WO2020066595A1

WO2020066595A1 - Production method for metal clad laminate and production method for circuit board

Info

Publication number: WO2020066595A1
Application number: PCT/JP2019/035510
Authority: WO
Inventors: 裕明山田; 平石　克文; 哲平西山; 康弘安達
Original assignee: 日鉄ケミカル＆マテリアル株式会社
Priority date: 2018-09-28
Filing date: 2019-09-10
Publication date: 2020-04-02
Also published as: CN112601656A; KR20210068022A; TW202026151A; CN115971017B; CN115971017A

Abstract

This production method for a metal clad laminate 100 comprises a step for forming a first polyamide resin layer 20A on a metal foil 10A, a step for imidizing a polyamide acid in the first polyamide resin layer 20A to form a first polyimide layer 20, a step for performing a surface treatment on the first polyimide layer 20, a step for forming a second polyamide resin layer 30A on the first polyimide layer 20, and a step for imidizing a polyamide acid in the second polyamide resin layer 30A to form a second polyimide layer 30, and thereby forming an insulating resin layer 40. The first polyimide layer 20 has a thickness (L1) in the range of 0.5-100 μm, the insulating resin layer 40 has an overall thickness (L) in the range of not less than 5 μm but less than 200 μm, and the ratio (L/L1) is in the range of more than 1 but less than 400.

Description

Method of manufacturing metal-clad laminate and method of manufacturing circuit board

The present invention relates to a method for manufacturing a metal-clad laminate that can be used as a material for a circuit board and the like, and a method for manufacturing a circuit board.

2. Description of the Related Art In recent years, with the progress of miniaturization, weight reduction, and space saving of electronic devices, a flexible printed circuit (FPC) that is thin and light, has flexibility, and has excellent durability even when repeatedly bent. ) Demand is increasing. Since FPCs can be mounted three-dimensionally and at high density even in limited space, their applications are expanding, for example, to wiring of electronic devices such as HDDs, DVDs, mobile phones, and smartphones, and to components such as cables and connectors. I am doing it. As an insulating resin used for the FPC, polyimide having excellent heat resistance and adhesiveness has attracted attention.

As a method of manufacturing a metal-clad laminate as an FPC material, a casting method is known in which a polyimide precursor layer is formed by applying a polyamic acid resin solution on a metal foil, and then imidized to form a polyimide layer. I have. When manufacturing a metal-clad laminate having a plurality of polyimide layers as an insulating resin layer by a casting method, generally, on a substrate such as a copper foil, after sequentially forming a plurality of polyimide precursor layers, these Are collectively imidized. However, when a plurality of polyimide precursor layers are simultaneously imidized, the solvent and imidized water in the polyimide precursor layer are not completely removed, and foaming and peeling between the polyimide layers are caused by the residual solvent and the imidized water, thereby increasing the yield. There is a problem that it causes a decrease in

The problems of foaming and peeling can be solved by repeatedly imidizing the polyimide precursor layer one by one and applying a polyamic acid resin solution thereon. However, if a resin solution of polyamic acid is further applied on the polyimide layer once imidized and imidized, it is difficult to sufficiently obtain adhesion between the layers. In the prior art, a proposal has been made to improve the adhesion between layers by applying a surface treatment such as a corona treatment or a plasma treatment to the surface of an underlying polyimide film or polyimide layer before applying a resin solution of polyamic acid. (For example, Patent Documents 1 and 2).

Japanese Patent No. 5615253 Japanese Patent No. 5480490

目的 An object of the present invention is to improve adhesion between polyimide layers while suppressing foaming when a metal-clad laminate having a plurality of polyimide layers as insulating resin layers is manufactured by a casting method.

(4) The present inventors have found that by controlling the thickness of a plurality of polyimide layers formed by a casting method, it is possible to suppress foaming and improve the adhesion between polyimide layers, and have completed the present invention.

That is, a method of manufacturing a metal-clad laminate of the present invention includes a metal-clad laminate including: an insulating resin layer including a plurality of polyimide layers; and a metal layer laminated on at least one surface of the insulating resin layer. It is a method of manufacturing.
The method for producing a metal-clad laminate of the present invention comprises the following steps 1 to 5:
Step 1) a step of forming a single layer or a plurality of first polyamide resin layers by applying a polyamic acid solution on the metal layer;
Step 2) a step of imidizing the polyamic acid in the first polyamide resin layer to form a single polyimide layer or a plurality of first polyimide layers;
Step 3) performing a surface treatment on the surface of the first polyimide layer;
Step 4) a step of forming a single-layer or multiple-layer second polyamide resin layer by applying a polyamic acid solution on the first polyimide layer,
Step 5) Polyamide acid in the second polyamide resin layer is imidized to form a second polyimide layer composed of a single layer or a plurality of layers, and the first polyimide layer and the second polyimide layer are Forming the laminated insulating resin layer,
Contains.
In the method for manufacturing a metal-clad laminate according to the present invention, the thickness (L1) of the first polyimide layer is in the range of 0.5 μm or more and 100 μm or less, and the thickness (L) of the entire insulating resin layer is Is in the range of 5 μm or more and less than 200 μm, and the ratio (L / L1) of L and L1 is more than 1 and less than 400.

は In the method for manufacturing a metal-clad laminate of the present invention, a polyimide constituting a layer in contact with the metal layer in the first polyimide layer may be a thermoplastic polyimide.

Method for producing a metal-clad laminate of the present invention, the moisture permeability of the metal layer, the thickness 25 [mu] m, when the 25 ° C., may be not more than 100g ^/ m 2 ^/ 24hr.

回路 The method for manufacturing a circuit board according to the present invention includes a step of processing a wiring circuit on the metal layer of the metal-clad laminate manufactured by the above method.

According to the method of the present invention, a metal-clad laminate having an insulating resin layer having excellent adhesion between polyimide layers can be manufactured by using a casting method while suppressing foaming.

It is a flowchart showing the procedure of the manufacturing method of the metal clad laminate of a 1st embodiment of the present invention. It is a flowchart showing the procedure of the manufacturing method of the metal clad laminate of a 2nd embodiment of the present invention. It is explanatory drawing of the target for position measurement used for measurement of the dimensional change rate after etching. It is explanatory drawing of the evaluation sample used for the measurement of the dimensional change rate after etching.

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

[First Embodiment]
A method for manufacturing a metal-clad laminate according to a first embodiment of the present invention includes an insulating resin layer including a plurality of polyimide layers, and a metal layer stacked on at least one surface of the insulating resin layer. This is a method for producing a metal-clad laminate.

FIG. 1 is a process chart showing main procedures of a method for manufacturing a metal-clad laminate according to the first embodiment. The method of the present embodiment includes the following steps 1 to 5. In FIG. 1, the numbers next to the arrows represent steps 1 to 5.

Step 1)
In step 1, a polyamic acid solution is applied onto the metal foil 10A to be the metal layer 10 to form a single-layer or multiple-layer first polyamide resin layer 20A. The method of applying the polyamic acid resin solution onto the metal foil 10A by the casting method is not particularly limited, and for example, it can be applied by a coater such as a comma, a die, a knife, a lip, or the like.
In the case where the first polyamide resin layer 20A has a plurality of layers, for example, a method of repeatedly applying and drying a polyamic acid solution to the metal foil 10A or a multi-layer extrusion may be used on the metal foil 10A. At the same time, a method of applying and drying polyamic acid in a state of being laminated in multiple layers can be adopted.

In step 1, as described below, the first polyamide resin layer 20A is cured so that the thickness (L1) of the first polyimide layer 20 after curing in step 2 is in the range of 0.5 μm to 100 μm. Preferably, it is formed. In the casting method, since the polyamic acid resin layer is imidized while being fixed to the metal foil 10A, a change in expansion and contraction of the polyimide layer during the imidization process can be suppressed, and the thickness and dimensional accuracy can be maintained.

The material of the metal foil 10A is not particularly limited, and examples thereof include copper, stainless steel, iron, nickel, beryllium, aluminum, zinc, indium, silver, gold, tin, zirconium, tantalum, titanium, lead, magnesium, manganese, and the like. These alloys etc. are mentioned. Among them, copper or a copper alloy is particularly preferable. As the copper foil, a rolled copper foil or an electrolytic copper foil may be used, and a commercially available copper foil can be preferably used.

において In the present embodiment, for example, the thickness of the metal layer 10 when used for manufacturing an FPC is preferably in the range of 3 to 80 μm, more preferably in the range of 5 to 30 μm.

金属 The surface of the metal foil 10A used as the metal layer 10 may be subjected to surface treatment such as rust prevention treatment, siding, aluminum alcoholate, aluminum chelate, and silane coupling agent. Further, the metal foil 10A can be formed in a cut sheet shape, a roll shape, an endless belt shape, or the like. It is efficient to have a format that is possible. Further, from the viewpoint of further improving the effect of improving the wiring pattern accuracy in the circuit board, the metal foil 10A is preferably a long roll-shaped metal foil.

Further, the moisture permeability of the metal layer 10, for example a thickness 25 [mu] m, at 25 ° C., preferably not more than 100g ^/ m 2 ^/ 24hr. When the moisture permeability of the metal layer 10 is low and the solvent or imidized water is hardly removed from the metal layer 10 side, the effect of the method of the present embodiment is greatly exerted.

Step 2)
In step 2, the polyamic acid in the first polyamide resin layer 20A formed in step 1 is imidized to form a single polyimide layer 20 or a plurality of first polyimide layers 20. By imidizing the polyamic acid contained in the first polyamide resin layer 20A, most of the solvent and imidized water contained in the first polyamide resin layer 20A can be removed.

方法 The method for imidizing the polyamic acid is not particularly limited, and for example, a heat treatment of heating at a temperature in the range of 80 to 400 ° C for a time in the range of 1 to 60 minutes is preferable. The heat treatment is preferably performed in a low oxygen atmosphere in order to suppress oxidation of the metal layer 10, specifically, in an inert gas atmosphere such as nitrogen or a rare gas, in a reducing gas atmosphere such as hydrogen, or in a vacuum. It is preferably carried out in

Step 3)
In step 3, the surface of the first polyimide layer 20 is subjected to a surface treatment.
The surface treatment is not particularly limited as long as it can improve the interlayer adhesion between the first polyimide layer 20 and the second polyimide layer 30. For example, plasma treatment, corona treatment, flame treatment, ultraviolet treatment, ozone Examples include treatment, electron beam treatment, radiation treatment, sandblasting, hairline treatment, embossing, chemical treatment, steam treatment, surface grafting treatment, electrochemical treatment, and primer treatment. In particular, when the first polyimide layer 20 is a thermoplastic polyimide layer, a surface treatment such as a plasma treatment, a corona treatment, and an ultraviolet treatment is preferable, and the condition is, for example, 300 W / min / m ² or less. preferable.

Step 4)
In step 4, a single-layer or multiple-layer second polyamide resin layer 30A is formed by applying a polyamic acid solution on the first polyimide layer 20 that has been subjected to the surface treatment in step 3, I do. The method of applying the polyamic acid resin solution on the first polyimide layer 20 by the casting method is not particularly limited, and for example, it can be applied by a coater such as a comma, a die, a knife, and a lip.
When the second polyamide resin layer 30A has a plurality of layers, for example, a method of repeatedly applying and drying a solution of a polyamic acid on the first polyimide layer 20 a plurality of times, or by multilayer extrusion, A method of applying and drying the polyamic acid in a state of being simultaneously laminated in multiple layers on the first polyimide layer 20 can be adopted.

In step 4, the second polyamide resin layer 30A is formed such that the thickness (L) of the entire insulating resin layer 40 is in the range of 5 μm or more and less than 200 μm after the next step 5, as described later. Is preferred.

Step 5)
In step 5, the polyamide acid contained in the second polyamide resin layer 30A is imidized to be converted into the second polyimide layer 30, and the insulating resin containing the first polyimide layer 20 and the second polyimide layer 30 The layer 40 is formed.
In step 5, the polyamide acid contained in the second polyamide resin layer 30A is imidized to synthesize polyimide. The imidation method is not particularly limited, and can be carried out under the same conditions as in Step 2.

<Optional process>
The method of the present embodiment can include any other steps than the above.

によって Through the above steps 1 to 5, the metal-clad laminate 100 having the insulating resin layer 40 having excellent adhesion between the first polyimide layer 20 and the second polyimide layer 30 can be manufactured. In the method of the present embodiment, even if the first polyimide layer 20 is formed on the metal layer 10 by a casting method, the imidation is performed before the formation of the second polyimide layer 30 so that the solvent or the imidization is performed. Since water is removed, problems such as foaming and delamination do not occur. In addition, before forming the second polyamide resin layer 30A, the first polyimide layer 20 is subjected to a surface treatment to secure the adhesion between the first polyimide layer 20 and the second polyimide layer 30. it can.

In the insulating resin layer 40 of the metal-clad laminate 100 manufactured by the method of the present embodiment, the thickness (L1) of the first polyimide layer is in the range of 0.5 μm to 100 μm.
Here, when the first polyimide layer 20 is a single layer, its thickness (L1) is preferably in the range of 0.5 μm or more and 5 μm or less, more preferably in the range of 1 μm or more and 3 μm or less. In this case, in step 2, the solvent and imidized water can be almost removed by curing in a thin state in which the thickness (L1) after imidization is 5 μm or less. Further, when the first polyimide layer 20 is a single layer, by controlling the thickness (L1) to 5 μm or less, the first polyimide layer 20 may be in contact with the metal layer 10 which is one of the causes of lowering the peel strength with the metal layer 10. Since the polyamic acid remains at the interface and can be completely imidized, the peel strength can be improved. When the thickness (L1) is less than 0.5 μm, the adhesion to the metal layer 10 is reduced, and the insulating resin layer 40 is easily peeled.
On the other hand, when the first polyimide layer 20 is composed of a plurality of layers, the thickness (L1) is preferably in the range of 5 μm to 100 μm, and more preferably in the range of 25 μm to 100 μm. When the first polyimide layer 20 is composed of a plurality of layers, when the thickness (L1) exceeds 100 μm, foaming easily occurs.

The thickness (L) of the entire insulating resin layer 40 is in the range of 5 μm or more and less than 200 μm.
Here, when the first polyimide layer 20 is a single layer, the thickness (L) of the entire insulating resin layer 40 is preferably in a range of 5 μm or more and less than 30 μm, and more preferably in a range of 10 μm or more and 25 μm or less. In the case where the first polyimide layer 20 is a single layer, if the thickness (L) of the entire insulating resin layer 40 is less than 5 μm, the foaming suppression effect, which is an effect of the present invention, is hardly exhibited and the dimensional stability is improved. The effect is difficult to obtain.
On the other hand, when the first polyimide layer 20 is composed of a plurality of layers, the thickness (L) of the entire insulating resin layer 40 is preferably in a range from 10 μm to less than 200 μm, and more preferably in a range from 50 μm to less than 200 μm. When the first polyimide layer 20 is composed of a plurality of layers, when the thickness (L) of the entire insulating resin layer 40 is 200 μm or more, foaming is likely to occur.

As described above, the thickness (L1) of the first polyimide layer 20 and the thickness (L) of the entire insulating resin layer 40 affect the suppression of foaming, the improvement in dimensional stability, and the adhesiveness to the metal layer 10. The ratio (L / L1) between the thickness (L) and the thickness (L1) is in the range of more than 1 and less than 400.
The ratio (L / L1) is preferably in the range of more than 1 and less than 60, more preferably 4 or more and 45 or less, and most preferably 5 or more and 30 or less.

The insulating resin layer 40 may include a polyimide layer other than the first polyimide layer 20 and the second polyimide layer 30. In addition, the polyimide layer constituting the insulating resin layer 40 may contain an inorganic filler as necessary. Specific examples include silicon dioxide, aluminum oxide, magnesium oxide, beryllium oxide, boron nitride, aluminum nitride, silicon nitride, aluminum fluoride, calcium fluoride, and the like. These can be used alone or in combination of two or more.

<Polyimide>
Next, a preferred polyimide for forming the first polyimide layer 20 and the second polyimide layer 30 will be described. In forming the first polyimide layer 20 and the second polyimide layer 30, an acid anhydride component and a diamine component generally used as a raw material for synthesizing polyimide can be used without any particular limitation.

In the metal-clad laminate 100, the polyimide constituting the first polyimide layer 20 may be either a thermoplastic polyimide or a non-thermoplastic polyimide, but it is easy to secure the adhesiveness with the metal layer 10 serving as a base. For that reason, thermoplastic polyimides are preferred.

The polyimide constituting the second polyimide layer 30 may be either a thermoplastic polyimide or a non-thermoplastic polyimide, but when the non-thermoplastic polyimide is used, the effect of the invention is remarkably exhibited.
That is, even if imidization is performed by laminating a resin layer of a polyamic acid that is a precursor of a non-thermoplastic polyimide on a polyimide layer that has been imidized by a method such as a casting method, the adhesion between the polyimide layers is usually The property is hardly obtained. However, in the present embodiment, the surface of the first polyimide layer 20 is subjected to the surface treatment as described above, and then the second polyamide resin layer 30A is laminated, so that the polyimide constituting the second polyimide layer 30 is thermally heated. Regardless of whether it is plastic or non-thermoplastic, excellent adhesion between the first polyimide layer 20 and the first polyimide layer 20 can be obtained. In addition, when the second polyimide layer 30 is made of non-thermoplastic polyimide, it can function as a main layer (base layer) that secures the mechanical strength of the polyimide layer in the metal-clad laminate 100.

From the above, in the metal-clad laminate 100, it is the most preferable embodiment to form a structure in which the thermoplastic polyimide layer is laminated as the first polyimide layer 20 and the non-thermoplastic polyimide layer is laminated as the second polyimide layer 30. .

Polyimides include low-thermal-expansion polyimide and high-thermal-expansion polyimide. Usually, thermoplastic polyimide has high-thermal expansion and non-thermoplastic polyimide has low-thermal expansion. For example, when the first polyimide layer 20 is a thermoplastic polyimide layer, the coefficient of thermal expansion is preferably in the range of more than 30 × 10 ⁻⁶ and 80 × 10 ⁻⁶ / K or less. By setting the coefficient of thermal expansion of the thermoplastic polyimide layer within the above range, the adhesiveness to the metal layer 10 as the first polyimide layer 20 can be ensured. In addition, when the second polyimide layer 30 is a low-expansion polyimide layer, it can function as a main layer (base layer) that secures the dimensional stability of the polyimide layer in the metal-clad laminate 100. Specifically, the thermal expansion coefficient of the low-expansion polyimide layer is in the range of 1 × 10 ⁻⁶ to 30 × 10 ⁻⁶ (1 / K), preferably 1 × 10 ⁻⁶ to 25 × 10 ⁻⁶ ( 1 / K), more preferably 10 × 10 ⁻⁶ to 25 × 10 ⁻⁶ (1 / K). Further, since the non-thermoplastic polyimide has a low thermal expansion property, the thermal expansion coefficient can be suppressed low by increasing the thickness ratio of the non-thermoplastic polyimide layer. The first polyimide layer 20 and the second polyimide layer 30 can be formed into polyimide layers having a desired coefficient of thermal expansion by appropriately changing the combination of the materials used, the thickness, and the drying and curing conditions.

In addition, “thermoplastic polyimide” generally refers to a polyimide whose glass transition temperature (Tg) can be clearly confirmed. In the present invention, 30 ° C. was measured using a dynamic viscoelasticity measuring device (DMA). Is a polyimide having a storage elastic modulus of 1.0 × 10 ⁹ Pa or more and a storage elastic modulus at 350 ° C. of less than 1.0 × 10 ⁸ Pa. In addition, “non-thermoplastic polyimide” generally refers to a polyimide that does not soften or exhibit adhesiveness even when heated, but in the present invention, it is measured using a dynamic viscoelasticity measuring device (DMA). It refers to a polyimide having a storage elastic modulus at 1.0 ° C. of 1.0 × 10 ⁹ Pa or more and a storage elastic modulus at 350 ° C. of 1.0 × 10 ⁸ Pa or more.

