JP2019104235A - Metal-clad laminate and circuit board - Google Patents

Abstract

To provide a metal-clad laminate capable of reducing changes in a temperature, humidity and a pressure during processes such as a circuit processing process, a substrate lamination process and a component mounting process, and a dimensional change to a temperature/humidity environmental change between the processes.SOLUTION: A metal-clad laminate includes an insulating resin layer and a metal layer, in which the insulating resin layer has a non-thermoplastic polyimide layer and a thermoplastic polyimide layer, and satisfies (i) a value of in-plane birefringence (Δn) of 2×10or less; (ii) variations [Δ(Δn)] in in-plane birefringence (Δn) in the width direction (TD direction) of 4×10or less; (iii) a difference (Δna-Δnb) between birefringence (Δna) at a point of 1.5 μm in the central part direction with one surface as a base point and birefringence (Δnb) at a point of 1.5 μm in the central part direction with the other surface as a base point, in the thickness direction of the non-thermoplastic polyimide layer of ±0.01 or less; and (iv) a difference between average values (Δnv) of the total (Δna+Δnb+Δnc) of Δna, Δnb and birefringence (Δnc) in the central part in the thickness direction of ±0.01 or less in both of Δna and Δnb.SELECTED DRAWING: None

Description

  The present invention relates to a metal-clad laminate and a circuit board.

  In recent years, with the progress of miniaturization, weight reduction, and space saving of electronic devices, a flexible printed wiring board (FPC; Flexible Printed) that is thin, light, flexible, and has excellent durability even when it is repeatedly bent The demand for Circuits is increasing. The FPC can be mounted three-dimensionally and in a high density even in a limited space, so its application is for wiring of movable parts of electronic devices such as HDDs, DVDs and mobile phones, parts for cables and connectors, etc. It is expanding.

  The FPC is manufactured by etching and wiring a copper layer of a copper clad laminate (CCL). Rolled copper foil is often used as a material of a copper layer for FPCs that are bent continuously or bent 180 ° in mobile phones and smartphones. For example, in patent document 1, the proposal which prescribes | regulates the bending resistance of the copper clad laminated board produced using the rolled copper foil by the number of times of roll-resistance is made | formed. Moreover, in patent document 2, the copper clad laminated board using the rolled copper foil prescribed | regulated by the glossiness and bending frequency is proposed.

  In the process of photolithography for a copper-clad laminate and in the process of mounting an FPC, various processes such as bonding, cutting, exposure, and etching are performed based on alignment marks provided on the copper-clad laminate. The processing accuracy in these steps is important in maintaining the reliability of the electronic device on which the FPC is mounted. However, since the copper-clad laminate has a structure in which copper layers and resin layers having different thermal expansion coefficients are laminated, stress is generated between the layers due to the difference in thermal expansion coefficient between the copper layer and the resin layer. This stress causes expansion or contraction by being released partially or entirely when the copper layer is etched and processed to cause a change in the dimension of the wiring pattern. Therefore, the dimensional change finally occurs at the stage of the FPC, which causes a connection failure between the wirings or between the wirings and the terminals, which lowers the reliability and the yield of the circuit board. Therefore, in a copper clad laminate as a circuit board material, dimensional stability is a very important characteristic. However, in the patent documents 1 and 2 mentioned above, the dimensional stability of the copper clad laminate is not considered at all.

  Moreover, in patent document 3, in order to lower the thermal expansion coefficient of an insulation resin layer and to improve dimensional stability, it does not darely provide a thermoplastic polyimide layer, but in the flexible metal-clad laminated board which consists of copper foil and a non-thermoplastic polyimide layer, A diamine compound comprising p-phenylenediamine (p-PDA) or 2,2'-dimethyl-4,4'-diaminobiphenyl (m-TB) as a diamine component of the non-thermoplastic polyimide layer; It has been proposed to use diamine compounds such as (4-aminophenoxy) benzene (TPE-R). Although p-PDA is a monomer that lowers the thermal expansion coefficient and contributes to dimensional stability, there is a problem that the imide group concentration increases and the hygroscopicity of the polyimide becomes high because the molecular weight is small. When the hygroscopicity of polyimide is increased, there is a problem that dimensional change and warpage are likely to occur due to environmental change such as heating at the time of circuit processing.

  On the other hand, Patent Document 4 discloses that, in a multilayer polyimide film in which generation of cracks during circuit processing is suppressed, m-TB and p-PDA are used in combination as a diamine compound as a raw material of non-thermoplastic polyimide. ing. However, in the monomer composition of Patent Document 4, since the molar ratio of p-PDA in the diamine compound is too large, the hygroscopicity of the polyimide becomes high as described above, and the dimensional change or warpage is caused by the environmental change at the time of circuit processing. Problem is likely to occur. In Patent Document 4, when a combination of m-TB, p-PDA and 2,2-bis [4- (4-aminophenoxy) phenyl] propane (BAPP) is used as a diamine compound, crack resistance is improved. It is described that it gets worse. Also in this case, the molar ratio of p-PDA in the diamine compound is too large, so it is considered that there is a problem that the hygroscopicity of the polyimide becomes high as described above.

JP, 2014-15674, A (claim, etc.) Unexamined-Japanese-Patent No. 2014-11451 (Claim etc.) Patent No. 5162379 (claims etc.) WO 2016/159104 (Synthesis Example 6, Synthesis Example 9 and the like)

  The present invention is a metal-clad laminate capable of reducing changes in temperature, humidity and pressure during processes such as circuit processing, substrate lamination and component mounting, and dimensional changes due to changes in temperature and humidity between processes. Intended to be provided.

  As a result of intensive investigations, the present inventors have found that the above problems can be solved by controlling the in-plane birefringence (Δn) of the insulating resin layer and the birefringence in the thickness direction, and the present invention has been completed. It came to

That is, the metal-clad laminate of the present invention is a metal-clad laminate including an insulating resin layer and a metal layer laminated on at least one surface of the insulating resin layer, and the insulating resin layer is non-thermoplastic A thermoplastic polyimide layer containing thermoplastic polyimide is provided on at least one surface of the non-thermoplastic polyimide layer containing polyimide. And the metal-clad laminate of the present invention is characterized in that the insulating resin layer satisfies the following conditions (i) to (iv).
(i) The value of in-plane birefringence (Δn) is 2 × 10 ⁻³ or less.
(ii) The variation [Δ (Δn)] of in-plane birefringence index (Δn) in the width direction (TD direction) is 4 × 10 ⁻⁴ or less.
(iii) In the thickness direction of the non-thermoplastic polyimide layer, the birefringence (Δna) at a point of 1.5 μm in the central portion direction starting from one surface and the central portion direction starting from the other surface In addition, the difference (Δna−Δnb) with the birefringence (Δnb) at a point of 1.5 μm is ± 0.01 or less.
(iv) The difference between the Δna and the Δnb and the average value (Δnv) of the sum (Δna + Δnb + Δnc) of the total birefringence (Δnc) at the central portion in the thickness direction is ± 0.01 in any of the Δna and Δnb Be less than or equal to

  In the metal-clad laminate of the present invention, the non-thermoplastic polyimide contains a tetracarboxylic acid residue and a diamine residue, and is represented by the following general formula (1) with respect to 100 mole parts of all diamine residues. The diamine residue derived from the compound may be 20 mole parts or more.

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

  In the metal-clad laminate of the present invention, the diamine residue derived from the diamine compound represented by the general formula (1) is 70 per 100 mol parts of all diamine residues contained in the non-thermoplastic polyimide. The total amount of diamine residues selected from the following general formulas (2) and (3) may be in the range of 5 to 30 parts by mole.

In the general formula (2) and the general formula (3), R ₅ , R ₆ , R ₇ and R ₈ are each independently a halogen atom, or an alkyl group or alkoxy which may be substituted with a halogen having 1 to 4 carbon atoms group, or an alkenyl group, X is independently -O -, - S -, - CH 2 -, - CH (CH 3) -, - C (CH 3) 2 -, - CO -, - COO-, It represents a divalent group selected from -SO _2- , -NH- or -NHCO-, and X ₁ and X ₂ each independently represent a single bond, -O-, -S-, -CH _2- , -CH ( CH ₃ )-, -C (CH ₃ ) _2- , -CO-, -COO-, -SO _2- , -NH- or -NHCO-, which is a divalent group selected from X ₁ and X ₂ Except that both are single bonds, and m, n, o and p independently represent an integer of 0 to 4.

  In the metal-clad laminate of the present invention, the thermoplastic polyimide contains a tetracarboxylic acid residue and a diamine residue, and the above general formulas (2) and (3) correspond to 100 mole parts of all diamine residues. The total amount of diamine residues selected may be 50 mole parts or more.

In the metal-clad laminate of the present invention, the diamine residue represented by the general formula (2) may be a diamine residue derived from 1,3-bis (4-aminophenoxy) benzene,
The diamine residue represented by the general formula (3) may be a diamine residue derived from 2,2-bis [4- (4-aminophenoxy) phenyl] propane.

  In the metal-clad laminate of the present invention, the thickness ratio (A) / (B) of the thickness (A) of the non-thermoplastic polyimide layer to the thickness (B) of the thermoplastic polyimide layer is in the range of 1 to 20. May be

  In the metal-clad laminate of the present invention, the length in the width direction (TD direction) may be 490 mm or more.

