TWI804658B - Metal-clad laminates and circuit boards - Google Patents

Abstract

A metal-clad laminate, comprising: a resin laminate containing a plurality of polyimide layers; and a metal layer laminated on at least one side of the resin laminate, wherein the resin laminate satisfies i) the overall thickness is 40 μm to 200 μm within the range; ii) comprising a first polyimide layer in contact with the metal layer, and a second polyimide layer directly or indirectly laminated on the first polyimide layer; iii) a second polyimide layer The ratio of the thickness of the imide layer to the thickness of the entire resin laminate is in the range of 70% to 97%; iv) E calculated based on E ₁ =√ε ₁ ×Tanδ ₁ as an index indicating the dielectric properties The value of ₁ is less than 0.009, [here, ε ₁ represents the dielectric constant at 10 GHz measured by a split dielectric resonator (SPDR), and Tanδ ₁ represents the dielectric constant measured by a split dielectric resonator (SPDR). Measured dielectric tangent at 10 GHz].

Description

Metal-clad laminates and circuit boards

The present invention relates to a device that can cope with the miniaturization of electronic equipment. High-performance, high-frequency metal-clad laminates and circuit boards.

In recent years, with the advancement of miniaturization, weight reduction, and space saving of electronic equipment, flexible circuit boards (flexible printed circuit boards (flexible printed circuit boards) (Flexible Printed Circuits, FPC)) needs to increase. Regarding FPC, even in a limited space, three-dimensional and high-density installation can be achieved, so for example, in hard disk drives (Hard Disk Drive, HDD), digital video discs (Digital Video Disk, DVD), mobile phones, smart phones, etc. Its use is gradually expanding in the wiring of electronic devices such as mobile phones, or in parts such as cables and connectors.

In information processing or information communication, in order to transmit and process large-capacity information, measures to increase the transmission frequency are implemented, and the circuit board material is required to reduce the transmission loss caused by the low dielectric of the insulating resin layer. Therefore, in order to cope with higher frequencies, FPCs using liquid crystal polymers featuring low dielectric constant and low dielectric tangent as a dielectric layer are used. However, although liquid crystal polymers have excellent dielectric properties, there is room for improvement in heat resistance and adhesion to metal foils. Therefore, polyimides have attracted attention as insulating resin materials excellent in heat resistance and adhesion.

In order to improve the high-frequency transmission characteristics of circuit boards, it has been proposed to use polyimides with improved dielectric properties (for example, Patent Document 1 to Patent Document 3).

On the other hand, it is also proposed to manufacture a double-sided copper-clad laminate with a thickness of 50 μm or more by bonding the polyimide resin surfaces of two single-sided copper-clad laminates (for example, Patent Document 4, Patent Document 5).

[Prior art literature] [Patent Document]

Patent Document 1: Japanese Patent Laid-Open No. 2016-193501

Patent Document 2: Japanese Patent Laid-Open No. 2016-192530

Patent Document 3: International Publication No. WO2018/061727

Patent Document 4: Japanese Patent No. 5886027

Patent Document 5: Japanese Patent No. 6031396

In circuit boards, it is expected that the demand for higher frequency will increase in the future, and the required level for high-frequency transmission characteristics will become stricter. From this point of view, not only the improvement of the dielectric properties of the insulating resin layer but also the option of increasing the thickness of the insulating resin layer becomes necessary. However, in the examples of Patent Document 1 to Patent Document 3, the thickness of the insulating resin layer is about 25 μm, and there is no study on increasing the thickness of the film to a thickness exceeding 50 μm, for example.

On the other hand, in Patent Document 4 and Patent Document 5, the response to high-frequency transmission is not considered, and the configuration of polyimide when a thick insulating resin layer is used is not studied.

The present invention aims to provide a metal-clad laminate and a circuit board capable of ensuring sufficient thickness of an insulating resin layer and capable of responding to high-frequency transmission accompanied by high-performance electronic devices.

The inventors of the present invention found that the above problems can be solved by providing a thick insulating resin layer and considering the dielectric properties of polyimide constituting the insulating resin layer, and completed the present invention.

That is, the metal-clad laminate of the present invention is a metal-clad laminate comprising: a resin laminate including a plurality of polyimide layers; and a metal layer laminated on at least one surface of the resin laminate.

The metal-clad laminate of the present invention is characterized in that the resin laminate satisfies the following conditions i) to iv): i) the overall thickness is in the range of 40 μm to 200 μm; ii) includes a second layer in contact with the metal layer. a polyimide layer, and a second polyimide layer laminated directly or indirectly on the first polyimide layer; iii) the thickness of the second polyimide layer is relative to the The ratio of the overall thickness of the resin laminate is in the range of 70% to 97%; iv) The E ₁ value calculated based on the following formula (a) as an index indicating the dielectric properties is less than 0.009:

[Here, ε ₁ represents the dielectric constant at 10 GHz measured by a split dielectric resonator (split post dielectric resonator (SPDR)), and Tan δ ₁ represents the dielectric constant measured by a split post dielectric resonator. (SPDR) measured dielectric tangent at 10 GHz].

Regarding the metal-clad laminate of the present invention, the polyimide constituting the second polyimide layer may be a non-thermoplastic polyimide obtained by reacting an acid anhydride component with a diamine component, and may contain tetracarboxylic acid residues. groups and diamine residues. In this case, 3,3',4,4'-biphenyltetracarboxylic dianhydride (3,3',4,4'-biphenyl tetracarboxylic dianhydride, BPDA) derived tetracarboxylic acid residues (BPDA residues) and 1,4-phenylene bis (trimellitic acid monoester) dianhydride (1,4-phenylene bis(trimellitic acid monoester) dianhydride , TAHQ) at least one of tetracarboxylic acid residues (TAHQ residues) derived from, and tetracarboxylic acid residues (PMDA residues) derived from pyromellitic dianhydride (pyromellitic dianhydride, PMDA) and derived from The total of at least one of the tetracarboxylic acid residues (NTCDA residues) derived from 2,3,6,7-naphthalene tetracarboxylic dianhydride (2,3,6,7-naphthalene tetracarboxylic dianhydride, NTCDA) may be More than 80 mole parts, the mol ratio of at least one of the BPDA residue and the TAHQ residue to at least one of the PMDA residue and the NTCDA residue {(BPDA residue+TAHQ residue Base)/(PMDA residue+NTCDA residue)} can be in the range of 0.4～1.5.

Regarding the metal-clad laminate of the present invention, with respect to all diamine components, all The diamine component may contain more than 80 mole % of 4,4'-diamino-2,2'-dimethylbiphenyl (2,2'-dimethyl-4,4'-diamino biphenyl, m-TB ).

In the metal-clad laminate of the present invention, the resin laminate may have a structure in which at least the first polyimide layer and the second polyimide layer are sequentially laminated from the side of the metal layer.

In the metal-clad laminate of the present invention, the resin laminate may have a laminate structure including at least four or more polyimide layers.

The circuit board of the present invention is obtained by subjecting the metal layer of any one of the metal-clad laminates to wiring circuit processing.

The metal-clad laminate of the present invention has a resin laminate made of polyimide having a sufficient thickness and excellent dielectric properties, and thus can be suitably used as an electronic material requiring high-speed signal transmission.

10A, 10B: copper foil layer

20A, 20B, 40A, 40B: thermoplastic polyimide layer

30A, 30B: Non-thermoplastic polyimide layer

50: resin laminate

60: joint surface

70A, 70B: single-sided CCL

100, 100A: double-sided CCL

FIG. 1 is a schematic cross-sectional view showing the configuration of a double-sided copper-clad laminate (double-sided copper-clad plate (CCL)) according to an embodiment of the present invention.

FIG. 2 is a schematic cross-sectional view showing the configuration of a modified example of a double-sided CCL.

FIG. 3 is a diagram illustrating a step of a method of manufacturing the double-sided CCL shown in FIG. 1 .

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

[Metal-clad laminate]

The metal-clad laminate of this embodiment includes: a resin laminate including a plurality of polyimide layers; and a metal layer laminated on at least one surface of the resin laminate.

<Resin laminate>

The resin laminate satisfies the conditions of i) to iv) below.

i) The overall thickness of the resin laminate is within the range of 40 μm to 200 μm, preferably within the range of 40 μm to 180 μm, more preferably within the range of 50 μm to 160 μm. If the overall thickness of the resin laminate is less than 40 μm, sufficient high-frequency transmission characteristics may not be obtained, and if it exceeds 200 μm, problems such as warpage may arise. In addition, there is a possibility of causing problems in terms of dimensional stability, flexibility, and the like, so the overall thickness of the resin laminate is preferably 180 μm or less.

ii) The resin laminate includes at least a first polyimide layer in contact with the metal layer, and a second polyimide layer laminated directly or indirectly on the first polyimide layer. The polyimide constituting the first polyimide layer is thermoplastic polyimide, and the polyimide constituting the second polyimide layer is non-thermoplastic polyimide. The resin laminate preferably has a structure in which at least a first polyimide layer and a second polyimide layer are sequentially laminated from the metal layer side. Furthermore, the resin laminate may have any resin layer other than the first polyimide layer and the second polyimide layer. In addition, the resin laminate preferably has a layer structure symmetrical to the thickness direction based on the center in the thickness direction, but may have a layer structure asymmetric to the thickness direction.

iii) Regarding the resin laminate, the ratio of the thickness of the second polyimide layer to the thickness of the entire resin laminate is in the range of 70% to 97%, preferably 75%. ~95% range. As described below, the second polyimide layer is a non-thermoplastic polyimide layer having low dielectric properties, so by calculating the ratio of the thickness of the second polyimide layer to the thickness of the entire resin laminate When controlled to be within the above range, circuit boards such as FPCs having excellent high-frequency transmission characteristics can be produced. If the ratio of the thickness of the second polyimide layer to the thickness of the entire resin laminate is less than 70%, the ratio of the non-thermoplastic polyimide layer in the insulating resin layer becomes too small, so the dielectric properties may be reduced. If the damage exceeds 97%, the thermoplastic polyimide layer as the first polyimide layer becomes thinner, so the adhesion reliability between the resin laminate and the metal layer tends to decrease.

iv) The resin laminate is based on the following formula (a):

ε₁是指ε₁的平方根] [Here, _ε1 represents the dielectric constant at 10 GHz measured by a split dielectric resonator (SPDR), and _Tanδ1 represents the dielectric constant at 10 GHz measured by a split dielectric resonator (SPDR). Tangent. Furthermore,

_ε1 means the square root of _ε1 ]

The calculated E ₁ value, which is an index showing the dielectric properties, is less than 0.009, preferably within a range of 0.0025 to 0.0085, more preferably within a range of 0.0025 to 0.008. When the E ₁ value is less than 0.009, circuit boards such as FPC having excellent high-frequency transmission characteristics can be produced. On the other hand, if the E ₁ value exceeds the above upper limit, when used in circuit boards such as FPC, defects such as loss of electrical signals are likely to occur on the transmission path of high-frequency signals.