As the diamine compound serving as a raw material of the polyimide, an aromatic diamine compound, an aliphatic diamine compound, or the like can be used. For example, an aromatic diamine compound represented by NH ₂ —Ar ₁ -NH ₂ is preferable. Here, Ar1 is exemplified by one selected from the group represented by the following formula. Ar1 can have a substituent, but preferably does not, or if it does, the substituent is preferably a lower alkyl or lower alkoxy group having 1 to 6 carbon atoms. One of these aromatic diamine compounds may be used alone, or two or more thereof may be used in combination.

As the acid anhydride to be reacted with the diamine compound, an aromatic tetracarboxylic anhydride is preferable from the viewpoint of easy synthesis of polyamic acid. The aromatic tetracarboxylic anhydride is not particularly limited, but for example, a compound represented by O (CO) ₂ Ar ₂ (CO) ₂ O is preferable. Here, Ar2 is exemplified by a tetravalent aromatic group represented by the following formula. The substitution position of the acid anhydride group [(CO) ₂ O] is arbitrary, but a symmetric position is preferable. Ar2 can have a substituent, but preferably does not, or if it does, the substituent is preferably a lower alkyl group having 1 to 6 carbon atoms.

(Synthesis of polyimide)
The polyimide constituting the polyimide layer can be produced by reacting an acid anhydride and a diamine in a solvent to form a precursor resin, and then heating and closing the ring. For example, a polyimide precursor is obtained by dissolving an acid anhydride component and a diamine component in substantially equimolar amounts in an organic solvent, and stirring at a temperature within a range of 0 to 100 ° C. for 30 minutes to 24 hours to cause a polymerization reaction. A polyamic acid is obtained. In the reaction, the reaction components are dissolved in an organic solvent so that the amount of the produced precursor is in the range of 5 to 30% by weight, preferably in the range of 10 to 20% by weight. Examples of the organic solvent used in the polymerization reaction include N, N-dimethylformamide, N, N-dimethylacetamide (DMAc), N-methyl-2-pyrrolidone, 2-butanone, dimethyl sulfoxide, dimethyl sulfate, cyclohexanone, and dioxane. , Tetrahydrofuran, diglyme, triglyme and the like. Two or more of these solvents can be used in combination, and further, an aromatic hydrocarbon such as xylene or toluene can be used in combination. The amount of the organic solvent used is not particularly limited, but may be such that the concentration of the polyamic acid solution (polyimide precursor solution) obtained by the polymerization reaction is about 5 to 30% by weight. It is preferable to use it after adjusting. Usually, the synthesized precursor is advantageously used as a reaction solvent solution, but can be concentrated, diluted, or replaced with another organic solvent if necessary. Further, the precursor is generally used because it is excellent in solvent solubility.

において In the synthesis of polyimide, each of the above-mentioned acid anhydrides and diamines may be used alone or in combination of two or more. Controlling thermal expansion, adhesion, storage modulus, glass transition temperature, etc. by selecting the type of acid anhydride and diamine, and the molar ratio when using two or more acid anhydrides or diamines can do. In the case where the polyimide has a plurality of polyimide structural units, it may be present as a block or may be present at random, but is preferably present at random.

As described above, the metal-clad laminate obtained in the present embodiment has excellent adhesion between the first polyimide layer 20 and the second polyimide layer 30, and can be used as a circuit board material represented by FPC. Thus, the reliability of the electronic device can be improved.

In the first embodiment, surface treatment was performed on imidized polyimide in order to obtain adhesion between layers. The surface treatment requires equipment for the treatment and may increase the number of steps. Therefore, in the second embodiment of the present invention described below, the polyimide precursor layer formed by the casting method is laminated with the next polyimide precursor layer in a semi-cured state, thereby suppressing foaming. The adhesiveness between polyimide layers can be improved without requiring a special step such as surface treatment.

[Second embodiment]
The method for manufacturing a metal-clad laminate according to the second embodiment of the present invention includes an insulating resin layer including a plurality of polyimide layers, and a metal layer stacked on at least one surface of the insulating resin layer. This is a method for manufacturing a metal-clad laminate provided with the above.

FIG. 2 is a process chart showing main procedures of a method for manufacturing a metal-clad laminate according to the second embodiment. The method of the present embodiment includes the following steps (a) to (d). In FIG. 2, the English characters next to the arrows represent steps (a) to (d).
In the present embodiment, the description of the same configuration as that of the first embodiment may be omitted by referring to the first embodiment.

Step (a)
In the step (a), a single-layer or multiple-layer first polyamide resin layer 20A is formed on the metal foil 10A to be the metal layer 10 by applying a polyamic acid solution. The method of applying the polyamic acid resin solution onto the metal foil 10A by the casting method is not particularly limited, and for example, it can be applied by a coater such as a comma, a die, a knife, a lip, or the like.
In the case where the first polyamide resin layer 20A has a plurality of layers, for example, a method of repeatedly applying and drying a polyamic acid solution to the metal foil 10A or a multi-layer extrusion may be used on the metal foil 10A. At the same time, a method of applying and drying polyamic acid in a state of being laminated in multiple layers can be adopted.

In the step (a), as described below, the first polyamide layer 20 is cured so that the thickness (L1) of the first polyimide layer 20 after curing in the step (d) is in the range of 0.5 μm to 10 μm. It is preferable to form the resin layer 20A. In the casting method, since the polyamic acid resin layer is imidized while being fixed to the metal foil 10A, a change in expansion and contraction of the polyimide layer during the imidization process can be suppressed, and the thickness and dimensional accuracy can be maintained.

材質 The material, thickness, surface treatment, shape and form, and moisture permeability of the metal foil 10A are the same as in the first embodiment.

Step (b)
The first polyamide resin layer such that the weight loss rate in the temperature range from 100 ° C. to 360 ° C. measured by a thermogravimetric differential thermal analyzer (TG-DTA) is in the range of 0.1 to 20%. A step of partially imidizing the polyamic acid contained in 20A to form a single layer or a plurality of semi-cured resin layers 20B.
In the step (b), most of the solvent and imidized water contained in the first polyamide resin layer 20A can be removed by semi-curing the polyamic acid contained in the first polyamide resin layer 20A. . In the case of the semi-cured state, unlike the cured state in which imidization has been completed, there is sufficient space between the second polyimide layer 30 formed in the subsequent steps (c) and (d). Interlayer adhesion can be obtained.

Here, the partially imidized semi-cured state is different from a mere dry state or a cured state in which imidization has been completed, and is a state in which an imidization reaction has occurred in the polyamic acid but has not been completed. . The degree of imidization can be evaluated, for example, by a weight reduction rate in a temperature range from 100 ° C. to 360 ° C. measured by a thermogravimetric differential thermal analyzer (TG-DTA). If the weight loss rate in this temperature range is within the range of 0.1 to 20%, it can be considered that the partially cured semi-cured state is imidized. If the weight reduction ratio is less than 0.1%, imidization may have progressed excessively, and sufficient interlayer adhesion may not be obtained. On the other hand, when the weight reduction rate exceeds 20%, the imidation reaction hardly progresses and cannot be distinguished from mere drying, so that the solvent contained in the first polyamide resin layer 20A remains. The possibility is high, and the amount of imidized water generated before the completion of imidization is large, which may cause foaming. In the step (b), it is preferable to adjust the degree of imidation so that the above-mentioned weight loss rate is in the range of 1 to 15%.

Further, the degree of imidization can also be evaluated by the imidization rate. In the step (b), it is preferable to adjust the imidization ratio of the semi-cured resin layer 20B to be in the range of 20 to 95%, and more preferably to be in the range of 22 to 90%. . When the imidation ratio is less than 20%, the imidization reaction hardly progresses and cannot be distinguished from mere drying, so that there is a high possibility that the solvent contained in the first polyamide resin layer 20A remains, In addition, since the amount of imidized water generated before the completion of imidization is large, it may cause foaming. On the other hand, if the imidization ratio exceeds 95%, imidization may have progressed excessively, and sufficient interlayer adhesion may not be obtained.
The imidation ratio was determined by measuring the infrared absorption spectrum of the resin layer by a single reflection ATR method using a Fourier transform infrared spectrophotometer, and based on a benzene ring carbon-hydrogen bond at 1009 cm ⁻¹ , It can be calculated from the absorbance derived from the imide group of ^-1 . Here, the stepwise heat treatment from 120 ° C. to 360 ° C. is performed on the first polyamide resin layer 20A, and the imidation ratio after the heat treatment at 360 ° C. is set to 100%.

The method for semi-curing the polyamic acid in the step (b) is not particularly limited, and for example, the above-mentioned weight loss rate or imide under the temperature condition in the range of 120 to 300 ° C, preferably 140 to 280 ° C. Heat treatment in which the time is adjusted so as to obtain a conversion rate and heating is preferred. Note that the heat treatment is preferably performed in a low oxygen atmosphere in order to suppress oxidation of the metal layer 10, specifically, in an inert gas atmosphere such as nitrogen or a rare gas, or in a reducing gas atmosphere such as hydrogen. Alternatively, it is preferably performed in a vacuum.

Step (c)
In the step (c), a single-layer or multiple-layer second polyamide resin layer 30A is formed on the semi-cured resin layer 20B formed in the step (b) by further applying a polyamic acid solution. I do. The method of applying the polyamic acid resin solution on the semi-cured resin layer 20B by the casting method is not particularly limited, and the application can be performed by a coater such as a comma, a die, a knife, and a lip.
In the case where the second polyamide resin layer 30A has a plurality of layers, for example, a method of repeatedly applying and drying a polyamic acid solution on the semi-cured resin layer 20B a plurality of times or a multilayer extrusion method is used. A method of applying and drying the polyamic acid in a state of being simultaneously laminated in multiple layers on the cured resin layer 20B can be adopted.

In the step (c), as described later, the second polyamide resin layer 30A is formed after the step (d) such that the thickness (L) of the entire insulating resin layer 40 is in the range of 10 μm to 200 μm. Is preferred.

Step (d)
In the step (d), the polyamic acid contained in the semi-cured resin layer 20B and the polyamic acid contained in the second polyamide resin layer 30A are imidized to form the first polyimide layer 20 and the second polyimide layer 30. By changing, the insulating resin layer 40 is formed.
In the step (d), the polyamide acid contained in the semi-cured resin layer 20B and the second polyamide resin layer 30A is simultaneously imidized to synthesize polyimide. The imidation method is not particularly limited, and a heat treatment such as heating at a temperature in the range of 80 to 400 ° C. for a time in the range of 1 to 60 minutes is preferably employed. The heat treatment is preferably performed in a low oxygen atmosphere in order to suppress oxidation of the metal layer 10, specifically, in an inert gas atmosphere such as nitrogen or a rare gas, in a reducing gas atmosphere such as hydrogen, or in a vacuum. It is preferably carried out in Note that the end point of the imidization in the step (d) is, for example, that the weight loss rate in a temperature range from 100 ° C. to 360 ° C. measured by a thermogravimetric differential thermal analyzer (TG-DTA) is less than 0.1. It can be used as an index to indicate that there is, or that the imidation ratio exceeds 95%.

<Optional process>
The method of the present embodiment can include any other steps than the above. For example, a step of performing a surface treatment on the surface of the semi-cured resin layer 20B after the step (b) and before the step (c) may be further included as long as the effects of the invention are not impaired. The surface treatment is not particularly limited as long as it can improve the interlayer adhesion between the first polyimide layer 20 and the second polyimide layer 30, and the same treatment as in the first embodiment can be mentioned. .

Through the above steps (a) to (d), the insulating resin layer 40 having excellent adhesion between the first polyimide layer 20 and the second polyimide layer 30 without causing a decrease in throughput due to an increase in the number of steps. Can be manufactured. In the method of the present embodiment, even if the first polyimide layer 20 is formed on the metal layer 10 by a casting method, the first polyimide layer 20 is semi-cured before the formation of the second polyimide layer 30 to provide a solvent or imidized water. Is removed, and problems such as foaming and delamination do not occur.

In the insulating resin layer 40 of the metal-clad laminate 100 manufactured by the method of the present embodiment, the thickness (L1) of the first polyimide layer 20 is preferably in a range from 0.5 μm to 10 μm, More preferably, it is in the range of 1 μm or more and 7 μm or less. In the step (b), most of the solvent and imidized water can be removed by semi-curing in a state where the thickness (L1) after imidization is 10 μm or less. If the thickness (L1) after imidization exceeds 10 μm, it becomes difficult to remove the solvent and the imidized water, and the dimensional stability also deteriorates. If the thickness (L1) of the first polyimide layer 20 is less than 0.5 μm, the adhesiveness with the metal layer 10 is reduced, and the insulating resin layer 40 is easily peeled.

厚み Further, the thickness (L) of the entire insulating resin layer 40 is preferably in the range of 10 μm to 200 μm, and more preferably in the range of 12 μm to 150 μm. When the thickness (L) is less than 10 μm, it is difficult to exhibit the foam suppressing effect, and it is difficult to obtain the effect of improving the dimensional stability. On the other hand, when the thickness (L) exceeds 200 μm, foaming tends to occur.

As described above, the thickness (L1) of the first polyimide layer 20 and the thickness (L) of the entire insulating resin layer 40 affect the suppression of foaming and the improvement of dimensional stability. Is preferably in the range of more than 1 and less than 400, more preferably 4 or more and 200 or less, further preferably 5 or more and 100 or less.

<Polyimide>
In the second embodiment, a preferred polyimide for forming the first polyimide layer 20 and the second polyimide layer 30 will be described. In forming the first polyimide layer 20 and the second polyimide layer 30, an acid anhydride component and a diamine component generally used as a raw material for synthesizing polyimide can be used without any particular limitation.

The polyimide constituting the second polyimide layer 30 may be either a thermoplastic polyimide or a non-thermoplastic polyimide, but when the non-thermoplastic polyimide is used, the effect of the invention is remarkably exhibited.
That is, even if imidization is performed by laminating a resin layer of a polyamic acid that is a precursor of a non-thermoplastic polyimide on a polyimide layer that has been imidized by a method such as a casting method, the adhesion between the polyimide layers is usually The property is hardly obtained. However, in the present embodiment, the polyimide constituting the second polyimide layer 30 is formed by laminating the second polyamide resin layer 30A in a state where the first polyamide resin layer 20A is semi-cured as described above. Regardless of whether it is thermoplastic or non-thermoplastic, excellent adhesion between the first polyimide layer 20 and the first polyimide layer 20 can be obtained. In addition, when the second polyimide layer 30 is made of non-thermoplastic polyimide, it can function as a main layer (base layer) that secures the mechanical strength of the polyimide layer in the metal-clad laminate 100.

In the second embodiment, the contents of the diamine compound and the acid anhydride as the raw materials of the polyimide, the synthesis of the polyimide, and the like are the same as those in the first embodiment.

As described above, the method for manufacturing a metal-clad laminate according to the second embodiment of the present invention includes the following steps (a) to (d);
Step (a) a step of forming a single layer or a plurality of first polyamide resin layers by applying a polyamic acid solution on the metal layer;
Step (b) The first step is performed so that the weight loss rate in the temperature range from 100 ° C. to 360 ° C. measured by a thermogravimetric differential thermal analyzer (TG-DTA) is in the range of 0.1 to 20%. A step of partially imidizing the polyamic acid contained in the polyamide resin layer of 1 to form a single layer or a plurality of semi-cured resin layers,
Step (c) a step of forming a single-layer or plural-layer second polyamide resin layer by applying a polyamic acid solution on the semi-cured resin layer,
(D) imidizing the polyamic acid contained in the semi-cured resin layer and the polyamic acid contained in the second polyamide resin layer to form the insulating resin layer;
Is included.

方法 In the method for manufacturing a metal-clad laminate according to the second embodiment of the present invention, the imidation ratio in the step (b) may be in the range of 20 to 95%.

In the method for manufacturing a metal-clad laminate according to the second embodiment of the present invention, the thickness (L1) of the resin layer formed by the first polyamide resin layer is in the range of 0.5 μm to 10 μm. And the thickness (L) of the entire insulating resin layer is in the range of 10 μm or more and 200 μm or less, and the ratio (L / L1) of L to L1 is more than 1 and less than 400. You may.

In the method for manufacturing a metal-clad laminate according to the second embodiment of the present invention, the polyimide constituting a layer in contact with the metal layer among the resin layers formed by the first polyamide resin layer is heat-resistant. It may be a plastic polyimide.

Manufacturing method of the second embodiment of the metal-clad laminate of the present invention, the moisture permeability of the metal layer, the thickness 25 [mu] m, when the 25 ° C., may be not more than 100g ^/ m 2 ^/ 24hr.

In the method for manufacturing a metal-clad laminate according to the second embodiment of the present invention, a surface treatment is performed on the surface of the semi-cured resin layer after the step (b) and before the step (c). The method may further include a step.

回路 A method of manufacturing a circuit board according to the second embodiment of the present invention includes a step of processing a wiring circuit of the metal layer of the metal-clad laminate manufactured by any of the above methods.

In the first embodiment, the surface treatment is performed on the imidized polyimide in order to obtain the adhesion between the layers. However, the surface treatment requires facilities for the treatment and increases the number of steps. There are cases. Therefore, in a third embodiment and a fourth embodiment of the present invention described below, the resin component of the polyimide precursor layer formed by the casting method and the resin component of the polyimide layer serving as the base are formed. By utilizing the interaction, the adhesion between polyimide layers can be improved without requiring a special step such as surface treatment.

[Third Embodiment: Method for Producing Polyimide Film]
The method for manufacturing a polyimide film according to the third embodiment includes a first polyimide layer (A) and a second polyimide layer (B) laminated on at least one surface of the first polyimide layer (A). This is a method for producing a polyimide film comprising: The polyimide film obtained according to the present embodiment may have a polyimide layer other than the first polyimide layer (A) and the second polyimide layer (B), and may be laminated on any substrate. You may.

ポリイミド The method for producing a polyimide film of the present embodiment includes the following steps I to III.

(Step I):
In step I, a first polyimide layer (A) containing a polyimide having a ketone group is prepared. A polyimide having a ketone group has a ketone group (—CO—) in the molecule. The ketone group is derived from an acid dianhydride and / or a diamine compound which is a raw material for polyimide. That is, the polyimide constituting the first polyimide layer (A) contains a tetracarboxylic acid residue (1a) and a diamine residue (2a), and contains a tetracarboxylic acid residue (1a) or a diamine residue. One or both of (2a) include a residue having a ketone group.
In the present invention, “tetracarboxylic acid residue” refers to a tetravalent group derived from tetracarboxylic dianhydride, and “diamine residue” refers to a divalent group derived from a diamine compound. It represents a valence group. In the “diamine compound”, the hydrogen atoms in the two terminal amino groups may be substituted.

Examples of the residue having a ketone group contained in the tetracarboxylic acid residue (1a) include 3,3 ′, 4,4′-benzophenonetetracarboxylic dianhydride, 2,3 ′, 3,4 ′ -Benzophenonetetracarboxylic dianhydride, 2,2 ', 3,3'-benzophenonetetracarboxylic dianhydride, 4,4'-(paraphenylenedicarbonyl) diphthalic anhydride, 4,4 '-(meta Residues derived from "tetracarboxylic dianhydride having a ketone group in the molecule" such as phenylenedicarbonyl) diphthalic anhydride can be mentioned.

In the tetracarboxylic acid residue (1a), other than the residue having a ketone group, for example, those derived from tetracarboxylic dianhydride generally used in the synthesis of polyimide, in addition to those shown in Examples described later. Residues may be mentioned.

Examples of the residue having a ketone group contained in the diamine residue (2a) include, for example, 3,3′-diaminobenzophenone, 3,4′-diaminobenzophenone, 4,4′-diaminobenzophenone, and 4,4′- Bis [4- (4-amino-α, α-dimethylbenzyl) phenoxy] benzophenone, 4,4′-bis (4-aminophenoxy)

benzophenone

4,4′-bis (3-aminophenoxy) benzophenone (BABP), "Molecules such as 1,3-bis [4- (3-aminophenoxy) benzoyl] benzene (BABB), 1,4-bis (4-aminobenzoyl) benzene, and 1,3-bis (4-aminobenzoyl) benzene And a residue derived from a "diamine compound having a ketone group therein".

