl-4,4'-di Amino biphenyl (m-NPB), 2,2'-divinyl-4,4'-diamino biphenyl (VAB), 4,4'-diamino biphenyl, 4,4'-di Amino-2,2'-bis(trifluoromethyl)biphenyl (TFMB), etc. Among these compounds, especially 2,2'-dimethyl-4,4'-diaminobiphenyl (m-TB) is easy to form an ordered structure, which can reduce the amount of change in in-plane retardation (RO) under high temperature environments , So it is particularly preferred.

The diamine residues other than the diamine residue represented by the general formula (2) may preferably include diamine residues derived from p-phenylenediamine (p-PDA), m-phenylenediamine (m-PDA), etc. The group is more preferably a diamine residue derived from p-PDA (hereinafter also referred to as a PDA residue). With respect to 100 mol parts of all diamine residues contained in the thermoplastic polyimide, the PDA residue is preferably in the range of 3 mol parts to 60 mol parts, more preferably 5 mol parts to 40 mol parts The range is appropriate. The PDA residue is arbitrary, but because it has a rigid structure, it has the effect of imparting an orderly structure to the polymer as a whole.

In addition, in order to improve the flexibility of the polyimide molecular chain and impart thermoplasticity, the thermoplastic polyimide preferably contains diamine residues selected from the group consisting of the following general formulas (6) to (12) At least one diamine residue in the group.

[化8]

In the above formulas (6) to (12), R ₉ independently represents a monovalent hydrocarbon group or alkoxy group having 1 to 6 carbons, and the linking group A independently represents selected from -O-, -S-, -CO -, -SO-, -SO ₂ -, -COO, -CH ₂ -, -C(CH ₃ ) ₂ -, -NH- or a divalent group in -CONH-, n ₁ independently represents 0～4 Integer. Among them, from the formula (8) will be excluded from the formula (7), except from the formula (10) will be excluded from the formula (9). In addition, the term "independently" means that in one or two or more of the above formulas (6) to (12), multiple linking groups A, multiple R ₉ or multiple n ₁ may be the same or different.

The diamine residues represented by the general formula (6) to the general formula (12) are preferably as follows: the total amount of at least one is preferably 100 mol parts of all the diamine residues contained in the thermoplastic polyimide Within the range of 40 mol parts to 97 mol parts. If the total amount of diamine residues represented by general formula (6) to general formula (12) is less than 40 mol parts, the flexibility of polyimide is insufficient and thermoplasticity cannot be obtained, and if it exceeds 97 mol parts, There is a tendency for the amount of change in the in-plane retardation (RO) of the polyimide film to increase in a high-temperature environment.

The diamine residue represented by the formula (6) is an aromatic diamine residue having two benzene rings. For the diamine compound that becomes the source of the diamine residue represented by the formula (6), it can be considered that at least one amine group directly bonded to the benzene ring is located in the meta position with the divalent linking group A, and the polyimide The degree of freedom of the molecular chain is increased and the flexibility is high, which helps to improve the flexibility of the polyimide molecular chain. Therefore, by using the diamine residue represented by Formula (6), the thermoplasticity of polyimide improves. Here, the linking group A is preferably -O-, -CH ₂ -, -C(CH ₃ ) ₂ -, -CO-, -SO ₂ -, -S-.

The diamine residue represented by the formula (6) includes, for example, diamine residues derived from the following diamine compounds: 3,3'-diaminodiphenylmethane, 3,3'-diamino Diphenylpropane, 3,3'-diaminodiphenyl sulfide, 3,3'-diaminodiphenyl sulfide, 3,3-diaminodiphenyl ether, 3,4'-di Aminodiphenyl ether, 3,4'-diaminodiphenylmethane, 3,4'-diaminodiphenylpropane, 3,4'-diaminodiphenyl sulfide, 3,3 '-Diaminobenzophenone, (3,3'-Diamino)diphenylamine, etc.

The diamine residue represented by the formula (7) is an aromatic diamine residue having three benzene rings. For the diamine compound that becomes the source of the diamine residue represented by the formula (7), it can be considered that at least one amine group directly bonded to the benzene ring and the divalent linking group A are located in the meta position, and the polyamide The degree of freedom of the amine molecular chain is increased and the flexibility is high, which helps to improve the flexibility of the polyimide molecular chain. Therefore, if the diamine residue represented by Formula (7) is used, the thermoplasticity of polyimide will improve. Here, the linking group A is preferably -O-.

The diamine residue represented by formula (7) includes, for example, diamine residues derived from the following diamine compounds: 1,4-bis(3-aminophenoxy)benzene, 3-[4- (4-aminophenoxy)phenoxy]aniline, 3-[3-(4-aminophenoxy)phenoxy]aniline and the like.

The diamine represented by formula (8) is an aromatic diamine residue having three benzene rings. For the diamine residue represented by the formula (8), it can be considered that the degree of freedom of the polyimide molecular chain is that the two divalent linking groups A directly bonded to a benzene ring are located in the meta position with each other Increased and has high flexibility, which helps to improve the flexibility of the polyimide molecular chain. Therefore, by using the diamine residue represented by Formula (8), the thermoplasticity of polyimide improves. Here, the linking group A is preferably -O-.

The diamine residue represented by formula (8) includes, for example, diamine residues derived from the following diamine compounds: 1,3-bis(4-aminophenoxy)benzene (TPE-R), 1,3-bis(3-aminophenoxy)benzene (APB), 4,4'-[2-methyl-(1,3-phenylene) bisoxy] bisaniline, 4,4' -[4-Methyl-(1,3-phenylene)bisoxy]bisaniline, 4,4'-[5-methyl-(1,3-phenylene)bisoxy]bisaniline, etc. .

The diamine residue represented by formula (9) is an aromatic diamine residue having four benzene rings. For the diamine compound that becomes the source of the diamine residue represented by the formula (9), it can be considered that at least one amine group directly bonded to the benzene ring and the divalent linking group A are located in the meta position, thereby having high The flexibility of the polyimide helps to improve the flexibility of the polyimide molecular chain. Therefore, by using the diamine residue represented by Formula (9), the thermoplasticity of polyimide improves. Here, the linking group A is preferably -O-, -CH ₂ -, -C(CH ₃ ) ₂ -, -SO ₂ -, -CO-, -CONH-.

The diamine residue represented by formula (9) includes diamine residues derived from the following diamine compounds: bis[4-(3-aminophenoxy)phenyl]methane, bis[4- (3-aminophenoxy)phenyl]propane, bis[4-(3-aminophenoxy)phenyl]ether, bis[4-(3-aminophenoxy)phenyl] chrysene, Bis[4-(3-aminophenoxy)]benzophenone, bis[4,4'-(3-aminophenoxy)]benzaniline, etc.

The diamine residue represented by the formula (10) is an aromatic diamine residue having four benzene rings. For the diamine residue represented by formula (10), it can be considered that the two divalent linking groups A directly bonded to at least one benzene ring are located in the meta position with each other, and the polyimide molecular chain has the freedom The degree of increase in the degree of bending has high flexibility, which helps to improve the flexibility of the polyimide molecular chain. Therefore, by using the diamine residue represented by Formula (10), the thermoplasticity of polyimide improves. Here, the linking group A is preferably -O-.

The diamine residue represented by the formula (10) includes 4-[3-[4-(4-aminophenoxy)phenoxy]phenoxy]aniline, 4,4'-[oxy Diamine residues derived from diamine compounds such as bis(3,1-phenyleneoxy)]bisaniline.

The diamine residue represented by the formula (11) is an aromatic diamine residue having four benzene rings. Regarding the diamine residue represented by the formula (11), it is considered that it 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 the diamine residue represented by Formula (11), the thermoplasticity of polyimide improves. Here, the linking group A is preferably -C(CH ₃ ) ₂ -, -O-, -SO ₂ -, -CO-.