In addition, with regard to the resin laminate, it is possible to suppress the From the viewpoint of warping or reduction in dimensional stability, it is preferable to control the coefficient of thermal expansion (Coefficient of Thermal Expansion, CTE) within the range of 10 ppm/K to 30 ppm/K as the entire resin laminate. In this case, the CTE of the second polyimide layer functioning as the base layer (main layer) in the resin laminate is preferably in the range of 1 ppm/K to 25 ppm/K, more preferably 10 ppm/K ~20ppm/K range.

(first polyimide layer)

The polyimide constituting the first polyimide layer is thermoplastic polyimide. The thermoplastic polyimide preferably has a glass transition temperature (Tg) of 360°C or lower, more preferably within a range of 200°C to 320°C. Here, the so-called thermoplastic polyimide is usually a polyimide whose glass transition temperature (Tg) can be clearly confirmed, and in the present invention refers to the use of a dynamic viscoelasticity measurement device (Dynamic Mechanical Analysis (Dynamic Mechanical Analysis, DMA)) On the other hand, the polyimide has a measured storage modulus of elasticity at 30°C of 1.0×10 ⁹ Pa or more and a storage modulus of elasticity at 300°C of less than 3.0×10 ⁸ Pa. The resin laminate has one or two first polyimide layers adjacent to one or two metal layers, respectively. In the case of having two first polyimide layers, the polyimides formed may be the same type or different types. In addition, the details about thermoplastic polyimide will be mentioned later.

(second polyimide layer)

The polyimide constituting the second polyimide layer is a low thermal expansion non-thermoplastic polyimide. In the case of having a plurality of layers of the second polyimide layer, the polyimides constituting each layer may be of the same type or different types. Here, the so-called non-thermoplastic polyimide is generally a polyimide that does not show softening and adhesiveness even when heated, but in the present invention refers to 30 A polyimide having a storage modulus of elasticity at 1.0×10 ⁹ Pa or more at °C and a storage modulus of elasticity at 300°C of 3.0×10 ⁸ Pa or more. In addition, the detail about non-thermoplastic polyimide is mentioned later.

<metal layer>

As the metal layer, metal foil can be preferably used. The material of the metal foil is not particularly limited, for example, copper, stainless steel, iron, nickel, beryllium, aluminum, zinc, indium, silver, gold, tin, zirconium, tantalum, titanium, lead, magnesium, manganese and the like Alloy etc. Among these, copper or a copper alloy is particularly preferable. As copper foil, rolled copper foil may be used, or electrolytic copper foil may be used.

The metal foil used as the metal layer may be subjected to surface treatments such as antirust treatment, siding, aluminum alcoholate, aluminum chelate, silane coupling agent, and the like.

In the metal-clad laminate of this embodiment, for example, the thickness of the metal layer used in the manufacture of FPC is preferably in the range of 3 μm to 50 μm, more preferably in the range of 5 μm to 30 μm, in order to adjust the line width of the circuit pattern Thinning, preferably within the range of 5 μm to 20 μm. From the viewpoint of suppressing the increase of conductor loss in high-frequency transmission, the thicker the thickness of the metal layer, the better. On the other hand, if the thickness becomes too large, the application to miniaturization becomes difficult, and the flexibility There is a risk that the adhesion between the wiring layer and the insulating resin layer will be damaged during circuit processing. Considering the trade-off relationship, the thickness of the metal layer can be set within the range described above.

In addition, from the standpoint of coexistence of high-frequency transmission characteristics and adhesiveness to the resin laminate, ten points of the surface of the metal layer in contact with the first polyimide layer The average roughness (Rz) is 1.2 μm or less, preferably within the range of 0.05 μm to 1.0 μm. From the same viewpoint, the arithmetic average height (Ra) of the surface of the metal layer in contact with the first polyimide layer is preferably 0.2 μm or less.

In the metal-clad laminate of this embodiment, a commercially available copper foil can be used as the metal layer. Specific examples thereof include copper foil CF-T49A-DS-HD (trade name) manufactured by Fukuda Metal Foil Powder Industry Co., Ltd., copper foil TQ-M4-VSP (trade name) manufactured by Mitsui Metal Mining Co., Ltd., Copper foil GHY5-HA-V2 (trade name) manufactured by JX Metal Co., Ltd., BHY(X)-HA-V2 (trade name) of the same company, and the like.

Next, the structure of the metal-clad laminate of this embodiment will be specifically described with reference to the drawings. FIG. 1 is a schematic cross-sectional view showing the configuration of a double-sided copper-clad laminate (double-sided CCL) 100 according to an embodiment of the present invention. The double-sided CCL 100 includes: a copper foil layer 10A and a copper foil layer 10B as metal layers; and a resin laminate 50 as a resin laminate, which has a structure in which the copper foil layer 10A and the copper foil layer 10B are laminated on both surfaces of the resin laminate 50 . Here, the resin laminate 50 is composed of a plurality of polyimide layers, including: a thermoplastic polyimide layer 20A and a thermoplastic polyimide layer 20B as the first polyimide layer; non-thermoplastic polyimide layer 30A, non-thermoplastic polyimide layer 30B of the amine layer; and thermoplastic polyimide layer 40A, thermoplastic polyimide layer 40B as the third polyimide layer.

In the double-sided CCL 100, the thermoplastic polyimide layer 20A and the thermoplastic polyimide layer 20B are in direct contact with the copper foil layer 10A and the copper foil layer 10B, respectively. The thermoplastic polyimide layer 20A and the thermoplastic polyimide layer 20B can have the same thickness, or can be With different thicknesses, the polyimides constituting these layers can be of the same type or different types.

In addition, in the double-sided CCL 100, the non-thermoplastic polyimide layer 30A and the non-thermoplastic polyimide layer 30B may be in contact with the thermoplastic polyimide layer 20A and the thermoplastic polyimide layer 20B respectively, or may be indirect without direct contact. Sexual stratum. The non-thermoplastic polyimide layer 30A and the non-thermoplastic polyimide layer 30B may have the same thickness or different thicknesses, and the polyimides constituting these layers may be the same type or different types.

In addition, in the double-sided CCL 100, in order to ensure adhesion, the thermoplastic polyimide layer 40A and the thermoplastic polyimide layer 40B are preferably in the range of 360° C. or less from the glass transition temperature (Tg), for example, 200° C. to 320° C. Constructed of thermoplastic polyimide. The thermoplastic polyimide layer 40A and the thermoplastic polyimide layer 40B can also be made of the same material as the thermoplastic polyimide layer 20A and the thermoplastic polyimide layer 20B. The thermoplastic polyimide layer 40A and the thermoplastic polyimide layer 40B may have the same thickness or different thicknesses, and the polyimides constituting these layers may be the same type or different types.

The resin laminate 50 is not limited to the six-layer structure shown in FIG. 1 . As long as the resin laminate 50 includes at least the thermoplastic polyimide layer 20A and the thermoplastic polyimide layer 20B (the first polyimide layer) in contact with the copper foil layer 10A and the copper foil layer 10B; and directly or indirectly The non-thermoplastic polyimide layer 30A and the non-thermoplastic polyimide layer 30B (second polyimide layer) laminated on the thermoplastic polyimide layer 20A and the thermoplastic polyimide layer 20B may be used. Therefore, in the case of a double-sided CCL, The resin laminate 50 only needs to include at least four or more polyimide layers. For example, like the double-sided CCL100A shown in FIG. 2, the resin laminate 50 may also have the following five-layer structure, including: a thermoplastic polyimide layer 20A and a thermoplastic polyimide layer 20B as the first polyimide layer; A non-thermoplastic polyimide layer 30A as a second polyimide layer; a non-thermoplastic polyimide layer 30B; and a thermoplastic polyimide layer 40A. In addition, the resin laminate 50 may include arbitrary layers other than those shown in FIGS. 1 and 2 . The resin laminate 50 may include resin layers other than the polyimide layer, and preferably includes only a plurality of polyimide layers.

The polyimide layer constituting the resin laminate 50 may contain an inorganic filler as needed. Specifically, examples thereof include silicon dioxide, aluminum oxide, magnesium oxide, beryllium oxide, boron nitride, aluminum nitride, silicon nitride, aluminum fluoride, calcium fluoride, and the like. These may be used alone or in combination of two or more.

The copper foil layer 10A and the copper foil layer 10B may be copper foils having the same thickness or material, or copper foils having different structures.

<Manufacturing method of metal-clad laminate>

The double-sided CCL 100 is preferably produced, for example, by the first method or the second method shown below.

(first method)

First, prepare two single-sided copper-clad laminates (single-sided CCL). That is, a single-sided copper-clad laminate (single-sided CCL) 70A with a copper foil layer 10A, a thermoplastic polyimide layer 20A, a non-thermoplastic polyimide layer 30A, and a thermoplastic polyimide layer 40A is produced respectively; Copper foil layer 10B, thermoplastic polyimide layer 20B, non-thermoplastic polyimide One-sided CCL 70B of imide layer 30B and thermoplastic polyimide layer 40B.

Next, as shown in FIG. 3 , the thermoplastic polyimide layer 40A and the thermoplastic polyimide layer 40B sides of the two single-sided CCL70A and single-sided CCL70B are arranged facing each other, and hot pressing is performed on the bonding surface 60 by hot pressing. Then, double-sided CCL100 can be manufactured. Furthermore, the bonding surface 60 is a thermocompression bonding surface. The two single-sided CCL70A and single-sided CCL70B may have completely the same configuration, or may be different in number of layers, resin types, metal layers, and the like. In addition, when the polyimide layers of single-sided CCL70A and single-sided CCL70B are set to four or more layers, it is preferable to constitute a thermoplastic polyimide layer and a non-thermoplastic polyimide layer adjacent thereto. It is a layered unit, which repeats alternately.

In terms of ease of control of thickness or physical properties, each polyimide layer constituting single-sided CCL70A and single-sided CCL70B is preferably formed by a so-called casting (coating) method. ) method is to apply a resin solution of polyamic acid as a precursor of polyimide on the copper foil which is the raw material of the copper foil layer 10A and the copper foil layer 10B, and perform heat treatment after the coating film is formed. Dry and harden. That is, in single-sided CCL70A and single-sided CCL70B, thermoplastic polyimide layer 20A, thermoplastic polyimide layer 20B, non-thermoplastic polyimide layer 30A, non-thermoplastic polyimide layer laminated on copper foil layer 10A and copper foil layer 10B The thermoplastic polyimide layer 30B, the thermoplastic polyimide layer 40A, and the thermoplastic polyimide layer 40B are all preferably sequentially formed by a casting method.