  The circuit board of the present invention is obtained by processing the metal layer of the metal-clad laminate described in any of the above into a wiring.

  By satisfying the conditions (i) to (iv), the metal-clad laminate of the present invention is excellent in the dimensional stability of the insulating resin layer even under high-temperature and high-pressure environments or in an environment of humidity change, Problems such as warpage are less likely to occur due to environmental changes (e.g., high temperature, high pressure, humidity change, etc.) in the circuit processing process, the substrate lamination process, and the component mounting process. In particular, even in a wide metal-clad laminate, the dimensional change rate is low over the entire width of the insulating resin layer, and the dimensions are stable, so that the FPC obtained from the metal-clad laminate is capable of high density mounting. be able to. Therefore, by using the metal-clad laminate of the present invention as an FPC material, it is possible to improve the reliability and yield of the circuit board.

  Next, an embodiment of the present invention will be described.

<Metal-clad laminates>
The metal-clad laminate of this embodiment includes an insulating resin layer and a metal layer laminated on at least one surface of the insulating resin layer.

<Insulating resin layer>
In the metal-clad laminate of this embodiment, the insulating resin layer has a thermoplastic polyimide layer on at least one of the non-thermoplastic polyimide layers. That is, the thermoplastic polyimide layer is provided on one side or both sides of the non-thermoplastic polyimide layer. For example, in the metal-clad laminate of this embodiment, the metal layer is laminated on the surface of the thermoplastic polyimide layer.
Here, non-thermoplastic polyimide generally refers to polyimide which does not show softening or adhesion even when heated, but in the present invention, it is measured at 30 ° C. using a dynamic viscoelasticity measuring device (DMA). The storage elastic modulus in the above is 1.0 × 10 ⁹ Pa or more, and the storage elastic modulus at 360 ° C. is 1.0 × 10 ⁸ Pa or more. Also, a thermoplastic polyimide is generally a polyimide whose glass transition temperature (Tg) can be clearly confirmed, but in the present invention, the storage elastic modulus at 30 ° C. measured using DMA is 1.0 × 10. ^{It is 9} Pa or more, and the storage elastic modulus at 360 ° C. is less than 1.0 × 10 ⁸ Pa.

In the metal-clad laminate of the present embodiment, the insulating resin layer satisfies the following conditions (i) to (iv).
(i) The value of in-plane birefringence (Δn) is 2 × 10 ⁻³ or less.
(ii) The variation [Δ (Δn)] of in-plane birefringence index (Δn) in the width direction (TD direction) is 4 × 10 ⁻⁴ or less.
(iii) In the thickness direction of the non-thermoplastic polyimide layer, the birefringence (Δna) at a point of 1.5 μm in the central portion direction starting from one surface and the central portion direction starting from the other surface In addition, the difference (Δna−Δnb) with the birefringence (Δnb) at a point of 1.5 μm is ± 0.01 or less.
(iv) The difference between the Δna and the Δnb and the average value (Δnv) of the sum (Δna + Δnb + Δnc) of the total birefringence (Δnc) at the central portion in the thickness direction is ± 0.01 in any of the Δna and Δnb Be less than or equal to

  By satisfying the above conditions (i) to (iv), the orientation of the polyimide constituting the insulating resin layer is enhanced, the dimensional stability is improved, and the occurrence of warpage is suppressed.

When the value of the in-plane birefringence (Δn) exceeds 2 × 10 ⁻³ , the anisotropy of the in-plane orientation becomes large, which causes the deterioration of the dimensional stability. The lower limit of the value of Δn is not particularly limited, but while the in-plane orientation is isotropic and the dimensional stability is improved, the thermal expansion coefficient is excessively reduced, and the warpage due to the mismatch with the thermal expansion coefficient of the metal foil is It is preferable to set it as 2 * 10 < ^-4 > or more from a viewpoint of suppression. From the above viewpoints, the value of the in-plane birefringence (Δn) of the insulating resin layer is preferably in the range of 2 × 10 ⁻⁴ or more and 8 × 10 ⁴ or less, more preferably 2 × 10 ⁴ or more and 6 × It is in the range of 10 ^-4 or less.

Further, if the variation [Δ (Δn)] of Δn in the TD direction exceeds 4 × 10 ⁻⁴ , the variation in in-plane orientation becomes large, which causes the in-plane variation in dimensional change rate. The variation [Δ (Δn)] of Δn in the TD direction is preferably 2 × 10 ⁻⁴ or less, more preferably 1.2 × 10 ⁻⁴ or less. Within such a range, high dimensional accuracy can be maintained, for example, even when scaled up.

  Further, the difference (Δna−Δnb) in birefringence in the thickness direction of the non-thermoplastic polyimide layer is ± 0.01 or less, and the difference (Δnv−Δna) between the Δna and Δnb and the average value (Δnv) ) And the difference (Δnv−Δnb) are both ± 0.01 or less, the homogeneity of the polyimide orientation in the thickness direction is enhanced, and the occurrence of warpage can be suppressed. The difference (Δnv−Δna) and the difference (Δnv−Δnb) are preferably ± 0.008 or less, and more preferably ± 0.006 or less.

  By satisfying the above conditions (i) to (iv), dimensional changes and warpage due to environmental changes (for example, high temperature and high pressure environments, humidity changes, etc.) in the circuit processing process, substrate lamination process and component mounting process are effectively achieved. Can be suppressed. If any one of the above conditions (i) to (iv) is not included, the amount of dimensional change becomes large due to high temperature, high pressure, humidity change, etc. at the time of circuit processing, board lamination process and component mounting process. Dimensional accuracy and warpage.

  For example, when the metal-clad laminate of this embodiment is applied as a circuit board material, the thermal expansion coefficient (CTE) of the insulating resin layer is 10 ppm / K in order to prevent the occurrence of warpage and the decrease in dimensional stability. It is important to be in the range of not less than 30 ppm / K, and preferably in the range of not less than 10 ppm / K and not more than 25 ppm / K. If the CTE is less than 10 ppm / K or more than 30 ppm / K, warpage may occur or dimensional stability may be reduced. In the metal-clad laminate of this embodiment, the CTE of the insulating resin layer is more preferably ± 5 ppm / K or less, more preferably ± 2 ppm / K or less with respect to the CTE of the metal layer made of copper foil or the like. The range is most preferable.

  In the insulating resin layer, 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 low thermal expansion polyimide layer preferably has a coefficient of thermal expansion (CTE) within the range of 1 ppm / K to 25 ppm / K, more preferably 3 ppm / K to 25 ppm / K. Say. The high thermal expansion polyimide layer preferably has a CTE of 35 ppm / K or more, more preferably 35 ppm / K or more and 80 ppm / K or less, and still more preferably 35 ppm / K or more and 70 ppm / K or less I say a layer. A polyimide layer can be made into a polyimide layer which has desired CTE by changing suitably the combination of the raw material to be used, thickness, and a drying and hardening conditions.

  The thickness of the insulating resin layer can be set to a thickness within a predetermined range depending on the purpose of use, but it is preferably in the range of 4 to 50 μm, for example, and in the range of 11 to 26 μm Is more preferred. If the thickness of the insulating resin layer is less than the above lower limit value, problems such as the inability to ensure electrical insulation and the difficulty in handling in the manufacturing process due to a decrease in handling may occur. On the other hand, when the thickness of the insulating resin layer exceeds the above upper limit, it is necessary to control the manufacturing conditions with high precision in order to control the in-plane birefringence (Δn) and the birefringence in the thickness direction (Δn). Yes, problems such as productivity decline occur.

  In the insulating resin layer, the thickness ratio ((A) / (B)) between the thickness (A) of the non-thermoplastic polyimide layer and the thickness (B) of the thermoplastic polyimide layer is in the range of 1 to 20. Is preferable, and the range of 2 to 12 is more preferable. In addition, when the number of layers of a non-thermoplastic polyimide layer and / or a thermoplastic polyimide layer is multiple, thickness (A) and thickness (B) mean the total thickness. If the value of this ratio is less than 1, the non-thermoplastic polyimide layer with respect to the whole insulating resin layer becomes thin, so the variation in in-plane birefringence (Δn) tends to be large, and when it exceeds 20, the thermoplastic polyimide layer Since it becomes thin, the adhesion reliability between the insulating resin layer and the metal layer tends to be lowered. Here, the control of the in-plane birefringence (Δn) is correlated with the resin configuration of each polyimide layer constituting the insulating resin layer and the thickness thereof. The thermoplastic polyimide layer, which is a resin composition having adhesiveness, that is, high thermal expansion or softening, has a greater effect on the value of Δn of the insulating resin layer as its thickness becomes larger. Therefore, it is preferable to increase the thickness ratio of the non-thermoplastic polyimide layer and decrease the thickness ratio of the thermoplastic polyimide layer to reduce the value of Δn of the insulating resin layer and the variation thereof. As described later, in this embodiment, even when the ratio of the thickness of the thermoplastic polyimide layer is reduced, the thermoplastic polyimide layer contains a predetermined amount of diamine residue selected from the general formulas (2) and (3). By designing in this way, the adhesion between the metal layer and the insulating resin layer can be secured.