The diamine residue represented by the formula (11) includes, for example, a diamine residue derived from the following diamine compound: 2,2-bis[4-(4-aminophenoxy)phenyl]propane (BAPP), bis[4-(4-aminophenoxy)phenyl] ether (BAPE), bis[4-(4-aminophenoxy)phenyl] ash (BAPS), bis[4- (4-Aminophenoxy)phenyl]ketone (BAPK) and the like.

The diamine residue represented by formula (12) is an aromatic diamine residue having four benzene rings. For the diamine residue represented by the formula (12), it is considered that the divalent linking group A with high flexibility is provided on both sides of the diphenyl skeleton, thereby contributing to the improvement of the polyimide molecular chain. The softness. Therefore, by using the diamine residue represented by Formula (12), the thermoplasticity of polyimide improves. Here, the linking group A is preferably -O-.

The diamine residue represented by the formula (12) includes, for example, bis[4-(3-aminophenoxy)]biphenyl, bis[4-(4-aminophenoxy)]biphenyl, etc. A diamine residue derived from a diamine compound.

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

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

(Synthesis of non-thermoplastic polyimide and thermoplastic polyimide) Generally, polyimide can be produced by reacting tetracarboxylic dianhydride and diamine compound in a solvent to generate polyimide and then heating and ring-closing. For example, the tetracarboxylic dianhydride and the diamine compound are dissolved in an organic solvent at approximately equal moles and stirred at a temperature in the range of 0°C to 100°C for 30 minutes to 24 hours to carry out the polymerization reaction. Polyimide is the precursor of polyimide. At the time of the reaction, the reaction components are dissolved so that the generated precursor is in the range of 5% by weight to 30% by weight, preferably in the range of 10% by weight to 20% by weight, in the organic solvent. Examples of organic solvents used in the polymerization reaction include: N,N-dimethylformamide (DMF), N,N-dimethylacetamide (DMAc), and N,N-diethylacetamide , N-methyl-2-pyrrolidone (NMP), 2-butanone, dimethyl sulfide (DMSO), hexamethylphosphamide, N-methylcaprolactone, dimethyl sulfate, Cyclohexanone, dioxane, tetrahydrofuran, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, cresol, etc. 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. In addition, the use amount of such an organic solvent is not particularly limited, and it is preferable to adjust the use amount such that the concentration of the polyamide acid solution obtained by the polymerization reaction becomes about 5 wt% to 30 wt%.

The synthesized polyamide acid is generally advantageously used in the form of a reaction solvent solution, which can be concentrated, diluted or replaced with other organic solvents as necessary. In addition, polyamide acid is generally excellent in solvent solubility, and therefore can be advantageously used. The viscosity of the polyamide acid solution is preferably in the range of 500 cps to 100,000 cps. If it deviates from this range, defects such as thickness unevenness and streaks are likely to occur when the coating operation is performed with a coater or the like. The method for imidizing the polyamide acid is not particularly limited, and 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 suitable.

＜Copper clad laminates＞ The copper clad laminate of this embodiment includes an insulating layer and a copper layer such as a copper foil located on at least one surface of the insulating layer, and the insulating layer may be formed using the polyimide film of this embodiment. In addition, in order to improve the adhesion between the insulating layer and the copper layer, the layer in contact with the copper layer of the insulating layer is a thermoplastic polyimide layer. The copper layer is arranged on one or both sides of the insulating layer. That is, the copper clad laminate of this embodiment may be a single-sided copper clad laminate (single-sided CCL) or a double-sided copper clad laminate (double-sided CCL). In the case of a single-sided CCL, the copper layer laminated on one surface of the insulating layer is regarded as the "first copper layer" of the present invention. In the case of a double-sided CCL, the copper layer laminated on one side of the insulating layer is regarded as the "first copper layer" of the present invention, and the surface laminated on the insulating layer and the surface on which the first copper layer is laminated is the opposite side The upper copper layer is regarded as the "second copper layer" of the present invention. The copper clad laminate of this embodiment is used as an FPC by etching the copper layer and performing wiring circuit processing to form copper wiring.

The copper-clad laminate can also be prepared, for example, by preparing a resin film including the polyimide film of the present embodiment, sputtering a metal on the resin film to form a seed layer, and then forming a copper layer by, for example, copper plating.

In addition, the copper-clad laminate can also be prepared by preparing a resin film composed of the polyimide film of this embodiment, and laminating copper foil on it by a method such as thermocompression bonding.

Furthermore, copper clad laminates can also be prepared by casting a coating solution containing polyamide acid as a precursor of polyimide on copper foil, drying to form a coating film, and then performing heat treatment to form a coating film. Amination to form a polyimide layer.

(The first copper layer) In the copper clad laminate of the present embodiment, the copper foil used for the first copper layer (hereinafter may be referred to as “first copper foil”) is not particularly limited, and may be, for example, rolled copper foil or electrolytic copper foil.

The thickness of the first copper foil is preferably 13 μm or less, more preferably in the range of 6 μm to 12 μm. If the thickness of the first copper foil exceeds 13 μm, the bending stress applied to the copper layer (or copper wiring) when the copper clad laminate (or FPC) is bent increases, thereby reducing the bending resistance. In addition, from the viewpoint of production stability and operability, the lower limit of the thickness of the first copper foil is preferably set to 6 μm.

In addition, the tensile modulus of the first copper foil is preferably in the range of 10 GPa to 35 GPa, and more preferably in the range of 15 GPa to 25 GPa, for example. In the case of using rolled copper foil as the first copper foil in the present embodiment, if annealing is performed by heat treatment, flexibility is easily improved. Therefore, if the tensile modulus of the copper foil is less than the lower limit, in the step of forming an insulating layer on the long first copper foil, the rigidity of the first copper foil itself is reduced due to heating. On the other hand, if the tensile modulus exceeds the upper limit, greater bending stress is applied to the copper wiring when the FPC is bent, thereby reducing its bending resistance. In addition, the rolled copper foil tends to change its tensile modulus depending on the heat treatment conditions when the insulating layer is formed on the copper foil, the annealing treatment of the copper foil after the insulating layer is formed, or the like. Therefore, in this embodiment, as long as the tensile modulus of the first copper foil is within the above-mentioned range in the finally obtained copper-clad laminate.

The first copper foil is not particularly limited, and a commercially available rolled copper foil can be used.

(Second copper layer) The second copper layer is laminated on the surface of the insulating layer opposite to the first copper layer. The copper foil (second copper foil) used for the second copper layer is not particularly limited. For example, it may be a rolled copper foil or an electrolytic copper foil. In addition, as the second copper foil, a commercially available copper foil can also be used. In addition, the same copper foil as the first copper foil can also be used as the second copper foil.

The copper clad laminate of this embodiment is preferably the ratio of the cumulative conversion size change of the wiring pattern of the circuit board size (FPC size) of 10 mm obtained by the following evaluation method to the sum of the wiring width and the wiring interval. The in-plane unevenness in the sheet is ±2% or less. The value of this non-uniformity is ±2% or less, which means that the dimensional change in the longitudinal direction (MD direction) and the dimensional change in the width direction (TD direction) before and after etching are both 2% or less. When the value of this non-uniformity exceeds ±2%, in the FPC processed by the copper clad laminate, it becomes the cause of poor contact between the wiring or the wiring and the terminal, resulting in the reliability or the good of the circuit board. The rate is reduced. Here, while referring to FIGS. 1 to 7, the method of evaluating the dimensional stability of the copper clad laminate used in this embodiment will be described. This evaluation method includes the following steps (1) to (6).

(1) Steps to prepare test piece: In this step, as illustrated in FIG. 1, the long copper clad laminate 100 is cut to a predetermined length, thereby preparing the test piece 10. In addition, in the following description, the longitudinal direction of the long copper clad laminate 100 is defined as the MD direction, and the width direction is defined as the TD direction (the same applies to the test piece 10). The test piece 10 is preferably such that the width (length in the TD direction) of the copper clad laminate 100 and the cutting interval (length in the MD direction) are approximately equal to each other so as to have a nearly square shape. Although not shown, the copper clad laminate 100 has an insulating resin layer and copper layers laminated on one side or both sides of the insulating resin layer.