In the casting method, the coating film can be formed by coating a resin solution of polyamic acid on a copper foil and then drying it. In the formation of single-sided CCL70A and single-sided CCL70B, it can be formed by sequentially coating other polyamic acid solutions containing different constituents on the polyamic acid solution. In addition, it is also possible to coat polyamide acid solutions of the same composition twice or more. Amide acid solution. In addition, it can also be formed by laminating a multilayer coating film at the same time by multilayer extrusion. In addition, it is also possible to temporarily imidize the coating film of polyamic acid to form a single-layer or multi-layer polyimide layer, and then further coat the resin solution of polyamic acid on it to carry out imidization. Aminated to form a polyimide layer. The method of coating is not particularly limited, for example, it can be coated by using a coating machine such as a notch wheel, a mold, a doctor blade, and a die lip. In this case, as the copper foil, copper foils in the shape of a slice, a roll, or an endless belt can be used. In order to obtain productivity, it is efficient to use a roll-like or endless belt-like form and make it into a form that can be continuously produced. Furthermore, from a viewpoint of expressing the improvement effect of the wiring pattern precision in a circuit board more, it is preferable that copper foil is formed in the shape of an elongated roll.

The imidization method is not particularly limited. For example, the following heat treatment can be preferably adopted: heating at a temperature in the range of 80° C. to 400° C. for a time in the range of 1 minute to 60 minutes. In order to suppress the oxidation of the copper foil layer 10A and the copper foil layer 10B, heat treatment in a low-oxygen environment is preferred, specifically, an inert gas environment such as nitrogen or a rare gas, a reducing gas environment such as hydrogen, or Do it in a vacuum. By the heat treatment, the polyamic acid in the coating film is imidized to form polyimide.

In this manner, a single-sided CCL 70A, a single-sided CCL 70B having a multilayer polyimide layer and a copper foil layer 10A or a copper foil layer 10B can be produced. As shown in FIG. 3 , the two single-sided CCL70A and single-sided CCL70B obtained in the above manner are arranged in such a way that the surfaces of the thermoplastic polyimide layer 40A and the thermoplastic polyimide layer 40B face each other, and are carried out on the bonding surface 60. Thermocompression bonding, whereby double-sided CCL100 can be produced. Thermocompression bonding is preferably Two single-sided CCL70A and single-sided CCL70B are formed into long strips, and are carried out while being conveyed in a roll-to-roll manner using a pair of heating rollers. In other words, it is more preferable to carry out the conveyance speed between the heating rollers in the range of 1 m/min to 10 m/min.

(second method)

Here, a case where a single-sided metal-clad laminate (single-sided CCL) or a double-sided metal-clad laminate (double-sided CCL) 100 in which the metal layer is a copper foil layer is produced by a tape-casting method is given as an example.

First, a copper foil (not shown) is prepared as the copper foil layer 10A. And, the first coating film was formed by coating and drying a resin solution of polyamic acid on the copper foil. The coating film is a precursor resin layer of thermoplastic polyimide.

Next, a second coating film was formed by further coating and drying a resin solution of polyamic acid on the first coating film. The second coating film is a precursor resin layer of non-thermoplastic polyimide.

Then, while selecting the type of polyamic acid, the third layer, the fourth layer, the fifth layer, and the sixth layer coating film are sequentially formed in the same manner, and then these are subjected to heat treatment, and each precursor resin layer imidization of polyamic acid. In this manner, a single-sided CCL in which multiple polyimide layers were laminated was produced.

Furthermore, it is also possible to temporarily imidize the layer of a single-layer or multi-layer polyamic acid coating film to form a single-layer or multi-layer polyimide layer, and then further form a polyamic acid layer on it. coating film.

The single-sided CCL obtained in the described manner has a layered layer on the copper foil layer 10A There is a structure of a resin laminate 50 . The resin laminate 50 is, for example, sequentially laminated from the copper foil layer 10A side with a thermoplastic polyimide layer 20A, a non-thermoplastic polyimide layer 30A, a thermoplastic polyimide layer 40A, a thermoplastic polyimide layer 40B, a non-thermoplastic polyimide layer Polyimide layer 30B and thermoplastic polyimide layer 20B.

When the purpose is to manufacture the double-sided CCL 100 , thermocompression bonding of copper foil may be further performed in addition to the above steps.

In the thermocompression bonding step, a new copper foil (not shown) is laminated by thermocompression bonding a new copper foil (not shown) on the side opposite to the copper foil layer 10A in the single-sided CCL (that is, on the thermoplastic polyimide layer 20B). Copper foil layer 10B. Thereby, the double-sided CCL 100 having the structure shown in FIG. 1 can be obtained. The thermocompression bonding of new copper foil and single-sided CCL is preferably carried out while being conveyed by a roll-to-roll system using a pair of heating rolls.

In the second method, the formation and imidization of the coating film by the casting method can be carried out in the same manner as the first method.

[Polyimide]

Next, preferable polyimides constituting the resin laminate 50 will be described in order of non-thermoplastic polyimide and thermoplastic polyimide.

<Non-thermoplastic polyimide>

The non-thermoplastic polyimide constituting the second polyimide layer (non-thermoplastic polyimide layer) contains tetracarboxylic acid residues and diamine residues. In addition, in this invention, a tetracarboxylic-acid residue shows the tetravalent group derived from tetracarboxylic dianhydride, and a diamine residue shows the divalent group derived from a diamine compound. The polyimide preferably comprises aromatic tetracarboxylic acid residues derived from aromatic tetracarboxylic dianhydrides and aromatic diamines derived from aromatic diamines. group of diamine residues.

(tetracarboxylic acid residue)

The non-thermoplastic polyimide that constitutes the non-thermoplastic polyimide layer contains 3,3',4,4'-biphenyltetracarboxylic dianhydride (BPDA) and 1,4-phenylene bis(trimellitic Tetracarboxylic acid residues derived from at least one of formic acid monoester) dianhydride (TAHQ), and pyromellitic dianhydride (PMDA) and 2,3,6,7-naphthalene tetracarboxylic dianhydride (NTCDA ) at least one derived tetracarboxylic acid residue as the tetracarboxylic acid residue.

Tetracarboxylic acid residues derived from BPDA (hereinafter also referred to as "BPDA residues") and tetracarboxylic acid residues derived from TAHQ (hereinafter also referred to as "TAHQ residues") easily form polymers The ordered structure can reduce the dielectric tangent or hygroscopicity by inhibiting the movement of molecules. However, on the other hand, BPDA residues can impart self-supporting properties to the gel film of polyamic acid, which is a precursor of polyimide, but appear to increase the CTE after imidization and lower the glass transition temperature. And the tendency to reduce heat resistance.

From this point of view, the total amount of non-thermoplastic polyimide constituting the non-thermoplastic polyimide layer is preferably 30 mole parts or more and 60 mole parts with respect to 100 mole parts of tetracarboxylic acid residues. It is controlled so that BPDA residues and TAHQ residues are contained within the range of 40 mole parts or less, more preferably 40 mole parts or more and 50 mole parts or less. If the total of BPDA residues and TAHQ residues is less than 30 mole parts, the formation of the ordered structure of the polymer becomes insufficient, the moisture absorption resistance decreases, or the reduction of the dielectric tangent becomes insufficient. If it exceeds 60 If the molar portion is used, in addition to an increase in CTE or an increase in the amount of change in in-plane retardation (RO), there is a possibility that heat resistance will decrease.

In addition, tetracarboxylic acid residues derived from pyromellitic dianhydride (hereinafter also referred to as "PMDA residues") and tetracarboxylic acid residues derived from 2,3,6,7-naphthalene tetracarboxylic dianhydride Acid residues (hereinafter, also referred to as "NTCDA residues") have rigidity, so they improve in-plane alignment, lower CTE suppression, and are responsible for controlling in-plane retardation (RO) or glass transition temperature. active residues. On the other hand, since the PMDA residue has a small molecular weight, if its amount becomes too much, the concentration of the imide group of the polymer becomes high, the polar group increases and the hygroscopicity becomes large, and due to the influence of moisture inside the molecular chain. Electric tangent increases. In addition, the NTCDA residue tends to increase the modulus of elasticity by easily making the film brittle due to the highly rigid naphthalene skeleton.

Therefore, the total amount of non-thermoplastic polyimide constituting the non-thermoplastic polyimide layer is preferably 40 mole parts or more and 70 mole parts or less with respect to 100 mole parts of tetracarboxylic acid residues, More preferably, the PMDA residue and the NTCDA residue are contained within the range of 50 molar parts or more and 60 molar parts or less, more preferably in the range of 50 molar parts to 55 molar parts. If the total of PMDA residues and NTCDA residues is less than 40 molar parts, there is a possibility that the CTE increases or the heat resistance decreases, and if it exceeds 70 molar parts, the concentration of the imide group of the polymer becomes high, and the polar group Increase and low hygroscopicity may be impaired, the dielectric tangent may increase, or the film may become brittle and the self-supporting property of the film may decrease.

In addition, the total of at least one of BPDA residues and TAHQ residues, and at least one of PMDA residues and NTCDA residues may be 80 mole parts or more relative to 100 mole parts of tetracarboxylic acid residues, Preferably it is more than 90 mole parts.

In addition, the molar ratio of at least one of BPDA residues and TAHQ residues to at least one of PMDA residues and NTCDA residues {(BPDA residues +TAHQ residue)/(PMDA residue+NTCDA residue)} is set within the range of 0.4 to 1.5, preferably 0.6 to 1.3, more preferably 0.8 to 1.2 , to control the formation of ordered structures of CTE and polymers.

PMDA and NTCDA have a rigid skeleton, so compared with other general anhydride components, they can control the in-plane alignment of molecules in polyimide, and have the effect of suppressing the coefficient of thermal expansion (CTE) and improving the glass transition temperature (Tg) . In addition, since BPDA and TAHQ have larger molecular weights than PMDA, the concentration of imide groups decreases due to an increase in the loading ratio, which is effective in reducing the dielectric tangent or the moisture absorption rate. On the other hand, when the loading ratio of BPDA and TAHQ increases, the in-plane alignment of molecules in polyimide decreases, leading to an increase in CTE. Furthermore, the formation of an ordered structure in the molecule is promoted, and the haze value increases. From this point of view, the total charged amount of PMDA and NTCDA can be within the range of 40 mole parts to 70 mole parts, preferably 50 mole parts relative to 100 mole parts of all acid anhydride components of the raw material. ~60 molar parts, more preferably 50 ~55 molar parts. If the total loading amount of PMDA and NTCDA is less than 40 mole parts with respect to 100 mole parts of all the acid anhydride components of the raw material, the in-plane alignment of the molecules will decrease, and it will be difficult to achieve a low CTE, and the Tg will also decrease. The resulting heat resistance or dimensional stability of the film during heating decreases. On the other hand, if the total loading amount of PMDA and NTCDA exceeds 70 molar parts, the moisture absorption rate will deteriorate due to the increase of the imide group concentration, or the modulus of elasticity will tend to increase.

