TWI726098B - Method for manufacturing metal/resin laminate, and electrical and electronic instrument - Google Patents

Abstract

An object of the present invention is to provide a mold release film for process which can be easily and sufficiently peeled from a metal surface having a high roughness such as a blackened copper foil or the like, even after a process under severe conditions such as a hot pressing under conditions of temperature, pressure or the like higher than conventional ones, or a hot pressing for a longer time. The object is solved by the mold release film for process composed of a thermoplastic resin, and at least one side of which has the following properties: (1) The film resilience value R measured by the nanoindentation method at a test temperature of 180 ℃ is R ≧ 70 (%).

Description

Manufacturing method of metal/resin laminate and electrical and electronic equipment

The present invention relates to a release film for the process, which has excellent release properties from a metal surface with high surface roughness such as so-called blackened copper foil. More specifically, the present invention relates to a release film for the process and the use of the release film. Process release film manufacturing method for metal/resin laminates such as multilayer printed wiring boards. The process release film is suitable for manufacturing metal/resin laminates such as multilayer printed wiring boards with roughened copper foil layers. body.

In recent years, with the rapid advancement of electronic equipment and the increase in IC integration, printed wiring boards have been commonly used for the purpose of higher precision, higher density, and higher reliability.

The printed wiring board includes a single-sided printed wiring board, a double-sided printed wiring board, a multilayer printed wiring board, and a flexible printed wiring board. Among them, in terms of the point where an insulating layer is provided between conductors of more than 3 layers and integrated, any conductors and mounted electronic parts can be connected to any conductor layer, especially a multilayer printed circuit board (hereinafter, also referred to as "MLB") The field of application is gradually expanding.

For this MLB, for example, a pair of single-sided copper-clad laminates or a pair of double-sided copper-clad laminates are used as a double-sided exterior, and one or more inner circuit boards are prepregped on the inside. The prepreg (epoxy resin, etc.) is alternately stacked, and the prepreg is sandwiched by a jig and pressed with a hot plate through a mat material to harden the prepreg to form a solid integration The layered body is formed by etching the surface after opening holes, through-hole plating, etc.

In this manufacturing process of MLB, a release film is usually used between the copper-clad laminate (exterior board) and the fixture. The release film for this process is made of 4-methyl-1-pentene copolymer, polytetrafluoroethylene, polyester, parapolystyrene, etc., which will not melt during the heating and pressing step during hot pressing. A film composed of a highly heat-resistant resin and excellent in rigidity, surface smoothness, etc. (for example, refer to Patent Document 1 to Patent Document 4, etc.).

For the copper foil of the copper-clad laminate, the so-called blackened copper foil is often used in which the surface is oxidized in order to improve the adhesion with the epoxy resin, or the so-called blackened copper foil is made rough by etching treatment caused by acid. Etc. copper foil whose surface has been roughened. At this time, the release film for each process described above has the problem that the copper foil surface invades the surface of the film during the heating and pressing step during hot pressing, and the release film cannot be peeled off.

In this regard, it has been proposed to use a stretched film, which is made of 4-methyl-1-pentene (co)polymer and is substantially free of wax or silicone on at least one of the layers (A). After the sheet formed by the polypropylene and/or polyethylene layer (B) on the outer layer is uniaxially stretched to more than 4.3 times, peel off at least one outermost polypropylene and/or polyethylene layer (B) of the sheet The resulting film has a thermal shrinkage rate of 20% or more in the extending direction (for example, refer to Patent Document 5).

However, with the development of this technical field, the level of requirements for release films for manufacturing processes such as release films for multilayer printed wiring boards has been increasing year by year, and it is strongly demanded even under severe process conditions such as hot pressing at higher temperatures and pressures. , It can still be easily and fully peeled off from the metal surface with high roughness. Only in terms of improving the rigidity and surface smoothness of the release film, it may not be able to meet such requirements.