The copper-clad laminate 100 used as an object of this evaluation method can use a copper-clad laminate prepared by any method. For example, the copper clad laminate 100 can be prepared by preparing a resin film, sputtering metal on it to form a seed layer, and then forming a copper layer by plating. In addition, the copper clad laminate 100 can also be prepared by laminating a resin film and copper foil by a method such as thermocompression bonding. Furthermore, the copper clad laminate 100 can also be prepared by coating a resin solution on copper foil to form an insulating resin layer.

(2) Steps to form multiple marks on the test piece: In this step, as shown in FIG. 2, first, an imaginary regular quadrilateral 20 having sides parallel to the MD direction and the TD direction is assumed in the test piece 10 (hereinafter sometimes simply referred to as "regular quadrilateral 20"). The length of one side of the imaginary regular quadrilateral 20 can be set to a length corresponding to the width of the copper clad laminate 100 (the length in the TD direction). In addition, regarding the area of the imaginary regular quadrilateral 20, when a large number of test pieces are taken, the limit of the range processed into FPC is included in the evaluation object, so it is preferably set to an area that can cover the range processed into FPC. Therefore, the length of one side of the regular quadrilateral 20 is preferably set in the range of 60% to 90% of the length of the test piece 10 in the TD direction (the width of the copper clad laminate 100), and more preferably set to 70% to 70%. Within 80%. For example, when the width of the copper clad laminate 100 (the length in the TD direction) is 250 mm, the length of one side of the imaginary regular quadrilateral 20 is preferably set in the range of 150 mm to 225 mm, and more preferably set to Within the range of 175 mm～200 mm.

Then, as shown in FIGS. 2 to 4, in the central region 21 including the center 20a of the imaginary regular quadrilateral 20, and the two corner regions 23a each including the two corners 20b sharing one side of the regular quadrilateral 20 in the TD direction, In the corner area 23b, a plurality of marks including a linear arrangement are formed respectively. The mark is, for example, a circular hole 30 penetrating the test piece 10. The plurality of holes 30 are preferably formed at equal intervals. In addition, the hole 30 as a mark may have a polygonal shape such as a triangle or a rectangle, for example. In addition, the mark is not limited to a through hole as long as its position can be recognized. For example, a groove, a cutout, etc. may be formed in the test piece 10, or a pattern printed with ink or the like may be used.

＜Central area＞ The center 20a of the imaginary regular quadrilateral 20 serves as a reference for measuring the coordinates of the expansion and contraction of the test piece 10. Therefore, in this evaluation method, the center region 21 including the center 20a is used as a measurement object. In the central region 21, as long as it includes a linear arrangement, the position where the plurality of holes 30 are formed is arbitrary. For example, it may be arranged in a T-shape, an L-shape, etc., and it is preferable to be able to move from the center 20a of the imaginary regular quadrilateral 20 in the MD direction. And cross-shaped evenly arranged in the TD direction. That is, as shown in FIG. 3, it is preferable to form a plurality of holes 30 in the MD direction and the TD direction along the cross shape passing through the center 20a of the imaginary regular quadrilateral 20, and it is more preferable to form the cross-shaped cross portion and the imaginary The centers 20a of the regular quadrilaterals 20 are arranged such that they overlap. In this case, the holes 30 overlapping the center 20a are repeatedly counted as the holes 30 constituting the array in both the MD direction and the TD direction.

In addition, in the central region 21, in order to accurately evaluate the dimensional stability including the unevenness of the dimensional change in the surface of the test piece 10, it is advisable to start from the center 20a of the regular quadrilateral 20 in the MD and TD directions. The pores 30 are formed in a range of at least 12.5% or more, preferably in a range of 12.5% to 32.5%, and more preferably in a range of 12.5% to 25% with respect to the length of one side of the regular quadrilateral 20, respectively.

<Corner area> In the long copper clad laminate 100 as shown in FIG. 1, the area around two corners 20 b sharing one side of the regular quadrilateral 20 in the TD direction is the easiest area to expand and contract, and the dimensional change is likely to increase. Therefore, in this evaluation method, the two corner regions 23a and the corner region 23b each including the two corners 20b sharing one side of the regular quadrilateral 20 in the TD direction are the measurement targets.

In the corner area 23a and the corner area 23b, as long as the linear arrangement is included, the position where the hole 30 is formed is arbitrary. For example, as shown in FIG. The strip side has a plurality of holes 30 formed in an L-shape in the MD direction and the TD direction. In this case, the holes 30 overlapping at the corner portion 20b are repeatedly counted as the holes 30 constituting the array in both the MD direction and the TD direction. In addition, FIG. 4 shows only one corner area 23b, but the same is true for the other corner area 23a.

In the two corner regions 23a and corner region 23b, in order to accurately evaluate the dimensional stability including the unevenness of dimensional changes in the surface of the test piece 10, the following situation is appropriate: from both ends of one side of the regular quadrilateral 20 in the TD direction (That is, the corner 20b of the regular quadrilateral 20) faces the central side in the MD direction, and is at least 12.5% or more, preferably in the range of 12.5% to 32.5%, more preferably 12.5% to 25% with respect to the length of one side in the MD direction. A hole 30 is formed in the range.

In addition, in the two corner regions 23a and the corner region 23b, in order to accurately evaluate the dimensional stability including the unevenness of the dimensional change in the surface of the test piece 10, the following situation is appropriate: Both ends (that is, the corners 20b of the regular quadrilateral 20) face the central side in the TD direction, and are at least 12.5% or more, preferably 12.5% to 32.5%, and more preferably 12.5% to 25 with respect to the length of one side in the TD direction. A hole 30 is formed in the range of %.

In addition, in order to cover the surface of the test piece 10 and accurately grasp the dimensional change of each part, the arrangement range between the holes 30 at both ends in the central area 21 that are arranged in a straight line can be compared with the corner area 23a and the corner area 23b. The array ranges between the holes 30 at both ends arranged linearly in the same direction overlap. Specifically, it can also be configured in such a way that when moving in parallel in the TD direction, at least the positions of the two ends of the plurality of holes 30 arranged in the MD direction in the central region 21 and the two corner regions 23a and corner regions The positions of the holes 30 on the innermost side (the side farther from the corner portion 20b) of the plurality of holes 30 arranged in the MD direction in 23b overlap (overlap). Similarly, it can also be arranged in the following manner: when moving in parallel in the MD direction, at least the position of the hole 30 in the corner region 23a and the corner region 23b among the plurality of holes 30 arranged in the TD direction in the central region 21 is closest, It overlaps with the position of the innermost hole 30 (the side far from the corner 20b) among the plurality of holes 30 arranged in the TD direction in the two corner regions 23a and the corner region 23b. In consideration of the above configuration, it is most reasonable to arrange the plurality of holes 30 in a cross shape in the central area 21. In addition, in the two corner areas 23a and 23b, it is most reasonable to arrange the plurality of holes 30 in an L shape.

In the imaginary regular quadrilateral 20 of the test piece 10, the range in which the holes 30 are formed can be adjusted by the size of the holes 30, the number of the holes 30, and the length of the interval between the holes 30 and the holes 30.

In order to improve the detection accuracy of the dimensional change, the size of the hole 30 is preferably set to be within a range of 20% or less of the length of the interval between the hole 30 and the hole 30.