In addition, BPDA and TAHQ have an effect on the inhibition of molecular motion or the reduction of the dielectric tangent and the decrease of the moisture absorption rate caused by the decrease of the imide group concentration, but they will cause The CTE of the imidized polyimide film increases. From this point of view, the total charged amount of BPDA and TAHQ may be within the range of 30 mole parts to 60 mole parts, preferably 40 mole parts relative to 100 mole parts of all acid anhydride components of the raw material. ~50 molar parts, more preferably 40 ~45 molar parts.

As tetracarboxylic acid residues other than the BPDA residue, TAHQ residue, PMDA residue, and NTCDA residue contained in the non-thermoplastic polyimide constituting the non-thermoplastic polyimide layer, for example, 3 ,3',4,4'-Diphenyltetracarboxylic dianhydride, 4,4'-oxydiphthalic anhydride, 2,3',3,4'-biphenyltetracarboxylic dianhydride , 2,2',3,3'-benzophenone tetracarboxylic dianhydride, 2,3,3',4'-benzophenone tetracarboxylic dianhydride or 3,3',4,4' -Benzophenone tetracarboxylic dianhydride, 2,3',3,4'-diphenyl ether tetracarboxylic dianhydride, bis(2,3-dicarboxyphenyl)ether dianhydride, 3,3" ,4,4"-terphenyltetracarboxylic dianhydride, 2,3,3",4"-terphenyltetracarboxylic dianhydride or 2,2",3,3"-terphenyltetracarboxylic dianhydride Dianhydride, 2,2-bis(2,3-dicarboxyphenyl)-propane dianhydride or 2,2-bis(3,4-dicarboxyphenyl)-propane dianhydride, bis(2,3-di Carboxyphenyl)methane dianhydride or bis(3,4-dicarboxyphenyl)methane dianhydride, bis(2,3-dicarboxyphenyl)pyridine dianhydride or bis(3,4-dicarboxyphenyl)pyridine Dianhydride, 1,1-bis(2,3-dicarboxyphenyl)ethanedianhydride or 1,1-bis(3,4-dicarboxyphenyl)ethanedianhydride, 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-naphthalene Tetracarboxylic dianhydride, 1,4,5,8-naphthalene tetracarboxylic dianhydride, 4,8-dimethyl-1,2,3,5,6,7-hexahydronaphthalene-1,2,5 ,6-tetracarboxylic dianhydride, 2,6-dichloronaphthalene-1,4,5,8-tetracarboxylic dianhydride or 2,7-dichloronaphthalene-1,4,5,8-tetracarboxylic acid Dianhydride, 2,3,6,7-(or 1,4,5,8-)tetrachloronaphthalene-1,4,5,8-(or 2,3,6,7-)tetracarboxylic dianhydride , 2,3,8,9-perylene-tetracarboxylic dianhydride, 3,4,9,10-perylene-tetracarboxylic dianhydride, 4,5,10,11-perylene-tetracarboxylic dianhydride or 5,6,11,12-perylene-tetracarboxylic dianhydride, cyclopenta Alkane-1,2,3,4-tetracarboxylic dianhydride, pyrazine-2,3,5,6-tetracarboxylic dianhydride, pyrrolidine-2,3,4,5-tetracarboxylic dianhydride, Aromatic tetracarboxylic acid such as thiophene-2,3,4,5-tetracarboxylic dianhydride, 4,4'-bis(2,3-dicarboxyphenoxy)diphenylmethane dianhydride, ethylene glycol bis-trimellitic anhydride, etc. Tetracarboxylic acid residues derived from acid dianhydrides.

(diamine residue)

As a diamine residue contained in the non-thermoplastic polyimide which comprises a non-thermoplastic polyimide layer, the diamine residue derived from the diamine compound represented by General formula (A1) is preferable.

In the formula (A1), the linking group X represents a single bond or a divalent group selected from -COO-, Y independently represents hydrogen, a monovalent hydrocarbon group or an alkoxy group with 1 to 3 carbons, and n represents 0 to 2 Integer, p and q independently represent the integer of 0-4. Here, "independently" means that a plurality of substituents Y in the formula (A1), and the integers p and q may be the same or different. Furthermore, in the formula (A1), the hydrogen atoms in the two terminal amine groups may be substituted, for example, -NR ₃ R ₄ (here, R ₃ and R ₄ independently represent any arbitrary group such as an alkyl group. substituents).

The diamine compound represented by the general formula (A1) (hereinafter, may be referred to as "diamine (A1)") is an aromatic diamine having at least one benzene ring. Since diamine (A1) has a rigid structure, it has the effect of imparting an ordered structure to the whole polymer. Therefore, polyimide with low gas permeability and low hygroscopicity can be obtained, and the moisture inside the molecular chain can be reduced, so the dielectric tangent can be reduced. Here, the linking group X is preferably a single bond.

Examples of the diamine (A1) include 1,4-diaminobenzene (p-phenylenediamine (p-PDA)), 2,2'-dimethyl-4,4'-di Aminobiphenyl (m-TB), 2,2'-n-propyl-4,4'-diaminobiphenyl (2,2'-n-propyl-4,4'-diamino biphenyl, m-NPB ), 4-aminophenyl-4'-aminobenzoate (4-aminophenyl-4'-amino benzoate, APAB), etc. Among these, 2,2'-dimethyl-4,4'-diaminobiphenyl (m-TB) which has a large effect of imparting an ordered structure to the whole polymer by a rigid structure is most suitable.

The non-thermoplastic polyimide constituting the non-thermoplastic polyimide layer may contain preferably 80 mole parts or more, more preferably 85 mole parts or more, of diamine ( A1) Derivatized diamine residues. By using the diamine (A1) in an amount within the above range, it is easy to form an ordered structure for the entire polymer by utilizing the rigid structure derived from the monomer, and it is easy to obtain low air permeability, low hygroscopicity and low dielectric strength. Tangential non-thermoplastic polyimide.

In addition, the diamine residue derived from diamine (A1) is in the range of 80 mole parts or more and 85 mole parts or less with respect to 100 mole parts of the diamine residue in the non-thermoplastic polyimide In the case of , it is more rigid and has excellent in-plane alignment From a structural viewpoint, it is preferable to use 1, 4- diaminobenzene as diamine (A1).

Examples of other diamine residues contained in the non-thermoplastic polyimide layer constituting the non-thermoplastic polyimide layer include 2,2-bis-[4-(3-aminophenoxy)phenyl ]propane, bis[4-(3-aminophenoxy)phenyl]pyridine, bis[4-(3-aminophenoxy)]biphenyl, bis[1-(3-aminophenoxy) )]biphenyl, bis[4-(3-aminophenoxy)phenyl]methane, bis[4-(3-aminophenoxy)phenyl]ether, bis[4-(3-aminophenoxy) Phenoxy)]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'-diaminobis Benzene, 4,4'-methylenedi-o-toluidine, 4,4'-methylenebis-2,6-xylaniline, 4,4'-methylene-2,6-diethylaniline , 3,3'-diaminodiphenylethane, 3,3'-diaminobiphenyl, 3,3'-dimethoxybenzidine, 3,3"-diamino-p-terphenyl, 4,4'-[1,4-Phenylbis(1-methylethylene)]bisaniline, 4,4'-[1,3-Phenylbis(1-methylethylene) ] Dianiline, bis(p-aminocyclohexyl)methane, bis(p-β-aminotert-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-aminotert-butyl)toluene, 2,4-diaminotoluene, m-xylene-2,5-diamine, p-xylene-2,5- Diamine, m-xylylenediamine, p-xylylenediamine, 2,6-diaminopyridine, 2,5-diaminopyridine, 2,5-diamino-1,3,4-oxadiazole , piperazine, 2'-methoxy-4,4'-diaminobenzamide, 4,4'-diaminobenzamide, 1,3-bis[2-(4-amino Diamine residues derived from aromatic diamine compounds such as phenyl)-2-propyl]benzene, 6-amino-2-(4-aminophenoxy)benzoxazole, and dimer acid The two terminal carboxylic acid groups are replaced by aliphatic diamine compounds such as dimer acid diamines with primary aminomethyl groups or amino groups. Derivatized diamine residues.

In the non-thermoplastic polyimide, by selecting the kinds of the tetracarboxylic acid residues and diamine residues, or the respective molar ratios when two or more kinds of tetracarboxylic acid residues or diamine residues are used, it is possible to Control thermal expansion coefficient, storage elastic coefficient, tensile elastic coefficient, etc. In addition, in the case of non-thermoplastic polyimide, in the case of having a plurality of structural units of polyimide, it may exist in the form of a block or randomly, but in order to suppress the deviation of the in-plane retardation (RO) From a viewpoint, random existence is preferable.

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

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

The weight average molecular weight of the non-thermoplastic polyimide is, for example, preferably within a range of 10,000 to 400,000, more preferably within a range of 50,000 to 350,000. When the weight average molecular weight is less than 10,000, the strength of the film tends to decrease and tend to become brittle. On the other hand, if the weight-average molecular weight exceeds 400,000, the viscosity will increase excessively, and problems such as uneven film thickness and streaks will easily occur during coating operations. tendency.

<Thermoplastic polyimide>

The thermoplastic polyimide constituting the first polyimide layer (thermoplastic polyimide layer) contains tetracarboxylic acid residues and diamine residues, and preferably contains aromatic tetracarboxylic acid dianhydrides derived from aromatic tetracarboxylic acid dianhydrides. Aromatic tetracarboxylic acid residues and aromatic diamine residues derived from aromatic diamines.