  The metal-clad laminate of this embodiment preferably has a length (film width) in the width direction (TD direction) in the range of 490 mm or more and 1200 mm or less from the viewpoint of achieving a greater improvement in the dimensional accuracy of the insulating resin layer. The inside length is preferably in the range of 520 mm to 1100 mm, and the long length is preferably 20 m or more. When the metal-clad laminate of the present embodiment is manufactured continuously, the wider the width direction (TD direction), the more remarkable the effects of the invention become. In addition, after the metal-clad laminate according to the present embodiment is continuously manufactured, the metal-clad laminate slit at a certain value in the longitudinal direction (MD direction) and the TD direction of the long metal-clad laminate. Also included.

  Moreover, it is preferable that the tensile elasticity modulus when it is set as a polyimide film exists in the range of 3.0-10.0 GPa, and, as for an insulating resin layer, it is more preferable to exist in the range of 4.5-8.0 GPa. When the tensile modulus of elasticity when it is formed into a polyimide film is less than 3.0 GPa, the strength of the polyimide itself is reduced, which causes problems in handling such as tearing of the insulating resin layer when processing a metal-clad laminate into a circuit board May occur. On the other hand, when the tensile modulus of elasticity when made into a polyimide film exceeds 10.0 GPa, the rigidity against bending of the metal-clad laminate increases, so that the bending stress applied to the metal wiring when bending the metal-clad laminate increases. And bending resistance is reduced. The strength and flexibility of the insulating resin layer can be secured by setting the tensile modulus of elasticity when forming a polyimide film within the above range.

(Non-thermoplastic polyimide)
In the present embodiment, the non-thermoplastic polyimide constituting the non-thermoplastic polyimide layer preferably contains a tetracarboxylic acid residue and a diamine residue, both of which preferably include an aromatic group. Both the tetracarboxylic acid residue and the diamine residue contained in the non-thermoplastic polyimide contain an aromatic group, which facilitates formation of an ordered structure of the non-thermoplastic polyimide, and the insulating resin layer in a high temperature environment The variation of the in-plane birefringence (Δn) can be reduced by reducing the amount of change in the in-plane birefringence (Δn), and the birefringence change in the thickness direction can be suppressed.

In the present invention, the term "tetracarboxylic acid residue" refers to a tetravalent group derived from tetracarboxylic acid dianhydride, and the diamine residue refers to a divalent group derived from a diamine compound. Represents that. Also, the “diamine compound” may have hydrogen atoms in the two terminal amino groups substituted, and for example, —NR ₃ R ₄ (wherein R ₃ and R ₄ independently represent an alkyl group etc.) (Means a substituent).

  The tetracarboxylic acid residue contained in the non-thermoplastic polyimide is not particularly limited, but is also referred to as, for example, a tetracarboxylic acid residue derived from pyromellitic dianhydride (PMDA) (hereinafter referred to as PMDA residue). And tetracarboxylic acid residues (hereinafter also referred to as BPDA residues) derived from 3,3 ′, 4,4′-biphenyltetracarboxylic acid dianhydride (BPDA). These tetracarboxylic acid residues tend to form an ordered structure, and reduce the amount of change in the in-plane birefringence (Δn) in a high temperature environment and suppress the change in the birefringence in the thickness direction. it can. In addition, PMDA residues are residues responsible for controlling the thermal expansion coefficient and controlling the glass transition temperature. Furthermore, since BPDA residues have no polar group among tetracarboxylic acid residues and have a relatively large molecular weight, the effect of suppressing the moisture absorption of the insulating resin layer can also be expected by lowering the imide group concentration of the non-thermoplastic polyimide. From such a viewpoint, the total amount of PMDA residues and / or BPDA residues is preferably 50 mol parts or more, more preferably to 100 mol parts of all tetracarboxylic acid residues contained in the non-thermoplastic polyimide. Is preferably in the range of 50 to 100 parts by mole, and most preferably in the range of 70 to 100 parts by mole.

  As another tetracarboxylic acid residue contained in the non-thermoplastic polyimide, for example, 2,3 ', 3,4'-biphenyltetracarboxylic acid dianhydride, 2,2', 3,3'-biphenyltetracarboxylic acid Acid dianhydride, 3,3 ', 4,4'-diphenyl sulfone tetracarboxylic acid dianhydride, 4,4'-oxydiphthalic anhydride, 2,2', 3,3'-, 2,3, 3 ', 4'- or 3,3', 4,4'-benzophenonetetracarboxylic acid dianhydride, 2,3 ', 3,4'-diphenylethertetracarboxylic acid dianhydride, bis (2,3-dicarboxy) Phenyl) ether dianhydride, 3,3 ′ ′, 4,4 ′ ′-, 2,3,3 ′ ′, 4 ′ ′-or 2,2 ′ ′, 3,3 ′ ′-p-terphenyltetra Carboxylic acid dianhydride, 2,2-bis (2,3- or 3,4-dicarboxyphenyl) -propane dianhydride, bis (2,3- or 3.4-dicarboxyphenyl) methane dianhydride , Bis (2,3- or 1, 4-dicarboxyphenyl) sulfone dianhydride, 1, 1-bis (2, 3- or 3, 4- dicarboxyphenyl) ethane dianhydride, 1, 2, 7, 8-, 1, 2, 6 7,7- or 1,2,9,10-phenanthrene-tetracarboxylic acid dianhydride, 2,3,6,7-anthracene tetracarboxylic acid dianhydride, 2,2-bis (3,4-dicarboxyphenyl) ) Tetrafluoropropane dianhydride, 2,3,5,6-cyclohexane dianhydride, 1,2,5,6-naphthalene tetracarboxylic acid dianhydride, 1,4,5,8 naphthalene tetracarboxylic acid Anhydride, 2,3,6,7-naphthalenetetracarboxylic acid dianhydride, 4,8-dimethyl-1,2,3,5,6,7-hexahydronaphthalene-1,2,5,6-tetra Carboxylic acid dianhydride, 2,6- or 2,7-dichloronaphthalene-1,4,5,8-tetracarboxylic acid dianhydride, 2,3,6,7- (or 1,4,5,8 - ) Tetrachloronaphthalene-1,4,5,8- (or 2,3,6,7-) tetracarboxylic acid dianhydride, 2,3,8,9-, 3,4,9,10-, 4 , 5, 10, 11-or 5,6, 11, 12-perylene-tetracarboxylic dianhydride, cyclopentane-1,2,3,4-tetracarboxylic dianhydride, pyrazine-2,3,5 , 6-tetracarboxylic acid dianhydride, pyrrolidine-2,3,4,5-tetracarboxylic acid dianhydride, thiophene-2,3,4,5-tetracarboxylic acid dianhydride, 4,4'-bis Examples include tetracarboxylic acid residues derived from aromatic tetracarboxylic acid dianhydrides such as (2,3-dicarboxyphenoxy) diphenylmethane dianhydride.

  As a diamine residue contained in a non-thermoplastic polyimide, the diamine residue derived | led-out from the diamine compound represented by General formula (1) is mentioned preferably.

  In the general formula (1), the linking group Z represents a single bond or -COO-, and Y is a monovalent hydrocarbon of 1 to 3 carbons which may be independently substituted with a halogen or a phenyl group or 1 to 1 carbon 3 represents an alkoxy group, or a perfluoroalkyl group having 1 to 3 carbon atoms, or an alkenyl group, n represents an integer of 0 to 2, and p and q each independently represent an integer of 0 to 4; Here, “independently” means that in the above formula (1), the plurality of substituents Y and the integers p and q may be the same or different.

  The diamine residue derived from the diamine compound represented by the general formula (1) (hereinafter sometimes referred to as “diamine residue (1)”) is likely to form an ordered structure, and improves dimensional stability, In particular, the change in birefringence in the thickness direction can be effectively suppressed together with the amount of change in in-plane birefringence (Δn) under a high temperature environment. From such a viewpoint, the diamine residue (1) is at least 20 mol parts, preferably 70 to 95 mol parts, per 100 mol parts of all diamine residues contained in the non-thermoplastic polyimide, Preferably, the content is in the range of 80 to 90 mol parts.

  Preferred specific examples of the diamine residue (1) include p-phenylenediamine (p-PDA), 2,2'-dimethyl-4,4'-diaminobiphenyl (m-TB), 2,2'-diethyl- 4,4'-Diaminobiphenyl (m-EB), 2,2'-diethoxy-4,4'-diaminobiphenyl (m-EOB), 2,2'-dipropoxy-4,4'-diaminobiphenyl (m- POB), 2,2'-n-propyl-4,4'-diaminobiphenyl (m-NPB), 2,2'-divinyl-4,4'-diaminobiphenyl (VAB), 4,4'-diaminobiphenyl And diamine residues derived from diamine compounds such as 4,4′-diamino-2,2′-bis (trifluoromethyl) biphenyl (TFMB). Among these, 2,2'-dimethyl-4,4'-diaminobiphenyl (m-TB) is particularly easy to form an ordered structure, and the amount of change in in-plane birefringence (Δn) in a high temperature environment is While making it small, since the birefringence change in the thickness direction can be suppressed, it is particularly preferable.