For the plurality of holes 30 formed in the central area 21 and the two corner areas 23a and the corner areas 23b, in order to accurately evaluate the dimensional stability including the unevenness of the dimensional change in the surface of the test piece 10, it is preferable It is a linear arrangement including at least 11 or more in the MD direction and the TD direction, and more preferably 20 or more linear arrays. Here, if the number of holes 30 is set to n, the number of intervals between the adjacent holes 30 and the holes 30 to be measured in the subsequent steps (3) and (5) becomes n-1. The distance between the adjacent holes 30 and the holes 30 is, for example, 9 places when the number of holes 30 is 10, and 20 places when the number of holes 30 is 21. In this case, it is preferable that the number of holes 30 is the same in the MD direction and the TD direction.

In order to improve the detection accuracy of the dimensional change, the distance between the hole 30 and the hole 30 is preferably set to 2 mm or more.

(3) The first measurement step: In this step, the positions of a plurality of holes 30 are measured. Then, the distance L0 between the adjacent hole 30 and the hole 30 is calculated based on the measurement result of the position of each hole 30. For example, if the number of holes 30 is 21, the distance L0 is calculated for the interval between adjacent holes 30 and holes 30 at 20 locations. Here, as shown in FIG. 5, the distance L0 between the adjacent holes 30 and the holes 30 refers to the distance from the center 30 a of a certain hole 30 to the center 30 a of the adjacent hole 30.

The measurement of the position of the hole 30 is not particularly limited. For example, it can be implemented by a method of detecting the position of the hole 30 based on the image of the test strip 10.

The measurement of the position of the hole 30 in this step can be performed after the step (2), but it is preferable to provide a step of adjusting the condition of the test strip 10 before the measurement. As an example of the state adjustment of the test piece 10, humidity control processing can be mentioned. The humidity control treatment can be performed by leaving the test piece 10 in a certain environment for a certain period of time (for example, in an environment of 23° C. and 50 RH% for 24 hours).

(4) Etching steps: In this step, part or all of the copper layer of the test piece 10 is etched. In order to evaluate realistic dimensional stability, the content of etching is preferably performed in accordance with the wiring pattern of the FPC formed by the copper-clad laminate 100. In the case where the test piece 10 is prepared from a double-sided copper clad laminate, the copper layers on both sides can also be etched. In addition, when heat treatment is involved in actual FPC processing, a process of heating the test piece 10 at an arbitrary temperature may be performed after etching.

(5) The second measurement step: This step is a step of measuring the positions of the plurality of holes 30 again after the etching in (4). Furthermore, as shown in FIG. 5, the distance L1 between the adjacent hole 30 and the hole 30 is calculated based on the measurement result of the position of each hole 30. The measurement of the position of the hole 30 in this step can be performed by the same method as the step (3).

The measurement of the position of the hole 30 in this step can be performed after the step (4), but it is preferable to provide a step of adjusting the state of the test strip 10 in the same manner as in the step (3). Especially in the case where the state adjustment is performed in the step (3), it is also preferable in this step to implement the state adjustment under the same conditions before the measurement.

(6) Steps to calculate the amount of dimensional change: In this step, as shown in FIG. 5, the distance L0 obtained in the first measurement step and the difference L1-L0 between the distance L1 obtained in the second measurement step and the distance L1 obtained in the second measurement step are calculated for the interval between the same two holes 30 before and after the etching. In addition, the difference L1-L0 is calculated in the same manner for two or more places, preferably ten or more places, and more preferably all of the gaps between the holes 30 and the holes 30 arranged in the same linear shape. Let this difference L1-L0 be "dimension change amount Δ".

(7) Steps to convert into wiring specifications: In this step, the dimensional change amount Δ obtained in step (6) is converted into the specification of the wiring pattern in the FPC formed by the copper clad laminate 100, in a ratio relative to the sum of the wiring width of the wiring pattern and the wiring interval To represent the converted value obtained. Through this step, when the copper-clad laminate 100 for testing is actually processed into an FPC, the influence of the dimensional change of the copper-clad laminate 100 on the wiring pattern of the FPC can be easily understood and shown.

In this step, first, the dimensional change amount Δ is converted into the specifications of the wiring width/wiring interval of the L/S wiring pattern in the predetermined FPC formed by the copper-clad laminate 100, and the calculated dimensional change is calculated by accumulating The cumulative converted size change amount. For example, in the case where the wiring width and the wiring interval of the wiring pattern in the planned FPC are respectively 1/Y of the distance L0 with respect to the distance L0 between the two holes 30 before etching, the size change is calculated according to the following formula Δ is converted to the value when downsizing is 2×(1/Y), and the cumulative conversion size change of 2×(1/Y) is calculated.

Cumulative conversion size change = [Σ _i=1 ⁱ (2×Δ _i /Y)]

In the above formula, the symbol Σ _i=1 ⁱ represents the sum of 1 to i. In addition, the dimensional change Δ represents a value obtained by subtracting the distance L0 between the nth hole 30 and the n-1th hole 30 before the etching from the distance L1 between the nth hole 30 and the n-1th hole 30 after etching (Here, n is an integer of 2 or more). For example, Δ ₁ is the dimensional change of the length of the first interval (the distance between two adjacent holes 30), and Δ _i is the dimensional change of the length of the i-th (i is a positive integer) interval.

Then, the displacement ratio of the wiring is obtained according to the following equation from the cumulatively converted dimensional change amount. The displacement ratio of the wiring is the ratio of the sum of the wiring width (Lmm) and the wiring interval (Smm) of the predetermined L/S wiring pattern to express the cumulative converted dimension change amount. Displacement ratio of wiring (%) = {[Σ _i=1 ⁱ (2×Δ _i /Y)]/[L＋S]}×100

The displacement ratio of the MD and TD wiring in the FPC calculated as described above is plotted on a graph, thereby obtaining an approximate straight line corresponding to the FPC size (in addition, the illustration of the graph is omitted). Here, the so-called "FPC size" refers to the distance between the wirings at both ends of the plurality of wirings formed in the FPC that are farthest away. The magnitude of the slope of the graph refers to the magnitude of the wiring displacement, and the magnitude of the unevenness of the slope of the graph refers to the magnitude of the in-plane unevenness of the wiring displacement.

Through this step, when the copper-clad laminate 100 for testing is actually processed into a circuit, the influence of the dimensional change of the copper-clad laminate 100 on the wiring pattern of the FPC can be easily understood and shown. In addition, by creating an approximate straight line graph, the size of the displacement or the in-plane unevenness of the wiring produced by the copper clad laminate 100 as the test body can be seen and expressed corresponding to the size of the FPC.

In addition, after the dimensional change amount Δ obtained in the step (6) is accumulated, the cumulative dimensional change amount may be converted into the wiring width of the L/S wiring pattern in the predetermined FPC formed by the copper clad laminate 100 / Wiring interval specifications, calculate the cumulative conversion size change. For example, the dimensional change amount Δ of each interval is accumulated to obtain the cumulative dimensional change amount Σ. This cumulative dimensional change amount Σ can be calculated by the following formula.

Σ=Δ ₁ ＋Δ ₂ ＋Δ ₃ ＋・・・＋Δ _i ＝Σ _i=1 ⁱ Δ _i

The cumulative dimensional change amount Σ can be obtained for any one of the MD direction and the TD direction of the copper clad laminate 100, preferably two directions. Based on the cumulative dimensional change Σ, the dimensional stability of the copper clad laminate 100 in the MD and TD directions can be evaluated. In addition, an approximate straight line that scales up is obtained based on the actual measurement value of the cumulative dimensional change amount Σ.

As described above, according to this evaluation method, the dimensional change of the copper-clad laminate 100 including in-plane unevenness can be evaluated with high accuracy through steps (1) to (7). In addition, even in the case where a plurality of test pieces are taken from the copper clad laminate 100, the dimensional stability can be evaluated separately for each area processed into FPC.