In the diamine residue (2a), other than the residue having a ketone group, for example, in addition to those shown in Examples described later, there may be mentioned residues derived from a diamine compound generally used in the synthesis of polyimide. it can.

The first polyimide layer (A) may contain another polyimide other than the polyimide having a ketone group. However, in order to ensure sufficient adhesion with the second polyimide layer (B), 10 mol% or more of the polyimide having a ketone group is based on the total amount of the polyimide constituting the first polyimide layer (A). It is more preferable that 30 mol% or more of the polyimide is a polyimide having a ketone group.
The amount of ketone groups (as -CO-) present in the polyimide constituting the first polyimide layer (A) is 100 mol parts in total of the tetracarboxylic acid residue (1a) and the diamine residue (2a). Is preferably in the range of 5 to 200 mol parts, more preferably in the range of 15 to 100 mol parts. When the ketone group present in the polyimide constituting the first polyimide layer (A) is less than 5 mol parts, the functional group present in the resin layer containing the polyamic acid (b) laminated in the step II (for example, In some cases, the probability of interaction with the terminal amino group) is reduced, and sufficient adhesion between layers may not be obtained.

As a method of forming the first polyimide layer (A), a method of applying a resin solution containing a polyamic acid (a) having a ketone group on an arbitrary base material (cast method), a method of forming an arbitrary base material It can be formed by a method of laminating a gel film containing a polyamic acid (a) having a ketone group thereon.

In the casting method, the method of applying the resin solution containing the polyamic acid (a) is not particularly limited, and for example, the resin solution can be applied using a coater such as a comma, a die, a knife, and a lip.

The first polyimide layer (A) may be in a state of being laminated with another resin layer, or may be in a state of being laminated on an arbitrary base material.

Further, the first polyimide layer (A) is formed by laminating a resin layer containing a polyamic acid (a) having a ketone group on a substrate and imidizing the polyamic acid (a) together with the substrate. It is preferred that As described above, even when the first polyimide layer (A) is formed on the base material by the casting method, the imidation is completed before the second polyimide layer (B) is formed. Since water is removed, problems such as foaming and delamination do not occur.

Further, the first polyimide layer (A) can be formed in a shape such as a cut sheet shape, a roll shape, or an endless belt shape. It is efficient to use a form that enables continuous production. Further, the first polyimide layer (A) is preferably a long roll formed from the viewpoint of further improving the effect of improving the wiring pattern accuracy on the circuit board.

(Step II)
In step II, a resin layer containing a polyamic acid (b) having a functional group having a property of interacting with the ketone group is laminated on the first polyimide layer (A) obtained in step I.
In step II, the “functional group having the property of interacting with a ketone group” includes, for example, a functional group capable of generating a physical interaction due to an intermolecular force or a chemical interaction due to a covalent bond with the ketone group. The group is not particularly limited as long as it is a group, but a typical example thereof is an amino group (—NH ₂ ).
When the functional group is an amino group, the polyamic acid (b) may be a polyamic acid having an amino group at a terminal, preferably a polyamic acid having most of terminal amino groups, more preferably Polyamic acids, all of whose ends are amino groups, can be used. Thus, the polyamic acid (b) having abundant amino terminals can be formed by adjusting the molar ratio of the two components so that the diamine compound is in excess with respect to the tetracarboxylic dianhydride in the raw material. . For example, by adjusting the charge ratio of the raw materials so that the amount of the tetracarboxylic dianhydride is less than 1 mol per 1 mol of the diamine compound, most of the synthesized polyamic acid is stochastically changed to the amino terminal ( —NH ₂ ). If the charging ratio of the tetracarboxylic dianhydride exceeds 1 mole per 1 mole of the diamine compound, it is not preferable because almost no amino terminal (—NH ₂ ) remains. On the other hand, if the charging ratio of the tetracarboxylic dianhydride to the diamine compound is too small, the increase in the molecular weight of the polyamic acid does not sufficiently proceed. Therefore, the charging ratio of tetracarboxylic dianhydride to 1 mol of the diamine compound is preferably, for example, in the range of 0.970 to 0.998 mol, and more preferably in the range of 0.980 to 0.995 mol. .

The polyamic acid (b) can be synthesized using a tetracarboxylic dianhydride and a diamine compound generally used for the synthesis of polyimide as raw materials. The raw material may be a tetracarboxylic dianhydride having a ketone group in the molecule or a diamine compound having a ketone group in the molecule.

In addition, a polyamic acid (b) having abundant amino terminals is synthesized by using a compound (for example, a triamine compound) rich in an amino group in a molecule instead of part or all of the diamine compound as a raw material. It is also possible.
Furthermore, the charge ratio of the tetracarboxylic dianhydride and the diamine compound in the raw materials is made equimolar, and by adding a small amount of a compound containing an amino group (for example, a triamine compound), a polyamic acid having a rich amino terminal ( It is also possible to form a resin layer containing b).

には For forming the resin layer containing the polyamic acid (b), other polyamic acid may be mixed with the polyamic acid (b). As the other polyimide acid, a polyamic acid synthesized using tetracarboxylic dianhydride and a diamine compound, which are generally used for the synthesis of polyimide, as raw materials and in an equimolar ratio thereof can be used. However, from the viewpoint of ensuring sufficient adhesiveness with the first polyimide layer (A), the resin layer containing the polyamic acid (b) has a polyamic acid content of 10 mol% or more based on the total amount of the constituent polyamic acid. (B), and more preferably 30% by mole or more of the polyamic acid is the polyamic acid (b).

The resin layer containing the polyamic acid (b) is formed by applying a resin solution containing the polyamic acid (b) on the first polyimide layer (A) (casting method). It can be formed by a method of laminating a gel film containing a polyamic acid (b) on the first layer. In order to increase the adhesion between the first polyimide layer (A) and the second polyimide layer (B), It is preferable to use a casting method. In addition, when forming the resin layer containing the polyamic acid (b), it is not necessary to previously perform a surface treatment such as a plasma treatment or a corona treatment on the surface of the first polyimide layer (A). It is also possible to do.

In the casting method, the method of applying the resin solution containing the polyamic acid (b) is not particularly limited, and it is possible to apply the resin solution using a coater such as a comma, a die, a knife, and a lip.

The resin layer containing the polyamic acid (b) thus obtained contains the tetracarboxylic acid residue (1b) and the diamine residue (2b), and is contained in 1 mole of the diamine residue (2b). Containing a tetracarboxylic acid residue (1b) of less than 1 mol, preferably in the range of 0.970 to 0.998 mol, more preferably in the range of 0.980 to 0.995 mol, and the amino terminal (—NH It becomes a resin layer containing ₂ ) abundantly.

(Step III)
In Step III, the resin layer containing the polyamic acid (b) is heat-treated together with the first polyimide layer (A), and the polyamic acid (b) is imidized to form a second polyimide layer (B).
The imidation method is not particularly limited, and a heat treatment such as heating at a temperature in the range of 80 to 400 ° C. for a time in the range of 1 to 60 minutes is preferably employed. When a metal layer is included, heat treatment in a low-oxygen atmosphere is preferable to suppress oxidation.Specifically, under an inert gas atmosphere such as nitrogen or a rare gas, a reducing gas atmosphere such as hydrogen, or a vacuum It is preferably carried out in

In parallel with the imidation, a ketone group present in the polyimide chain of the first polyimide layer (A) and the functional group present in the resin layer containing the polyamic acid (b) (for example, abundant terminal Interaction occurs between the first polyimide layer (A) and the second polyimide layer (B), and the adhesion between the first polyimide layer (A) and the second polyimide layer (B) is a property of the polyimide constituting both layers (for example, thermoplastic). Or non-thermoplastic, etc.). Although all the mechanisms of such an interaction have not been elucidated, when the functional group is an amino group, one possibility is that the heat treatment at the time of imidizing the polyamic acid (b) causes It is presumed that an imine bond has occurred between the ketone group and the terminal amino group. That is, a heating causes a dehydration condensation reaction between the ketone group in the polyimide chain of the first polyimide layer (A) and the amino group at the terminal of the polyamic acid (b) to form an imine bond. Is chemically bonded to the second polyimide layer (B) after imidization, whereby the first polyimide layer (A) and the second polyimide layer (B) are chemically bonded to each other. It is presumed that the adhesive strength is increased.

In the case where the first polyimide layer (A) and the second polyimide layer (B) have the opposite relationship, the effect of improving the adhesion between the layers cannot be obtained. That is, first, a resin layer containing a polyamic acid (b) having a functional group having a property of interacting with a ketone group is imidized to form a first polyimide layer, and a polyamic acid having a ketone group is formed thereon. When a resin layer containing (a) is formed and then imidized by heat treatment to form a second polyimide layer, the adhesion between the first and second layers is determined by the properties of the polyimide constituting both layers (for example, , Thermoplastic or non-thermoplastic, etc.). It is considered that the reason for this is that in the cured polyimide, the movement of the terminal amino group as the functional group is restricted and the reactivity is reduced, so that the above-mentioned interaction hardly occurs.

The first polyimide layer (A) and the second polyimide layer (B) may contain an inorganic filler as needed. Specific examples include silicon dioxide, aluminum oxide, magnesium oxide, beryllium oxide, boron nitride, aluminum nitride, silicon nitride, aluminum fluoride, calcium fluoride, and the like. These can be used alone or in combination of two or more.

Through the above steps I to III, a polyimide film having excellent adhesion between the first polyimide layer (A) and the second polyimide layer (B) is produced without causing a decrease in throughput due to an increase in the number of steps. be able to.

[Fourth Embodiment: Method for Manufacturing Metal-Clad Laminate]
In a fourth embodiment of the present invention, a metal layer, a first polyimide layer (A), and a second polyimide layer (B) laminated on one surface of the first polyimide layer (A) And a method for producing a metal-clad laminate, comprising the following steps i to iv.

(Step i)
In step i, at least one or more polyamic acid resin layers having a polyamic acid (a) resin layer having a ketone group on the surface layer are formed on the metal layer.

金属 As the metal layer, a 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 And the like. Among them, copper or a copper alloy is particularly preferable. As the copper foil, a rolled copper foil or an electrolytic copper foil may be used, and a commercially available copper foil can be preferably used.

において In the present embodiment, for example, the thickness of the metal layer when used for manufacturing an FPC is preferably in the range of 3 to 50 μm, and more preferably in the range of 5 to 30 μm.

金属 The surface of the metal foil used as the metal layer may be subjected to surface treatment such as rust prevention treatment, siding, aluminum alcoholate, aluminum chelate, and silane coupling agent. In addition, the metal foil can be in a shape such as a cut sheet shape, a roll shape, or an endless belt shape. It is efficient to use a simple format. Further, from the viewpoint of further improving the effect of improving the accuracy of the wiring pattern on the circuit board, the metal foil is preferably a roll formed in a long shape.

In forming the first polyimide layer (A), at least one or more resin layers of polyamic acid are formed on the metal layer so that the resin layer containing the polyamic acid (a) having a ketone group becomes a surface layer. To form In this case, it can be formed by a method of applying a polyamic acid resin solution on the metal layer (casting method), a method of laminating a gel film containing the polyamic acid (a) on the metal layer, or the like.
Note that an arbitrary resin layer (including a resin layer of another polyamic acid) may be provided between the metal layer and the resin layer containing the polyamic acid (a) having a ketone group. Can form a resin layer containing a polyamic acid (a) having a ketone group on the arbitrary resin layer by the above method. When a resin layer of a polyamic acid (a) having a ketone group is directly formed on the metal layer, a cast method is used in order to increase the adhesion between the metal layer and the first polyimide layer (A). Is preferred.

(Step ii)
In step ii, the polyamic acid resin layer having a resin layer containing a polyamic acid (a) having a ketone group in the surface layer is heat-treated together with the metal layer to imidize the polyamic acid. As a result, an intermediate is formed in which the polyimide layer having the first polyimide layer (A) containing the polyimide having a ketone group as a surface layer is laminated on the metal layer.

イミド The imidization of the polyamic acid can be performed by the method described in the step (III) of the third embodiment. In the present embodiment, even when a resin layer of a polyamic acid having a surface layer with a resin layer containing a polyamic acid (a) having a ketone group is formed on a metal foil by a casting method, the second polyimide Since the imidization is completed before the formation of the layer (B), the solvent and the imidized water are removed, so that problems such as foaming and delamination do not occur.

(Step iii)
In step iii, a resin layer containing a polyamic acid (b) having a functional group having a property of interacting with the ketone group is laminated on the first polyimide layer (A).
This step iii can be performed in the same manner as in step II of the third embodiment.

(Step iv)
The resin layer containing the polyamic acid (b) laminated on the intermediate in step iii is heat-treated together with the intermediate to imidize the polyamic acid (b) to form a second polyimide layer (B).
This step iv can be performed in the same manner as in step III of the third embodiment.

By the above steps i to iv, a metal-clad laminate excellent in adhesion between the first polyimide layer (A) and the second polyimide layer (B) can be obtained without causing a decrease in throughput due to an increase in the number of steps. Can be manufactured.

他 Other configurations and effects of the present embodiment are the same as those of the third embodiment.

<Polyimide>
Next, a preferred polyimide for forming the first polyimide layer (A) and the second polyimide layer (B) will be described. In forming the first polyimide layer (A), the above-mentioned “tetracarboxylic dianhydride having a ketone group in the molecule” and / or “diamine compound having a ketone group in the molecule” and generally a polyimide It is preferable to use a combination of an acid anhydride component and a diamine component used as a raw material for synthesis. In forming the second polyimide layer (B), an acid anhydride component and a diamine component generally used as a raw material for synthesizing polyimide can be used without any particular limitation.

In the polyimide film or the metal-clad laminate, the polyimide constituting the first polyimide layer (A) may be either a thermoplastic polyimide or a non-thermoplastic polyimide. Thermoplastic polyimide is preferred because it is easy to secure adhesion.

Further, the polyimide constituting the second polyimide layer (B) may be either a thermoplastic polyimide or a non-thermoplastic polyimide. However, when the non-thermoplastic polyimide is used, the effect of the invention is remarkably exhibited.
That is, even when a resin layer of a polyamic acid, which is a precursor of a non-thermoplastic polyimide, is laminated on the first polyimide layer (A) which has been imidized by a method such as a casting method, imidization is usually performed. Has little adhesion between polyimide layers. However, in the present embodiment, the polyimide constituting the second polyimide layer (B) is thermoplastic or non-thermoplastic due to the interaction between the ketone group and the functional group (for example, terminal amino group). Regardless of whether or not there is, excellent adhesion between the first polyimide layer (A) and the first polyimide layer (A) can be obtained. Further, by making the second polyimide layer (B) a non-thermoplastic polyimide, it can function as a main layer (base layer) for securing the mechanical strength of the polyimide layer in the polyimide film or the metal-clad laminate. it can.

From the above, it is not possible to form a structure in which a thermoplastic polyimide layer is laminated as the first polyimide layer (A) and a non-thermoplastic polyimide layer is laminated as the second polyimide layer (B) in the polyimide film or the metal-clad laminate. This is the most preferred embodiment.

(Thermoplastic polyimide)
Thermoplastic polyimide is obtained by reacting an acid anhydride component with a diamine component. As the acid anhydride component used as a raw material of the thermoplastic polyimide, a general acid anhydride used for the synthesis of polyimide can be used without any particular limitation, and in particular, both the adhesion to the metal layer and the low dielectric property are compatible. In view of this, it is preferable to use a combination of biphenyltetracarboxylic dianhydride and pyromellitic dianhydride (PMDA). Biphenyltetracarboxylic dianhydride has an effect of lowering the glass transition temperature so as not to affect the decrease in solder heat resistance of the polyimide, and can secure a sufficient adhesive force with a metal layer or the like. In addition, biphenyltetracarboxylic dianhydride reduces the concentration of imide groups in the polyimide, facilitates the formation of an ordered structure of the polymer, and improves the dielectric properties by suppressing the movement of molecules. Furthermore, biphenyltetracarboxylic dianhydride contributes to the reduction in the number of polar groups in the polyimide, so that the hygroscopic property is improved. For this reason, biphenyltetracarboxylic dianhydride can reduce the transmission loss of FPC. 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.

Examples of the biphenyltetracarboxylic dianhydride include 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride (BPDA), 2,3 ′, 3,4′-biphenyltetracarboxylic dianhydride, 2,2 ', 3,3'-biphenyltetracarboxylic dianhydride and the like can be mentioned. By using biphenyltetracarboxylic dianhydride within the above range, an ordered structure with a rigid structure is formed, so that a low dielectric loss tangent is possible, and while being thermoplastic, gas permeability is low, A thermoplastic polyimide having excellent long-term heat resistance can be obtained. Pyromellitic dianhydride is a monomer that plays a role in controlling the glass transition temperature, and contributes to improving the solder heat resistance of polyimide.

In the thermoplastic polyimide, acid anhydrides other than those described above can be used as the acid anhydride component. Such acid anhydrides include, for example, 3,3 ′, 4,4′-diphenylsulfonetetracarboxylic dianhydride, 4,4′-oxydiphthalic anhydride, 2,2 ′, 3,3′- 2,3,3 ′, 4′- or 3,3 ′, 4,4′-benzophenonetetracarboxylic dianhydride, 2,3 ′, 3,4′-diphenylethertetracarboxylic dianhydride, bis ( 2,3-dicarboxyphenyl) ether dianhydride, 3,3 ", 4,4"-, 2,3,3 ", 4"-or 2,2 ", 3,3" -p-terphenyltetracarboxylic dianhydride, 2,2-bis (2,3- or 3,4-dicarboxyphenyl) -propane dianhydride, bis (2,3- or 3.4-dicarboxy) Phenyl) methane dianhydride, bis (2,3- or 3,4-dicarboxyphenyl) sulfone dianhydride, 1,1-bis (2,3- or 3,4-dicarboxyphenyl) ethane dianhydride 1,2,7,8-, 1,2,6,7- or 1 2,2,9,10-phenanthrene-tetracarboxylic dianhydride, 2,3,6,7-anthracenetetracarboxylic dianhydride, 2,2-bis (3,4-dicarboxyphenyl) tetrafluoropropane dianhydride Anhydride, 2,3,5,6-cyclohexane dianhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride, 1,2,5,6-naphthalenetetracarboxylic dianhydride, 1, 4,5,8-Naphthalenetetracarboxylic dianhydride, 4,8-dimethyl-1,2,3,5,6,7-hexahydronaphthalene-1,2,5,6-tetracarboxylic dianhydride 2,2,6- or 2,7-dichloronaphthalene-1,4,5,8-tetracarboxylic dianhydride, 2,3,6,7- (or 1,4,5,8-) tetrachloronaphthalene -1,4,5,8- (or 2,3,6,7-) tetracarboxylic dianhydride, 2,3,8,9-, 3,4,9,10-, 4,5,10 , 11- or 5,6,1 , 12-Perylene-tetracarboxylic dianhydride, cyclopentane-1,2,3,4-tetracarboxylic dianhydride, pyrazine-2,3,5,6-tetracarboxylic dianhydride, pyrrolidine-2 , 3,4,5-tetracarboxylic dianhydride, thiophene-2,3,4,5-tetracarboxylic dianhydride, 4,4'-bis (2,3-dicarboxyphenoxy) diphenylmethane dianhydride And 2,2-bis [4- (3,4-dicarboxyphenoxy) phenyl] propane dianhydride.

As the diamine component used as a raw material of the thermoplastic polyimide, a general diamine used in the synthesis of polyimide can be used without any particular limitation, and is selected from diamine compounds represented by the following general formulas (1) to (8). It is preferable to contain at least one of these.

In the above formulas (1) to (7), R ₁ independently represents a monovalent hydrocarbon group or an alkoxy group having 1 to 6 carbon atoms, and the linking group A independently represents -O-, -S-, -CO —, —SO—, —SO ₂ —, —COO—, —CH ₂ —, —C (CH ₃ ) ₂ —, —NH— or —CONH— represents a divalent group, and n ₁ is independently Shows an integer of 0 to 4. However, those overlapping with Expression (2) are excluded from Expression (3), and those overlapping with Expression (4) are excluded from Expression (5). Here, “independently” means that in one or two or more of the above formulas (1) to (7), a plurality of linking groups A, a plurality of R _1, or a plurality of n ₁ are the same. Or may be different.