  Further, in order to lower the elastic modulus of the insulating resin layer and improve the elongation and bending resistance, etc., the non-thermoplastic polyimide can be prepared from the group consisting of diamine residues represented by the following general formulas (2) and (3) It is preferred to include at least one type of diamine residue selected.

In the above formulas (2) and (3), R ₅ , R ₆ , R ₇ and R ₈ each independently represent a halogen atom, or an alkyl group or alkoxy having 1 to 4 carbon atoms, which may be substituted by a halogen atom group, or an alkenyl group, X is independently -O -, - S -, - CH 2 -, - CH (CH 3) -, - C (CH 3) 2 -, - CO -, - COO-, It represents a divalent group selected from -SO _2- , -NH- or -NHCO-, and X ₁ and X ₂ each independently represent a single bond, -O-, -S-, -CH _2- , -CH ( CH ₃ )-, -C (CH ₃ ) _2- , -CO-, -COO-, -SO _2- , -NH- or -NHCO-, which is a divalent group selected from X ₁ and X ₂ Except that both are single bonds, and m, n, o and p independently represent an integer of 0 to 4.
Note that “independently” refers to a plurality of linking groups X, linking groups X ₁ and X ₂ , and a plurality of substituents R ₅ in one or both of the above formulas (2) and (3). R ₆ , R ₇ and R ₈ and the integers m, n, o and p mean that they may be the same or different.

Since the diamine residue represented by General formula (2) and (3) has a site | part of a flexibility, it can provide a softness | flexibility to an insulation resin layer. Here, since the diamine residue represented by the general formula (3) has four benzene rings, the terminal group bonded to the benzene ring has a para position in order to suppress an increase in the thermal expansion coefficient (CTE). It is preferable to Further, from the viewpoint of suppressing the increase of the thermal expansion coefficient (CTE) while providing flexibility to the insulating resin layer, the diamine residue represented by the general formulas (2) and (3) is included in the non-thermoplastic polyimide Preferably, it is contained in the range of 5 to 30 mol parts, more preferably in the range of 10 to 20 mol parts, with respect to 100 mol parts of all diamine residues to be produced. If the diamine residue represented by the general formulas (2) and (3) is less than 5 parts by mole, the elastic modulus of the insulating resin layer is increased to decrease the elongation, and the bending resistance or the like may be reduced. If the amount is more than 30 parts by mole, the orientation of the molecule may be reduced, which may make it difficult to reduce CTE.

The diamine residue represented by the general formula (2) is preferably one in which one or more of m, n and o is 0, and preferred examples of the groups R ₅ , R ₆ and R ₇ include carbon atoms The alkyl group which may be substituted by the halogen atom of 1-4, or a C1-C3 alkoxy group, or a C2-C3 alkenyl group can be mentioned. In the general formula (2), preferred examples of the linking group X include -O-, -S-, -CH _2- , -CH (CH ₃ )-, -SO ₂ -or -CO-. Can. Preferred specific examples of the diamine residue represented by the general formula (2) include 1,3-bis (4-aminophenoxy) benzene (TPE-R) and 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 Examples include diamine residues derived from diamine compounds such as-(4-aminophenyl) -2-propyl] benzene and 1,4-bis [2- (4-aminophenyl) -2-propyl] benzene.

The diamine residue represented by the general formula (3) is preferably one in which one or more of m, n, o and p is 0, and preferred examples of the groups R ₅ , R ₆ , R ₇ and R ₈ As an example, the alkyl group which may be substituted by a C1-C4 halogen atom, or a C1-C3 alkoxy group, or a C2-C3 alkenyl group can be mentioned. In the general formula (3), preferred examples of the linking groups X ₁ and X ₂ include a single bond, -O-, -S-, -CH _2- , -CH (CH ₃ )-and -SO _2- Or -CO- can be mentioned. However, from the viewpoint of providing a bending site, the case where both of the linking groups X ₁ and X ₂ are single bonds is excluded. Preferred specific examples of the diamine residue represented by the general formula (3) include 4,4′-bis (4-aminophenoxy) biphenyl (BAPB), 2,2′-bis [4- (4-aminophenoxy) ) Derived from diamine compounds such as phenyl] propane (BAPP), 2,2'-bis [4- (4-aminophenoxy) phenyl] ether (BAPE), bis [4- (4-aminophenoxy) phenyl] sulfone and the like And diamine residues.

  Among diamine residues represented by the general formula (2), a diamine residue (“TPE-R residue”) derived from 1,3-bis (4-aminophenoxy) benzene (TPE-R) Particularly preferred among the diamine residues represented by the general formula (3) is a diamine residue derived from 2,2'-bis [4- (4-aminophenoxy) phenyl] propane (BAPP) (Sometimes referred to as "BAPP residues") are particularly preferred. Since the TPE-R residue and the BAPP residue have a flexible site, the elastic modulus of the insulating resin layer can be reduced to impart flexibility. Further, since the BAPP residue has a large molecular weight, the effect of suppressing the moisture absorption of the insulating resin layer can also be expected by lowering the imide group concentration of the non-thermoplastic polyimide.

  Examples of other diamine residues contained in non-thermoplastic polyimides include m-phenylenediamine (m-PDA), 4,4'-diaminodiphenyl ether (4,4'-DAPE), 3,3'-diaminodiphenyl ether 3,4'-Diaminodiphenyl ether, 4,4'-diaminodiphenylmethane, 3,3'-diaminodiphenylmethane, 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 sulfone, 3,3 ' -Diaminodiphenyl sulfone, 4,4'-diaminobenzophenone, 3,4'-diaminobenzo Henone, 3,3'-diaminobenzophenone, 2,2-bis- [4- (3-aminophenoxy) phenyl] propane, bis [4- (3-aminophenoxy) phenyl] sulfone, bis [4- (3- (3-aminophenoxy) phenyl] sulfone Aminophenoxy) biphenyl, bis [1- (3-aminophenoxy)] biphenyl, bis [4- (3-aminophenoxy) phenyl] methane, bis [4- (3-aminophenoxy) phenyl] ether, bis [4- (3-aminophenoxy) benzophenone, 9,9-bis [4- (3-aminophenoxy) phenyl] fluorene, 2,2-bis- [4- (4-aminophenoxy) phenyl] hexafluoropropane, 2, 2-Bis- [4- (3-aminophenoxy) phenyl] hexafluoropropane, 3,3'-dimethyl-4,4'-diaminobiphenyl, 4,4'-methylenedi-o-toluidine, 4,4'- Methylenedi-2,6-xylidine, 4,4'-methylene -2,6-diethylaniline, 3,3'-diaminodiphenylethane, 3,3'-diaminobiphenyl, 3,3'-dimethoxybenzidine, 3,3 ''-diamino-p-terphenyl, 4,4 ' -[1,4-phenylenebis (1-methylethylidene)] bisaniline, 4,4 '-[1,3-phenylenebis (1-methylethylidene)] bisaniline, bis (p-aminocyclohexyl) methane, bis (p -β-amino-t-butylphenyl) ether, bis (p-β-methyl-δ-aminopentyl) benzene, p-bis (2-methyl-4-aminopentyl) benzene, p-bis (1,1-) Dimethyl-5-aminopentyl) benzene, 1,5-diaminonaphthalene, 2,6-diaminonaphthalene, 2,4-bis (β-amino-t-butyl) toluene, 2,4-diaminotoluene, m-xylene 2,5-diamine, p-xylene-2,5-diamine, m-xylylenediamine, p-xylylenediamine, 2,6-diaminopyridine, 2,5-dia Nopirijin, 2,5-diamino-1,3,4-oxadiazole, and a diamine residue derived from an aromatic diamine compound of piperazine.

  Thermal expansion by selecting the types of the above-mentioned tetracarboxylic acid residue and diamine residue, and the molar ratios of two or more tetracarboxylic acid residues or diamine residues in the non-thermoplastic polyimide Modulus, storage modulus, tensile modulus, etc. can be controlled. Moreover, in the non-thermoplastic polyimide, in the case of having a plurality of structural units of polyimide, they may be present as a block or may be present randomly, but from the viewpoint of suppressing the variation in in-plane birefringence (Δn) Preferably, they exist randomly.

The imide group concentration of the non-thermoplastic polyimide is preferably 35% by weight or less. Here, "imide group concentration" means the value which remove | divided the molecular weight of the imide base (-(CO) ₂ -N-) in a polyimide by the molecular weight of the whole structure of a polyimide. When the imide group concentration exceeds 35% by weight, the molecular weight of the resin itself decreases, and the low hygroscopicity also deteriorates due to the increase of the polar group. By controlling the orientation of the molecules in the non-thermoplastic polyimide by selecting the combination of the above acid anhydride and diamine compound, the increase in CTE accompanying the decrease in imide group concentration is suppressed, and low moisture absorption is ensured. ing.

  The weight average molecular weight of the non-thermoplastic polyimide is, for example, preferably in the range of 10,000 to 400,000, and more preferably in the range of 50,000 to 350,000. If the weight-average molecular weight is less than 10,000, the strength of the insulating resin layer tends to be reduced and the resin tends to be brittle. On the other hand, when the weight average molecular weight exceeds 400,000, the viscosity is excessively increased, and defects such as thickness unevenness and streaks tend to easily occur during the coating operation.