＜FPC＞ The copper clad laminate of this embodiment is mainly useful as an FPC material. That is, by processing the copper layer of the copper clad laminate of this embodiment into a pattern by a conventional method to form a wiring layer, the FPC as one embodiment of the present invention can be manufactured. [Example]

The following examples illustrate the features of the present invention in more detail. However, the scope of the present invention is not limited to the examples. In addition, in the following examples, unless otherwise specified, the following methods are used for various measurements and evaluations.

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

[Determination of weight average molecular weight] The weight average molecular weight is measured using a gel permeation chromatography (Tosoh Co., Ltd. product, trade name: HLC-8220GPC). Polystyrene was used as a standard substance, and N,N-dimethylacetamide was used as a developing solvent.

[Measurement of glass transition temperature (Tg)] Regarding the glass transition temperature, a dynamic viscoelasticity measuring device (DMA: manufactured by UBM, trade name: E4000F) was used, from 30°C to 400°C at a heating rate of 4°C/min, frequency 11 Hz measured a polyimide film with a size of 5 mm×20 mm, and the temperature at which the change in elastic modulus (tanδ) reached the maximum was taken as the glass transition temperature. In addition, the storage modulus at 30°C measured by DMA is 1.0×10 ⁹ Pa or more, and the storage modulus at 360°C is less than 1.0×10 ⁸ Pa as “thermoplastic”, and the storage modulus at 30°C If the number is 1.0×10 ⁹ Pa or more, and the storage modulus at 360°C shows 1.0×10 ⁸ Pa or more, it is regarded as "non-thermoplastic".

[Determination of Coefficient of Thermal Expansion (CTE)] Using a thermomechanical analyzer (manufactured by Bruker, trade name: 4000SA), a load of 5.0 g is applied to a polyimide film with a size of 3 mm×20 mm, and a load of 5.0 g is applied to the polyimide film at a certain heating rate. The temperature was raised to 265°C, and the temperature was maintained at that temperature for 10 minutes, and then cooled at a rate of 5°C/min to obtain an average thermal expansion coefficient (thermal expansion coefficient) from 250°C to 100°C.

[Measurement of surface roughness of copper foil] Regarding the surface roughness of the copper foil, an atomic force microscope (Atomic Force Microscope, AFM) (manufactured by Bruker AXS (Bruker AXS), trade name: Dimension Icon type SPM), probe (Bruker AXS (Bruker AXS) ) Manufactured by the company, trade name: TESPA (NCHV), tip curvature radius 10 nm, spring constant 42 N/m), in tapping mode (tapping mode) to measure the copper foil surface in the range of 80 μm×80 μm, find The ten-point average roughness (Rz) is calculated.

[Measurement of peel strength] 1) Pouring side of single-sided copper clad laminate (resin coating side) After the copper foil of the single-sided copper clad laminate (copper foil/resin layer) was circuit-processed with a width of 1.0 mm, it was cut with width: 8 cm × length: 4 cm to prepare a measurement sample 1. Regarding the measurement of the peel strength of the casting side of the sample 1, a tensile tester (Tensilon tester) (manufactured by Toyo Seiki Seisakusho, trade name: Strograph VE-1D) was used, and the resin of the sample 1 was measured using double-sided tape The layer side was fixed to an aluminum plate, and the copper foil was peeled in a 90° direction at a speed of 50 mm/min, and the central strength when the copper foil was peeled from the resin layer by 10 mm was obtained. Let this value be peel strength 1A. 2) Pouring side of double-sided copper clad laminate (resin coating side) The copper foil on both sides of the double-sided copper-clad laminate (copper foil/resin layer/copper foil) on the thermocompression bonding side and the casting side is processed with a width of 0.8 mm (wiring processing is performed so that the copper foils on both sides become the same position) ), cut with width: 8 cm × length: 4 cm to prepare measurement sample 2. Regarding the measurement of the peel strength of the pouring side of the sample 2, a tensile tester (Tensilon tester) (manufactured by Toyo Seiki Seisakusho Co., Ltd., trade name: Strograph VE-1D) was used to measure the heat of the sample 2 using double-sided tape. The copper foil surface on the crimping side was fixed to an aluminum plate, and the copper foil was peeled in a 90° direction at a speed of 50 mm/min. The median strength when the copper foil on the resin coated side was peeled off the resin layer by 10 mm was obtained. Let this value be peeling strength 2A.

[Measurement of in-plane delay (RO)] Regarding the in-plane retardation (RO), a birefringence meter (manufactured by Photonic-Lattice), trade name: wide range birefringence evaluation system WPA-100, measurement area: MD: 140 mm× TD: 100 mm) to find the in-plane retardation of a given sample. In addition, the incident angle is 0°, and the measurement wavelength is 543 nm.

[Determination of Tensile Modulus] Regarding the tensile modulus of the copper foil, the copper foil, which has been heat-treated in a vacuum oven with the same processing steps as the copper-clad laminate, is used, and the universal testing machine (Strograph) R-1 manufactured by Toyo Seiki Seisakusho Co., Ltd. is used. The tensile modulus is measured under an environment with a temperature of 23°C and a relative humidity of 50%.

The abbreviations used in Examples and Comparative Examples indicate the following compounds. NTCDA: 2,3,6,7-naphthalenetetracarboxylic dianhydride BPDA: 3,3',4,4'-biphenyltetracarboxylic dianhydride PMDA: Pyromellitic dianhydride m-TB: 2,2'-dimethyl-4,4'-diaminobiphenyl m-EOB: 2,2'-diethoxy-4,4'-diaminobiphenyl TPE-R: 1,3-bis(4-aminophenoxy)benzene DAPE: 4,4'-diaminodiphenyl ether BAPP: 2,2-bis[4-(4-aminophenoxy)phenyl]propane DMAc: N,N-Dimethylacetamide

(Synthesis example 1) Under nitrogen flow, put 1146.4 parts by weight of m-TB (5.4 mol parts) and 175.4 parts by weight of TPE-R (0.6 mol parts) into the reaction tank, and the solid content concentration after polymerization becomes 15% by weight. DMAc is dissolved by stirring at room temperature. Then, after adding 706.1 parts by weight of BPDA (2.4 mol parts) and 965.4 parts by weight of NTCDA (3.6 mol parts), stirring was continued for 3 hours at room temperature to perform polymerization reaction, and a polyamide acid solution 1 was obtained. The solution viscosity of polyamide acid solution 1 is 41,100 cps.

Then, after the polyamide acid solution 1 was uniformly coated on the stainless steel support base material so that the thickness after curing became about 25 μm, it was heated and dried at 120° C. to remove the solvent. Furthermore, stepwise heat treatment was performed within 30 minutes from 120°C to 360°C to complete the imidization to prepare polyimide film 1 (biphenyltetrayl and biphenylene: 65 mol%, non-thermoplastic, Tg: above 400℃, CTE: 7.7 ppm/K).

(Synthesis example 2) Under nitrogen flow, 743.0 parts by weight of m-TB (3.5 mol parts) and 672.4 parts by weight of TPE-R (2.3 mol parts) were put into the reaction tank, and the solid content concentration after polymerization became 15% by weight. DMAc is dissolved by stirring at room temperature. Then, after adding 353.1 parts by weight of BPDA (1.2 mol parts) and 1233.6 parts by weight of NTCDA (4.6 mol parts), stirring was continued for 3 hours at room temperature to perform polymerization reaction, and a polyamide acid solution 2 was obtained. The solution viscosity of the polyamide acid solution 2 is 41,900 cps.

Then, after the polyamide acid solution 2 was uniformly applied on the stainless steel support base material so that the thickness after curing became about 25 μm, it was heated and dried at 120° C. to remove the solvent. Furthermore, stepwise heat treatment was performed within 30 minutes from 120°C to 360°C to complete the imidization to prepare polyimide film 2 (biphenyltetrayl and biphenylene: 41 mol%, non-thermoplastic, Tg: 391°C, CTE: 19.1 ppm/K).