In the above formula (8), the connecting group X represents a single bond or —CONH—, and Y represents a monovalent hydrocarbon group or an alkoxy group having 1 to 3 carbon atoms which may be independently substituted with a halogen atom. And n represents an integer of 0 to 2, and p and q independently represent an integer of 0 to 4.

In the above formulas (1) to (8), hydrogen atoms in the two terminal amino groups may be substituted, for example, -NR ₂ R ₃ (where R ₂ and R ₃ are independently Any substituent such as an alkyl group).

The diamine represented by the formula (1) (hereinafter sometimes referred to as “diamine (1)”) is an aromatic diamine having two benzene rings. The diamine (1) has a high flexibility by increasing the degree of freedom of the polyimide molecular chain because the amino group directly bonded to at least one benzene ring and the divalent linking group A are at the meta position. This is considered to contribute to the improvement of the flexibility of the polyimide molecular chain. Accordingly, the use of the diamine (1) increases the thermoplasticity of the polyimide. Here, as the linking group A, —O—, —CH ₂ —, —C (CH ₃ ) ₂ —, —CO—, —SO ₂ —, and —S— are preferable.

Examples of the diamine (1) include 3,3'-diaminodiphenylmethane, 3,3'-diaminodiphenylpropane, 3,3'-diaminodiphenylsulfide, 3,3'-diaminodiphenylsulfone, and 3,3-diaminodiphenylether , 3,4'-diaminodiphenylether, 3,4'-diaminodiphenylmethane, 3,4'-diaminodiphenylpropane, 3,4'-diaminodiphenylsulfide, 3,3'-diaminobenzophenone, (3,3'-bisamino ) Diphenylamine and the like.

ジアミン The diamine represented by the formula (2) (hereinafter sometimes referred to as “diamine (2)”) is an aromatic diamine having three benzene rings. Since the diamine (2) has at least one amino group directly bonded to the benzene ring and the divalent linking group A at the meta position, the degree of freedom of the polyimide molecular chain is increased, and the diamine (2) has high flexibility. This is considered to contribute to the improvement of the flexibility of the polyimide molecular chain. Accordingly, the use of the diamine (2) increases the thermoplasticity of the polyimide. Here, the connecting group A is preferably -O-.

Examples of the diamine (2) include 1,4-bis (3-aminophenoxy) benzene, 3- [4- (4-aminophenoxy) phenoxy] benzeneamine, and 3- [3- (4-aminophenoxy) phenoxy] Benzenamine and the like can be mentioned.

ジアミン The diamine represented by the formula (3) (hereinafter, sometimes referred to as “diamine (3)”) is an aromatic diamine having three benzene rings. The diamine (3) has a high flexibility by increasing the degree of freedom of the polyimide molecular chain because the two divalent linking groups A directly bonded to one benzene ring are at the meta position with each other. It is considered that this contributes to the improvement of the flexibility of the polyimide molecular chain. Accordingly, the use of the diamine (3) increases the thermoplasticity of the polyimide. Here, the connecting group A is preferably -O-.

Examples of the diamine (3) include 1,3-bis (4-aminophenoxy) benzene (TPE-R), 1,3-bis (3-aminophenoxy) benzene (APB), and 4,4 ′-[2- Methyl- (1,3-phenylene) bisoxy] bisaniline, 4,4 ′-[4-methyl- (1,3-phenylene) bisoxy] bisaniline, 4,4 ′-[5-methyl- (1,3-phenylene) ) Bisoxy] bisaniline and the like. Among these, 1,3-bis (4-aminophenoxy) benzene (TPE-R) is a monomer that contributes to a higher CTE of the thermoplastic polyimide, reduces the imide group concentration, and improves the dielectric properties. preferable.

The diamine represented by the formula (4) (hereinafter sometimes referred to as “diamine (4)”) is an aromatic diamine having four benzene rings. The diamine (4) has high flexibility by having at least one amino group directly bonded to the benzene ring and the divalent linking group A at the meta position, and is useful for improving the flexibility of the polyimide molecular chain. It is thought to contribute. Accordingly, the use of the diamine (4) increases the thermoplasticity of the polyimide. Here, as the linking group A, —O—, —CH ₂ —, —C (CH ₃ ) ₂ —, —SO ₂ —, —CO—, and —CONH— are preferable.

Examples of the diamine (4) include bis [4- (3-aminophenoxy) phenyl] methane, bis [4- (3-aminophenoxy) phenyl] propane, bis [4- (3-aminophenoxy) phenyl] ether, [4- (3-aminophenoxy) phenyl] sulfone, bis [4- (3-aminophenoxy)] benzophenone, bis [4,4 ′-(3-aminophenoxy)] benzanilide and the like can be mentioned.

ジアミン The diamine represented by the formula (5) (hereinafter, sometimes referred to as “diamine (5)”) is an aromatic diamine having four benzene rings. The diamine (5) has a high flexibility by increasing the degree of freedom of the polyimide molecular chain because two divalent linking groups A directly bonded to at least one benzene ring are at meta positions with each other. This is considered to contribute to the improvement of the flexibility of the polyimide molecular chain. Accordingly, the use of the diamine (5) increases the thermoplasticity of the polyimide. Here, the connecting group A is preferably -O-.

Examples of the diamine (5) include 4- [3- [4- (4-aminophenoxy) phenoxy] phenoxy] aniline and 4,4 ′-[oxybis (3,1-phenyleneoxy)] bisaniline. .

The diamine represented by the formula (6) (hereinafter sometimes referred to as “diamine (6)”) is an aromatic diamine having four benzene rings. The diamine (6) has high flexibility by having at least two ether bonds, and is considered to contribute to improvement in flexibility of the polyimide molecular chain. Accordingly, the use of the diamine (6) increases the thermoplasticity of the polyimide. Here, the connecting group A is preferably —C (CH ₃ ) ₂ —, —O—, —SO ₂ —, or —CO—.

Examples of the diamine (6) include, for example, 2,2-bis [4- (4-aminophenoxy) phenyl] propane (BAPP), bis [4- (4-aminophenoxy) phenyl] ether (BAPE), bis [4 -(4-aminophenoxy) phenyl] sulfone (BAPS), bis [4- (4-aminophenoxy) phenyl] ketone (BAPK) and the like. Among these, 2,2-bis [4- (4-aminophenoxy) phenyl] propane (BAPP) is particularly preferred as a monomer that greatly contributes to the improvement in adhesion to the metal layer.

ジアミン The diamine represented by the formula (7) (hereinafter sometimes referred to as “diamine (7)”) is an aromatic diamine having four benzene rings. Since the diamine (7) has the highly flexible divalent linking group A on both sides of the diphenyl skeleton, it is considered that the diamine (7) contributes to the improvement of the flexibility of the polyimide molecular chain. Accordingly, the use of the diamine (7) increases the thermoplasticity of the polyimide. Here, the connecting group A is preferably -O-.

(4) Examples of the diamine (7) include bis [4- (3-aminophenoxy)] biphenyl and bis [4- (4-aminophenoxy)] biphenyl.

ジアミン The diamine represented by the general formula (8) (hereinafter sometimes referred to as “diamine (8)”) is an aromatic diamine having one to three benzene rings. Since the diamine (8) has a rigid structure, it has an action of giving an ordered structure to the entire polymer. Therefore, by using one or more of the diamines (1) to (7) and one or more of the diamines (8) in combination at a predetermined ratio, the dielectric loss tangent can be reduced and the thermoplastic resin can have a low dielectric loss tangent. However, a polyimide having low gas permeability and excellent long-term heat resistance can be obtained. Here, the connecting group X is preferably a single bond or —CONH—.

Examples of the diamine (8) include, for example, paraphenylenediamine (PDA), 4,4′-diamino-2,2′-dimethylbiphenyl (m-TB), 4,4′-diamino-3,3′-

dimethyldiphenyl

4,4′-diamino-2,2′-n-propylbiphenyl (m-NPB), 2′-methoxy-4,4′-diaminobenzanilide (MABA), 4,4′-diaminobenzanilide (DABA) ), 2,2′-bis (trifluoromethyl) -4,4′-diaminobiphenyl and the like. Among these, 4,4′-diamino-2,2′-dimethylbiphenyl (m-TB) is particularly preferred as a monomer that greatly contributes to the improvement of the dielectric properties of the thermoplastic polyimide, and further to the low moisture absorption and high heat resistance. .

By using the diamines (1) to (7), the flexibility of the polyimide molecular chain can be improved and thermoplasticity can be imparted.

In addition, by using the diamine (8), an ordered structure is formed throughout the polymer due to the rigid structure derived from the monomer, so that a low dielectric loss tangent can be achieved, and gas permeability is obtained while being thermoplastic. A polyimide which is low and has excellent long-term heat resistance can be obtained.

In the thermoplastic polyimide, a diamine other than the above can be used as the diamine component.

(Non-thermoplastic polyimide)
The non-thermoplastic polyimide is obtained by reacting an acid anhydride component and a diamine component. As the acid anhydride component serving as the raw material of the non-thermoplastic polyimide, a general acid anhydride used for the synthesis of polyimide can be used without any particular limitation, but in order to impart low dielectric properties, the acid anhydride component of the raw material is used. It is preferable to use at least one selected from the group consisting of pyromellitic dianhydride (PMDA), biphenyltetracarboxylic dianhydride, and naphthalenetetracarboxylic dianhydride. Here, as the biphenyltetracarboxylic dianhydride, 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride (BPDA) is particularly preferable, and as the naphthalenetetracarboxylic dianhydride, 2,3 ′, 4,4′-biphenyltetracarboxylic dianhydride is particularly preferable. 6,6,7-Naphthalenetetracarboxylic dianhydride (NTCDA) is particularly preferred.

PMDA can reduce the coefficient of thermal expansion (CTE) of polyimide. BPDA has the effect of lowering the glass transition temperature to such an extent that it does not affect the solder heat resistance of polyimide. In addition, BPDA reduces the imide group concentration of the polyimide, facilitates the formation of an ordered structure of the polymer, and improves the dielectric properties by suppressing the movement of molecules. In addition, BPDA improves the moisture absorption properties since it contributes to the reduction of the polar groups of the polyimide. Therefore, the transmission loss of FPC can be reduced by using BPDA.

非 As the non-thermoplastic polyimide, acid anhydrides other than those described above can be used as the acid anhydride component.

As the diamine component used as a raw material of the non-thermoplastic polyimide, a general diamine used in the synthesis of polyimide can be used without any particular limitation, and the diamines (1) to (8) exemplified in the description of the thermoplastic polyimide can be used. Diamines selected from among them are preferred, and diamine (8) is more preferred.

(4) Diamine (8) is an aromatic diamine, and contributes to lowering the CTE and improving the dielectric properties, as well as lowering the moisture absorption and increasing the heat resistance. Among the diamines (8), those in which Y is an alkyl group having 1 to 3 carbon atoms in the above general formula (8) are preferable, and 4,4′-diamino-2,2′-dimethyldiphenyl (m-TB) 4,4′-Diamino-3,3′-dimethyldiphenyl is more preferred. Of these, 4,4'-diamino-2,2'-dimethyldiphenyl (m-TB) is most preferred.

非 As the non-thermoplastic polyimide, a diamine other than the above can be used as the diamine component as long as the effects of the present invention are not impaired.

(Synthesis of polyimide)
The polyimide constituting the polyimide layer can be produced by reacting an acid anhydride and a diamine in a solvent to form a precursor resin, and then heating and closing the ring. For example, the acid anhydride component and the diamine component are dissolved in an organic solvent in approximately equimolar amounts (however, in the case of forming the second polyimide layer (B), the ratio of the diamine component is increased), and 0 to 100 The polyamic acid, which is a precursor of polyimide, is obtained by performing a polymerization reaction by stirring at a temperature within the range of 30 ° C. for 30 minutes to 24 hours. In the reaction, the reaction components are dissolved in an organic solvent so that the amount of the produced precursor is in the range of 5 to 30% by weight, preferably in the range of 10 to 20% by weight. Examples of the organic solvent used in the polymerization reaction include N, N-dimethylformamide, N, N-dimethylacetamide (DMAc), N-methyl-2-pyrrolidone, 2-butanone, dimethyl sulfoxide, dimethyl sulfate, cyclohexanone, and dioxane. , Tetrahydrofuran, diglyme, triglyme and the like. Two or more of these solvents can be used in combination, and further, an aromatic hydrocarbon such as xylene or toluene can be used in combination. The amount of the organic solvent used is not particularly limited, but may be such that the concentration of the polyamic acid solution (polyimide precursor solution) obtained by the polymerization reaction is about 5 to 30% by weight. It is preferable to use it after adjusting.

において In the synthesis of polyimide, each of the above-mentioned acid anhydrides and diamines may be used alone or in combination of two or more. By selecting the types of the acid anhydride and the diamine and the respective molar ratios when using two or more acid anhydrides or diamines, it is possible to control the thermal expansion property, the adhesive property, the glass transition temperature, and the like. .

The synthesized precursor is usually advantageously used as a reaction solvent solution, but can be concentrated, diluted, or replaced with another organic solvent, if necessary. Further, the precursor is generally used because it is excellent in solvent solubility. The method of imidizing the precursor is not particularly limited. For example, a heat treatment in which the precursor is heated in the solvent under a temperature condition of 80 to 400 ° C. for 1 to 24 hours is suitably employed.

As described above, in the method for manufacturing a polyimide film according to the third embodiment of the present invention, the first polyimide layer (A) is laminated on at least one surface of the first polyimide layer (A). And a second polyimide layer (B).
The method for producing a polyimide film according to the third embodiment of the present invention includes the following steps I to III;
I) a step of preparing a first polyimide layer (A) containing a polyimide having a ketone group;
II) laminating a resin layer containing a polyamic acid (b) having a functional group having a property of interacting with the ketone group on the first polyimide layer (A);
III) a step of heat-treating the resin layer containing the polyamic acid (b) together with the first polyimide layer (A) to imidize the polyamic acid (b) to form a second polyimide layer (B);
Is included.

In the method for producing a polyimide film according to the third embodiment of the present invention, the polyimide constituting the first polyimide layer (A) includes a tetracarboxylic acid residue (1a) and a diamine residue (2a). The ketone group may be 5 mol parts or more based on 100 mol parts in total of the tetracarboxylic acid residue (1a) and the diamine residue (2a).

In the method for producing a polyimide film according to the third embodiment of the present invention, the resin layer containing the polyamic acid (b) contains a tetracarboxylic acid residue (1b) and a diamine residue (2b). The tetracarboxylic acid residue (1b) may be less than 1 mol per 1 mol of the diamine residue (2b).

In the method for producing a polyimide film according to the third embodiment of the present invention, the first polyimide layer (A) is formed by laminating a resin layer containing a polyamic acid (a) having a ketone group on a base material, The substrate may be formed by imidizing the polyamic acid (a) together with the substrate.

The method for manufacturing a metal-clad laminate according to the fourth embodiment of the present invention includes the steps of: laminating a metal layer, a first polyimide layer (A), and one surface of the first polyimide layer (A). And a second polyimide layer (B).
The method for producing a metal-clad laminate according to the fourth embodiment of the present invention includes the following steps i to iv:
i) a step of forming at least one or more polyamic acid resin layers having a resin layer containing a polyamic acid (a) having a ketone group on the surface layer on the metal layer;
ii) heat treating the polyamic acid resin layer together with the metal layer to imidize the polyamic acid, thereby forming a first polyimide layer (A) containing a polyimide having a ketone group on the metal layer; Step of forming an intermediate in which a polyimide layer having a part is laminated,
iii) laminating a resin layer containing a polyamic acid (b) having a functional group having a property of interacting with the ketone group on the first polyimide layer (A);
iv) heat treating the resin layer of the polyamic acid (b) together with the intermediate, and imidizing the polyamic acid (b) to form a second polyimide layer (B);
Is included.

方法 A method of manufacturing a circuit board according to an embodiment of the present invention includes a step of performing a wiring circuit processing on the metal layer of the metal-clad laminate manufactured by the method of the fourth embodiment.

As described above, the polyimide film obtained in the third embodiment of the present invention and the metal-clad laminate obtained in the fourth embodiment consist of the first polyimide layer (A) and the second polyimide layer (B ), And by using it as a circuit board material represented by FPC, the reliability of electronic equipment can be improved.

<Circuit board>
A circuit board according to one embodiment of the present invention includes an insulating resin layer including a plurality of polyimide layers, and a wiring layer laminated on at least one surface of the insulating resin layer. This circuit board is manufactured by processing a metal layer of a metal-clad laminate obtained by the method of the first, second or fourth embodiment into a pattern by a conventional method to form a wiring layer. be able to. The patterning of the metal layer can be performed by any method using, for example, photolithography technology and etching.

In addition, when manufacturing a circuit board, for example, processes such as through-hole processing in a previous process, terminal plating, and outer shape processing in a subsequent process can be performed according to a conventional method.

実施 Examples are shown below to describe the features of the present invention more specifically. However, the scope of the present invention is not limited to the examples. In the following Examples, Comparative Examples and Reference Examples, various measurements and evaluations are as follows unless otherwise specified.

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

[Evaluation of foaming]
When peeling is confirmed between the first polyimide layer and the second polyimide layer, or when the polyimide layer is cracked, it is regarded as “foamed”, and when there is no peeling or cracking, “no foaming”. And

[Measurement of dimensional change after etching]
A metal-clad laminate having a size of 80 mm x 80 mm was prepared. After providing a dry film resist on the metal layer of this laminated board, it is exposed and developed to form, as shown in FIG. 2, 16 resist patterns having a diameter of 1 mm so that the whole forms a square. Then, position measurement targets capable of measuring five points at 50 mm intervals in the vertical direction (MD) and the horizontal direction (TD) were prepared.

Regarding the prepared sample, the distance between the target in the vertical direction (MD) and the horizontal direction (TD) of the resist pattern on the target for position measurement was measured in an atmosphere at a temperature of 23 ± 2 ° C. and a relative humidity of 50 ± 5%. After the measurement, the exposed portion of the metal layer at the opening of the resist pattern was removed by etching (etching solution temperature: 40 ° C. or less, etching time: within 10 minutes), and as shown in FIG. An evaluation sample having a residual point was prepared. This evaluation sample was allowed to stand for 24 ± 4 hours in an atmosphere having a temperature of 23 ± 2 ° C. and a relative humidity of 50 ± 5%, and then the distance between the metal layer residual points in the machine direction (MD) and the transverse direction (TD). Was measured. The dimensional change rates with respect to the normal state at each of the five positions in the vertical direction and the horizontal direction are calculated, and the average value of each is defined as the dimensional change rate after etching.
Each dimensional change rate was calculated by the following equation.
Dimensional change rate after etching (%) = (BA) / A × 100
A: distance between targets after resist development B: distance between metal layer residual points after metal layer etching “good” when the absolute value of the dimensional change rate after etching is 0.2% or less, 0.2 % And 0.4% or less are regarded as “OK”, and if it exceeds 0.4% as “NO”.

[Evaluation of curl]
The film curl is obtained by etching the copper foil of the metal-clad laminate over its entire surface, and setting the floating heights of the four corners when the first polyimide layer of the polyimide film having the dimensions of 100 mm × 100 mm after the copper foil is laid down. It was measured. The case where the average value of the floating heights at the four corners exceeded 10 mm was evaluated as "curl".

[Evaluation of moisture permeability]
In accordance with JIS Z0208, a moisture absorbent / calcium chloride (anhydrous) was sealed in a moisture-permeable cup, and the increase in the mass of the cup after 24 hours was evaluated as a water vapor transmission rate.