(Thermoplastic polyimide)
In the present embodiment, it is preferable that the thermoplastic polyimide constituting the thermoplastic polyimide layer contains a tetracarboxylic acid residue and a diamine residue, both of which contain an aromatic group. The tetracarboxylic acid residue and the diamine residue contained in the thermoplastic polyimide both contain an aromatic group, thereby suppressing the amount of change in the in-plane birefringence (Δn) of the insulating resin layer in a high temperature environment In addition, it is possible to suppress the change in birefringence in the thickness direction.

  The tetracarboxylic acid residue contained in the thermoplastic polyimide is not particularly limited, but is, for example, a tetracarboxylic acid residue derived from pyromellitic dianhydride (PMDA) (hereinafter, also referred to as PMDA residue). Preferred are tetracarboxylic acid residues derived from 3,3 ′, 4,4′-biphenyltetracarboxylic acid dianhydride (BPDA) (hereinafter also referred to as BPDA residues). These tetracarboxylic acid residues tend to form an ordered structure, and reduce the amount of change in the in-plane birefringence (Δn) in a high temperature environment and suppress the change in the birefringence in the thickness direction. it can. In addition, PMDA residues are residues responsible for controlling the thermal expansion coefficient and controlling the glass transition temperature. Furthermore, since the BPDA residue has no polar group among tetracarboxylic acid residues and has a relatively large molecular weight, the imide group concentration of the thermoplastic polyimide can be lowered to suppress the moisture absorption of the insulating resin layer. From such a viewpoint, the total amount of PMDA residues and / or BPDA residues is preferably 50 mol parts or more, more preferably 100 mol parts or more with respect to 100 mol parts of all tetracarboxylic acid residues contained in the thermoplastic polyimide. It may be in the range of 50 to 100 parts by mole, most preferably in the range of 70 to 100 parts by mole.

  Other tetracarboxylic acid residues contained in the thermoplastic polyimide include tetracarboxylic acid residues derived from aromatic tetracarboxylic acid dianhydride similar to those exemplified for the non-thermoplastic polyimide.

  In the present embodiment, as the diamine residue contained in the thermoplastic polyimide, at least one diamine residue selected from the above general formulas (2) and (3) is preferable. The diamine residue selected from the general formulas (2) and (3) is preferably 50 mol parts or more in total with respect to 100 mol parts of all diamine residues, and is 50 to 100 mol parts. More preferably, it is most preferably in the range of 70 to 100 parts by mole. By containing a diamine residue selected from the general formulas (2) and (3) in a total amount of 50 mol parts or more in total with respect to 100 mol parts of all diamine residues, flexibility and adhesiveness are obtained in the thermoplastic polyimide layer. Can be applied and function as an adhesive layer to the metal layer. Moreover, among the diamine residues represented by General Formula (2), a TPE-R residue is particularly preferable, and among the diamine residues represented by General Formula (3), a BAPP residue is particularly preferable. Since the TPE-R residue and the BAPP residue have a flexible site, the elastic modulus of the insulating resin layer can be reduced to impart flexibility. Further, since the BAPP residue has a large molecular weight, the effect of suppressing the moisture absorption of the insulating resin layer can also be expected by lowering the imide group concentration of the thermoplastic polyimide.

  Further, as described above, when the non-thermoplastic polyimide constituting the non-thermoplastic polyimide layer contains a diamine residue selected from the general formulas (2) and (3), the thermoplastic polyimide layer is constituted. The thermoplastic polyimide may also contain, as a diamine residue, a similar structure, preferably a diamine residue of the same type selected from general formulas (2) and (3). In this case, the thermoplastic polyimide and the non-thermoplastic polyimide differ in the content ratio of diamine residues, but when containing similar or identical diamine residues, particularly when forming a polyimide film by a casting method The orientation control of the thermoplastic polyimide layer and the non-thermoplastic polyimide layer becomes easy, and the dimensional accuracy can be easily managed. From this point of view, in the present embodiment, the non-thermoplastic polyimide constituting the non-thermoplastic polyimide layer and the thermoplastic polyimide constituting the thermoplastic polyimide layer are both from the general formulas (2) and (3). It is preferable to contain at least one selected diamine residue, and it is most preferable that the diamine residue contains a TPE-R residue and / or a BAPP residue.

  In the present embodiment, examples of the diamine residue other than the general formulas (2) and (3) contained in the thermoplastic polyimide include, for example, 2,2'-dimethyl-4,4'-diaminobiphenyl (m- TB), 2,2'-diethyl-4,4'-diaminobiphenyl (m-EB), 2,2'-diethoxy-4,4'-diaminobiphenyl (m-EOB), 2,2'-dipropoxy- 4,4'-Diaminobiphenyl (m-POB), 2,2'-n-propyl-4,4'-diaminobiphenyl (m-NPB), 2,2'-divinyl-4,4'-diaminobiphenyl VAB), 4,4′-diaminobiphenyl, 4,4′-diamino-2,2′-bis (trifluoromethyl) biphenyl (TFMB), p-phenylenediamine (p-PDA), m-phenylenediamine (m -PDA), 3, 3 -Diaminodiphenylmethane, 3,3'-diaminodiphenylpropane, 3,3'-diaminodiphenyl sulfide, 3,3'-diaminodiphenyl sulfone, 3,3-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 3,4 ' -Diaminodiphenylmethane, 3,4'-diaminodiphenylpropane, 3,4'-diaminodiphenyl sulfide, 3,3'-diaminobenzophenone, (3,3'-bisamino) diphenylamine, 1,4-bis (3-aminophenoxy ) Benzene, 3- [4- (4-aminophenoxy) phenoxy] benzeneamine, 3- [3- (4-aminophenoxy) phenoxy] benzeneamine, 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) Sulfoxy] bisaniline, bis [4- (3-aminophenoxy) phenyl] methane, bis [4- (3-aminophenoxy) phenyl] propane, bis [4- (3-aminophenoxy) phenyl] ether, bis [4- (3-aminophenoxy) phenyl] sulfone, bis [4- (3-aminophenoxy)] benzophenone, bis [4,4 '-(3-aminophenoxy)] benzanilide, 4- [3- [4- (4-) Aminophenoxy) phenoxy] phenoxy] aniline, 4,4 '-[oxybis (3,1-phenyleneoxy)] bisaniline, bis [4- (4-aminophenoxy) phenyl] ether (BAPE), bis [4- (4) -Diamine residue derived from diamine compounds such as -aminophenoxy) phenyl] ketone (BAPK), bis [4- (3-aminophenoxy)] biphenyl, bis [4- (4-aminophenoxy)] biphenyl Can be mentioned.

  In the thermoplastic polyimide, the thermal expansion coefficient is selected by selecting the types of the above-mentioned tetracarboxylic acid residue and diamine residue, and the respective molar ratios in the case of applying two or more kinds of tetracarboxylic acid residues or diamine residues. , Tensile modulus, glass transition temperature, etc. can be controlled. Moreover, in the thermoplastic polyimide, when it has a plurality of structural units of polyimide, it may be present as a block or randomly, but it is preferably present randomly.

  The thermoplastic polyimide which comprises a thermoplastic polyimide layer can improve adhesiveness with a metal layer. Such a thermoplastic polyimide has a glass transition temperature in the range of 200 ° C. to 350 ° C., preferably in the range of 200 ° C. to 320 ° C.

The imide group concentration of the thermoplastic polyimide is preferably 35% by weight or less. Here, "imide group concentration" means the value which remove | divided the molecular weight of the imide base (-(CO) ₂ -N-) in a polyimide by the molecular weight of the whole structure of a polyimide. When the imide group concentration exceeds 35% by weight, the molecular weight of the resin itself decreases, and the low hygroscopicity also deteriorates due to the increase of the polar group. By selecting the combination of the acid anhydride and the diamine compound, by controlling the orientation of the molecules in the thermoplastic polyimide, it is possible to suppress the increase in CTE associated with the reduction of the imide group concentration and ensure low hygroscopicity. There is.

  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 insulating resin layer tends to be reduced and the resin tends to be brittle. On the other hand, when the weight average molecular weight exceeds 400,000, the viscosity is excessively increased, and defects such as thickness unevenness and streaks tend to easily occur during the coating operation.

(Synthesis of non-thermoplastic polyimide and thermoplastic polyimide)
In general, a polyimide can be produced by reacting tetracarboxylic acid dianhydride and a diamine compound in a solvent to form a polyamic acid and then thermally cyclizing the ring. For example, a precursor of polyimide is obtained by dissolving tetracarboxylic acid dianhydride and a diamine compound in an equimolar amount in an organic solvent and stirring for 30 minutes to 24 hours at a temperature in the range of 0 to 100 ° C. The polyamic acid which is In the reaction, the reaction components are dissolved in the organic solvent such that the precursor produced is in the range of 5 to 30% by weight, preferably in the range of 10 to 20% by weight. Examples of the organic solvent used for the polymerization reaction include N, N-dimethylformamide (DMF), N, N-dimethylacetamide (DMAc), N, N-diethylacetamide, N-methyl-2-pyrrolidone (NMP), 2 -Butanone, dimethyl sulfoxide (DMSO), hexamethylphosphoramide, N-methylcaprolactam, dimethyl sulfate, cyclohexanone, dioxane, tetrahydrofuran, diglyme, triglyme, cresol and the like. Two or more of these solvents can be used in combination, and further, a combination of aromatic hydrocarbons such as xylene and toluene is also possible. The amount of such an organic solvent used is not particularly limited, but it is preferable to adjust the amount of the polyamic acid solution obtained by the polymerization reaction to be about 5 to 30% by weight. Is preferred.