(tetracarboxylic acid residue)

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

(diamine residue)

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

[Chem 2]

In the formula (B1) ~ formula (B7), R ₁ independently represents a monovalent hydrocarbon group or alkoxy group with 1 to 6 carbons, and the linking group A independently represents a group selected from -O-, -S-, -CO-, A divalent group in -SO-, -SO ₂ -, -COO-, -CH ₂ -, -C(CH ₃ ) ₂ -, -NH- or -CONH-, n ₁ independently represents an integer of 0~4 . Among them, the duplicates of formula (B2) are removed from formula (B3), and the duplicates of formula (B4) are removed from formula (B5). Here, the so-called "independently" means that in one formula or two or more formulas in the formula (B1) ~ formula (B7), multiple linking groups A, multiple R ₁ or multiple n ₁ may be the same or different . Furthermore, in the formulas (B1) to (B7), the hydrogen atoms in the two terminal amine groups may be substituted, for example, -NR ₃ R ₄ (here, R ₃ and R ₄ are independently represents an arbitrary substituent such as an alkyl group).

Diamine represented by formula (B1) (hereinafter, may be described as "diamine (B1)") is an aromatic diamine having two benzene rings. It is considered that the diamine (B1) is in the meta-position between the amine group directly bonded to at least one benzene ring and the divalent linking group A, and the polyimide molecular chain has increased degrees of freedom and high flexibility, Contributes to the improvement of the flexibility of the polyimide molecular chain. Therefore, the thermoplasticity of polyimide improves by using diamine (B1). Here, the linking group A is preferably -O-, -CH ₂ -, -C(CH ₃ ) ₂ -, -CO-, -SO ₂ -, -S-.

Examples of the diamine (B1) include: 3,3'-diaminodiphenylmethane, 3,3'-diaminodiphenylpropane, 3,3'-diaminodiphenylsulfide , 3,3'-diaminodiphenyl ether, 3,3'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 3,4'-diaminodiphenyl methyl methane, 3,4'-diaminodiphenylpropane, 3,4'-diaminodiphenylsulfide, 3,3'-diaminobenzophenone, (3,3'-bis Amino) diphenylamine, etc.

Diamine represented by formula (B2) (hereinafter, may be described as "diamine (B2)") is an aromatic diamine having three benzene rings. It is considered that the diamine (B2) is in the meta-position between the amine group directly bonded to at least one benzene ring and the divalent linking group A, and the polyimide molecular chain has increased degrees of freedom and high flexibility, Contributes to the improvement of the flexibility of the polyimide molecular chain. Therefore, the thermoplasticity of polyimide improves by using diamine (B2). Here, the linking group A is preferably -O-.

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

Diamine represented by formula (B3) (hereinafter, may be described as "diamine (B3)") is an aromatic diamine having three benzene rings. It is considered that the diamine (B3) is in the meta-position to each other through two divalent linking groups A directly bonded to a benzene ring, and the polyimide molecular chain has increased degrees of freedom and high flexibility. Contributes to the improvement of the flexibility of the polyimide molecular chain. Therefore, by using diamine (B3), the thermoplasticity of polyimide improves. Here, the linking group A is preferably -O-.

Examples of the diamine (B3) include: 1,3-bis(4-aminophenoxy)benzene (1,3-Bis(4-aminophenoxy)benzene, TPE-R), 1,3-bis( 3-aminophenoxy)benzene (1,3-Bis(3-aminophenoxy)benzene, APB), 4,4'-[2-methyl-(1,3-phenylene)dioxy]bis Aniline, 4,4'-[4-methyl-(1,3-phenylene)dioxy]bisaniline, 4,4'-[5-methyl-(1,3-phenylene)bis Oxygen] dianiline, etc.

Diamine represented by formula (B4) (hereinafter, may be described as "diamine (B4)") is an aromatic diamine having four benzene rings. It is believed that the diamine (B4) has high flexibility due to the fact that the amine group directly bonded to at least one benzene ring is in the meta-position with the divalent linking group A, which contributes to the flexibility of the polyimide molecular chain improvement. Therefore, by using diamine (B4), the thermoplasticity of polyimide improves. Here, the linking group A is preferably -O-, -CH ₂ -, -C(CH ₃ ) ₂ -, -SO ₂ -, -CO-, -CONH-.

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

Diamine represented by formula (B5) (hereinafter, may be described as "diamine (B5)") is an aromatic diamine having four benzene rings. It is considered that the diamine (B5) is in the meta-position to each other through two divalent linking groups A directly bonded to at least one benzene ring, and the polyimide molecular chain has increased degrees of freedom and high flexibility, Contributes to the improvement of the flexibility of the polyimide molecular chain. Therefore, by using diamine (B5), the thermoplasticity of polyimide improves. Here, the linking group A is preferably -O-.

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

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

Examples of diamines (B6) include 2,2-bis[4-(4-aminophenoxy)phenyl]propane (2,2-Bis[4-(4-aminophenoxy)phenyl]propane, BAPP), bis[4-(4-aminophenoxy)phenyl]ether (Bis[4-(4-aminophenoxy)phenyl]ether, BAPE), bis[4-(4-aminophenoxy) Phenyl]sulfone (Bis[4-(4-aminophenoxy)phenyl]sulfone, BAPS), bis[4-(4-aminophenoxy)phenyl]ketone (Bis[4-(4-aminophenoxy)phenyl] ketone, BAPK) and so on.

Diamine represented by formula (B7) (hereinafter, may be described as "diamine (B7)") is an aromatic diamine having four benzene rings. Since the diamine (B7) has a highly flexible divalent linking group A on both sides of the diphenyl skeleton, it is considered that it contributes to the improvement of the flexibility of the polyimide molecular chain. Therefore, by using diamine (B7), the thermoplasticity of polyimide improves. Here, the linking group A is preferably -O-.

As diamine (B7), bis[4-(3-aminophenoxy)]biphenyl, bis[4-(4-aminophenoxy)]biphenyl etc. are mentioned, for example.

The thermoplastic polyimide constituting the thermoplastic polyimide layer may be within a range of 60 mole parts or more, preferably 60 mole parts or more and 99 mole parts or less, relative to 100 mole parts of diamine residues. , More preferably, a diamine residue derived from at least one diamine compound selected from diamine (B1) to diamine (B7) is contained in the range of 70 mole parts or more and 95 mole parts or less. Diamines (B1) to diamines (B7) contain a flexible molecular structure, so by using at least one diamine compound selected from these compounds in an amount within the range, the polyimide can be improved. Molecular chain flexibility, and impart thermoplasticity. When the total amount of diamine (B1) to diamine (B7) is less than 60 mole parts with respect to 100 mole parts of all diamine components, the flexibility of the polyimide resin is insufficient and sufficient thermoplasticity cannot be obtained. .

Moreover, as a diamine residue contained in the thermoplastic polyimide which comprises a thermoplastic polyimide layer, the diamine residue derived from the diamine compound represented by general formula (A1) is also preferable. The diamine compound [diamine (A1)] represented by the formula (A1) is as described in the description of the non-thermoplastic polyimide. Diamine (A1) has a rigid structure and has the effect of imparting an ordered structure to the polymer as a whole, so it can be inhibited by The movement of molecules reduces the dielectric tangent or hygroscopicity. Furthermore, by using it as a raw material for thermoplastic polyimide, polyimide having low air permeability and excellent long-term heat-resistant adhesion can be obtained.

The thermoplastic polyimide constituting the thermoplastic polyimide layer can be preferably within the range of 1 mole part or more and 40 mole parts or less, more preferably 5 mole parts or more and 30 mole parts or less. Contains a diamine residue derived from diamine (A1). By using the diamine (A1) in an amount within the above range, the polymer as a whole forms an ordered structure by utilizing the rigid structure derived from the monomer, so that it is thermoplastic and has low air permeability and hygroscopicity, and long-term heat resistance can be obtained. Polyimide with excellent adhesion.

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

In thermoplastic polyimides, by selecting the types of the tetracarboxylic acid residues and diamine residues, or the respective molar ratios when two or more tetracarboxylic acid residues or diamine residues are used, it is possible to control Coefficient of thermal expansion, tensile modulus of elasticity, glass transition temperature, etc. In addition, in thermoplastic polyimide, when having a plurality of structural units of polyimide, it may exist in the form of a block or may exist randomly, but it is preferably present randomly.

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

The imide group concentration of the thermoplastic polyimide is preferably 33% by weight or less. Here, the "imide group concentration" means a value obtained by dividing the molecular weight of the imide group (-(CO) ₂ -N-) in the polyimide by the molecular weight of the entire structure of the polyimide. If the imide group concentration exceeds 33% by weight, the molecular weight of the resin itself decreases, and the low hygroscopicity also deteriorates due to the increase of polar groups. By controlling the alignment of molecules in the thermoplastic polyimide by selecting the combination of the diamine compounds, the increase in CTE accompanying the decrease in the concentration of imide groups is suppressed, and low hygroscopicity is ensured.

The weight average molecular weight of the thermoplastic polyimide is, for example, preferably within a range of 10,000 to 400,000, more preferably within a range of 50,000 to 350,000. When the weight average molecular weight is less than 10,000, the strength of the film tends to decrease and tend to become brittle. On the other hand, if the weight-average molecular weight exceeds 400,000, the viscosity tends to increase excessively, and defects such as film thickness unevenness and streaks tend to easily occur during coating operations.

The thermoplastic polyimide constituting the thermoplastic polyimide layer is, for example, an adhesive layer in an insulating resin of a circuit board. Therefore, in order to suppress diffusion of copper, a completely imidized structure is preferable. Among them, a part of the polyimide may also be an amide acid. The imidization rate is to use a Fourier transform infrared spectrophotometer (commercially available: FT/IR620 manufactured by JASCO), and utilize a reflection attenuated total reflection (Attenuated Total Reflectance, ATR) method to measure the polyimide film Based on the infrared absorption spectrum of 1015cm ^-1 , the absorbance derived from the C=O stretching of the imide group was calculated based on the benzene ring absorber around 1015cm ^-1 .

(Synthesis of Polyimide)

The polyimide constituting the resin laminate 50 can be produced by reacting the acid anhydride and diamine in a solvent, and heating to close the ring after forming a precursor resin. For example, approximately equimolar acid anhydride components and diamine components are dissolved in an organic solvent, and The polyamic acid which is a polyimide precursor can be obtained by carrying out a polymerization reaction by performing stirring at the temperature in the range of 0 degreeC - 100 degreeC for 30 minutes - 24 hours. During 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 10% by weight to 20% by weight, in the organic solvent. Examples of the organic solvent used in the polymerization reaction include N,N-dimethylformamide, N,N-dimethylacetamide (N,N-dimethyl acetamide, DMAc), N-methyl- 2-pyrrolidone, 2-butanone, dimethylsulfide, dimethyl sulfate, cyclohexanone, dioxane, tetrahydrofuran, diglyme, triethylene glycol dimethyl ether wait. These solvents may be used in combination of two or more, and further aromatic hydrocarbons such as xylene and toluene may also be used in combination. In addition, the amount of the organic solvent used is not particularly limited, but it is preferably adjusted so that the concentration of the polyamic acid solution (polyimide precursor solution) obtained by the polymerization reaction becomes 5% by weight to 5% by weight. It is used in an amount of about 30% by weight.