[Measurement of moisture absorption rate]
Two test pieces (width 4 cm × length 25 cm) of a polyimide film were prepared and dried at 80 ° C. for 1 hour. Immediately after drying, it was placed in a constant temperature / humidity room at 23 ° C./50% RH, allowed to stand still for 24 hours or more, and determined from the weight change before and after that according to the following equation.
Moisture absorption (% by weight) = [(weight after moisture absorption−weight after drying) / weight after drying] × 100

[Measurement of glass transition temperature (Tg)]
The polyimide film (10 mm × 40 mm) was heated from 20 ° C. to 500 ° C. at a rate of 5 ° C./min from a dynamic thermomechanical analyzer (DMA: manufactured by TA Instruments Japan, trade name: RSA-G2). The dynamic viscoelasticity at that time was measured, and the glass transition temperature (Tanδ maximum value: ° C) was determined.

[Measurement of storage modulus]
The storage elastic modulus was measured using a dynamic viscoelasticity measuring device (DMA). A polyimide having a storage elastic modulus at 30 ° C. of 1.0 × 10 ⁹ Pa or more and a storage elastic modulus at 350 ° C. of 1.0 × 10 ⁸ Pa or more is referred to as “non-thermoplastic polyimide”. A polyimide having a modulus of 1.0 × 10 ⁹ Pa or more and a storage elastic modulus at 350 ° C. of less than 1.0 × 10 ⁸ Pa is referred to as “thermoplastic polyimide”.

[Measurement of thermal expansion coefficient (CTE)]
A polyimide film having a thickness of 25 μm and a size of 3 mm × 20 mm was heated from 30 ° C. to 300 ° C. at a constant heating rate while applying a load of 5.0 g using a thermomechanical analyzer (manufactured by Bruker, trade name: 4000SA). After being kept at that temperature for 10 minutes, it was cooled at a rate of 5 ° C./min, and an average thermal expansion coefficient (thermal expansion coefficient) from 250 ° C. to 100 ° C. was determined.

[Measurement of volatile component ratio]
The volatile component ratio in each example was determined by measuring the TG-DTA of the semi-cured first polyamide resin layer film in the range of 30 ° C. to 500 ° C. at a rate of 10 ° C./min. %, The rate of weight loss from 100 ° C. to 360 ° C. was taken as the volatile component rate.

[Evaluation of imidation rate]
The imidation ratio of the polyimide layer is determined by measuring the infrared absorption spectrum of the polyimide film in a single reflection ATR method using a Fourier transform infrared spectrophotometer (manufactured by JASCO Corporation, trade name: FT / IR). Calculated from the absorbance derived from the imide group at 1778 cm ^{-1 based on} the benzene ring carbon-hydrogen bond at 1009 cm ^-1 . The first polyamide resin layer was subjected to a stepwise heat treatment from 120 ° C. to 360 ° C., and the imidation ratio of the polyimide film after the heat treatment at 360 ° C. was set to 100%.

[Measurement of peel strength]
The peel strength was determined by using a tensilon tester (trade name: Strograph VE-1D, manufactured by Toyo Seiki Seisaku-sho, Ltd.), fixing the second polyimide layer side of the sample having a width of 10 mm to an aluminum plate with a double-sided tape, and removing the first polyimide. The metal-clad laminate on the layer side was pulled in the direction of 180 ° at a speed of 50 mm / min, and the force at the time of peeling between the first polyimide layer and the second polyimide layer was determined.

The abbreviations used in the synthesis examples indicate the following compounds.
m-TB: 2,2'-dimethyl-4,4'-diaminobiphenyl TPE-R: 1,3-bis (4-aminophenoxy) benzene BAPP: 2,2-bis [4- (4-aminophenoxy) Phenyl] propane TFMB: 2,2'-bis (trifluoromethyl) -4,4'-diaminobiphenyl BAFL: 9,9-bis (4-aminophenyl) fluorene APB: 1,3-bis (3-aminophenoxy ) Benzene TPE-Q: 1,4-bis (4-aminophenoxy) benzene 4,4'-DAPE: 4,4'-diaminodiphenyl ether 3,4'-DAPE: 3,4'-diaminodiphenyl ether PDA: p- Phenylenediamine PMDA: pyromellitic dianhydride BPDA: 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride BTDA: 3,3 ′, , 4'-benzophenonetetracarboxylic dianhydride ODPA: 4,4'-oxydiphthalic dianhydride DMAc: N, N-dimethylacetamide

(Synthesis example A1)
75.149 g of m-TB (353.42 mmol) and 850 g of DMAc were charged into a 1000 ml separable flask, and the mixture was stirred at room temperature under a nitrogen stream. After complete dissolution, 74.851 g of PMDA (342.82 mmol) was added and stirred at room temperature for 4 hours to obtain a polyamic acid solution AA. The viscosity of the obtained polyamic acid solution AA was 22,700 cP. The polyimide after imidization of the obtained polyamic acid was non-thermoplastic. Further, the CTE of the obtained polyimide film (thickness: 25 μm) was 6.4 ppm / K.

(Synthesis example A2)
To a 1000 ml separable flask were charged 65.054 g of m-TB (310.65 mmol), 10.090 g of TPE-R (34.52 mmol) and 850 g of DMAc, and the mixture was stirred at room temperature under a nitrogen stream. After complete dissolution, 73.856 g of PMDA (338.26 mmol) was added and stirred at room temperature for 4 hours to obtain a polyamic acid solution AB. The viscosity of the obtained polyamic acid solution AB was 26,500 cP. The imidized polyimide of the obtained polyamic acid was non-thermoplastic, and had a glass transition temperature (Tg) of 303 ° C. The obtained polyimide film (thickness; 25 [mu] m) CTE of is 16.2ppm / K, moisture absorption is 0.61% by weight, the moisture permeability was ^64g / m 2 / 24hr.

(Synthesis example A3)
89.621 g of TFMB (279.33 mmol) and 850 g of DMAc were charged into a 1000 ml separable flask, and the mixture was stirred at room temperature under a nitrogen stream. After complete dissolution, 60.379 g of PMDA (276.54 mmol) was added and stirred at room temperature for 4 hours to obtain a polyamic acid solution AC. The viscosity of the obtained polyamic acid solution AC was 21,200 cP. The polyimide after imidization of the obtained polyamic acid was non-thermoplastic. The CTE of the obtained polyimide film (thickness: 25 μm) was 0.5 ppm / K.

(Synthesis example A4)
To a 1000 ml separable flask were charged 49.928 g of TFMB (155.70 mmol), 33.102 g of m-TB (155.70 mmol), and 850 g of DMAc, and the mixture was stirred at room temperature under a nitrogen stream. After complete dissolution, 66.970 g of PMDA (307.03 mmol) was added and stirred at room temperature for 4 hours to obtain a polyamic acid solution AD. The viscosity of the obtained polyamic acid solution AD was 21,500 cP. The polyimide after imidization of the obtained polyamic acid was non-thermoplastic. The CTE of the obtained polyimide film (thickness: 25 μm) was 6.0 ppm / K.

(Synthesis example A5)
A 300 ml separable flask was charged with 29.492 g of BAPP (71.81 mmol) and 255 g of DMAc, and stirred at room temperature under a nitrogen stream. After complete dissolution, 15.508 g of PMDA (71.10 mmol) was added and stirred at room temperature for 4 hours to obtain a polyamic acid solution AE. The viscosity of the obtained polyamic acid solution AE was 10,700 cP. The polyimide after imidization of the obtained polyamic acid was thermoplastic and had a glass transition temperature (Tg) of 312 ° C. The obtained polyimide film (thickness; 25 [mu] m) CTE of is 63.1ppm / K, moisture absorption is 0.54% by weight, the moisture permeability was ^64g / m 2 / 24hr.

(Synthesis example A6)
25.889 g of TPE-R (88.50 mmol) and 255 g of DMAc were charged into a 300 ml separable flask, and the mixture was stirred at room temperature under a nitrogen stream. After complete dissolution, 19.111 g of PMDA (87.62 mmol) was added and stirred at room temperature for 4 hours to obtain a polyamic acid solution AF. The viscosity of the obtained polyamic acid solution AF was 13,200 cP. The polyimide after imidization of the obtained polyamic acid was non-thermoplastic. Further, the CTE of the obtained polyimide film (thickness: 25 μm) was 57.7 ppm / K.

(Synthesis example A7)
27.782 g of BAFL (79.73 mmol) and 255 g of DMAc were charged into a 300 ml separable flask, and the mixture was stirred at room temperature under a nitrogen stream. After complete dissolution, 17.218 g of PMDA (78.94 mmol) was added and stirred at room temperature for 4 hours to obtain a polyamic acid solution AG. The viscosity of the obtained polyamic acid solution AG was 10,400 cP. The polyimide after imidization of the obtained polyamic acid was non-thermoplastic. The CTE of the obtained polyimide film (thickness: 25 μm) was 52.0 ppm / K.

[Example A1]
A polyamic acid solution AE to be a first polyimide layer is uniformly applied on a 12 μm-thick electrolytic copper foil so as to have a cured thickness of 2 μm, and then the temperature is raised stepwise from 120 ° C. to 360 ° C. The solvent was removed and imidation was performed. The obtained first polyimide layer was subjected to a corona treatment at 120 W · min / m ² . Next, a polyamic acid solution AA to be a second polyimide layer was uniformly applied thereon so as to have a cured thickness of 25 μm, and then heated and dried at 120 ° C. for 3 minutes to remove the solvent. . Thereafter, the temperature was increased stepwise from 130 ° C. to 360 ° C. to perform imidization, thereby preparing a metal-clad laminate A1. The thickness (L1) of the first polyimide layer was 2 μm, the thickness (L) of the entire insulating resin layer was 27 μm, and the ratio (L / L1) was 13.5. An adhesive tape was applied to the resin surface of the prepared metal-clad laminate A1, and a peeling test was performed by instantaneous peeling in the vertical direction. However, peeling between the first polyimide layer and the second polyimide layer was observed. Did not.

[Example A2]
A metal-clad laminate A2 was prepared in the same manner as in Example A1, except that the polyamic acid solution AE was used instead of the polyamic acid solution AE. A peeling test was conducted on the prepared metal-clad laminate A2 in the same manner as in Example A1, but no peeling was observed between the first polyimide layer and the second polyimide layer.

[Example A3]
A metal-clad laminate A3 was prepared in the same manner as in Example A1, except that the polyamic acid solution AE was used instead of the polyamic acid solution AE. A peeling test of the prepared metal-clad laminate A3 was performed in the same manner as in Example A1, but no peeling was observed between the first polyimide layer and the second polyimide layer.

[Example A4]
A metal-clad laminate A4 was prepared in the same manner as in Example A1, except that the polyamic acid solution AC was used instead of the polyamic acid solution AE. A peeling test of the prepared metal-clad laminate A4 was performed in the same manner as in Example A1, but no peeling was observed between the first polyimide layer and the second polyimide layer.

[Example A5]
A metal-clad laminate A5 was prepared in the same manner as in Example A1, except that the polyamic acid solution AB was used instead of the polyamic acid solution AA. A peeling test of the prepared metal-clad laminate A5 was performed in the same manner as in Example A1, but no peeling between the first polyimide layer and the second polyimide layer was observed.

[Example A6]
A polyamic acid solution AB was used in place of the polyamic acid solution AA, and a polyamic acid solution AF was used in place of the polyamic acid solution AE in the same manner as in Example A1. A metal-clad laminate A6 was prepared. A peeling test of the prepared metal-clad laminate A6 was performed in the same manner as in Example A1, but no peeling was observed between the first polyimide layer and the second polyimide layer.

[Example A7]
In the same manner as in Example A1, except that the polyamic acid solution AB was used instead of the polyamic acid solution AA, and the polyamic acid solution AG was used instead of the polyamic acid solution AE, A metal-clad laminate A7 was prepared. A peeling test of the prepared metal-clad laminate A7 was performed in the same manner as in Example A1, but no peeling was observed between the first polyimide layer and the second polyimide layer.

[Example A8]
In the same manner as in Example A1, except that the polyamic acid solution AB was used instead of the polyamic acid solution AA, and the polyamic acid solution AA was used instead of the polyamic acid solution AE, A metal-clad laminate A8 was prepared. A peeling test of the prepared metal-clad laminate A8 was performed in the same manner as in Example A1, but no peeling between the first polyimide layer and the second polyimide layer was observed.

[Example A9]
A polyamic acid solution AB was used in place of the polyamic acid solution AA, and a polyamic acid solution AC was used in place of the polyamic acid solution AE in the same manner as in Example A1. A metal-clad laminate A9 was prepared. A peeling test was conducted on the prepared metal-clad laminate A9 in the same manner as in Example A1, but no peeling was observed between the first polyimide layer and the second polyimide layer.

[Example A10]
A metal-clad laminate A10 was prepared in the same manner as in Example A1, except that the polyamic acid solution AA was used instead of the polyamic acid solution AA. A peeling test of the prepared metal-clad laminate A10 was performed in the same manner as in Example A1, but no peeling was observed between the first polyimide layer and the second polyimide layer.

[Example A11]
In the same manner as in Example A1, except that the polyamic acid solution AC was used instead of the polyamic acid solution AA, and the polyamic acid solution AF was used instead of the polyamic acid solution AE, A metal-clad laminate A11 was prepared. A peeling test was conducted on the prepared metal-clad laminate A11 in the same manner as in Example A1, but no peeling was observed between the first polyimide layer and the second polyimide layer.

[Example A12]
In the same manner as in Example A1, except that the polyamic acid solution AC was used instead of the polyamic acid solution AA, and the polyamic acid solution AG was used instead of the polyamic acid solution AE, A metal-clad laminate A12 was prepared. A peeling test of the prepared metal-clad laminate A12 was performed in the same manner as in Example A1, but no peeling was observed between the first polyimide layer and the second polyimide layer.

[Example A13]
In the same manner as in Example A1, except that the polyamic acid solution AC was used instead of the polyamic acid solution AA, and the polyamic acid solution AA was used instead of the polyamic acid solution AE, A metal-clad laminate A13 was prepared. A peeling test of the prepared metal-clad laminate A13 was performed in the same manner as in Example A1, but no peeling was observed between the first polyimide layer and the second polyimide layer.

[Example A14]
A metal-clad laminate A14 was prepared in the same manner as in Example A1, except that the polyamic acid solution AA was used instead of the polyamic acid solution AA. A peeling test was conducted on the prepared metal-clad laminate A14 in the same manner as in Example A1, but no peeling was observed between the first polyimide layer and the second polyimide layer.

[Example A15]
In the same manner as in Example A1, except that the polyamic acid solution AD was used instead of the polyamic acid solution AA, and the polyamic acid solution AF was used instead of the polyamic acid solution AE, A metal-clad laminate A15 was prepared. A peel test of the prepared metal-clad laminate A15 was performed in the same manner as in Example A1, but no peeling between the first polyimide layer and the second polyimide layer was observed.

[Example A16]
In the same manner as in Example A1, except that the polyamic acid solution AD was used instead of the polyamic acid solution AA, and the polyamic acid solution AG was used instead of the polyamic acid solution AE, A metal-clad laminate A16 was prepared. A peeling test was conducted on the prepared metal-clad laminate A16 in the same manner as in Example A1, but no peeling was observed between the first polyimide layer and the second polyimide layer.

[Example A17]
In the same manner as in Example A1, except that the polyamic acid solution AD was used instead of the polyamic acid solution AA, and the polyamic acid solution AA was used instead of the polyamic acid solution AE, A metal-clad laminate A17 was prepared. A peel test of the prepared metal-clad laminate A17 was performed in the same manner as in Example A1, but no peeling between the first polyimide layer and the second polyimide layer was observed.

[Example A18]
In the same manner as in Example A1, except that the polyamic acid solution AD was used instead of the polyamic acid solution AA, and the polyamic acid solution AC was used instead of the polyamic acid solution AE, A metal-clad laminate A18 was prepared. A peeling test of the prepared metal-clad laminate A18 was performed in the same manner as in Example A1, but no peeling was observed between the first polyimide layer and the second polyimide layer.

Comparative example A1
A metal-clad laminate A19 was prepared in the same manner as in Example A1, except that the corona treatment was not performed. When a peel test was conducted on the prepared metal-clad laminate A19 in the same manner as in Example A1, delamination between the first polyimide layer and the second polyimide layer occurred.

Comparative Example A2
A metal-clad laminate A20 was prepared in the same manner as in Example A2, except that the corona treatment was not performed. When the prepared metal-clad laminate A20 was subjected to a peel test in the same manner as in Example A1, delamination between the first polyimide layer and the second polyimide layer occurred.

Comparative Example A3
A metal-clad laminate A21 was prepared in the same manner as in Example A14, except that the corona treatment was not performed. When a peel test was performed on the prepared metal-clad laminate A21 in the same manner as in Example A1, delamination between the first polyimide layer and the second polyimide layer occurred.

Comparative Example A4
A metal-clad laminate A22 was prepared in the same manner as in Example A15, except that the corona treatment was not performed. When a peel test was performed on the prepared metal-clad laminate A22 in the same manner as in Example A1, delamination between the first polyimide layer and the second polyimide layer occurred.

[Example A19]
After a polyamic acid solution AE to be a first polyimide layer is uniformly applied on a 12 μm-thick electrolytic copper foil so as to have a thickness of 2.5 μm after curing, the polyamic acid solution AE is gradually applied from 120 ° C. to 360 ° C. The temperature was raised to remove the solvent and perform imidization. The obtained first polyimide layer was subjected to a corona treatment at 120 W · min / m ² . Next, a polyamic acid solution AA to be a second polyimide layer is uniformly applied thereon so as to have a cured thickness of 20 μm, and then a polyamic acid to be a third polyimide layer is formed thereon. The solution AE was uniformly applied so that the thickness after curing became 2.5 μm, and was heated and dried at 120 ° C. for 3 minutes to remove the solvent. Thereafter, the temperature was increased stepwise from 130 ° C. to 360 ° C. to perform imidization, thereby preparing a metal-clad laminate A23. The thickness (L1) of the first polyimide layer was 2.5 μm, the thickness (L) of the entire insulating resin layer was 25 μm, and the ratio (L / L1) was 10.0. No foaming was observed, and no curling of the polyimide film was observed after copper foil etching. The dimensional change rate was "good".

[Example A20]
Instead of the polyamic acid solution AE to be the first polyimide layer and the third polyimide layer, a polyamic acid solution AF is uniformly applied so that the thickness after curing becomes 2.7 μm each, A metal-clad laminate A24 was prepared in the same manner as in Example A19, except that the polyamic acid solution AA to be a polyimide layer was uniformly applied so that the thickness after curing became 19.6 μm. The thickness (L1) of the first polyimide layer was 2.7 μm, the thickness (L) of the entire insulating resin layer was 25 μm, and the ratio (L / L1) was 9.3. No foaming was observed, and no curling of the polyimide film was observed after copper foil etching. The dimensional change rate was "good".

[Example A21]
Instead of the polyamic acid solution AE to be the first polyimide layer and the third polyimide layer, a polyamic acid solution AG is uniformly applied so that the thickness after curing becomes 3.2 μm, respectively. A metal-clad laminate A25 was prepared in the same manner as in Example A19, except that the polyamic acid solution AA to be a polyimide layer was uniformly applied so that the thickness after curing became 18.6 μm. The thickness (L1) of the first polyimide layer was 3.2 μm, the thickness (L) of the entire insulating resin layer was 25 μm, and the ratio (L / L1) was 7.8. No foaming was observed, and no curling of the polyimide film was observed after copper foil etching. In addition, the dimensional change rate was “OK”.

[Example A22]
The polyamic acid solution AE to be the first polyimide layer and the third polyimide layer was uniformly applied so that the thickness after curing was 1.7 μm each, and the polyamic acid solution A to be the second polyimide layer was -A was uniformly applied so that the thickness after curing became 22 μm, and 130 ° C. to 360 ° C. after application of the polyamic acid solution AA and the polyamic acid solution AE to be the third polyimide layer A metal-clad laminate A26 was prepared in the same manner as in Example A19, except that the temperature rise time until was shortened to 1/3. The thickness (L1) of the first polyimide layer was 1.7 μm, the thickness (L) of the entire insulating resin layer was 25.4 μm, and the ratio (L / L1) was 14.9. No foaming was observed, and no curling of the polyimide film was observed after copper foil etching. The dimensional change rate was "good".