(Synthesis example 3) Under nitrogen flow, put 1040.2 parts by weight of m-TB (4.9 mole parts) and 350.8 parts by weight of TPE-R (1.2 mole parts) into the reaction tank, and the solid content concentration after polymerization becomes 15% by weight. DMAc is dissolved by stirring at room temperature. Then, 529.6 parts by weight of BPDA (1.8 mol parts), 643.6 parts by weight of NTCDA (2.4 mol parts), and 392.6 parts by weight of PMDA (1.8 mol parts) were added, followed by stirring at room temperature for 3 hours. Polymerization reaction, polyamide acid solution 3 is obtained. The solution viscosity of the polyamide acid solution 3 is 32,500 cps.

Then, after the polyamide acid solution 3 was uniformly coated on the stainless steel support base material so that the thickness after curing became about 25 μm, it was heated and dried at 120° C. to remove the solvent. Furthermore, stepwise heat treatment was performed within 30 minutes from 120°C to 360°C to complete the imidization to prepare polyimide film 3 (biphenyltetrayl and biphenylene: 55 mol%, non-thermoplastic, Tg: 377°C, CTE: 14.8 ppm/K).

(Synthesis example 4) Under a nitrogen flow, 552.0 parts by weight of m-TB (2.6 mol parts) and 760.9 parts by weight of DAPE (3.8 mol parts) and DMAc in an amount such that the solid content concentration after polymerization becomes 15% by weight are put into the reaction tank, Stir at room temperature to dissolve. Then, after adding 1716.3 parts by weight of NTCDA (6.4 parts by mole), stirring was continued for 3 hours at room temperature to proceed the polymerization reaction, and a polyamide acid solution 4 was obtained. The solution viscosity of the polyamide acid solution 4 is 42,300 cps.

Then, after the polyamide acid solution 4 was uniformly coated on the stainless steel support base material so that the thickness after curing became about 25 μm, it was heated and dried at 120° C. to remove the solvent. Furthermore, stepwise heat treatment was performed within 30 minutes from 120°C to 360°C to complete the imidization to prepare polyimide film 4 (biphenylene: 20 mol%, non-thermoplastic, Tg: 400°C or higher , CTE: 32.1 ppm/K).

(Synthesis example 5) Under a nitrogen stream, 898.7 parts by weight of m-EOB (3.3 mol parts) and 660.8 parts by weight of DAPE (3.3 mol parts) and DMAc in an amount such that the solid content concentration after polymerization becomes 15% by weight are put into the reaction tank, Stir at room temperature to dissolve. Then, after adding 1439.6 parts by weight of PMDA (6.6 mol parts), stirring was continued for 3 hours at room temperature to perform a polymerization reaction, and a polyamide acid solution 5 was obtained. The solution viscosity of the polyamide acid solution 5 was 31,700 cps.

Then, after the polyamide acid solution 5 was uniformly coated on the stainless steel support base material so that the thickness after curing became about 25 μm, it was heated and dried at 120° C. to remove the solvent. Furthermore, stepwise heat treatment was performed within 30 minutes from 120°C to 360°C to complete the imidization to prepare polyimide film 5 (biphenylene: 25 mol%, non-thermoplastic, Tg: 376°C, CTE: 33.5 ppm/K).

(Synthesis example 6) Under nitrogen flow, 63.7 parts by weight of m-TB (0.3 parts by mole) and 1490.9 parts by weight of TPE-R (5.1 parts by mole) are put into the reaction tank, and the solid content concentration after polymerization becomes 15% by weight. DMAc is dissolved by stirring at room temperature. Then, after adding 1118.0 parts by weight of BPDA (3.8 mol parts) and 349.0 parts by weight of PMDA (1.6 mol parts), stirring was continued for 3 hours at room temperature to perform polymerization reaction, and a polyamide acid solution 6 was obtained. The solution viscosity of the polyamide acid solution 6 was 6,700 cps, and the weight average molecular weight was 163,400.

Then, after the polyamide acid solution 6 was uniformly coated on a stainless steel support base material so that the thickness after curing became about 25 μm, it was heated and dried at 120° C. to remove the solvent. Furthermore, stepwise heat treatment was performed within 30 minutes from 120°C to 360°C to complete the imidization to prepare polyimide film 6 (biphenyltetrayl and biphenylene: 38 mol%, thermoplastic, Tg : 242℃, 30℃ storage modulus: 4.3×10 ⁹ Pa, 360℃ storage modulus: 1.4×10 ⁷ Pa).

(Synthesis example 7) Under nitrogen flow, 743.0 parts by weight of m-TB (3.5 mol parts) and 672.4 parts by weight of TPE-R (2.3 mol parts) were put into the reaction tank, and the solid content concentration after polymerization became 15% by weight. DMAc is dissolved by stirring at room temperature. Then, after adding 1206.3 parts by weight of BPDA (4.1 mol parts) and 370.8 parts by weight of PMDA (1.7 mol parts), stirring was continued for 3 hours at room temperature to perform a polymerization reaction, and a polyamide acid solution 7 was obtained. The solution viscosity of the polyamide acid solution 7 was 7,200 cps, and the weight average molecular weight was 112,000.

Then, after the polyamide acid solution 7 was uniformly coated on the stainless steel support base material so that the thickness after curing became about 25 μm, it was heated and dried at 120° C. to remove the solvent. Furthermore, stepwise heat treatment was performed within 30 minutes from 120°C to 360°C to complete the imidization to prepare polyimide film 7 (biphenyltetrayl and biphenylene: 66 mol%, thermoplasticity, Tg : 266℃, 30℃ storage modulus: 4.3×10 ⁹ Pa, 360℃ storage modulus: 7.1×10 ⁷ Pa).

(Synthesis example 8) Under nitrogen flow, put 233.5 parts by weight of m-TB (1.1 mol parts) and 1344.7 parts by weight of TPE-R (4.6 mol parts) into the reaction tank, and the solid content concentration after polymerization becomes 15% by weight. DMAc is dissolved by stirring at room temperature. Then, after adding 676.7 parts by weight of BPDA (2.3 mol parts) and 741.6 parts by weight of PMDA (3.4 mol parts), stirring was continued for 3 hours at room temperature to perform a polymerization reaction, and a polyamide acid solution 8 was obtained. The solution viscosity of the polyamide acid solution 8 was 7,400 cps, and the weight average molecular weight was 163,400.

Then, after the polyamide acid solution 8 was uniformly coated on the stainless steel support base material so that the thickness after curing became about 25 μm, it was heated and dried at 120° C. to remove the solvent. Furthermore, stepwise heat treatment was carried out within 30 minutes from 120°C to 360°C to complete the imidization to prepare polyimide film 8 (biphenyltetrayl and biphenylene is 30 mol%, thermoplasticity, Tg : 279℃, 30℃ storage modulus: 4.1×10 ⁹ Pa, 360℃ storage modulus: 7.9×10 ⁷ Pa).

[Example 1-1] A multi-manifold type three-layer co-extrusion multi-layer die is used on an endless belt-shaped stainless steel support substrate, with polyamide acid solution 7/polyamide acid solution 1/polyamide acid solution The sequential three-layer structure of 7 was extrusion coated continuously, and the solvent was removed by heating and drying at 130°C for 3 minutes. Then, heat treatment stepwise from 130°C to 360°C to complete the imidization, and the thickness of the thermoplastic polyimide layer/non-thermoplastic polyimide layer/thermoplastic polyimide layer is 2.5 μm/20, respectively. μm/2.5 μm polyimide film 1a'. The polyimide film 1a' on the supporting substrate was peeled off by the knife edge method to prepare a long polyimide film 1a with a length of 1100 mm in the width direction.

＜Preparation of samples for in-plane delay (RO) evaluation＞ The left and right ends (Left and Right) and the center of the long polyimide film 1a in the TD direction are respectively A4 size (TD: 210 mm × MD: 297 mm) ) Cut off and prepare sample L1 (Left), sample R1 (Right) and sample C1 (Center).