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

Synthetic precursors are generally advantageously used as reaction solvent solutions, but can be concentrated, diluted or replaced with other organic solvents as needed. In addition, precursors are generally excellent in solvent solubility, so they can be used advantageously. The method for imidizing the precursor is not particularly limited. For example, the following heat treatment can be preferably used: in the solvent at a temperature in the range of 80° C. to 400° C. for 1 hour to 24 hours. heating.

<circuit board>

The circuit board of this embodiment can be manufactured by processing the metal layer of a metal-clad laminate into a pattern shape by a conventional method, and forming a wiring layer. The patterning of the metal layer can be performed by any method such as photolithography and etching, for example.

In addition, when manufacturing a circuit board, as a process normally performed, for example, the processing of a through-hole in the previous process, or the process of terminal plating and outline processing in a subsequent process, etc., can be performed according to a conventional method.

As described above, by using the metal-clad laminate of this embodiment as a circuit board material represented by FPC, it can impart excellent impedance matching to the circuit board and improve the transmission characteristics of electrical signals, thereby improving the reliability of electronic equipment.

[Example]

Examples are shown below, and the features of the present invention will be described more specifically. However, the scope of the present invention is not limited to the Examples. In addition, in the following examples, unless otherwise specified, various measurements and evaluations used the following.

[Measurement of viscosity]

The viscosity was measured using an E-type viscometer (manufactured by Brookfield, trade name: DV-II+Pro), and the viscosity in 25 degreeC was measured. Set the rotational speed so that the torque becomes 10% to 90%, and read the value when the viscosity is stable 2 minutes after the start of the measurement.

[Measurement of glass transition temperature (Tg)]

Regarding the glass transition temperature, using a dynamic viscoelasticity measuring device (DMA: manufactured by UBM Corporation, trade name: E4000F), from 30°C to 400°C, at a heating rate of 4°C/min and a frequency of 1 Hz for 5mm x 20mm The measurement was performed on a polyimide film having a size of , and the temperature at which the elastic coefficient change (tan δ) was the maximum was defined as the glass transition temperature. In addition, the storage modulus of elasticity at 30°C measured using DMA is 1.0×10 ⁹ Pa or more and the storage modulus of elasticity at 300°C is less than 3.0×10 ⁸ Pa as "thermoplastic", and the temperature at 30°C is displayed. A storage modulus of 1.0×10 ⁹ Pa or more and a storage modulus of 3.0×10 ⁸ Pa or more at 300° C. were defined as “non-thermoplastic”.

[Measurement of Coefficient of Thermal Expansion (CTE)]

Using a thermomechanical analyzer (manufactured by Bruker, trade name: 4000SA), while applying a load of 5.0 g to a polyimide film having a size of 3 mm×20 mm, the temperature was raised from 30° C. to After keeping at the temperature for 10 minutes up to 265°C, it was cooled at a rate of 5°C/min, and the average coefficient of thermal expansion (coefficient of thermal expansion) from 250°C to 100°C was obtained.

[Measurement of moisture absorption rate]

Two test pieces (width 4 cm x length 25 cm) of the polyimide film were prepared, and dried at 80° C. for 1 hour. Immediately after drying, put it in a constant temperature and humidity room at 23°C/50%RH, let it stand for more than 24 hours, and use the following formula to calculate the weight change before and after.

Moisture absorption rate (weight%)=[(weight after moisture absorption-weight after drying)/weight after drying]×100

[Measurement of dielectric constant and dielectric tangent]

Dielectric constant and dielectric tangent were measured on a resin sheet (hardened resin sheet) at a frequency of 10 GHz using a vector network analyzer (manufactured by Agilent, trade name: Vector Network Analyzer E8363C) and an SPDR resonator. The dielectric constant (ε ₁ ) and dielectric tangent (Tanδ ₁ ). In addition, the resin sheet used in the measurement was the thing left for 24 hours under the conditions of temperature: 24-26 degreeC, and humidity: 45%-55%.

In addition, E _{1 ,} which is an index showing the dielectric properties of the resin laminate, was calculated based on the above formula (a).

[Measurement of Surface Roughness of Copper Foil]

Determination of ten-point average roughness (Rz) and arithmetic mean height (Ra):

Using a stylus surface roughness meter (manufactured by Kosaka Laboratory Co., Ltd., trade name: SURFCODER ET-3000), by force (Force): 100μN, speed (Speed): 20μm, range (Range) ): Obtained under the measurement conditions of 800 μm. Furthermore, the calculation of the surface roughness was calculated according to the method of Japanese Industrial Standards (Japanese Industrial Standards, JIS)-B0601:1994.

[Measurement of Peel Strength]

After the metal-clad laminate was processed to a width of 1.0 mm, it was cut into a width: 8 cm×length: 4 cm, and a measurement sample was prepared. Using a Tensilon Tester (manufactured by Toyo Seiki Seisakusho, trade name: Strograph VE-1D), fix one side of the measurement sample on an aluminum plate with double-sided tape, and test the other side , peel 10mm along the 90° direction at a speed of 50mm/min, and obtain the central strength at this time. "Copper foil peel strength" is the peel strength when the copper foil layer on the casting side and the resin laminate interface are peeled off, and "The peel strength of the thermocompression bonded surface" is the Peel strength when the bonded surfaces of two resin layers bonded by thermocompression are peeled off.

The abbreviations used in the synthesis examples indicate the following compounds.

BTDA: 3,3',4,4'-Benzophenone tetracarboxylic dianhydride

PMDA: pyromellitic dianhydride

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

DSDA: 3,3',4,4'-Diphenyltetracarboxylic dianhydride

DAPE: 4,4'-Diaminodiphenyl ether

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

m-TB: 2,2'-dimethyl-4,4'-diaminobiphenyl

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

DMAc: N,N-Dimethylacetamide

(Synthesis Example 1)

312 g of DMAc was placed in a reaction vessel equipped with a thermocouple and a stirrer and capable of introducing nitrogen gas. 14.67 g of DAPE (0.073 moles) was stirred and dissolved in the vehicle in a vessel. Next, 23.13 g of BTDA (0.072 mol) was added. Thereafter, the stirring was continued for 3 hours, and the viscosity of the prepared solution was 2,960mPa. s polyamide resin solution a.

Next, on one side (Rz: 2.1 μm) of an electrolytic copper foil with a thickness of 12 μm, the resin solution a of polyamic acid is uniformly applied so that the thickness after curing becomes about 25 μm, and then heated and dried at 120° C. Remove solvent. Furthermore, stepwise heat treatment is performed from 120°C to 360°C within 30 minutes to complete imidization. Copper foil is etched away using ferric chloride aqueous solution to prepare polyimide film a (thermoplasticity, Tg: 283°C, CTE: 53ppm/K, moisture absorption rate: 1.30% by weight).

(Synthesis Example 2)

312 g of DMAc was placed in a reaction vessel equipped with a thermocouple and a stirrer and capable of introducing nitrogen gas. 6.60 g of spherical fillers (silicon dioxide, average particle diameter: 1.2 μm, manufactured by ADMATECHS, “SE4050”) were added to the reaction vessel, and dispersed for 3 hours by an ultrasonic disperser. 14.67 g of DAPE (0.073 moles) was stirred and dissolved in the solution in a vessel. Next, 23.13 g of BTDA (0.072 mol) was added. Thereafter, the stirring was continued for 3 hours, and the viscosity of the prepared solution was 3,160mPa. The polyamic acid resin solution b (silicon dioxide content: 10% by volume) of s.

(Synthesis Example 3)

308 g of DMAc was placed in a reaction vessel equipped with a thermocouple and a stirrer and capable of introducing nitrogen gas. 27.14 g of BAPP (0.066 moles) were stirred and dissolved in the vehicle in a vessel. Next, 14.86 g of PMDA (0.068 mol) was added. Thereafter, the stirring was continued for 3 hours, and the viscosity of the prepared solution was 2,850mPa. s polyamide resin solution c. A polyimide film c (thermoplastic, Tg: 312° C., CTE: 55 ppm/K, moisture absorption rate: 0.54% by weight) was prepared in the same manner as in Synthesis Example 1 using the resin solution c.

(Synthesis Example 4)

308 g of DMAc was placed in a reaction vessel equipped with a thermocouple and a stirrer and capable of introducing nitrogen gas. 22.57 g of m-TB (0.106 moles) were stirred and dissolved in the vehicle in a vessel. Next, 6.20 g of BPDA (0.021 mol) and 18.37 g of PMDA (0.084 mol) were added. Thereafter, stirring was continued for 3 hours, The viscosity of the prepared solution is 20,000mPa. s polyamide resin solution d. Polyimide film d (non-thermoplastic, Tg: 385° C., CTE: 15 ppm/K) was prepared in the same manner as in Synthesis Example 1 using resin solution d.

(Synthesis Example 5)

255 g of DMAc was placed in a reaction vessel equipped with a thermocouple and a stirrer and capable of introducing nitrogen gas. 22.13 g of TPE-R (0.076 moles) were stirred and dissolved in the vehicle in a vessel. Next, 16.17 g of DSDA (0.047 mol) and 6.78 g of PMDA (0.031 mol) were added. Thereafter, the stirring was continued for 2 hours, and the viscosity of the prepared solution was 2,640mPa. s polyamide resin solution e. A polyimide film e (thermoplastic, Tg: 277° C., CTE: 61 ppm/K, moisture absorption rate: 0.90% by weight) was produced in the same manner as in Synthesis Example 1 using the resin solution e.

(Synthesis Example 6)

200 g of DMAc was placed in a reaction vessel equipped with a thermocouple and a stirrer and capable of introducing nitrogen gas. 1.335 g of m-TB (0.0063 mol) and 10.414 g of TPE-R (0.0356 mol) were stirred and dissolved in the vehicle in a vessel. Next, 0.932 g of PMDA (0.0043 mol) and 11.319 g of BPDA (0.0385 mol) were added. Thereafter, the stirring was continued for 2 hours, and the viscosity of the prepared solution was 1,420mPa. s polyamide resin solution f. Using the resin solution f, a polyimide film f (thermoplastic, Tg: 220° C., CTE: 52 ppm/K, moisture absorption rate: 0.36% by weight) was produced in the same manner as in Synthesis Example 1.