[Example A23]
The polyamic acid solution AE to be the first polyimide layer and the third polyimide layer was uniformly applied so that the thickness after curing was 1.8 μm each, and the polyamic acid solution A to be the second polyimide layer was -A was uniformly applied so that the thickness after curing became 22 μm, and 130 ° C. to 360 ° C. after application of the polyamic acid solution AA and the polyamic acid solution AE to be the third polyimide layer A metal-clad laminate A27 was prepared in the same manner as in Example A19, except that the temperature rise time until was shortened to 1/3. The thickness (L1) of the first polyimide layer was 1.8 μm, the thickness (L) of the entire insulating resin layer was 25.6 μm, and the ratio (L / L1) was 14.2. No foaming was observed, and no curling of the polyimide film was observed after copper foil etching. The dimensional change rate was "good".

[Example A24]
The polyamic acid solution AE to be the first polyimide layer and the third polyimide layer was uniformly applied so that the thickness after curing was 2.2 μm each, and the polyamic acid solution A to be the second polyimide layer was -A was uniformly applied so as to have a thickness of 20 μm after curing, and 130 ° C. to 360 ° C. after application of the polyamic acid solution AA and the polyamic acid solution AE to be the third polyimide layer. A metal-clad laminate A28 was prepared in the same manner as in Example A19, except that the temperature rise time until was shortened to 1/3. The thickness (L1) of the first polyimide layer was 2.2 μm, the thickness (L) of the entire insulating resin layer was 24.4 μm, and the ratio (L / L1) was 11.1. No foaming was observed, and no curling of the polyimide film was observed after copper foil etching. The dimensional change rate was "good".

[Example A25]
The polyamic acid solutions AE to be the first polyimide layer and the third polyimide layer are uniformly applied so that the thickness after curing is 2.4 μm, respectively, and the polyamic acid to be the second polyimide layer is A metal-clad laminate A29 was prepared in the same manner as in Example A19, except that the solution AD was uniformly applied so that the thickness after curing became 20.2 μm. The thickness (L1) of the first polyimide layer was 2.4 μm, the thickness (L) of the entire insulating resin layer was 25 μm, and the ratio (L / L1) was 10.4. No foaming was observed, and no curling of the polyimide film was observed after copper foil etching. The dimensional change rate was "good".

[Example A26]
The polyamic acid solution AF to be the first polyimide layer and the third polyimide layer was uniformly applied so that the thickness after curing was 2.7 μm, respectively, and the polyamic acid to be the second polyimide layer was A metal-clad laminate A30 was prepared in the same manner as in Example A19, except that the solution AD was uniformly applied so that the thickness after curing became 20 μm. The thickness (L1) of the first polyimide layer was 2.7 μm, the thickness (L) of the entire insulating resin layer was 25.4 μm, and the ratio (L / L1) was 9.4. No foaming was observed, and no curling of the polyimide film was observed after copper foil etching. The dimensional change rate was "good".

[Example A27]
The polyamic acid solution AG to be the first polyimide layer and the third polyimide layer is uniformly applied so that the thickness after curing becomes 3.2 μm, respectively, and the polyamic acid to be the second polyimide layer A metal-clad laminate A31 was prepared in the same manner as in Example A19, except that the solution AD was uniformly applied so that the thickness after curing became 19 μm. The thickness (L1) of the first polyimide layer was 3.2 μm, the thickness (L) of the entire insulating resin layer was 25.4 μm, and the ratio (L / L1) was 7.9. No foaming was observed, and no curling of the polyimide film was observed after copper foil etching. In addition, the dimensional change rate was “OK”.

[Example A28]
The polyamic acid solution AE was uniformly applied on a 12 μm-thick electrolytic copper foil so that the cured thickness became 2.0 μm, and then the solvent was removed at 120 ° C. The polyamic acid solution AA was uniformly applied thereon so as to have a cured thickness of 50 μm, and then the solvent was removed at 120 ° C. for 3 minutes. Furthermore, after a polyamic acid solution AE was uniformly applied thereon so that the thickness after curing became 2.0 μm, the solvent was removed at 120 ° C., and the temperature was raised stepwise from 120 ° C. to 360 ° C. The solvent was removed and imidation was performed to obtain a single-sided metal-clad laminate A28B on which a first polyimide layer was formed. The polyimide layer of the obtained single-sided metal-clad laminate A28B was subjected to a corona treatment at 120 W · min / m ² . Next, a polyamic acid solution AA to be a second polyimide layer is uniformly applied thereon so as to have a cured thickness of 50 μm, the solvent is removed, and then a third polyimide layer is provided thereon. The polyamic acid solution AE was uniformly applied so that the thickness after curing became 2.0 μm, and was heated and dried at 120 ° C. for 3 minutes to remove the solvent. Thereafter, the temperature was increased stepwise from 130 ° C. to 360 ° C. to perform imidization, thereby preparing a single-sided metal-clad laminate A28. The thickness (L1) of the first polyimide layer was 54 μm, the thickness (L) of the entire insulating resin layer was 106 μm, and the ratio (L / L1) was 1.96. No foaming was observed, and no curling of the polyimide film was observed after copper foil etching. The dimensional change rate was "good".

[Example A29]
A polyamic acid solution AE for forming two layers of the first polyimide layer and a polyamic acid solution AE for forming the third polyimide layer are uniformly applied so that the thickness after curing becomes 10 μm. Aside from the above, a single-sided metal-clad laminate A29 was prepared in the same manner as in Example A28. The thickness (L1) of the first polyimide layer was 70 μm, the thickness (L) of the entire insulating resin layer was 130 μm, and the ratio (L / L1) was 1.86. No foaming was observed, and no curling of the polyimide film was observed after copper foil etching. The dimensional change rate was "good".

[Example A30]
A polyamic acid solution AE for forming two layers of the first polyimide layer and a polyamic acid solution AE for forming the third polyimide layer are respectively referred to as polyamic acid solutions AF, and the thickness after curing is set as follows. The same procedure as in Example A28 was carried out except that the solution was uniformly applied so as to have a thickness of 2.0 μm, and that the polyamic acid solution AB serving as the second polyimide layer was uniformly applied so that the thickness after curing became 50 μm. Thus, a single-sided metal-clad laminate A30 was prepared. The thickness (L1) of the first polyimide layer was 54 μm, the thickness (L) of the entire insulating resin layer was 106 μm, and the ratio (L / L1) was 1.96. No foaming was observed, and no curling of the polyimide film was observed after copper foil etching. The dimensional change rate was "good".

[Example A31]
A polyamic acid solution AF for forming two layers of the first polyimide layer and a polyamic acid solution AF for forming the third polyimide layer are uniformly applied so that the thickness after curing becomes 10 μm, respectively. Aside from the above, a single-sided metal-clad laminate A31 was prepared in the same manner as in Example A30. The thickness (L1) of the first polyimide layer was 70 μm, the thickness (L) of the entire insulating resin layer was 130 μm, and the ratio (L / L1) was 1.86. No foaming was observed, and no curling of the polyimide film was observed after copper foil etching. The dimensional change rate was "good".

Comparative Example A5
When a metal-clad laminate A32 was prepared in the same manner as in Example A19 except that the corona treatment was not performed, curling of the polyimide film was confirmed after etching of the copper foil.

Comparative Example A6
When a metal-clad laminate A33 was prepared in the same manner as in Example A20, except that the corona treatment was not performed, curling of the polyimide film was confirmed after copper foil etching.

Comparative Example A7
When a metal-clad laminate A34 was prepared in the same manner as in Example A21 except that the corona treatment was not performed, curling of the polyimide film was confirmed after copper foil etching.

Comparative Example A8
When a metal-clad laminate A35 was prepared in the same manner as in Example A22 except that the corona treatment was not performed, foaming was confirmed.

Comparative Example A9
When a metal-clad laminate A36 was prepared in the same manner as in Example A23 except that the corona treatment was not performed, foaming was confirmed.

Comparative Example A10
When a metal-clad laminate A37 was prepared in the same manner as in Example A24 except that the corona treatment was not performed, foaming was confirmed.

(Synthesis example B1)
75.149 g of m-TB (353.42 mmol) and 850 g of DMAc were charged into a 1000 ml separable flask, and the mixture was stirred at room temperature under a nitrogen stream. After complete dissolution, 74.851 g of PMDA (342.82 mmol) was added and stirred at room temperature for 4 hours to obtain a polyamic acid solution BA. The viscosity of the obtained polyamic acid solution BA was 22,700 cP.

(Synthesis example B2)
To a 1000 ml separable flask were charged 65.054 g of m-TB (310.65 mmol), 10.090 g of TPE-R (34.52 mmol) and 850 g of DMAc, and the mixture was stirred at room temperature under a nitrogen stream. After complete dissolution, 73.856 g of PMDA (338.26 mmol) was added and stirred at room temperature for 4 hours to obtain a polyamic acid solution BB. The viscosity of the obtained polyamic acid solution BB was 26,500 cP.

(Synthesis example B3)
89.621 g of TFMB (279.33 mmol) and 850 g of DMAc were charged into a 1000 ml separable flask, and the mixture was stirred at room temperature under a nitrogen stream. After complete dissolution, 60.379 g of PMDA (276.54 mmol) was added and stirred at room temperature for 4 hours to obtain a polyamic acid solution BC. The viscosity of the obtained polyamic acid solution BC was 21,200 cP.

(Synthesis example B4)
To a 1000 ml separable flask were charged 49.928 g of TFMB (155.70 mmol), 33.102 g of m-TB (155.70 mmol), and 850 g of DMAc, and the mixture was stirred at room temperature under a nitrogen stream. After complete dissolution, 66.970 g of PMDA (307.03 mmol) was added and stirred at room temperature for 4 hours to obtain a polyamic acid solution BD. The viscosity of the obtained polyamic acid solution BD was 21,500 cP.

(Synthesis example B5)
A 300 ml separable flask was charged with 29.492 g of BAPP (71.81 mmol) and 255 g of DMAc, and stirred at room temperature under a nitrogen stream. After complete dissolution, 15.508 g of PMDA (71.10 mmol) was added, and the mixture was stirred at room temperature for 4 hours to obtain a polyamic acid solution BE. The viscosity of the obtained polyamic acid solution BE was 10,700 cP.

(Synthesis example B6)
25.889 g of TPE-R (88.50 mmol) and 255 g of DMAc were charged into a 300 ml separable flask, and the mixture was stirred at room temperature under a nitrogen stream. After complete dissolution, 19.111 g of PMDA (87.62 mmol) was added and stirred at room temperature for 4 hours to obtain a polyamic acid solution BF. The viscosity of the obtained polyamic acid solution BF was 13,200 cP.

(Synthesis example B7)
27.782 g of BAFL (79.73 mmol) and 255 g of DMAc were charged into a 300 ml separable flask, and the mixture was stirred at room temperature under a nitrogen stream. After complete dissolution, 17.218 g of PMDA (78.94 mmol) was added and stirred at room temperature for 4 hours to obtain a polyamic acid solution BG. The viscosity of the obtained polyamic acid solution BG was 10,400 cP.

[Example B1]
After a polyamic acid solution BE serving as a first polyimide layer is uniformly applied on a 12 μm-thick electrolytic copper foil so as to have a cured thickness of 2 μm, the temperature is increased stepwise from 120 ° C. to 240 ° C. Then, an appropriate solvent was removed and imidization was performed. At this time, the volatile component ratio and the imidation ratio of the semi-cured first polyimide layer were 3.0% and 80%. Next, a polyamic acid solution BA serving as a second polyimide layer was uniformly applied thereon so as to have a cured thickness of 25 μm, and then heated and dried at 120 ° C. for 3 minutes to remove the solvent. . Thereafter, the temperature was increased stepwise from 130 ° C. to 360 ° C. to perform imidization, and a first polyimide layer and a second polyimide layer were formed, thereby preparing a metal-clad laminate B1. An adhesive tape was applied to the resin surface of the prepared metal-clad laminate B1, and a peel test was performed by instantaneous peeling in the vertical direction. However, peeling between the first polyimide layer and the second polyimide layer was observed. Did not.

[Example B2]
A metal-clad laminate B2 was prepared in the same manner as in Example B1, except that a polyamic acid solution BF was used instead of the polyamic acid solution BE. At this time, the volatile component ratio and the imidation ratio of the semi-cured first polyimide layer were 5.6% and 55%. A peeling test of the prepared metal-clad laminate B2 was performed in the same manner as in Example B1, but no peeling was observed between the first polyimide layer and the second polyimide layer.

[Example B3]
A metal-clad laminate B3 was prepared in the same manner as in Example B1, except that a polyamic acid solution BG was used instead of the polyamic acid solution BE. At this time, the volatile component ratio and the imidation ratio of the first polyimide layer in the semi-cured state were 6.7% and 28%. A peeling test of the prepared metal-clad laminate B3 was performed in the same manner as in Example B1, but no peeling between the first polyimide layer and the second polyimide layer was observed.

[Example B4]
A metal-clad laminate B4 was prepared in the same manner as in Example B1 except that the polyamic acid solution BC was used instead of the polyamic acid solution BE. At this time, the volatile component ratio and the imidation ratio of the first cured polyimide layer were 2.6% and 73%. A peeling test was conducted on the prepared metal-clad laminate B4 in the same manner as in Example B1, but no peeling was observed between the first polyimide layer and the second polyimide layer.

[Example B5]
A metal-clad laminate B5 was prepared in the same manner as in Example B1, except that the polyamic acid solution BB was used instead of the polyamic acid solution BA. At this time, the volatile component ratio and the imidation ratio of the semi-cured first polyimide layer were 3.2% and 70%. A peeling test of the prepared metal-clad laminate B5 was performed in the same manner as in Example B1, but no peeling was observed between the first polyimide layer and the second polyimide layer.

[Example B6]
A polyamic acid solution BB was used instead of the polyamic acid solution BA, and a polyamic acid solution BF was used instead of the polyamic acid solution BE in the same manner as in Example B1. A metal-clad laminate B6 was prepared. At this time, the volatile component ratio and the imidation ratio of the semi-cured first polyimide layer were 4.0% and 65%. A peeling test of the prepared metal-clad laminate B6 was performed in the same manner as in Example B1, but no peeling between the first polyimide layer and the second polyimide layer was observed.

[Example B7]
A polyamic acid solution BB was used instead of the polyamic acid solution BA, and a polyamic acid solution BG was used instead of the polyamic acid solution BE in the same manner as in Example B1. A metal-clad laminate B7 was prepared. At this time, the volatile component ratio and the imidation ratio of the first polyimide layer in the semi-cured state were 5.5% and 53%. A peeling test was conducted on the prepared metal-clad laminate B7 in the same manner as in Example B1, but no peeling was observed between the first polyimide layer and the second polyimide layer.

[Example B8]
Instead of the polyamic acid solution BA, a polyamic acid solution BB was used, and instead of the polyamic acid solution BE, a polyamic acid solution BA was used. A metal-clad laminate B8 was prepared. At this time, the volatile component ratio and the imidation ratio of the semi-cured first polyimide layer were 4.0% and 66%. A peeling test of the prepared metal-clad laminate B8 was performed in the same manner as in Example B1, but no peeling between the first polyimide layer and the second polyimide layer was observed.

[Example B9]
A polyamic acid solution BB was used instead of the polyamic acid solution BA, and a polyamic acid solution BC was used instead of the polyamic acid solution BE in the same manner as in Example B1. A metal-clad laminate B9 was prepared. At this time, the volatile component ratio and the imidation ratio of the semi-cured first polyimide layer were 1.2% and 80%. A peeling test was conducted on the prepared metal-clad laminate B9 in the same manner as in Example B1, but no peeling between the first polyimide layer and the second polyimide layer was observed.

[Example B10]
A metal-clad laminate B10 was prepared in the same manner as in Example B1, except that the polyamic acid solution BC was used instead of the polyamic acid solution BA. At this time, the volatile component ratio and the imidation ratio of the first cured polyimide layer were 2.6% and 83%. A peeling test of the prepared metal-clad laminate B10 was performed in the same manner as in Example B1, but no peeling was observed between the first polyimide layer and the second polyimide layer.

[Example B11]
A polyamic acid solution BC was used in place of the polyamic acid solution BA, and a polyamic acid solution BF was used instead of the polyamic acid solution BE in the same manner as in Example B1. A metal-clad laminate B11 was prepared. At this time, the volatile component ratio and the imidation ratio of the semi-cured first polyimide layer were 4.4% and 59%. A peeling test of the prepared metal-clad laminate B11 was performed in the same manner as in Example B1, but no peeling was observed between the first polyimide layer and the second polyimide layer.

[Example B12]
In the same manner as in Example B1, except that the polyamic acid solution BC was used instead of the polyamic acid solution BA, and the polyamic acid solution BG was used instead of the polyamic acid solution BE, A metal-clad laminate B12 was prepared. At this time, the volatile component ratio and the imidation ratio of the first cured polyimide layer were 10.1% and 23%. A peeling test of the prepared metal-clad laminate B12 was performed in the same manner as in Example B1, but no peeling between the first polyimide layer and the second polyimide layer was observed.

[Example B13]
In the same manner as in Example B1, except that the polyamic acid solution BC was used instead of the polyamic acid solution BA, and the polyamic acid solution BA was used instead of the polyamic acid solution BE, A metal-clad laminate B13 was prepared. At this time, the volatile component ratio and the imidation ratio of the semi-cured first polyimide layer were 10.0% and 22%. A peeling test of the prepared metal-clad laminate B13 was performed in the same manner as in Example B1, but no peeling between the first polyimide layer and the second polyimide layer was observed.

[Example B14]
A metal-clad laminate B14 was prepared in the same manner as in Example B1, except that the polyamic acid solution BD was used instead of the polyamic acid solution BA. At this time, the volatile component ratio and the imidation ratio of the first polyimide layer in a semi-cured state were 15.1% and 20%. A peeling test of the prepared metal-clad laminate B14 was performed in the same manner as in Example B1, but no peeling was observed between the first polyimide layer and the second polyimide layer.

[Example B15]
A polyamic acid solution BD was used instead of the polyamic acid solution BA, and a polyamic acid solution BF was used instead of the polyamic acid solution BE in the same manner as in Example B1. A metal-clad laminate B15 was prepared. At this time, the volatile component ratio and the imidation ratio of the first polyimide layer in the semi-cured state were 8.3% and 31%. A peeling test of the prepared metal-clad laminate B15 was performed in the same manner as in Example B1, but no peeling was observed between the first polyimide layer and the second polyimide layer.

[Example B16]
In the same manner as in Example B1, except that the polyamic acid solution BD was used instead of the polyamic acid solution BA, and the polyamic acid solution BG was used instead of the polyamic acid solution BE, A metal-clad laminate B16 was prepared. At this time, the volatile component ratio and the imidation ratio of the first polyimide layer in the semi-cured state were 12.0% and 22%. A peeling test of the prepared metal-clad laminate B16 was performed in the same manner as in Example B1, but no peeling between the first polyimide layer and the second polyimide layer was observed.

[Example B17]
In the same manner as in Example B1, except that the polyamic acid solution BD was used instead of the polyamic acid solution BA, and the polyamic acid solution BA was used instead of the polyamic acid solution BE, A metal-clad laminate B17 was prepared. At this time, the volatile component ratio and the imidation ratio of the semi-cured first polyimide layer were 7.0% and 25%. A peeling test of the prepared metal-clad laminate B17 was performed in the same manner as in Example B1, but no peeling was observed between the first polyimide layer and the second polyimide layer.

[Example B18]
In the same manner as in Example B1, except that the polyamic acid solution BD was used instead of the polyamic acid solution BA, and the polyamic acid solution BC was used instead of the polyamic acid solution BE, A metal-clad laminate B18 was prepared. At this time, the volatile component ratio and the imidation ratio of the semi-cured first polyimide layer were 8.2% and 21%. A peeling test was conducted on the prepared metal-clad laminate B18 in the same manner as in Example B1, but no peeling was observed between the first polyimide layer and the second polyimide layer.