  Although it is usually advantageous to use the synthesized polyamic acid as a reaction solvent solution, it can be concentrated, diluted or replaced with another organic solvent as required. Also, polyamic acids are advantageously used because they are generally excellent in solvent solubility. The viscosity of the solution of polyamic acid is preferably in the range of 500 cps to 100,000 cps. If the thickness is out of this range, defects such as thickness unevenness and streaks tend to occur in the film during coating operation with a coater or the like. The method for imidizing the polyamic acid is not particularly limited, and for example, heat treatment such as heating in the solvent at temperature conditions within a range of 80 to 400 ° C. for 1 to 24 hours is suitably adopted.

<Metal layer>
Examples of the metal constituting the metal layer include copper, aluminum, stainless steel, iron, silver, palladium, nickel, chromium, molybdenum, tungsten, zirconium, gold, cobalt, titanium, tantalum, zinc, lead, tin, silicon, bismuth And metals selected from indium and alloys thereof. The metal layer can be formed by a method such as sputtering, vapor deposition, plating or the like, but it is preferable to use a metal foil from the viewpoint of adhesiveness. Particularly preferred in terms of conductivity is copper foil. The copper foil may be either an electrolytic copper foil or a rolled copper foil. In addition, when manufacturing the metal-clad laminated board of this Embodiment continuously, the elongate metal foil by which the thing of predetermined | prescribed thickness was wound up by roll shape as metal foil is used.

  Hereinafter, as a preferred embodiment of the metal-clad laminate, a copper-clad laminate having a copper layer will be described and described.

<Copper-clad laminates>
The copper-clad laminate of this embodiment may be provided with an insulating layer and a copper layer such as copper foil on at least one surface of the insulating layer. Further, in order to enhance the adhesion between the insulating layer and the copper layer, the layer in contact with the copper layer in the insulating layer is a thermoplastic polyimide layer. The copper layer is provided on one side 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 single-sided CCL, the copper layer laminated on one side of the insulating layer is referred to as the "first copper layer" in the present invention. In the case of double-sided CCL, the copper layer laminated on one side of the insulating layer is referred to as the “first copper layer” in the present invention, and the insulating layer is on the side opposite to the side on which the first copper layer is laminated. Let the laminated | stacked copper layer be "the 2nd copper layer" in this invention. The copper-clad laminate of this embodiment is used as an FPC by forming a copper wiring by processing a wiring circuit by etching a copper layer or the like.

  The copper-clad laminate may be prepared, for example, by preparing a resin film and sputtering a metal thereon to form a seed layer, and then forming a copper layer by, for example, copper plating.

  Alternatively, a copper-clad laminate may be prepared by preparing a resin film and laminating a copper foil thereon by a method such as thermocompression bonding.

  Furthermore, a copper-clad laminate is cast on a copper foil with a coating solution containing a polyamide acid which is a precursor of polyimide, dried to form a coating film, and then heat treated to form an polyimide layer. It may be prepared by

(First copper layer)
In the copper clad laminate of the present embodiment, the copper foil used in the first copper layer (hereinafter sometimes referred to as "first copper foil") is not particularly limited, and, for example, It may be a rolled copper foil or an electrolytic copper foil.

  The thickness of the first copper foil is preferably 13 μm or less, more preferably 6 to 12 μm. When the thickness of the first copper foil exceeds 13 μm, the bending resistance applied to the copper layer (or copper wiring) when bending the copper-clad laminate (or FPC) becomes large, and the bending resistance decreases. Become. Moreover, it is preferable that the lower limit of the thickness of a 1st copper foil shall be 6 micrometers from a viewpoint of production stability and handling property.

  The tensile modulus of elasticity of the first copper foil is, for example, preferably in the range of 10 to 35 GPa, and more preferably in the range of 15 to 25 GPa. In the case of using a rolled copper foil as the first copper foil in the present embodiment, the flexibility tends to be high when annealed by heat treatment. Therefore, if the tensile modulus of the copper foil does not reach the above lower limit, the rigidity of the first copper foil itself is reduced by heating in the step of forming the insulating layer on the long first copper foil. . On the other hand, when the tensile elastic modulus exceeds the above upper limit value, a large bending stress is applied to the copper wiring when the FPC is bent, and the bending resistance thereof is reduced. The tensile elastic modulus of the rolled copper foil tends to change due to heat treatment conditions when forming the insulating layer on the copper foil, annealing treatment of the copper foil after forming the insulating layer, and the like. Therefore, in the present embodiment, in the copper clad laminate finally obtained, the tensile modulus of the first copper foil may be in the above range.

  The first copper foil is not particularly limited, and 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. It does not specifically limit as copper foil (2nd copper foil) used for a 2nd copper layer, For example, a rolled copper foil or an electrolytic copper foil may be sufficient. Moreover, the copper foil marketed can also be used as a 2nd copper foil. In addition, you may use the same thing as 1st copper foil as 2nd copper foil.

<Circuit board>
The metal-clad laminate of this embodiment is mainly useful as a material of a circuit board such as FPC. For example, by processing the copper layer of the copper-clad laminate exemplified above into a pattern according to a conventional method to form a wiring layer, a circuit board such as an FPC according to an embodiment of the present invention can be manufactured.

  EXAMPLES The features of the present invention will be more specifically described below with reference to examples. However, the scope of the present invention is not limited to the examples. In the following examples, unless otherwise specified, various measurements and evaluations are as follows.

[Measurement of viscosity]
The viscosity was measured at 25 ° C. using an E-type viscometer (trade name: DV-II + Pro, manufactured by Brookfield, Inc.). The rotational speed was set so that the torque was 10% to 90%, and after 2 minutes from the start of the measurement, the value when the viscosity was stabilized was read.

[Measurement of glass transition temperature (Tg)]
The glass transition temperature is a polyimide film having a size of 5 mm × 20 mm, and a temperature rising rate from 30 ° C. to 400 ° C. using a dynamic viscoelasticity measuring apparatus (DMA: made by UBM Co., Ltd., trade name; E4000F) The measurement was carried out at 4 ° C./minute and a frequency of 11 Hz, and the temperature at which the change in elastic modulus (tan δ) became maximum was taken as the glass transition temperature. In addition, the storage elastic modulus at 30 ° C. measured using DMA is 1.0 × 10 ⁹ Pa or more, and the storage elastic modulus at 360 ° C. is less than 1.0 × 10 ⁸ Pa as “thermoplastic”. The storage elastic modulus at 30 ° C. is 1.0 × 10 ⁹ Pa or more, and the storage elastic modulus at 360 ° C. is 1.0 × 10 ⁸ Pa or more as “non-thermoplastic”.

[Measurement of coefficient of thermal expansion (CTE)]
Using a thermomechanical analyzer (trade name: 4000SA, manufactured by Bruker), a polyimide film of 3 mm × 20 mm in size is heated from 30 ° C. to 265 ° C. at a constant temperature rising rate while applying a load of 5.0 g. Furthermore, after holding at that temperature for 10 minutes, it cooled at a rate of 5 ° C./min, and an average thermal expansion coefficient (thermal expansion coefficient) from 250 ° C. to 100 ° C. was determined.

[Measurement of in-plane retardation (RO)]
Retardation in the in-plane direction of a predetermined sample is determined using a birefringence meter (Photonic Lattice, product name; wide range birefringence evaluation system WPA-100, measurement area; MD: 140 mm × TD: 100 mm) The The incident angle is 0 °, and the measurement wavelength is 543 nm.

[Preparation of sample for evaluation of in-plane retardation (RO)]
A4 size (TD: 210 mm) at each of two left and right ends (Left and Right) in the TD direction and center part (Center) in a polyimide film obtained by etching a metal layer of a long metal-clad laminate × MD: 297 mm) cut, and sample L (Left), sample R (Right) and sample C (Center) were prepared.

[Evaluation of in-plane birefringence (Δn)]
In-plane retardation (RO) was measured for each of Sample L, Sample R, and Sample C, respectively. The value obtained by dividing the maximum value of the measured values of each sample by the thickness of the sample for evaluation is the “in-plane birefringence (Δn)”, and the difference between the maximum value and the minimum value in the measured values of in-plane retardation (RO) The “in-plane retardation (RO) variation (ΔRO) in the width direction (TD direction)”, and the value obtained by dividing this ΔRO by the thickness of the sample for evaluation is “in-plane birefringence index in the width direction (TD direction) Variation of Δn) [Δ (Δn)] ”.