<Evaluation of in-plane retardation (RO)> The in-plane retardation (RO) was measured for each of sample L1, sample R1, and sample C1. The maximum value of the measured value of each sample is regarded as the "in-plane retardation (RO)", and the difference between the maximum and the minimum of the measured values of the in-plane retardation (RO) is regarded as the "in-plane retardation in the width direction (TD direction)" The heterogeneity of (RO) (ΔRO)”. In addition, "The amount of change in the in-plane retardation (RO) before and after pressurization at a temperature of 360°C at a pressure of 340 MPa/m ² and a holding time of 15 minutes" is set as the sample C1 before and after pressurization The difference between the maximum value of the measured values of the in-plane retardation (RO). In addition, the measurement area in each sample is as follows. Sample L1: Left end area in TD direction and central area in MD direction Sample R1: Right end area in TD direction and central area in MD direction Sample C1: Central area in TD direction and MD direction

The evaluation results of the long polyimide film 1a are as follows. CTE: 17 ppm/K In-plane retardation (RO): 11 nm In-plane retardation (RO) non-uniformity (ΔRO) in the width direction (TD direction): 1 nm at a pressure of 340 MPa/ m ² , hold time 15 minutes, the amount of change in the in-plane retardation (RO) before and after pressurization: 3 nm

[Example 1-2] Except that the length in the width direction (TD direction) was 540 mm, a long polyimide film 1b was prepared in the same manner as in Example 1-1.

The evaluation results of the long polyimide film 1b are as follows. CTE: 17 ppm/K In-plane retardation (RO): 11 nm In-plane retardation (RO) non-uniformity (ΔRO) in the width direction (TD direction): 1 nm at a pressure of 340 MPa/ m ² , hold time 15 minutes, the amount of change in the in-plane retardation (RO) before and after pressurization: 3 nm

[Example 1-3] In a long strip of copper foil 1 (rolled copper foil, manufactured by JX Metal Co., Ltd., trade name: GHY5-93F-HA-V2 foil, thickness: 12 μm, tensile modulus after heat treatment: 18 GPa, width direction (Length: 540 mm), uniformly apply polyamide acid solution 7 so that the cured thickness becomes 2.5 μm, and heat and dry at 120°C for 1 minute to remove the solvent. After the polyamide acid solution 1 was uniformly applied thereon so that the thickness after curing became 20 μm, it was heated and dried at 120° C. for 3 minutes to remove the solvent. Furthermore, after the polyamide 7 was uniformly coated thereon so that the thickness after curing became 2.5 μm, it was heated and dried at 120° C. for 1 minute to remove the solvent. Then, heat treatment is performed stepwise from 130°C to 360°C to complete the imidization, and then a single-sided copper-clad laminate 1a is prepared.

The evaluation results of the elongated polyimide film prepared by etching and removing the copper foil of the single-sided copper-clad laminate 1a are as follows. CTE: 17 ppm/K In-plane retardation (RO): 11 nm In-plane retardation (RO) non-uniformity (ΔRO) in the width direction (TD direction): 1 nm

The copper foil 1 is superimposed on the polyimide layer side of the single-sided copper clad laminate 1a, and thermal compression bonding is performed at a temperature of 360° C. and a pressure of 340 MPa/m ² for 15 minutes to prepare a double-sided copper clad laminate 1a . The in-plane retardation (RO) of the long polyimide film prepared by etching and removing the copper foil of the double-sided copper-clad laminate 1a was 8 nm.

The central portion of the prepared double-sided copper-clad laminate 1a was cut to prepare an elongated copper-clad laminate 1a' (end width: 250 mm) as a material for a sample for evaluation of dimensional stability.

＜Preparation of samples for evaluation of dimensional stability＞ The copper-clad laminate 1a' was cut in the MD direction with a length of 250 mm to produce MD: 250 mm×TD: 250 mm. As shown in FIG. 6, a virtual regular quadrilateral is assumed in the range of MD: 200 mm×TD: 200 mm of the cut copper clad laminate. The left and right corner areas (Left and Right) of the imaginary regular quadrilateral that each include two corners sharing one side in the TD direction and the center area (Center) that includes the center of the imaginary regular quadrilateral are in the MD and TD directions, respectively 21 holes were continuously drilled at intervals of 2.5 mm to prepare samples for evaluation. In addition, drills with a diameter of 0.105 mm are used for drilling.

＜Evaluation of dimensional stability＞ Using a non-contact Computer Numerical Control (CNC) image measuring machine (manufactured by Mitutoyo, trade name: Quick Vision QV-X404PIL-C), the evaluation of both sides of the sample All the copper foil layers were etched and the positions of the holes before and after removal were measured. Calculate the dimensional change and the cumulative dimensional change of the distance between two adjacent holes before and after etching based on the measured value.

An elongated copper-clad laminated board 1a' is prepared, and a sample for evaluation 1 and a sample for evaluation 2 are prepared as shown in FIG. 7. The position of each hole before and after the etching of Center, Left, and Right was measured for the sample 1 for evaluation 1 and the sample 2 for evaluation, respectively. From the measured value, the dimensional change of the distance between two adjacent holes before and after the etching and the cumulative dimensional change of the total (20 locations) of these were calculated.

Based on the evaluation results of the copper-clad laminate 1a', the cumulative dimensional change amount and unevenness of MD are shown in Table 1. In addition, in Table 1, the cumulative dimensional change rate of Left, Center, Right and the cumulative dimensional change converted to the assumed FPC size of 10 mm are shown, and the entire range of Left, Center, and Right is also shown. The inhomogeneity. In addition, the "cumulative dimensional change rate" refers to the ratio (%) of the cumulative dimensional change to the total value of the distance between the two holes before etching. In addition, the numerical value of the "range" in the table refers to the central value of the entire range of Left, Center, and Right ± the upper and lower ranges (the same in Table 2 and Table 3).

[Table 1] Copper clad laminate 1a' Left Center Right scope FPC size % mm % mm % mm % 10 mm 6.2 0.00305 5.5 0.00275 7.2 0.00360 6.3±1.6

Based on the results, it was confirmed that the circuit wiring board (L/S=0.025 mm/0.0025 mm) formed by using the copper clad laminate 1a' as a material can evaluate the unevenness of the displacement ratio of the wiring and the dimensional change rate in the surface of the test piece. It was confirmed that the double-sided copper-clad laminate 1a of Example 1-3 had a small unevenness in the displacement ratio of the wiring at each FPC size. In addition, it can be confirmed that in order to achieve high dimensional stability accuracy of the copper clad laminate that cannot be achieved when only controlling the CTE of the polyimide film, it is important to control the in-plane retardation.

[Example 1-4] The long polyimide film 1b prepared in Example 1-2 was superimposed on both sides of the copper foil 1, and thermocompression-bonded 15 under the conditions of ^{a temperature of 360°C and a pressure of 340 MPa/m 2} Minutes, a double-sided copper-clad laminate 1b was prepared, and a long copper-clad laminate 1b' (end width: 250 mm) was prepared in the same manner as in Example 1-3, and the dimensional stability was evaluated. The results are shown in Table 2.

[Table 2] Copper clad laminate 1b' Left Center Right scope FPC size % mm % mm % Mm % 10 mm 6.0 0.00300 5.2 0.00265 7.1 0.00353 6.0±1.8

[Comparative Example 1-1] A long polyimide film 1c (thickness: 25 μm, manufactured by Kaneka, trade name: Pixeo) was prepared. The evaluation results of the long polyimide film 1c are as follows. CTE: 17 ppm/K In-plane retardation (RO): 200 nm In-plane retardation (RO) non-uniformity (ΔRO) in the width direction (TD direction): 80 nm at a temperature of 360°C at a pressure of 340 MPa/ m ² , hold time 15 minutes, the amount of change in the in-plane retardation (RO) before and after pressurization: 30 nm

[Comparative Example 1-2] Copper foil 1 was laminated on both sides of a long polyimide film 1c, and ^{thermocompression bonding was performed at a temperature of 360°C and a pressure of 340 MPa/m 2} for 15 minutes to prepare a double-sided copper-clad laminate For the board 1c, a long copper-clad laminate 1c' (end width: 250 mm) was prepared in the same manner as in Example 1-3, and the dimensional stability was evaluated. The results are shown in Table 3.