(Synthesis Example 7)

Add 250 DMAc for g. 12.323 g of m-TB (0.0580 mol) and 1.886 g of TPE-R (0.0064 mol) were stirred and dissolved in the vehicle in a vessel. Next, 8.314 g of PMDA (0.0381 mol) and 7.477 g of BPDA (0.0254 mol) were added. Thereafter, the stirring was continued for 3 hours, and the viscosity of the prepared solution was 31,500mPa. s polyamide resin solution g. Using the resin solution g, polyimide film g (non-thermoplastic, Tg: 303° C., CTE: 15.6 ppm/K, moisture absorption rate: 0.61% by weight) was produced in the same manner as in Synthesis Example 1.

[Example 1]

On the surface of long electrodeposited copper foil (Rz: 0.8μm, Ra: 0.2μm), apply resin solution f uniformly so that the thickness after curing becomes about 2μm~3μm, heat and dry at 120℃, remove solvent. Next, the resin solution g was uniformly applied thereon so that the thickness after curing was about 21 μm, and then heated and dried at 120° C. to remove the solvent. Furthermore, after the resin solution b was uniformly apply|coated so that the thickness after hardening may become about 2 micrometers - 3 micrometers, it heat-dried at 120 degreeC, and removed the solvent. Furthermore, after the resin solution f was uniformly apply|coated so that the thickness after hardening may become about 2 micrometers - 3 micrometers, it heat-dried at 120 degreeC, and removed the solvent. Next, the resin solution g was uniformly applied thereon so that the thickness after curing was about 21 μm, and then heated and dried at 120° C. to remove the solvent. Furthermore, after the resin solution f was uniformly apply|coated so that the thickness after hardening may become about 2 micrometers - 3 micrometers, it heat-dried at 120 degreeC, and removed the solvent. In this way, after the six polyamide layers are formed, heat treatment is carried out in stages from 120°C to 360°C to complete the imidization, and the thickness of the resin laminate is 50 μm, and the non-thermoplastic polyimide layer is prepared. (formed from resin solution g A single-sided copper-clad laminate 1B in which the ratio of the thickness of the polyimide layer) to the entire resin laminate is 82%.

At the same time, the polyimide layer and the electrolytic copper foil (Rz: 0.8 μm, Ra: 0.2 μm) of the single-sided copper-clad laminate 1B are continuously supplied between a pair of heating rollers at a speed of 4 m/min and bonded by thermocompression (roll surface temperature: 320° C., linear pressure between rolls: 134 kN/m), thereby producing a double-sided copper-clad laminate 1 with a resin laminate thickness of 50 μm. The copper foil peeling strength in the double-sided copper-clad laminated board 1 exceeded 1.0 kN/m. The polyimide film 1 is prepared by etching and removing the copper foil of the double-sided copper-clad laminate 1 . The dielectric constant ε ₁ of the polyimide film 1 is 3.45, the dielectric tangent Tan δ ₁ is 0.0039, and the E ₁ calculated according to these dielectric properties is 0.0072.

[Example 2]

Except for using resin solution a instead of resin solution b, the thickness of the resin laminate was 50 μm and the thickness of the non-thermoplastic polyimide layer (polyimide layer formed from resin solution g) was prepared in the same manner as in Example 1. Single-sided copper-clad laminate 2B having a ratio of 82% to the entire resin laminate.

A single-sided copper-clad laminate 2B and an electrolytic copper foil (Rz: 0.8 μm, Ra: 0.2 μm) were prepared, and a double-sided copper-clad laminate 2 with a polyimide layer thickness of 50 μm was prepared in the same manner as in Example 1. The copper foil peeling strength in the double-sided copper-clad laminated board 2 exceeded 1.0 kN/m. The polyimide film 2 is prepared by etching and removing the copper foil of the double-sided copper-clad laminate 2 . The dielectric constant ε ₁ of the polyimide film 2 is 3.45, the dielectric tangent Tan δ ₁ is 0.0038, and the E ₁ calculated according to these dielectric properties is 0.0071.

[Example 3]

Except for using resin solution f instead of resin solution b, a polyimide layer having a thickness of 50 μm and a non-thermoplastic polyimide layer (polyimide layer formed from resin solution g) was prepared in the same manner as in Example 1. Single-sided copper-clad laminate 3B in which the ratio of thickness to the entire resin laminate is 82%.

A single-sided copper-clad laminate 3B and an electrolytic copper foil (Rz: 0.8 μm, Ra: 0.2 μm) were prepared, and a double-sided copper-clad laminate 3 with a polyimide layer thickness of 50 μm was prepared in the same manner as in Example 1. The copper foil peeling strength in the double-sided copper-clad laminated board 3 exceeded 1.0 kN/m. The polyimide film 3 is prepared by etching and removing the copper foil of the double-sided copper-clad laminate 3 . The dielectric constant ε ₁ of the polyimide film 3 is 3.43, the dielectric tangent Tan δ ₁ is 0.0032, and the E ₁ calculated according to these dielectric properties is 0.0059.

[Example 4]

On the surface of long electrodeposited copper foil (Rz: 0.8μm, Ra: 0.2μm), apply resin solution f uniformly so that the thickness after curing becomes about 2μm~3μm, heat and dry at 120℃, remove solvent. Next, the resin solution g was uniformly applied thereon so that the thickness after curing was about 34 μm, and then heated and dried at 120° C. to remove the solvent. Furthermore, after the resin solution c was uniformly apply|coated so that the thickness after hardening may become about 2 micrometers - 3 micrometers, it heat-dried at 120 degreeC, and removed the solvent. Furthermore, after the resin solution c was uniformly apply|coated so that the thickness after hardening may become about 2 micrometers - 3 micrometers, it heat-dried at 120 degreeC, and removed the solvent. Next, the resin solution g was uniformly applied thereon so that the thickness after curing was about 34 μm, and then heated and dried at 120° C. to remove the solvent. Furthermore, after the resin solution f was evenly coated thereon so that the thickness after curing became about 2 μm to 3 μm, it was heated at 120° C. Heat dry and remove solvent. In this way, after the six polyamide layers are formed, heat treatment is carried out in stages from 120°C to 360°C to complete the imidization, and the thickness of the resin laminate is 76 μm, and the non-thermoplastic polyimide layer is prepared. The single-sided copper-clad laminate 4B in which the ratio of the thickness of (the polyimide layer formed from the resin solution g) to the entire resin laminate is 87%.

A single-sided copper-clad laminate 4B and an electrolytic copper foil (Rz: 0.8 μm, Ra: 0.2 μm) were prepared, and a double-sided copper-clad laminate 4 having a resin laminate thickness of 76 μm was prepared in the same manner as in Example 1. The copper foil peel strength in the double-sided copper-clad laminate 4 exceeded 1.0 kN/m. The polyimide film 4 is prepared by etching and removing the copper foil of the double-sided copper-clad laminate 4 . The dielectric constant ε ₁ of the polyimide film 4 is 3.20, the dielectric tangent Tan δ ₁ is 0.0032, and the E ₁ calculated according to these dielectric properties is 0.0057.

[Example 5]

On the surface of long electrodeposited copper foil (Rz: 0.8μm, Ra: 0.2μm), apply resin solution f uniformly so that the thickness after curing becomes about 2μm~3μm, heat and dry at 120℃, remove solvent. Next, the resin solution g was uniformly applied thereon so that the thickness after curing was about 35 μm, and then heated and dried at 120° C. to remove the solvent. Furthermore, after the resin solution f was uniformly apply|coated so that the thickness after hardening may become about 2 micrometers - 3 micrometers, it heat-dried at 120 degreeC, and removed the solvent. Next, the resin solution g was uniformly applied thereon so that the thickness after curing was about 34 μm, and then heated and dried at 120° C. to remove the solvent. Furthermore, after the resin solution f was uniformly apply|coated so that the thickness after hardening may become about 2 micrometers - 3 micrometers, it heat-dried at 120 degreeC, and removed the solvent. Thus, after forming five polyamide layers, Step-by-step heat treatment from 120°C to 360°C completes imidization to prepare a resin laminate with a thickness of 76 μm and a non-thermoplastic polyimide layer (a polyimide layer formed from a resin solution g) A single-sided copper-clad laminate 5B in which the ratio of thickness to the entire resin laminate is 90%.

A single-sided copper-clad laminate 5B and an electrolytic copper foil (Rz: 0.8 μm, Ra: 0.2 μm) were prepared, and a double-sided copper-clad laminate 5 having a resin laminate thickness of 76 μm was prepared in the same manner as in Example 1. The copper foil peeling strength in the double-sided copper-clad laminated board 5 exceeded 1.0 kN/m. The polyimide film 5 was prepared by etching and removing the copper foil of the double-sided copper-clad laminate 5 . The dielectric constant ε ₁ of the polyimide film 5 is 3.41, the dielectric tangent Tan δ ₁ is 0.0033, and the E ₁ calculated according to these dielectric properties is 0.0061.

[Example 6]

On the surface of long electrodeposited copper foil (Rz: 0.8μm, Ra: 0.2μm), apply resin solution f uniformly so that the thickness after curing becomes about 2μm~3μm, heat and dry at 120℃, remove solvent. Next, the resin solution g was uniformly applied thereon so that the thickness after curing was about 21 μm, and then heated and dried at 120° C. to remove the solvent. Furthermore, after the resin solution b was uniformly apply|coated so that the thickness after hardening may become about 2 micrometers - 3 micrometers, it heat-dried at 120 degreeC, and removed the solvent. Furthermore, after the resin solution g was uniformly apply|coated so that the thickness after hardening might become about 23 micrometers, it heat-dried at 120 degreeC, and removed the solvent. Furthermore, after the resin solution f was uniformly apply|coated so that the thickness after hardening may become about 2 micrometers - 3 micrometers, it heat-dried at 120 degreeC, and removed the solvent. In this way, after forming five layers of polyamic acid layers, heat treatment is carried out step by step from 120°C to 360°C to complete imidization, On the other hand, the thickness of the resin laminate was 50 μm, and the ratio of the thickness of the non-thermoplastic polyimide layer (polyimide layer formed from the resin solution g) to the entire resin laminate was 86%. Plate 6B.

A single-sided copper-clad laminate 6B and an electrolytic copper foil (Rz: 0.8 μm, Ra: 0.2 μm) were prepared, and a double-sided copper-clad laminate 6 having a resin laminate thickness of 50 μm was prepared in the same manner as in Example 1. The copper foil peeling strength in the double-sided copper-clad laminated board 6 exceeded 1.0 kN/m. The polyimide film 6 is prepared by etching and removing the copper foil of the double-sided copper-clad laminate 6 . The dielectric constant ε ₁ of the polyimide film 6 is 3.45, the dielectric tangent Tan δ ₁ is 0.0039, and the E ₁ calculated according to these dielectric properties is 0.0072.