Comparative Example B1
A metal-clad laminate B19 was prepared in the same manner as in Example B1, except that the temperature of the polyamic acid solution serving as the first polyimide layer was gradually increased from 120 ° C to 360 ° C. At this time, the volatile component ratio and the imidation ratio of the first polyimide layer were 0.0% and 100%. A peel test of the prepared metal-clad laminate B19 was performed in the same manner as in Example B1, and delamination between the first polyimide layer and the second polyimide layer occurred.

Comparative Example B2
A metal-clad laminate B20 was prepared in the same manner as in Example B2, except that the temperature of the polyamic acid solution serving as the first polyimide layer was gradually increased from 120 ° C to 360 ° C. At this time, the volatile component ratio and the imidation ratio of the first polyimide layer were 0.0% and 100%. When a peel test was conducted on the prepared metal-clad laminate B20 in the same manner as in Example B1, delamination between the first polyimide layer and the second polyimide layer occurred.

Comparative Example B3
A metal-clad laminate B21 was prepared in the same manner as in Example B14, except that the temperature of the polyamic acid solution serving as the first polyimide layer was gradually increased from 120 ° C. to 360 ° C. At this time, the volatile component ratio and the imidation ratio of the first polyimide layer were 0.0% and 100%. A peel test of the prepared metal-clad laminate B21 was performed in the same manner as in Example B1, and delamination between the first polyimide layer and the second polyimide layer occurred.

Comparative Example B4
A metal-clad laminate B22 was prepared in the same manner as in Example B15, except that the temperature of the polyamic acid solution serving as the first polyimide layer was gradually increased from 120 ° C to 360 ° C. At this time, the volatile component ratio and the imidation ratio of the first polyimide layer were 0.0% and 100%. When a peel test was performed on the prepared metal-clad laminate B22 in the same manner as in Example B1, delamination between the first polyimide layer and the second polyimide layer occurred.

[Example B19]
After a polyamic acid solution BE serving as a first polyimide layer is uniformly applied on a 12 μm-thick electrolytic copper foil so as to have a cured thickness of 2.5 μm, the polyamic acid solution BE is gradually applied from 120 ° C. to 240 ° C. The temperature was raised to remove an appropriate solvent and imidation. At this time, the volatile component ratio and the imidation ratio of the first polyimide layer in the semi-cured state were 5.5% and 53%. Next, after a polyamic acid solution BA serving as a second polyimide layer is uniformly applied thereon so as to have a cured thickness of 20 μm, a polyamic acid solution serving as a third polyimide layer is formed thereon. The solution BE was uniformly applied so that the thickness after curing became 2.5 μm, and was heated and dried at 120 ° C. for 3 minutes to remove the solvent. Thereafter, the temperature was increased stepwise from 130 ° C. to 360 ° C. to perform imidization to prepare a metal-clad laminate B23. However, no foaming was observed, and no curling of the polyimide film was observed after copper foil etching. The dimensional change rate was "good".

[Example B20]
Instead of the polyamic acid solution BE to be the first polyimide layer and the third polyimide layer, a polyamic acid solution BF is uniformly applied so that the thickness after curing becomes 2.7 μm, respectively, A metal-clad laminate B24 was prepared in the same manner as in Example B19, except that the polyamic acid solution BA serving as a polyimide layer was uniformly applied so that the thickness after curing became 19.6 μm. No curl of the polyimide film was observed after etching of the copper foil. The dimensional change rate was "good". At this time, the volatile component ratio and the imidation ratio of the first cured polyimide layer were 2.6% and 83%.

[Example B21]
Instead of the polyamic acid solution BE to be the first polyimide layer and the third polyimide layer, a polyamic acid solution BG is uniformly applied so that the thickness after curing becomes 3.2 μm, respectively. A metal-clad laminate B25 was prepared in the same manner as in Example B19, except that the polyamic acid solution BA serving as a polyimide layer was uniformly applied so that the thickness after curing became 18.6 μm. No curl of the polyimide film was observed after etching of the copper foil. In addition, the dimensional change rate was “OK”. At this time, the volatile component ratio and the imidation ratio of the semi-cured first polyimide layer were 3.2% and 70%.

[Example B22]
The polyamic acid solution BE to be the first and third polyimide layers was uniformly applied so as to have a thickness of 1.7 μm after curing, and the polyamic acid solution BA to be the second polyimide layer was cured. After the application, the temperature was raised from 130 ° C. to 360 ° C. after the application of the polyamic acid solution BA and the polyamic acid solution BE to be the third polyimide layer. A metal-clad laminate B26 was prepared in the same manner as in Example B19 except that the time was reduced to 1/3. As a result, no foaming was observed, and no curling of the polyimide film was observed after etching the copper foil. The dimensional change rate was "good". At this time, the volatile component ratio and the imidation ratio of the first cured polyimide layer were 10.1% and 23%.

[Example B23]
The polyamic acid solution BE to be the first and third polyimide layers was uniformly applied so as to have a thickness of 1.8 μm after curing, and the polyamic acid solution BA to be the second polyimide layer was cured. After the application, the temperature was raised from 130 ° C. to 360 ° C. after the application of the polyamic acid solution BA and the polyamic acid solution BE to be the third polyimide layer. A metal-clad laminate B27 was prepared in the same manner as in Example B19, except that the time was reduced to 1/3. As a result, no foaming was observed, and no curling of the polyimide film was observed after copper foil etching. The dimensional change rate was "good". At this time, the volatile component ratio and the imidation ratio of the first polyimide layer in the semi-cured state were 6.7% and 28%.

[Example B24]
The polyamic acid solution BE to be the first and third polyimide layers was uniformly applied so as to have a thickness of 2.2 μm after curing, and the polyamic acid solution BA to be the second polyimide layer was cured. After the application, the temperature was increased from 130 ° C. to 360 ° C. after the application of the polyamic acid solution BA and the polyamic acid solution BE to be the third polyimide layer. A metal-clad laminate B28 was prepared in the same manner as in Example B19, except that the time was reduced to 1/3. As a result, no foaming was observed, and no curling of the polyimide film was observed after etching the copper foil. The dimensional change rate was "good". At this time, the volatile component ratio and the imidation ratio of the first polyimide layer in a semi-cured state were 15.1% and 20%.

[Example B25]
The polyamic acid solution BE to be the first and third polyimide layers was uniformly applied so as to have a thickness of 2.4 μm after curing, and the polyamic acid solution BD to be the second polyimide layer. Was prepared in the same manner as in Example B19, except that the resin composition was uniformly coated so that the thickness after curing became 20 μm. No foaming was observed, and the curl of the polyimide film after copper foil etching was confirmed. Was also not confirmed. The dimensional change rate was "good". At this time, the volatile component ratio and the imidation ratio of the first polyimide layer in a semi-cured state were 15.1% and 20%.

[Example B26]
The polyamic acid solution BF to be the first and third polyimide layers was uniformly applied so as to have a cured thickness of 2.7 μm, and the polyamic acid solution BD to be the second polyimide layer Was prepared in the same manner as in Example B19, except that the resin was uniformly coated so that the thickness after curing became 20 μm. When a metal-clad laminate B30 was prepared, foaming was not confirmed. Was also not confirmed. The dimensional change rate was "good". At this time, the volatile component ratio and the imidation ratio of the first polyimide layer in the semi-cured state were 8.3% and 31%.

[Example B27]
The polyamic acid solution BG to be the first and third polyimide layers was uniformly applied so as to have a cured thickness of 3.2 μm, and the polyamic acid solution BD to be the second polyimide layer. Was prepared in the same manner as in Example B19, except that the resin was uniformly coated so that the thickness after curing became 19 μm. No foaming was observed. Was also not confirmed. In addition, the dimensional change rate was “OK”. At this time, the volatile component ratio and the imidation ratio of the first polyimide layer in the semi-cured state were 12.0% and 22%.

Comparative Example B5
A metal-clad laminate B32 was prepared in the same manner as in Example B19, except that the polyamic acid solution serving as the first polyimide layer was dried by heating at 120 ° C. for 3 minutes. confirmed. At this time, the volatile component ratio and the imidation ratio in a state where the layer to be the first polyimide layer was dried by heating were 35.0% and 0%.

Comparative Example B6
A metal-clad laminate B33 was prepared in the same manner as in Example B20, except that the polyamic acid solution serving as the first polyimide layer was dried by heating at 120 ° C. for 3 minutes. confirmed. At this time, the volatile component ratio and the imidation ratio in a state where the layer to be the first polyimide layer was dried by heating were 32.0% and 0%.

Comparative Example B7
A metal-clad laminate B34 was prepared in the same manner as in Example B21, except that the polyamic acid solution serving as the first polyimide layer was heated and dried at 120 ° C. for 3 minutes. confirmed. At this time, the volatile component ratio and the imidation ratio in a state where the layer to be the first polyimide layer was dried by heating were 30.0% and 0%.

Comparative Example B8
When a metal-clad laminate B35 was prepared in the same manner as in Example B22, except that the polyamic acid solution serving as the first polyimide layer was heated and dried at 120 ° C. for 3 minutes, foaming was confirmed. At this time, the volatile component ratio and the imidation ratio in a state where the layer to be the first polyimide layer was dried by heating were 34.0% and 0%.

Comparative Example B9
When a metal-clad laminate B36 was prepared in the same manner as in Example B23 except that the polyamic acid solution serving as the first polyimide layer was heated and dried at 120 ° C. for 3 minutes, foaming was confirmed. At this time, the volatile component ratio and the imidation ratio in a state where the layer to be the first polyimide layer was dried by heating were 30.0% and 0%.

Comparative Example B10
When a metal-clad laminate B37 was prepared in the same manner as in Example B24 except that the polyamic acid solution serving as the first polyimide layer was heated and dried at 120 ° C. for 3 minutes, foaming was confirmed. At this time, the volatile component ratio and the imidation ratio in a state where the layer to be the first polyimide layer was dried by heating were 31.0% and 0%.

(Synthesis example C1)
45.989 g of m-TB (216.63 mmol), 15.832 g of TPE-R (54.16 mmol) and 680 g of DMAc were charged into a 1000 ml separable flask, and the mixture was stirred at room temperature under a nitrogen stream. After complete dissolution, 58.179 g of PMDA (266.73 mmol) was added and stirred at room temperature for 4 hours to obtain a polyamic acid solution CA. The viscosity of the obtained polyamic acid solution CA was 22,000 cP.

(Synthesis example C2)
9.244 g of 4,4′-DAPE (46.16 mmol) and 176 g of DMAc were charged into a 300 ml separable flask, and the mixture was stirred at room temperature under a nitrogen stream. After complete dissolution, 14.756 g of BTDA (45.79 mmol) was added, and the mixture was stirred at room temperature for 4 hours to obtain a polyamic acid solution CB. The viscosity of the obtained polyamic acid solution CB was 1,200 cP.

(Synthesis example C3)
11.464 g of TPE-Q (39.22 mmol) and 176 g of DMAc were charged into a 300 ml separable flask, and the mixture was stirred at room temperature under a nitrogen stream. After complete dissolution, 12.536 g of BTDA (38.90 mmol) was added and stirred at room temperature for 4 hours to obtain a polyamic acid solution CC. The viscosity of the obtained polyamic acid solution CC was 2,200 cP.

(Synthesis example C4)
11.64 g of TPE-R (39.22 mmol) and 176 g of DMAc were charged into a 300 ml separable flask, and the mixture was stirred at room temperature under a nitrogen stream. After complete dissolution, 12.536 g of BTDA (38.90 mmol) was added and stirred at room temperature for 4 hours to obtain a polyamic acid solution CD. The viscosity of the obtained polyamic acid solution CD was 1,100 cP.

(Synthesis example C5)
11.386 g of APB (38.95 mmol) and 176 g of DMAc were charged into a 300 ml separable flask and stirred at room temperature under a nitrogen stream. After complete dissolution, 12.614 g of BTDA (39.14 mmol) was added and stirred at room temperature for 4 hours to obtain a polyamic acid solution CE. The viscosity of the obtained polyamic acid solution CE was 200 cP.

(Synthesis example C6)
13.493 g of BAPP (32.87 mmol) and 176 g of DMAc were charged into a 300 ml separable flask, and the mixture was stirred at room temperature under a nitrogen stream. After complete dissolution, 10.507 g of BTDA (32.61 mmol) was added, and the mixture was stirred at room temperature for 4 hours to obtain a polyamic acid solution CF. The viscosity of the obtained polyamic acid solution CF was 1,400 cP.

(Synthesis example C7)
9.227 g of 3,4′-DAPE (46.08 mmol) and 176 g of DMAc were charged into a 300 ml separable flask, and the mixture was stirred at room temperature under a nitrogen stream. After complete dissolution, 14.773 g of BTDA (45.85 mmol) was added and stirred at room temperature for 4 hours to obtain a polyamic acid solution CG. The viscosity of the obtained polyamic acid solution CG was 500 cP.

(Synthesis example C8)
4.660 g of PDA (43.09 mmol), 2.157 g of 4,4'-DAPE (10.77 mmol) and 176 g of DMAc were added to a 300 ml separable flask, and the mixture was stirred at room temperature under a nitrogen stream. After complete dissolution, 17.183 g of BTDA (53.33 mmol) was added and stirred at room temperature for 4 hours to obtain a polyamic acid solution CH. The viscosity of the obtained polyamic acid solution CH was 1,500 cP.

(Synthesis example C9)
In a 300 ml separable flask, 12.053 g of TFMB (37.64 mmol) and 176 g of DMAc were charged, and the mixture was stirred at room temperature under a nitrogen stream. After complete dissolution, 11.947 g of BTDA (37.07 mmol) was added, and the mixture was stirred at room temperature for 4 hours to obtain a polyamic acid solution CI. The viscosity of the obtained polyamic acid solution CI was 1,200 cP.

(Synthesis example C10)
9.498 g of 4,4′-DAPE (47.43 mmol) and 176 g of DMAc were charged into a 300 ml separable flask, and the mixture was stirred at room temperature under a nitrogen stream. After complete dissolution, 7.581 g of BTDA (23.53 mmol) and 6.922 g of BPDA (23.53 mmol) were added, and the mixture was stirred at room temperature for 4 hours to obtain a polyamic acid solution CJ. The viscosity of the obtained polyamic acid solution CJ was 2,500 cP.

(Synthesis example C11)
9.727 g of 4,4′-DAPE (48.58 mmol) and 176 g of DMAc were charged into a 300 ml separable flask, and the mixture was stirred at room temperature under a nitrogen stream. After complete dissolution, 11.646 g of BTDA (36.14 mmol) and 2.628 g of PMDA (12.05 mmol) were added, and the mixture was stirred at room temperature for 4 hours to obtain a polyamic acid solution CK. The viscosity of the obtained polyamic acid solution CK was 1,100 cP.

(Synthesis example C12)
4.575 g of 4,4′-DAPE (22.85 mmol), 4.850 g of m-TB (22.85 mmol), and 176 g of DMAc were charged into a 300 ml separable flask, and stirred at room temperature under a nitrogen stream. did. After complete dissolution, 14.576 g of BTDA (45.23 mmol) was added, and the mixture was stirred at room temperature for 4 hours to obtain a polyamic acid solution CL. The viscosity of the obtained polyamic acid solution CL was 1,100 cP.

(Synthesis example C13)
9.807 g of 4,4′-DAPE (48.97 mmol) and 176 g of DMAc were charged into a 300 ml separable flask, and the mixture was stirred at room temperature under a nitrogen stream. After complete dissolution, 14.193 g of BPDA (48.24 mmol) was added and stirred at room temperature for 4 hours to obtain a polyamic acid solution CM. The viscosity of the resulting polyamic acid solution CM was 1,000 cP.

(Synthesis example C14)
To a 1000 ml separable flask were charged 62.734 g of BAPP (152.82 mmol) and 704 g of DMAc, and the mixture was stirred at room temperature under a nitrogen stream. After complete dissolution, 33.266 g of PMDA (152.51 mmol) was added and stirred at room temperature for 4 hours to obtain a polyamic acid solution CN. The viscosity of the obtained polyamic acid solution CN was 4,800 cP.

(Synthesis example C15)
38.27 g of m-TB (180.27 mmol) and 704 g of DMAc were charged into a 1000 ml separable flask, and the mixture was stirred at room temperature under a nitrogen stream. After complete dissolution, 57.102 g of BTDA (177.21 mmol) and 0.629 g of PMDA (2.88 mmol) were added and stirred at room temperature for 4 hours to obtain a polyamic acid solution CO. The viscosity of the obtained polyamic acid solution CO was 43,000 cP.

(Synthesis example C16)
Into a 1000 ml separable flask, 19.536 g of PDA (180.66 mmol), 13.087 g of BAPP (31.88 mmol) and 704 g of DMAc were charged, and the mixture was stirred at room temperature under a nitrogen stream. After complete dissolution, 56.73 g of BPDA (192.82 mmol) and 6.646 g of ODPA (21.42 mmol) were added and stirred at room temperature for 4 hours to obtain a polyamic acid solution CP. The viscosity of the obtained polyamic acid solution CP was 51,000 cP.

(Synthesis example C17)
76.91 g of BAPP (187.35 mmol) and 680 g of DMAc were charged into a 1000 ml separable flask, and the mixture was stirred at room temperature under a nitrogen stream. After complete dissolution, 34.805 g of PMDA (159.57 mmol) and 8.285 g of BPDA (28.16 mmol) were added and stirred at room temperature for 4 hours to obtain a polyamic acid solution CQ. The viscosity of the resulting polyamic acid solution CQ was 9,500 cP.

(Synthesis example C18)
77.298 g of BAPP (188.30 mmol) and 680 g of DMAc were charged into a 1000 ml separable flask, and the mixture was stirred at room temperature under a nitrogen stream. After complete dissolution, 34.492 g of PMDA (158.13 mmol) and 8.210 g of BPDA (27.91 mmol) were added and stirred at room temperature for 4 hours to obtain a polyamic acid solution CR. The viscosity of the obtained polyamic acid solution CR was 2,200 cP.

(Synthesis example C19)
50.803 g of m-TB (239.31 mmol), 7.773 g of TPE-R (26.59 mmol) and 680 g of DMAc were charged into a 1000 ml separable flask, and the mixture was stirred at room temperature under a nitrogen stream. After complete dissolution, 45.934 g of PMDA (210.59 mmol) and 15.490 g of BPDA (52.65 mmol) were added and stirred at room temperature for 4 hours to obtain a polyamic acid solution CS. The viscosity of the obtained polyamic acid solution CS was 23,000 cP.

(Synthesis example C20)
44.203 g of m-TB (208.22 mmol), 6.763 g of TPE-R (23.14 mmol) and 680 g of DMAc were charged into a 1000 ml separable flask, and the mixture was stirred at room temperature under a nitrogen stream. After complete dissolution, 59.043 g of BTDA (183.23 mmol) and 9.992 g of PMDA (45.81 mmol) were added, and the mixture was stirred at room temperature for 4 hours to obtain a polyamic acid solution CT. The viscosity of the obtained polyamic acid solution CT was 12,000 cP.

(Synthesis example C21)
33.475 g of TPE-R (114.51 mmol), 14.346 g of TPE-Q (49.08 mmol) and 704 g of DMAc were charged into a 1000 ml separable flask, and the mixture was stirred at room temperature under a nitrogen stream. After complete dissolution, 48.179 g of BPDA (163.75 mmol) was added and stirred at room temperature for 4 hours to obtain a polyamic acid solution CU. The viscosity of the obtained polyamic acid solution CU was 15,000 cP.

(Synthesis example C22)
33.542 g of TPE-R (114.74 mmol), 14.375 g of TPE-Q (49.17 mmol) and 704 g of DMAc were put into a 1000 ml separable flask, and the mixture was stirred at room temperature under a nitrogen stream. After complete dissolution, 48.083 g of BPDA (163.42 mmol) was added and stirred at room temperature for 4 hours to obtain a polyamic acid solution CV. The viscosity of the obtained polyamic acid solution CV was 10,000 cP.