[table 3] Copper clad laminate 1c' Left Center Right scope FPC size % mm % mm % mm % 10 mm -0.8 -0.00042 -3.2 -0.00159 -4.2 -0.00212 -5.3±5.1

[Example 2-1] The length in the width direction was prepared in the same manner as in Example 1-1, except that the three-layer structure of the sequence of polyamide acid solution 8/polyamide acid solution 1 and polyamide acid solution 8 was 1100 mm long polyimide film 2. The evaluation results of the long polyimide film 2 are as follows. CTE: 17 ppm/K In-plane retardation (RO): 11 nm In-plane retardation (RO) non-uniformity (ΔRO) in the width direction (TD direction): 1 nm at a pressure of 340 MPa/ m ² , hold time 15 minutes, the amount of change in the in-plane retardation (RO) before and after pressurization: 5 nm

[Example 3-1] Except for the sequential three-layer structure of polyamide acid solution 6/polyamide acid solution 2 and polyamide acid solution 6, the length in the width direction was prepared in the same manner as in Example 1-1. 1100 mm long polyimide film 3. The evaluation results of the long polyimide film 3 are as follows. CTE: 17 ppm/K In-plane retardation (RO): 17 nm In-plane retardation (RO) non-uniformity (ΔRO) in the width direction (TD direction): 3 nm at a pressure of 340 MPa/ m ² , hold time 15 minutes, the amount of change in the in-plane retardation (RO) before and after pressurization: 7 nm

[Example 4-1] Except for the sequential three-layer structure of polyamide acid solution 8/polyamide acid solution 3/polyamide acid solution 8, the length in the width direction was prepared in the same manner as in Example 1-1. 1100 mm long polyimide film4. The evaluation results of the long polyimide film 4 are as follows. CTE: 17 ppm/K In-plane retardation (RO): 15 nm In-plane retardation (RO) non-uniformity (ΔRO) in the width direction (TD direction): 2 nm at a temperature of 360°C at a pressure of 340 MPa/ m ² , hold time 15 minutes, the amount of change in the in-plane retardation (RO) before and after pressurization: 10 nm

As mentioned above, the embodiment of the present invention has been described in detail for the purpose of illustration, but the present invention is not limited to the embodiment described above, and various modifications can be made.

This application claims priority based on Japanese Patent Application No. 2016-89514 filed on April 27, 2016, and all the contents of this application are incorporated herein.

10: Test piece 20: imaginary regular quadrilateral 20a: center 20b: corner 21: central area 23a, 23b: corner area 30: hole 30a: center of hole 30 100: copper clad laminate L0, L1: distance MD, TD: Direction Δ ₁ , Δ ₁ ＋Δ ₂ : Dimensional change

Fig. 1 is a perspective view showing a schematic configuration of a copper-clad laminate and a test piece used in an evaluation method for evaluating the dimensional stability of a copper-clad laminate according to an embodiment of the present invention. Fig. 2 is a diagram for explaining the position of the mark in the test piece. Fig. 3 is a partial enlarged view of the central area of the test piece. Fig. 4 is a partial enlarged view of the corner area of the test piece. Fig. 5 is a diagram for explaining the dimensional change amount of the gap between the holes. Fig. 6 is a diagram for explaining the evaluation sample of the embodiment. Fig. 7 is a diagram for explaining the preparation of an evaluation sample of an embodiment.

Claims (10)

A polyimide film having a long thermoplastic polyimide layer containing a thermoplastic polyimide on at least one side of a non-thermoplastic polyimide layer containing a non-thermoplastic polyimide, and The film width of the polyimide film is in the range of 490 mm or more and 1100 mm or less, and the polyimide film satisfies the following conditions (i) to (iv): (I) The coefficient of thermal expansion is within the range of 10 ppm/K to 30 ppm/K; (Ii) The glass transition temperature of the thermoplastic polyimide is within the range of 200°C or more and 350°C or less; (Iii) The value of the in-plane retardation is within the range of 5 nm or more and 50 nm or less; (Iv) The non-uniformity of the in-plane retardation in the width direction is 10 nm or less. The polyimide film according to claim 1, wherein, in addition to the conditions (i) to (iv), it further satisfies: (v) a pressure of 340 MPa/m ^{2 in} an environment with a temperature of 360°C, The amount of change in the in-plane retardation before and after pressure is 20 nm or less when the holding time is 15 minutes. The polyimide film according to claim 1 or 2, wherein In addition to the conditions of (i) to (iv), further satisfy: (Vi) The non-thermoplastic polyimide contains a tetracarboxylic acid residue and a diamine residue, the tetracarboxylic acid residue and the diamine residue are both aromatic groups, and the aromatic group includes biphenyl tetrakis The biphenyl tetrayl group or biphenylene group is 40 mol parts or more with respect to the total of 100 mol parts of the tetracarboxylic acid residue and the diamine residue. The polyimide film according to claim 1 or 2, wherein In addition to the conditions of (i) to (iv), further satisfy: (Vii) The thermoplastic polyimide contains a tetracarboxylic acid residue and a diamine residue, the tetracarboxylic acid residue and the diamine residue are both aromatic groups, and the aromatic group includes biphenyltetrayl Or biphenylene group, and the biphenyltetrayl group or biphenylene group is 30 mol parts or more and 80 mol parts relative to the total of 100 mol parts of the tetracarboxylic acid residue and diamine residue Within the following range. The polyimide film according to claim 1 or 2, wherein Relative to 100 mole parts of all tetracarboxylic acid residues contained in the non-thermoplastic polyimide, tetracarboxylic acid residues derived from 3,3',4,4'-biphenyltetracarboxylic dianhydride It is in the range of 20 mol parts or more and 70 mol parts or less. The polyimide film according to claim 1 or 2, wherein Relative to 100 mole parts of all tetracarboxylic acid residues contained in the thermoplastic polyimide, the tetracarboxylic acid residue derived from 3,3',4,4'-biphenyltetracarboxylic dianhydride is More than 40 moles. The polyimide film according to claim 1 or claim 2, wherein, with respect to 100 mole parts of all diamine residues contained in the non-thermoplastic polyimide, it is represented by the following general formula (1) The diamine residue represented is more than 20 mol parts,

In the formula, R ₁ and R ₂ independently represent an alkyl group having 1 to 3 carbons or an alkoxy group having 1 to 3 carbons or an alkenyl group having 2 to 3 carbons which may be substituted with a halogen atom or a phenyl group. The polyimide film according to claim 1 or claim 2, wherein, with respect to 100 mole parts of all diamine residues contained in the thermoplastic polyimine, it is represented by the following general formula (2) The diamine residue of is within the range of 3 mol parts or more and 60 mol parts or less,

In the formula, R ₃ and R ₄ independently represent an alkyl group having 1 to 3 carbon atoms or an alkoxy group or alkenyl group having 1 to 3 carbon atoms which may be substituted with a halogen atom or a phenyl group. A copper clad laminated board has an insulating layer and a copper layer located on at least one surface of the insulating layer, and in the copper clad laminated board, The insulating layer has a thermoplastic polyimide layer in contact with the surface of the copper layer, and a non-thermoplastic polyimide layer laminated indirectly, The insulating layer includes the polyimide film according to any one of claims 1 to 8. The copper clad laminate according to claim 9, wherein the dimensional change in the longitudinal direction and the dimensional change in the width direction of the copper layer before and after etching are both 2% or less.

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