[Measurement of retardation in the thickness direction and birefringence]
With respect to the polyimide layer as the insulating resin layer, a thin film section of 0.5 μm in thickness was produced by an ultramicrotome, and retardation measurement in the thickness direction was carried out. At this time, a birefringence meter (trade name: manufactured by Photonic Lattice, Inc .; a birefringence distribution observation camera PI-micro for microscope attachment) was used. The measurement wavelength is 520 nm, and the incident angle is 0 °.
ROa is a value of retardation at a point of 1.5 μm in the central portion direction starting from one surface of the non-thermoplastic polyimide layer in the polyimide layer (film).
ROb is a value of retardation at a point of 1.5 μm in the central portion direction starting from the other surface of the non-thermoplastic polyimide layer in the polyimide layer (film).
ROv is an average value of the sum (ROa + ROb + ROc) of the retardation value (ROc) at the center in the thickness direction of ROa, ROb, and the non-thermoplastic polyimide layer in the polyimide layer (film).
In addition, the value obtained by dividing the value of ROa by the thickness (0.5 μm) of the thin-film slice is calculated as follows: “In the thickness direction of the non-thermoplastic polyimide layer, the point at 1.5 μm in the central direction from one side The birefringence is (Δna), and the value obtained by dividing the ROb value by the thickness (0.5 μm) of the thin-film slice is “the direction of the center in the thickness direction of the non-thermoplastic polyimide layer, starting from the other surface. And the value obtained by dividing the ROc value by the thickness (0.5 μm) of the thin film section, “the birefringence at the central portion in the thickness direction of the non-thermoplastic polyimide layer”. It is referred to as “refractive index (Δnc)”.
Δnv is an average value of the sum (Δna + Δnb + Δnc) of Δna, Δnb and Δnc.

[Measurement of warpage]
After conditioning a polyimide film of 50 mm × 50 mm size at 23 ° C. and 50% RH for 24 hours, the curling direction was set as the upper surface and placed on a smooth table. The amount of curling at that time was measured using a vernier caliper. Under the present circumstances, the case where a film curled to the base material etching side was made into plus notation, the case where it curled to the opposite side was made into minus notation, and the average of the measured value of four corners of a film was made into curl amount.

[Measurement of peel strength]
A copper foil of a single-sided copper-clad laminate (copper foil / resin layer) was subjected to circuit processing to a width of 1.0 mm and then cut to a width of 8 cm × length of 4 cm to prepare a measurement sample. The resin layer side of the measurement sample is fixed to an aluminum plate with a double-sided tape using a Tensilon Tester (made by Toyo Seiki Seisakusho, trade name; Strograph VE-1D), and the copper foil is rotated 90 ° at a speed of 50 mm / min The central strength was determined when the copper foil was peeled off from the resin layer by 10 mm.

The abbreviations used in Examples and Comparative Examples indicate the following compounds.
PMDA: pyromellitic dianhydride BPDA: 3,3 ', 4,4'-biphenyltetracarboxylic dianhydride m-TB: 2,2'-dimethyl-4,4'-diaminobiphenyl TPE-R: 1 3, 3-bis (4-amino phenoxy) benzene DAPE: 4, 4 '-diamino diphenyl ether BAPP: 2, 2- bis [4- (4- amino phenoxy) phenyl] propane p-PDA: p-phenylene diamine DMAc: N , N-Dimethylacetamide

Synthesis Example 1
In a nitrogen stream, 23.0 parts by weight of m-TB (0.108 mole parts) and 3.5 parts by weight of TPE-R (0.012 mole parts) and a solid content concentration after polymerization were added to the reaction vessel. An amount of 15% by weight of DMAc was added and dissolved by stirring at room temperature. Next, 26.0 parts by weight of PMDA (0.119 mol part) was added, and then stirring was continued at room temperature for 3 hours to carry out a polymerization reaction to obtain a polyamic acid solution a. The solution viscosity of the polyamic acid solution a was 41,100 cps. The glass transition temperature of the polyimide obtained from this polyamic acid solution a was 421 ° C., the non-thermoplasticity and the thermal expansion coefficient were 10 (ppm / K).

(Composition example 2)
In a nitrogen stream, 17.3 parts by weight of m-TB (0.081 mole parts) and 10.2 parts by weight of TPE-R (0.035 mole parts) in the reaction vessel and the solid concentration after polymerization An amount of 15% by weight of DMAc was added and dissolved by stirring at room temperature. Next, 25.1 parts by weight of PMDA (0.115 mole parts) was added, and then stirring was continued for 3 hours at room temperature to carry out a polymerization reaction to obtain a polyamic acid solution b. The solution viscosity of the polyamic acid solution b was 38,200 cps. The glass transition temperature of the polyimide obtained from this polyamic acid solution b was 427 ° C., its non-thermoplasticity, and its thermal expansion coefficient was 22 (ppm / K).

(Composition example 3)
In a nitrogen stream, 16.4 parts by weight of m-TB (0.077 mole parts) and 9.7 parts by weight of TPE-R (0.033 mole parts) and a solid content concentration after polymerization were added to the reaction vessel. An amount of 15% by weight of DMAc was added and dissolved by stirring at room temperature. Next, 16.7 parts by weight of PMDA (0.077 mole parts) and 9.7 parts by weight of BPDA (0.033 mole parts) are added, and stirring is continued at room temperature for 3 hours to carry out a polymerization reaction, A polyamic acid solution c was obtained. The solution viscosity of the polyamic acid solution c was 46,700 cps. The glass transition temperature of the polyimide obtained from this polyamic acid solution c was 366 ° C., its non-thermoplasticity, and its thermal expansion coefficient was 23 (ppm / K).

(Composition example 4)
In a nitrogen stream, 22.4 parts by weight of m-TB (0.105 mole parts) and 4.8 parts by weight of BAPP (0.012 mole parts) and a solid content concentration after polymerization of 15 % Amount of DMAc was added and dissolved by stirring at room temperature. Next, 25.3 parts by weight of PMDA (0.116 mole parts) was added, and then stirring was continued at room temperature for 3 hours to carry out a polymerization reaction to obtain a polyamic acid solution d. The solution viscosity of the polyamic acid solution d was 36,800 cps. The glass transition temperature of the polyimide obtained from this polyamic acid solution d was 408 ° C., the non-thermoplasticity and the thermal expansion coefficient were 9 (ppm / K).

(Composition example 5)
In a nitrogen stream, 12.3 parts by weight of m-TB (0.058 mole parts), 10.1 parts by weight of TPE-R (0.035 mole parts) and 2.5 parts by weight of p in the reaction vessel -PDA (0.023 mol part) and DMAc in an amount such that the concentration of solids after polymerization was 15% by weight were added and dissolved by stirring at room temperature. Next, 17.5 parts by weight of PMDA (0.080 mole parts) and 10.1 parts by weight of BPDA (0.034 mole parts) are added, and then stirring is continued at room temperature for 3 hours to carry out a polymerization reaction, A polyamic acid solution e was obtained. The solution viscosity of the polyamic acid solution e was 42,700 cps. The glass transition temperature of the polyimide obtained from this polyamic acid solution e was 360 ° C., the non-thermoplasticity and the thermal expansion coefficient were 18 (ppm / K).

Synthesis Example 6
In a nitrogen stream, 2.2 parts by weight of m-TB (0.010 parts by mole) and 27.6 parts by weight of TPE-R (0.094 parts by mole) in the reaction vessel and the solid concentration after polymerization An amount of 15% by weight of DMAc was added and dissolved by stirring at room temperature. Next, 22.7 parts by weight of PMDA (0.104 mol part) was added, and then stirring was continued at room temperature for 3 hours to carry out a polymerization reaction to obtain a polyamic acid solution f. The solution viscosity of the polyamic acid solution f was 33,900 cps. The glass transition temperature of the polyimide obtained from this polyamic acid solution f was 446 ° C., and its thermoplasticity and thermal expansion coefficient were 55 (ppm / K).

Synthesis Example 7
In a nitrogen stream, 30.2 parts by weight of BAPP (0.074 mole parts) and DMAc in an amount such that the solid content concentration after polymerization is 15% by weight were charged into a reaction vessel, and dissolved by stirring at room temperature. The Next, 22.3 parts by weight of BPDA (0.076 mole parts) was added, and then stirring was continued for 3 hours at room temperature to carry out a polymerization reaction to obtain a polyamic acid solution g. The solution viscosity of the polyamic acid solution g was 9,800 cps. The glass transition temperature of the polyimide obtained from this polyamic acid solution g was 252 ° C., its thermoplasticity and its thermal expansion coefficient were 46 (ppm / K).

Synthesis Example 8
In a nitrogen stream, 25.8 parts by weight of TPE-R (0.088 mol parts) and DMAc in an amount such that the solid content concentration after polymerization is 15% by weight are charged into the reaction vessel and stirred at room temperature. It was dissolved. Next, 26.7 parts by weight of BPDA (0.091 mole parts) was added, and then stirring was continued for 3 hours at room temperature to carry out a polymerization reaction to obtain a polyamic acid solution h. The solution viscosity of the polyamic acid solution h was 8,800 cps. The glass transition temperature of the polyimide obtained from this polyamic acid solution h was 243 ° C., and its thermoplasticity and thermal expansion coefficient were 65 (ppm / K).

Synthesis Example 9
In a nitrogen stream, 17.6 parts by weight of TPE-R (0.060 mole parts) and 1.6 parts by weight of p-PDA (0.015 mole parts) were added to the reaction vessel, and the solid concentration after polymerization was An amount of 15% by weight of DMAc was added and dissolved by stirring at room temperature. Next, 22.8 parts by weight of BPDA (0.077 mole parts) was added, and then stirring was continued at room temperature for 3 hours to carry out a polymerization reaction to obtain a polyamic acid solution i. The solution viscosity of the polyamic acid solution i was 7,800 cps. The glass transition temperature of the polyimide obtained from this polyamic acid solution i was 239 ° C., the thermoplasticity and the thermal expansion coefficient were 65 (ppm / K).