[Prior Technical Literature] [Patent Literature]

[Patent Document 1] JP 2004-082717 A

[Patent Document 2] Japanese Patent Application Laid-Open No. 10-67027

[Patent Document 3] JP 2014-8720 A

[Patent Document 4] JP 2001-246635 A

[Patent Document 5] Japanese Patent No. 4489699 Specification

The present invention is made in view of the above situation, and aims to provide the release film for the following process, even if the release film for the process is hot-pressed or longer than the previous conditions at temperature, pressure, etc. It can still be easily and fully peeled off from blackened copper foil and other high-roughness metal surfaces after severe processing conditions such as hot pressing.

In order to solve the above-mentioned problems, the inventors of the present invention repeated the results of intensive review. They focused on the film recoverability value R measured by the nanoindentation method at a test temperature of 180°C, and found that the film recoverability value R is more than a certain value. The above-mentioned problems are effectively solved, and the present invention is completed.

That is, the present invention and its various aspects are as described in the following [1] to [10].

[1] A release film for manufacturing process, which contains thermoplastic resin and has the following characteristics on at least one side: (1) Film recovery value R measured by nanoindentation at a test temperature of 180°C For: R≧70(%).

[2] The release film for the manufacturing process as described in [1], which contains a thermoplastic resin and has the following characteristics on at least one side: (2) Measured by the nanoindentation method at a test temperature of 180°C The hardness H is: H≧40 (MPa).

[3] The release film for a process as described in [2], wherein at least one side having the characteristics of (1) is the same as at least one side having the characteristics of (2).

[4] The release film for a process according to any one of [1] to [3], which contains a polyester resin and/or a polyamide resin.

[5] The release film for a process as described in any one of [1] to [4], which has a polyester film layer with or without extension, or a polyamide film layer with or without extension.

[6] The release film for a process as described in any one of [1] to [5], which is used for peeling from a roughened metal surface.

[7] The release film for a process as described in any one of [1] to [6], which is used for peeling from a metal surface with a surface roughness Ra of 1.0 to 6.5 μm.

[8] A method of manufacturing a metal/resin laminate, comprising: applying the release film according to any one of [1] to [7] on at least one surface having the characteristics of (1) above and a rough surface The step of contacting the metal foil layer of chemical treatment and performing hot pressing; and the step of peeling the release film for the process from the metal foil layer.

[9] The manufacturing method according to [8], wherein the metal/resin laminate system multilayer printed wiring board.

[10] An electrical and electronic device having a multilayer printed circuit board manufactured by the manufacturing method described in [9].

The release film for the manufacturing process of the present invention realizes "even after the hot pressing with higher temperature and pressure than the previous conditions, or hot pressing for a longer period of time, etc., without the use of release agents, etc., And without the need to use expensive and difficult-to-process high-melting engineering plastics, etc., it can be easily and fully peeled off from blackened copper foils and other high-roughness metal surfaces." It has a high practical value that cannot be achieved by the prior art. Technical effect.

The manufacturing method using the release film for the process of the present invention can manufacture electrical and electronic parts with a metal/resin laminated structure such as a multilayer printed wiring board with high degree of freedom and good productivity.

1, 10‧‧‧Glass fiber-epoxy resin composite insulator

2, 3, 7, 9, 11‧‧‧Copper foil layer

4、5‧‧‧Release film

6, 8‧‧‧Next to prepreg

Figure 1 is a schematic cross-sectional view of a double-sided copper-clad laminate in which the copper foil is layered on a glass fiber-epoxy composite insulator and hardened.

Figure 2 is a schematic cross-sectional view showing a state where the prepreg and copper foil are laminated on the double-sided copper-clad laminate of Figure 1, and the release film is layered on both surfaces.

Fig. 3 is a schematic cross-sectional view of a multilayer laminate obtained by press-forming the multilayer laminate of Fig. 2.

Fig. 4 is a schematic cross-sectional view showing the state in which the prepreg and the double-sided copper-clad laminate are laminated on the multilayer laminate in Fig. 3, and the release film is laminated on both surface areas.

Fig. 5 is a schematic cross-sectional view of a multilayer laminate obtained by press-forming the multilayer laminate of Fig. 4.