[Example 7]

Except for using resin solution e instead of resin solution b, the thickness of the resin laminate was 50 μm and the thickness of the non-thermoplastic polyimide layer (polyimide layer formed from resin solution g) was prepared in the same manner as in Example 6. Single-sided copper-clad laminate 7B having a ratio of 86% to the entire resin laminate.

A single-sided copper-clad laminate 7B and an electrolytic copper foil (Rz: 0.8 μm, Ra: 0.2 μm) were prepared, and a double-sided copper-clad laminate 7 having a resin laminate thickness of 50 μm was prepared in the same manner as in Example 1. The copper foil peeling strength in the double-sided copper-clad laminated board 7 exceeded 1.0 kN/m. The polyimide film 7 was prepared by etching and removing the copper foil of the double-sided copper-clad laminate 7 . The dielectric constant ε ₁ of the polyimide film 7 is 3.42, the dielectric tangent Tan δ ₁ is 0.0041, and the E ₁ calculated according to these dielectric properties is 0.0076.

[Example 8]

On the surface of long electrolytic copper foil (Rz: 0.8μm, Ra: 0.2μm), with After the resin solution g was uniformly applied so that the thickness after curing became about 35 μm, it was heated and dried at 120° C. to remove the solvent. Furthermore, after the resin solution b was uniformly apply|coated so that the thickness after hardening may become about 2 micrometers - 3 micrometers, it heat-dried at 120 degreeC, and removed the solvent. Furthermore, after the resin solution g was uniformly apply|coated so that the thickness after hardening might become about 35 micrometers, it heat-dried at 120 degreeC, and removed the solvent. Furthermore, after the resin solution f was uniformly apply|coated so that the thickness after hardening may become about 2 micrometers - 3 micrometers, it heat-dried at 120 degreeC, and removed the solvent. In this way, after the formation of four polyamide layers, heat treatment is carried out in stages from 120°C to 360°C to complete imidization, and the thickness of the resin laminate is 76 μm, and the non-thermoplastic polyimide layer is prepared. The single-sided copper-clad laminate 8B in which the ratio of the thickness of (the polyimide layer formed from the resin solution g) to the entire resin laminate is 93%.

A single-sided copper-clad laminate 8B and an electrolytic copper foil (Rz: 0.8 μm, Ra: 0.2 μm) were prepared, and a double-sided copper-clad laminate 8 having a resin laminate thickness of 76 μm was prepared in the same manner as in Example 1. The copper foil peeling strength in the double-sided copper-clad laminated board 8 exceeds 1.0 kN/m. The polyimide film 8 is prepared by etching and removing the copper foil of the double-sided copper-clad laminate 8 . The dielectric constant ε ₁ of the polyimide film 8 is 3.34, the dielectric tangent Tan δ ₁ is 0.0037, and the E ₁ calculated according to these dielectric properties is 0.0068.

[Example 9]

On the surface of long electrodeposited copper foil (Rz: 0.8μm, Ra: 0.2μm), apply resin solution f uniformly so that the thickness after curing becomes about 2μm~3μm, heat and dry at 120℃, remove solvent. Next, apply the resin solution g uniformly thereon so that the thickness after curing becomes approximately 21 μm, and then heat at 120° C. Dry and remove solvent. Furthermore, after the resin solution b was uniformly apply|coated so that the thickness after hardening may become about 2 micrometers - 3 micrometers, it heat-dried at 120 degreeC, and removed the solvent. Furthermore, after the resin solution g was uniformly apply|coated so that the thickness after hardening might become about 23 micrometers, it heat-dried at 120 degreeC, and removed the solvent. Furthermore, after the resin solution b was uniformly apply|coated so that the thickness after hardening may become about 2 micrometers - 3 micrometers, it heat-dried at 120 degreeC, and removed the solvent. In this way, after forming five layers of polyamic acid layers, stepwise heat treatment is carried out from 120°C to 360°C to complete imidization, and a non-thermoplastic polyimide layer ( A single-sided copper-clad laminate 9B in which the ratio of the thickness of the polyimide layer formed from the resin solution g to the entire resin laminate was 86%.

The copper foil peeling strength in the single-sided copper-clad laminated board 9B exceeded 1.0 kN/m. The polyimide film 9 was prepared by etching and removing the copper foil of the single-sided copper-clad laminate 9B. The dielectric constant ε ₁ of the polyimide film 9 is 3.44, the dielectric tangent Tan δ ₁ is 0.0043, and the E ₁ calculated according to these dielectric properties is 0.0080.

[Example 10]

Two single-sided copper-clad laminates 4B were prepared in the same manner as in Example 4, and were bonded to each other on the polyimide layer, while being continuously supplied between a pair of heating rollers at a speed of 1 m/min and subjected to thermocompression bonding ( Roll surface temperature: 390° C., linear pressure between rolls: 134 kN/m), thereby preparing a double-sided copper-clad laminate 10 with a resin laminate thickness of 152 μm. The peel strength of the thermocompression bonding surface in the double-sided copper-clad laminate 10 exceeds 1.0 kN/m. The polyimide film 10 is prepared by etching and removing the copper foil of the double-sided copper-clad laminate 10 . The dielectric constant ε ₁ of the polyimide film 10 is 3.20, the dielectric tangent Tan δ ₁ is 0.0032, and the E ₁ calculated according to these dielectric properties is 0.0057.

[Comparative example 1]

On the surface of long electrodeposited copper foil (Rz: 0.8μm, Ra: 0.2μm), apply resin solution c uniformly so that the thickness after curing becomes about 2μm~3μm, heat and dry at 120℃, remove solvent. Next, the resin solution d was uniformly applied thereon so that the thickness after curing was about 21 μm, and then heated and dried at 120° C. to remove the solvent. Furthermore, after the resin solution e was uniformly apply|coated so that the thickness after hardening may become about 2 micrometers - 3 micrometers, it heat-dried at 120 degreeC, and removed the solvent. Furthermore, after the resin solution e was uniformly apply|coated so that the thickness after hardening may become about 2 micrometers - 3 micrometers, it heat-dried at 120 degreeC, and removed the solvent. Next, the resin solution d was uniformly applied thereon so that the thickness after curing was about 21 μm, and then heated and dried at 120° C. to remove the solvent. Furthermore, after the resin solution c was uniformly apply|coated so that the thickness after hardening may become about 2 micrometers - 3 micrometers, it heat-dried at 120 degreeC, and removed the solvent. In this way, after the six polyamide layers are formed, heat treatment is carried out in stages from 120°C to 360°C to complete the imidization, and the thickness of the resin laminate is 50 μm, and the non-thermoplastic polyimide layer is prepared. The single-sided copper-clad laminate 1'B in which the ratio of the thickness of (the polyimide layer formed from the resin solution d) to the entire resin laminate is 82%.

At the same time, the polyimide layer and the electrolytic copper foil (Rz: 0.8 μm, Ra: 0.2 μm) of the single-sided copper-clad laminate 1'B are continuously supplied between a pair of heating rollers at a speed of 4 m/min and heated. Press bonding (roll surface temperature: 390° C., linear pressure between rolls: 134 kN/m) was used to prepare a double-sided copper-clad laminate 1 ′ having a resin laminate thickness of 50 μm. The polyimide film 1' is prepared by etching and removing the copper foil of the double-sided copper-clad laminate 1'. The dielectric constant ε ₁ of the polyimide film 1' is 3.08, the dielectric tangent Tan δ ₁ is 0.0071, and the E ₁ calculated according to these dielectric properties is 0.0125.

As mentioned above, although the embodiment of this invention was demonstrated in detail for the purpose of illustration, this invention is not restricted by the said embodiment.

10A, 10B: copper foil layer

20A, 20B, 40A, 40B: thermoplastic polyimide layer

30A, 30B: Non-thermoplastic polyimide layer

50: resin laminate

100: CCL on both sides

Claims (6)

A metal-clad laminate, characterized in that it includes: a resin laminate containing a plurality of polyimide layers, the resin laminate has a layer structure symmetrical to the thickness direction based on the center in the thickness direction, and is located at The layer at the center in the thickness direction or the two layers adjacent to the center in the thickness direction are thermoplastic polyimides with a glass transition temperature of 360° C. or lower; and a metal layer laminated on at least one side of the resin laminate, and The resin laminate satisfies the following conditions i) to iv): i) the overall thickness is in the range of 76 μm to 200 μm; ii) includes a first polyimide layer in contact with the metal layer, and directly or indirectly The second polyimide layer laminated on the first polyimide layer; iii) The ratio of the thickness of the second polyimide layer to the thickness of the entire resin laminate is 70 %~97%; iv) The _E1 value calculated based on the following formula (a) as an indicator of dielectric properties is less than 0.009:

[Here, _ε1 represents the dielectric constant at 10 GHz measured by a split dielectric resonator (SPDR), and _Tanδ1 represents the dielectric constant at 10 GHz measured by a split dielectric resonator (SPDR). tangent]. The metal-clad laminate as described in item 1 of the scope of the patent application, wherein the composition The polyimide of the second polyimide layer is a non-thermoplastic polyimide obtained by reacting an acid anhydride component with a diamine component, and contains tetracarboxylic acid residues and diamine residues, and is relatively 100 molar parts of the tetracarboxylic acid residues, tetracarboxylic acid residues (BPDA residues) derived from 3,3',4,4'-biphenyltetracarboxylic dianhydride (BPDA) and 1, At least one of the tetracarboxylic acid residues (TAHQ residues) derived from 4-phenylene bis(trimellitic acid monoester) dianhydride (TAHQ), and pyromellitic dianhydride (PMDA) The sum of at least one of tetracarboxylic acid residues (PMDA residues) and tetracarboxylic acid residues (NTCDA residues) derived from 2,3,6,7-naphthalene tetracarboxylic dianhydride (NTCDA) is More than 80 mole parts, the mol ratio of at least one of the BPDA residue and the TAHQ residue to at least one of the PMDA residue and the NTCDA residue {(BPDA residue+TAHQ residue base)/(PMDA residue+NTCDA residue)} in the range of 0.4~1.5. The metal-clad laminate described in claim 2, wherein the diamine component contains 80 mol% or more of 4,4'-diamino-2,2'-diamine relative to all diamine components. Methylbiphenyl (m-TB). The metal-clad laminate according to claim 1, wherein the resin laminate has at least the first polyimide layer and the second polyimide layer stacked in sequence from the side of the metal layer. Structure of the imine layer. The metal-clad laminate according to claim 1, wherein the resin laminate has a laminate structure including at least five or more polyimide layers. A circuit substrate, which is a gold-coated substrate as described in item 1 of the scope of the patent application The metal layer belonging to the laminate is processed by wiring circuits.

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