Synthesis Example 10
In a nitrogen stream, 11.7 parts by weight of DAPE (0.058 mole parts) and 11.4 parts by weight of TPE-R (0.039 mole parts) were added to the reaction vessel in a reaction vessel, and the solid concentration after polymerization was 15 parts % Amount of DMAc was added and dissolved by stirring at room temperature. Next, 29.5 parts by weight of BPDA (0.100 mole parts) was added, and then stirring was continued at room temperature for 3 hours to carry out a polymerization reaction to obtain a polyamic acid solution j. The solution viscosity of the polyamic acid solution j was 11,200 cps. The glass transition temperature of the polyimide obtained from this polyamic acid solution j was 265 ° C., its thermoplasticity and its thermal expansion coefficient were 58 (ppm / K).

Example 1
The polyamide acid solution g prepared in Synthesis Example 7 is uniformly coated on one surface of a long electrolytic copper foil having a thickness of 12 μm and a width of 1,080 mm so that the thickness after curing is 2.5 μm (first Layer), dried by heating at 120 ° C. to remove the solvent. The polyamide acid solution a prepared in Synthesis Example 1 was uniformly coated thereon so that the thickness after curing was 20 μm (second layer), and the solvent was removed by heating and drying at 120 ° C. Furthermore, after the polyamide acid solution g prepared in Synthesis Example 7 was uniformly coated thereon so that the thickness after curing was 2.5 μm (third layer), the solvent was removed by heating and drying at 120 ° C. . Thereafter, stepwise heat treatment was performed from 130 ° C. to 360 ° C. to complete imidization, and a single-sided copper-clad laminate was prepared.

[Examples 2 to 8 and Comparative Examples 1 to 3]
After applying a resin solution of polyamide acid on one side of the electrodeposited copper foil, heat drying and stepwise heat treatment are performed to prepare a single-sided copper-clad laminate, the resin and thickness used in the first to third layers are A single-sided copper-clad laminate was obtained in the same manner as in Example 1 except that the configuration was changed to that shown in Table 1 below.

  In Table 1, the thickness ratio (non-thermoplastic polyimide layer (A) to thermoplastic polyimide layer (B) in the insulating resin layer of the single-sided copper-clad laminate obtained in Examples 1 to 8 and Comparative Examples 1 to 3 (non-) Thermoplastic polyimide layer (A) / thermoplastic polyimide layer (B), in-plane retardation (RO), variation in in-plane retardation (RO) in width direction (TD direction) (ΔRO), thickness of non-thermoplastic polyimide layer The difference in the retardation in the longitudinal direction (| ROa-ROb |, | ROv-ROa |, | ROv-ROb |), the amount of warpage, and the peel strength are shown. Further, in Table 2, in-plane birefringence (Δn) and in-plane birefringence in the width direction (TD direction) in the insulating resin layer of the single-sided copper-clad laminate obtained in Examples 1 to 8 and Comparative Examples 1 to 3 It shows the difference [Δ (Δn)] of the rate (Δn) and the difference in birefringence (| Δn−Δnb |, | Δnv−Δna |, | Δnv−Δnb |) in the thickness direction of the non-thermoplastic polyimide layer.

<IC chip mounting property>
A dry film is laminated on the copper foil surface of the single-sided copper-clad laminate prepared in Examples 1 to 8 and Comparative Examples 1 to 3, and after patterning a dry film resist, the copper foil is etched along the pattern to form a circuit. To prepare a circuit board. When an IC chip was mounted on the copper wiring side of the obtained circuit board by bonding at 400 ° C. for 0.5 seconds, in Examples 1 to 8, there was no misalignment between the copper wiring and the IC chip, which is a problem Did not occur. On the other hand, in Comparative Example 1, positional deviation between the copper wiring and the IC chip occurs, and in Comparative Examples 2 and 3, positional deviation between the copper wiring and the IC chip and warpage of the circuit board occur, which causes problems in mounting. Arose.

Although the embodiments of the present invention have been described in detail for the purpose of illustration, the present invention is not limited to the above-described embodiments, and various modifications are possible.

Claims (8)

A metal-clad laminate comprising an insulating resin layer and a metal layer laminated on at least one side of the insulating resin layer,
The insulating resin layer has a thermoplastic polyimide layer containing a thermoplastic polyimide on at least one surface of the non-thermoplastic polyimide layer,
The insulating resin layer has the following conditions (i) to (iv):
(i) the value of in-plane birefringence (Δn) is 2 × 10 ⁻³ or less;
(ii) The variation [Δ (Δn)] of the in-plane birefringence index (Δn) in the width direction (TD direction) is 4 × 10 ⁻⁴ or less;
(iii) In the thickness direction of the non-thermoplastic polyimide layer, the birefringence (Δna) at a point of 1.5 μm in the central portion direction starting from one surface and the central portion direction starting from the other surface And the difference (Δna−Δnb) with the birefringence (Δnb) at a point of 1.5 μm is ± 0.01 or less;
(iv) The difference between the Δna and the Δnb and the average (Δnv) of the sum (Δna + Δnb + Δnc) of the total birefringence (Δnc) at the central portion in the thickness direction is ± 0.01 in any of the Δna and Δnb Not more than
A metal-clad laminate characterized in that The non-thermoplastic polyimide contains a tetracarboxylic acid residue and a diamine residue, and a diamine residue derived from a diamine compound represented by the following general formula (1) is based on 100 mole parts of all diamine residues. The metal-clad laminate according to claim 1, characterized in that it is 20 molar parts or more.

[In the general formula (1), the linking group Z represents a single bond or -COO-, and Y is a monovalent hydrocarbon of 1 to 3 carbons which may be independently substituted with a halogen or a phenyl group or 1 carbon An alkoxy group of -3 or a perfluoroalkyl group of 1 to 3 carbon atoms or an alkenyl group is shown, n is an integer of 0-2 and p and q are independently an integer of 0-4. ] Within 100 mole parts of all diamine residues contained in the non-thermoplastic polyimide, the diamine residue derived from the diamine compound represented by the general formula (1) is within a range of 70 mole parts to 95 mole parts The metal-clad laminate according to claim 2, wherein the total amount of diamine residues selected from the following general formulas (2) and (3) is in the range of 5 to 30 mol parts.

[In the general formula (2) and the general formula (3), R ₅ , R ₆ , R ₇ and R ₈ are each independently a halogen atom, or an alkyl group which may be substituted by a halogen atom having 1 to 4 carbon atoms or alkoxy group, or an alkenyl group, X independently is -O -, - S -, - CH 2 -, - CH (CH 3) -, - C (CH 3) 2 -, - CO -, - COO- , A divalent group selected from -SO _2- , -NH- or -NHCO-, X ₁ and X ₂ each independently represent a single bond, -O-, -S-, -CH _2- , -CH ₂ (CH ₃ )-, -C (CH ₃ ) _2- , -CO-, -COO-, -SO _2- , -NH- or -NHCO-, which is a divalent group selected from X ₁ and X Except when both of ₂ are single bonds, m, n, o and p independently represent an integer of 0-4. ] The thermoplastic polyimide contains a tetracarboxylic acid residue and a diamine residue, and the total amount of diamine residues selected from the following general formulas (2) and (3) is based on 100 mol parts of all diamine residues. The metal-clad laminate according to claim 2 or 3, which is 50 molar parts or more.

[In the general formula (2) and the general formula (3), R ₅ , R ₆ , R ₇ and R ₈ are each independently a halogen atom, or an alkyl group which may be substituted by a halogen atom having 1 to 4 carbon atoms or alkoxy group, or an alkenyl group, X independently is -O -, - S -, - CH 2 -, - CH (CH 3) -, - C (CH 3) 2 -, - CO -, - COO- , A divalent group selected from -SO _2- , -NH- or -NHCO-, X ₁ and X ₂ each independently represent a single bond, -O-, -S-, -CH _2- , -CH ₂ (CH ₃ )-, -C (CH ₃ ) _2- , -CO-, -COO-, -SO _2- , -NH- or -NHCO-, which is a divalent group selected from X ₁ and X Except when both of ₂ are single bonds, m, n, o and p independently represent an integer of 0-4. ] The diamine residue represented by the general formula (2) is a diamine residue derived from 1,3-bis (4-aminophenoxy) benzene,
4. The diamine residue represented by the above general formula (3) is a diamine residue derived from 2,2-bis [4- (4-aminophenoxy) phenyl] propane. The metal-clad laminated board as described in 4.   The thickness ratio (A) / (B) of the thickness (A) of the non-thermoplastic polyimide layer and the thickness (B) of the thermoplastic polyimide layer is in the range of 1 to 20. The metal-clad laminated board of any one of 5 items. The metal-clad laminate according to any one of claims 1 to 6, wherein the length in the width direction (TD direction) is 490 mm or more. The circuit board formed by processing the said metal layer of the metal-clad laminated board of any one of Claims 1-7 into wiring.