(Release film for process)

The release film for the process of the present invention is a film made of a thermoplastic resin, and at least one side of the film has a film restorability value R of 70 as measured by the nanoindentation method with a maximum indentation load of 2mN at a test temperature of 180°C (%) above characteristics (characteristic (1)).

By making the film recoverability value R within the above range, it is easier to peel off from the blackened copper foil and other metal surfaces with high roughness, especially for high temperature, high pressure, and/or long-term and high-roughness metals It becomes easy to peel off after the surface is closely adhered. Therefore, the release film for the process of the present invention can be particularly suitable for the production of metal/resin laminates with a metal layer with a high roughness surface, and is particularly suitable for the production of blackened and roughened products. Multilayer printed wiring board with copper foil layer.

The film restorability value R is measured at a temperature of 180°C, using a nanoindenter to press a triangular pyramid diamond indenter (Berkovich indenter) with an edge angle of 115° into the measuring surface of the film with a maximum indentation load of 2mN and then remove it. The load is measured and the ratio of the indentation depth at the maximum indentation load (2mN) to the indentation depth after the load is unloaded (0mN) is calculated according to the following formula.

Film restorability value R(%)=(indentation depth after unloading/indentation depth at maximum indentation load)×100

The mechanism by which the film recoverability value R is within the above-mentioned range makes it easier to peel off from the surface of a metal surface with high roughness, such as a blackened copper foil surface. Although it is not yet clear, and it is not intended to apply a specific theory, it is estimated to be the same as the following Relevant: At higher temperature, high pressure, and/or long-term contact with high-roughness metal surface and hot pressing, the deformed film surface is restored to a smoother shape following the uneven pattern of the high-roughness metal surface , By this, a part of the close contact with the metal surface is released.

The film recovery value R is more preferably 73% or more, particularly preferably 75% or more.

From the standpoint of releasability, the higher the film recovery value R is, the better. Although there is no particular upper limit in the present invention, from the standpoint of workability and handling, it is preferably 90% or less. Especially good line is below 85%.

The type of resin used to set the film recovery value R of the release film of the present invention within the above-mentioned range is not particularly limited, and can be selected from polyester resins, polyamide resins, and those containing structural units derived from tetrafluoroethylene. Among resins such as fluororesins such as polytetrafluoroethylene and ethylene-tetrafluoroethylene copolymers, urethane resins, and polystyrene resins, they are appropriately selected and used. Moreover, these can also be used together.

In addition, the usable resin may be a thermoplastic resin, or a thermosetting resin and an active energy ray curable resin that is crosslinked by applying active energy rays such as ultraviolet rays and electron rays.

If it is desired to set the film recoverability value R of the release film of the present invention within the above range, it can be appropriately adjusted by the following method: the method of polymerizing the aforementioned resin and making the resin film contain epoxy groups A method such as a crosslinking agent of a reactive group, a method of aligning the orientation of resin molecules by stretching and orientation, a method of applying heat treatment to the resin film, etc. For the release film of the present invention, other methods for achieving the recovery value R of the film include, for example, applying a rubbing treatment to the surface of the film. When it is desired to achieve the aforementioned surface hardness by applying a rubbing treatment to the surface of the release film, the rubbing method is not particularly limited. For example, a known rubbing device can be used.

The release film used in the process of the present invention preferably has at least one side having a hardness H of 40 (MPa) or more as measured by the nanoindentation method with a test temperature of 180°C and a maximum indentation load of 2 mN (characteristic (2) )).

By setting the hardness H in the above range, peeling from the roughened copper foil surface and other metal surfaces with high roughness, especially at higher temperature, high pressure, and/or after a long time contact with the metal surface with high roughness It becomes easier. Therefore, the release film of the present invention having the characteristics of (2) above can be more suitable for manufacturing multilayer printed wiring boards with blackened copper foil layers and other metal surfaces with high roughness. .

Hardness H is measured at a temperature of 180°C, using a nanoindenter to press a triangular pyramid diamond indenter (Berkovich indenter) with an edge angle of 115° into the measuring surface of the film with a maximum indentation load of 2mN, and then unload the load. The maximum press-in load (F _max ) and press-in depth (h _c ) at the time are calculated according to the following formula.