[Example C1]
After a polyamic acid solution CB to be a first polyimide layer is uniformly applied on a 12 μm-thick electrolytic copper foil so as to have a cured thickness of 2 μm, the temperature is raised stepwise from 120 ° C. to 360 ° C. The solvent was removed and imidation was performed. Next, a polyamic acid solution CA to be a second polyimide layer was uniformly applied thereon so as to have a cured thickness of 25 μm, and then heated and dried at 120 ° C. for 3 minutes to remove the solvent. . Thereafter, the temperature was increased stepwise from 130 ° C. to 360 ° C. to perform imidization, thereby preparing a metal-clad laminate C1. An adhesive tape was applied to the resin surface of the prepared metal-clad laminate C1, and a peeling test was performed by instantaneous peeling in the vertical direction. However, peeling between the first polyimide layer and the second polyimide layer was observed. Did not.

[Example C2]
A metal-clad laminate C2 was prepared in the same manner as in Example C1, except that the polyamic acid solution CA was replaced by the polyamic acid solution CN. A peeling test of the prepared metal-clad laminate C2 was performed in the same manner as in Example C1, but no peeling between the first polyimide layer and the second polyimide layer was observed.

[Example C3]
A metal-clad laminate C3 was prepared in the same manner as in Example C1, except that the polyamic acid solution CC was used instead of the polyamic acid solution CB. A peeling test of the prepared metal-clad laminate C3 was performed in the same manner as in Example C1, but no peeling was observed between the first polyimide layer and the second polyimide layer.

[Example C4]
A polyamic acid solution CC was used in place of the polyamic acid solution CB, and a polyamic acid solution CN was used in place of the polyamic acid solution CA in the same manner as in Example C1. A metal-clad laminate C4 was prepared. A peeling test of the prepared metal-clad laminate C4 was performed in the same manner as in Example C1, but no peeling between the first polyimide layer and the second polyimide layer was observed.

[Example C5]
A metal-clad laminate C5 was prepared in the same manner as in Example C1, except that the polyamic acid solution CD was used instead of the polyamic acid solution CB. A peeling test of the prepared metal-clad laminate C5 was performed in the same manner as in Example C1, but no peeling between the first polyimide layer and the second polyimide layer was observed.

[Example C6]
In the same manner as in Example C1, except that the polyamic acid solution CD was used instead of the polyamic acid solution CB, and the polyamic acid solution CN was used instead of the polyamic acid solution CA, A metal-clad laminate C6 was prepared. A peeling test of the prepared metal-clad laminate C6 was performed in the same manner as in Example C1, but no peeling was observed between the first polyimide layer and the second polyimide layer.

[Example C7]
A metal-clad laminate C7 was prepared in the same manner as in Example C1 except that the polyamic acid solution CE was used instead of the polyamic acid solution CB. A peeling test of the prepared metal-clad laminate C7 was performed in the same manner as in Example C1, but no peeling between the first polyimide layer and the second polyimide layer was observed.

[Example C8]
In the same manner as in Example C1, except that the polyamic acid solution CE was used instead of the polyamic acid solution CB, and the polyamic acid solution CN was used instead of the polyamic acid solution CA, A metal-clad laminate C8 was prepared. A peeling test of the prepared metal-clad laminate C8 was performed in the same manner as in Example C1, but no peeling between the first polyimide layer and the second polyimide layer was observed.

[Example C9]
A metal-clad laminate C9 was prepared in the same manner as in Example C1, except that the polyamic acid solution CB was used instead of the polyamic acid solution CB. A peeling test of the prepared metal-clad laminate C9 was performed in the same manner as in Example C1, but no peeling between the first polyimide layer and the second polyimide layer was observed.

[Example C10]
In the same manner as in Example C1, except that a polyamic acid solution CF was used instead of the polyamic acid solution CB, and a polyamic acid solution CN was used instead of the polyamic acid solution CA, A metal-clad laminate C10 was prepared. A peeling test was conducted on the prepared metal-clad laminate C10 in the same manner as in Example C1, but no peeling was observed between the first polyimide layer and the second polyimide layer.

[Example C11]
A metal-clad laminate C11 was prepared in the same manner as in Example C1, except that the polyamic acid solution CB was used instead of the polyamic acid solution CB. A peeling test of the prepared metal-clad laminate C11 was performed in the same manner as in Example C1, but no peeling between the first polyimide layer and the second polyimide layer was observed.

[Example C12]
A polyamic acid solution CG was used in place of the polyamic acid solution CB, and a polyamic acid solution CN was used in place of the polyamic acid solution CA in the same manner as in Example C1. A metal-clad laminate C12 was prepared. A peeling test of the prepared metal-clad laminate C12 was performed in the same manner as in Example C1, but no peeling between the first polyimide layer and the second polyimide layer was observed.

[Example C13]
A metal-clad laminate C13 was prepared in the same manner as in Example C1, except that the polyamic acid solution CB was used instead of the polyamic acid solution CB. A peeling test of the prepared metal-clad laminate C13 was performed in the same manner as in Example C1, but no peeling between the first polyimide layer and the second polyimide layer was observed.

[Example C14]
Instead of the polyamic acid solution CB, a polyamic acid solution CH was used, and instead of the polyamic acid solution CA, a polyamic acid solution CN was used, in the same manner as in Example C1, A metal-clad laminate C14 was prepared. A peeling test of the prepared metal-clad laminate C14 was performed in the same manner as in Example C1, but no peeling was observed between the first polyimide layer and the second polyimide layer.

[Example C15]
A metal-clad laminate C15 was prepared in the same manner as in Example C1 except that the polyamic acid solution CI was used instead of the polyamic acid solution CB. A peel test of the prepared metal-clad laminate C15 was performed in the same manner as in Example C1, but no peeling between the first polyimide layer and the second polyimide layer was observed.

[Example C16]
In the same manner as in Example C1, except that the polyamic acid solution CI was used instead of the polyamic acid solution CB, and the polyamic acid solution CN was used instead of the polyamic acid solution CA, A metal-clad laminate C16 was prepared. A peel test of the prepared metal-clad laminate C16 was performed in the same manner as in Example C1, but no peeling between the first polyimide layer and the second polyimide layer was observed.

[Example C17]
A metal-clad laminate C17 was prepared in the same manner as in Example C1, except that the polyamic acid solution CB was used instead of the polyamic acid solution CB. A peeling test of the prepared metal-clad laminate C17 was performed in the same manner as in Example C1, but no peeling between the first polyimide layer and the second polyimide layer was observed.

[Example C18]
A polyamic acid solution CJ was used in place of the polyamic acid solution CB, and a polyamic acid solution CN was used in place of the polyamic acid solution CA in the same manner as in Example C1. A metal-clad laminate C18 was prepared. A peeling test of the prepared metal-clad laminate C18 was performed in the same manner as in Example C1, but no peeling was observed between the first polyimide layer and the second polyimide layer.

[Example C19]
A metal-clad laminate C19 was prepared in the same manner as in Example C1, except that the polyamic acid solution CB was used instead of the polyamic acid solution CB. A peeling test of the prepared metal-clad laminate C19 was performed in the same manner as in Example C1, but no peeling between the first polyimide layer and the second polyimide layer was observed.

[Example C20]
A polyamic acid solution CK was used instead of the polyamic acid solution CB, and a polyamic acid solution CN was used instead of the polyamic acid solution CA in the same manner as in Example C1. A metal-clad laminate C20 was prepared. A peeling test was conducted on the prepared metal-clad laminate C20 in the same manner as in Example C1, but no peeling was observed between the first polyimide layer and the second polyimide layer.

[Example C21]
A metal-clad laminate C21 was prepared in the same manner as in Example C1 except that the polyamic acid solution CL was used instead of the polyamic acid solution CB. A peeling test of the prepared metal-clad laminate C21 was performed in the same manner as in Example C1, but no peeling was observed between the first polyimide layer and the second polyimide layer.

[Example C22]
In the same manner as in Example C1, except that the polyamic acid solution CL was used instead of the polyamic acid solution CB, and the polyamic acid solution CN was used instead of the polyamic acid solution CA, A metal-clad laminate C22 was prepared. A peeling test of the prepared metal-clad laminate C22 was performed in the same manner as in Example C1, but no peeling between the first polyimide layer and the second polyimide layer was observed.

[Example C23]
A metal-clad laminate C23 was prepared in the same manner as in Example C1, except that the polyamic acid solution CB was used instead of the polyamic acid solution CB. A peeling test of the prepared metal-clad laminate C23 was performed in the same manner as in Example C1, but no peeling was observed between the first polyimide layer and the second polyimide layer.

[Example C24]
In the same manner as in Example C1, except that the polyamic acid solution CO was used instead of the polyamic acid solution CB, and the polyamic acid solution CN was used instead of the polyamic acid solution CA, A metal-clad laminate C24 was prepared. A peeling test of the prepared metal-clad laminate C24 was performed in the same manner as in Example C1, but no peeling between the first polyimide layer and the second polyimide layer was observed.

[Example C25]
A metal-clad laminate C25 was prepared in the same manner as in Example C1, except that the polyamic acid solution CB was used instead of the polyamic acid solution CB. A peeling test of the prepared metal-clad laminate C25 was performed in the same manner as in Example C1, but no peeling between the first polyimide layer and the second polyimide layer was observed.

[Example C26]
In the same manner as in Example C1, except that the polyamic acid solution CT was used instead of the polyamic acid solution CB, and the polyamic acid solution CN was used instead of the polyamic acid solution CA, A metal-clad laminate C26 was prepared. A peeling test was conducted on the prepared metal-clad laminate C26 in the same manner as in Example C1, but no peeling was observed between the first polyimide layer and the second polyimide layer.

Comparative Example C1
A metal-clad laminate C27 was prepared in the same manner as in Example C1, except that the polyamic acid solution CB was used instead of the polyamic acid solution CB. A peel test of the prepared metal-clad laminate C27 was performed in the same manner as in Example C1, and as a result, delamination of the first polyimide layer and the second polyimide layer occurred.

Comparative Example C2
A polyamic acid solution CM was used instead of the polyamic acid solution CB, and a polyamic acid solution CN was used instead of the polyamic acid solution CA in the same manner as in Example C1. A metal-clad laminate C28 was prepared. A peel test of the prepared metal-clad laminate C28 was performed in the same manner as in Example C1, and as a result, delamination of the first polyimide layer and the second polyimide layer occurred.

Comparative Example C3
A metal-clad laminate C29 was prepared in the same manner as in Example C1, except that the polyamic acid solution CB was used instead of the polyamic acid solution CB. A peel test of the prepared metal-clad laminate C29 was performed in the same manner as in Example C1, and as a result, delamination of the first polyimide layer and the second polyimide layer occurred.

Comparative Example C4
A metal-clad laminate C30 was prepared in the same manner as in Example C1, except that the polyamic acid solution CP was used instead of the polyamic acid solution CA. A peel test of the prepared metal-clad laminate C30 was performed in the same manner as in Example C1, and as a result, delamination of the first polyimide layer and the second polyimide layer occurred.

Comparative Example C5
In the same manner as in Example C1, except that the polyamic acid solution CA was used instead of the polyamic acid solution CB, and the polyamic acid solution CB was used instead of the polyamic acid solution CA, A metal-clad laminate C31 was prepared. A peel test of the prepared metal-clad laminate C31 was performed in the same manner as in Example C1, and as a result, delamination of the first polyimide layer and the second polyimide layer occurred.

[Example C27]
A metal-clad laminate C32 was prepared in the same manner as in Example C1, except that the temperature-raising time from 130 ° C. to 360 ° C. after the application of the polyamic acid solution CA was shortened to 1/3. Not confirmed.

[Example C28]
Instead of using the polyamic acid solution CB instead of the polyamic acid solution CB, except that the heating time from 130 ° C. to 360 ° C. after the application of the polyamic acid solution CA was shortened to 1/3. A metal-clad laminate C33 was prepared in the same manner as in Example C1, but no foaming was confirmed.

Comparative Example C6
Instead of using the polyamic acid solution CB instead of the polyamic acid solution CB, except that the heating time from 130 ° C. to 360 ° C. after the application of the polyamic acid solution CA was shortened to 1/3. When a metal-clad laminate C34 was prepared in the same manner as in Example C1, foaming occurred.

Comparative Example C7
Instead of using the polyamic acid solution CB instead of the polyamic acid solution CB, except that the heating time from 130 ° C. to 360 ° C. after the application of the polyamic acid solution CA was shortened to ３ When a metal-clad laminate C35 was prepared in the same manner as in Example C1, foaming occurred.

[Example C29]
A polyamic acid solution CO serving as a first polyimide layer was applied on a stainless steel base material, and then dried at 120 ° C. to prepare a polyamic acid gel film. After the prepared gel film was peeled from the stainless steel substrate, it was fixed to a tenter clip, and the temperature was increased stepwise from 130 ° C. to 360 ° C. to perform imidation to prepare a 12.5 μm-thick polyimide film C36. A polyamic acid solution CR to be a second polyimide layer was applied to the prepared polyimide film C36 so as to have a cured thickness of 3 μm, and dried at 120 ° C. Thereafter, the temperature was increased stepwise from 130 ° C. to 360 ° C. to perform imidization, thereby preparing a laminated polyimide film C36. The prepared laminated polyimide film C36 was cut with a cutter, and no delamination between the first polyimide layer and the second polyimide layer was observed by SEM observation.

[Example C30]
A laminated polyimide film C37 was prepared in the same manner as in Example C29 except that the polyamic acid solution CT was used instead of the polyamic acid solution CO. No delamination was observed by SEM observation of the prepared laminated polyimide film C37.

[Example C31]
Same as Example C29 except that the thickness of the first polyimide layer was 17 μm, and that the thickness after curing was 4 μm using a polyamic acid solution CV instead of the polyamic acid solution CR. Thus, a laminated polyimide film C38 was prepared. No delamination was observed by SEM observation of the prepared laminated polyimide film C38.

[Example C32]
Instead of the polyamic acid solution CO, a polyamic acid solution CT was used, the thickness of the first polyimide layer was set to 17 μm, and a polyamic acid solution CV was used instead of the polyamic acid solution CR. And a laminated polyimide film C39 was prepared in the same manner as in Example C29, except that the thickness after curing was 4 μm. No delamination was observed by SEM observation of the prepared laminated polyimide film C39.

Comparative Example C8
A laminated polyimide film C40 was prepared in the same manner as in Example C29, except that the polyamic acid solution CR was replaced by the polyamic acid solution CQ. SEM observation of the prepared laminated polyimide film C40 confirmed delamination.

Comparative Example C9
A laminated polyimide film C41 was prepared in the same manner as in Example C29 except that the polyamic acid solution CP was used instead of the polyamic acid solution CO. SEM observation of the prepared laminated polyimide film C41 confirmed delamination.

Comparative Example C10
Same as Example C29, except that the thickness of the first polyimide layer was 17 μm, and that the thickness after curing was 4 μm using a polyamic acid solution CU instead of the polyamic acid solution CR, Thus, a laminated polyimide film C42 was prepared. SEM observation of the prepared laminated polyimide film C42 confirmed delamination.

[Example C33]
After a polyamic acid solution CT serving as a first polyimide layer is uniformly applied on a 12 μm-thick electrolytic copper foil so as to have a cured thickness of 25 μm, the temperature is raised stepwise from 120 ° C. to 360 ° C. The solvent was removed and imidation was performed. Next, a polyamic acid solution CS to be a second polyimide layer was uniformly applied thereon so as to have a cured thickness of 25 μm, and then heated and dried at 120 ° C. to remove the solvent. Thereafter, the temperature was increased stepwise from 130 ° C. to 360 ° C. to perform imidization, thereby preparing a metal-clad laminate C43. The peel strength of the first polyimide layer and the second polyimide layer in the prepared metal-clad laminate C43 was 1.5 kN / m or more.

[Example C34]
The polyamic acid solution CS was uniformly applied on a 12 μm-thick electrolytic copper foil so as to have a cured thickness of 23 μm, and dried by heating at 120 ° C. to remove the solvent. The polyamic acid solution CB was evenly applied thereon so that the thickness after curing became 2 μm, and dried by heating at 120 ° C. to remove the solvent. Thereafter, the temperature was increased stepwise from 130 ° C. to 360 ° C. to perform imidization, thereby forming a first polyimide layer. Next, a polyamic acid solution CS to be a second polyimide layer was uniformly applied thereon so as to have a cured thickness of 25 μm, and then heated and dried at 120 ° C. to remove the solvent. Thereafter, the temperature was increased stepwise from 130 ° C. to 360 ° C. to perform imidization, thereby preparing a metal-clad laminate C44. The peel strength of the first polyimide layer and the second polyimide layer in the prepared metal-clad laminate C44 was 1.5 kN / m or more.

Comparative Example C11
A metal-clad laminate C45 was prepared in the same manner as in Example C33 except that the polyamic acid solution CS was used instead of the polyamic acid solution CT. The peel strength of the first polyimide layer and the second polyimide layer in the prepared metal-clad laminate C45 was 0.1 kN / m or less.

Comparative Example C12
A metal-clad laminate C46 was prepared in the same manner as in Example C34, except that the polyamic acid solution CM was used instead of the polyamic acid solution CB. The peel strength of the first polyimide layer and the second polyimide layer in the prepared metal-clad laminate C46 was 0.1 kN / m or less.

Reference Example C
0.45 g of phthalic anhydride (3.02 mmol) was added to 100 g of the polyamic acid solution CA, and the mixture was stirred for 4 hours to prepare a polyamic acid solution CA2. When a metal-clad laminate C47 was prepared in the same manner as in Example C1, except that the polyamic acid solution CA was replaced with the polyamic acid solution CA2, foaming occurred. Further, a peeling test of the prepared metal-clad laminate C47 was performed in the same manner as in Example C1, and as a result, delamination of the first polyimide layer and the second polyimide layer occurred.
This is presumably because the amino group of the second polyimide layer reacted with phthalic anhydride, so that there was no functional group capable of reacting with the first polyimide layer, and no chemical adhesion between the resin layers occurred.

Although the embodiments of the present invention have been described in detail for the purpose of illustration, the present invention is not limited to the above embodiments.

This international application is described in Japanese Patent Application No. 2018-185874 (filing date: September 28, 2018), Japanese Patent Application No. 2018-185875 (filing date: September 28, 2018), and Japanese Patent Application 2018. No. 185876 (filing date: September 28, 2018), the entire content of which is incorporated herein by reference.

Reference Signs List 10: metal layer, 10A: metal foil, 20: first polyimide layer, 20A: first polyamide resin layer, 30: second polyimide layer, 30A: second polyamide resin layer, 40: insulating resin layer, 100 ... metal-clad laminate

Claims

An insulating resin layer including a plurality of polyimide layers, and a metal layer laminated on at least one surface of the insulating resin layer, a method of manufacturing a metal-clad laminate including:
The following steps 1 to 5;
Step 1) a step of forming a single layer or a plurality of first polyamide resin layers by applying a polyamic acid solution on the metal layer;
Step 2) a step of imidizing the polyamic acid in the first polyamide resin layer to form a single polyimide layer or a plurality of first polyimide layers;
Step 3) performing a surface treatment on the surface of the first polyimide layer;
Step 4) a step of forming a single-layer or multiple-layer second polyamide resin layer by applying a polyamic acid solution on the first polyimide layer,
Step 5) Polyamide acid in the second polyamide resin layer is imidized to form a second polyimide layer composed of a single layer or a plurality of layers, and the first polyimide layer and the second polyimide layer are Forming the laminated insulating resin layer,
Including
The thickness (L1) of the first polyimide layer is in a range of 0.5 μm or more and 100 μm or less, and the thickness (L) of the entire insulating resin layer is in a range of 5 μm or more and less than 200 μm. A method for producing a metal-clad laminate, wherein a ratio (L / L1) to the L1 is in a range of more than 1 and less than 400.
The method for producing a metal-clad laminate according to claim 1, wherein the polyimide constituting the layer in contact with the metal layer in the first polyimide layer is a thermoplastic polyimide.
Moisture permeability of the metal layer, the thickness 25 [mu] m, when 25 ℃, 100g / m 2 / 24hr or less method for producing a metal-clad laminate according to claim 1 or 2.
A method of manufacturing a circuit board, comprising a step of processing a wiring circuit of the metal layer of the metal-clad laminate manufactured by the method according to claim 1.