Hardness H=F _max /(23.96×h _c ² )

The mechanism for making the hardness H within the above range makes it easier to peel off from the surface of the blackened copper foil and other metal surfaces with high roughness. Although it is not yet clear, and it is not intended to apply a specific theory, it is assumed to be related to the following Related: Even when the film surface with high hardness follows the uneven pattern of the metal surface with high roughness, the degree of deformation is small even when it is in close contact with the metal surface with high roughness at higher temperature, high pressure, and/or for a long time and hot pressing. The degree of close contact with the metal surface is small.

The hardness H is more preferably 45MPa or more, particularly preferably 55MPa or more.

From the standpoint of peelability, the higher the hardness H of the film, the better. Although there is no particular upper limit in the present invention, from the standpoint of workability and handling, it is preferably 130 MPa or less, and particularly preferably 115 MPa the following.

If the hardness H of the release film of the present invention is set to the above range, it can be appropriately adjusted by the following method: the method of polymerizing the aforementioned resin, and the resin film containing reactive groups such as epoxy groups The method of cross-linking agent, the method of aligning the orientation of resin molecules by stretching and the method, the method of applying heat treatment to the resin film, etc.

In the above aspect of the release film for the process of the present invention, it is preferable that at least one side having the characteristics of (1) and at least one side having the characteristics of (2) be the same. That is, in the above aspect of the present invention, it is preferable that at least one side has both the above-mentioned (1) characteristic and the above-mentioned (2) characteristic.

By making the at least one surface have both the characteristics of (1) and the characteristics of (2) above, it becomes easier to peel from the metal surface with high roughness, so this kind of surface is particularly suitable for use in hot pressing and the like. Chemical treatment of copper foil and other so-called metal surface contact with high surface roughness.

The release film for the process of the present invention preferably has at least one side (preferably at least one side having the characteristics of (1) above) with a contact angle of 90° to 130° with water. By having such a contact angle, the release film of this aspect has low wettability and excellent peelability from the metal surface with high roughness, especially from the surface of the blackened copper foil. It makes it easier to release molded products such as multilayer printed wiring boards after hot pressing.

The contact angle of at least one surface to water is preferably 95° to 120°, more preferably 98° to 115°, and still more preferably 100° to 110°.

In addition, the release film for the manufacturing process of the present invention preferably has a tensile elastic modulus of 75 MPa to 500 MPa at 120°C, or a tensile elastic modulus of 75 MPa to 500 MPa at 170°C. Furthermore, the release film for the manufacturing process of the present invention preferably has a tensile modulus of 75 MPa to 500 MPa at 120°C and a tensile modulus of 75 MPa to 500 MPa at 170°C.

By having a tensile elastic modulus of 75 MPa to 500 MPa at 120° C., or a tensile elastic modulus of 75 MPa to 500 MPa at 170° C., wrinkles can be effectively suppressed during the hot pressing step.

The release film for the manufacturing process of this embodiment preferably has a tensile elastic modulus at 120°C of 80 MPa to 400 MPa, more preferably 85 MPa to 350 MPa, still more preferably 88 MPa to 300 MPa, particularly preferably 90 MPa to 280 MPa.

The release film for the process of this embodiment preferably has a tensile elastic modulus at 170°C of 80 MPa to 400 MPa, more preferably 85 MPa to 350 MPa, more preferably 88 MPa to 300 MPa, more preferably 90 MPa to 280 MPa, and more The best range is from 95MPa to 200MPa, and the particularly best range is from 105MPa to 170MPa.

Since the degree of freedom and use during processing will become wider, the release film for the manufacturing process of this embodiment is particularly preferred to have a tensile modulus of elasticity at 120°C and a tensile modulus of elasticity at 170°C. Within range.

Moreover, the release film for the process of the present invention preferably has a thermal dimensional change rate of 23°C to 120°C in the TD direction (horizontal direction) of 3% or less, or 23°C to 170 in the TD direction (horizontal direction) The thermal dimensional change rate at ℃ is below 4%. Furthermore, it is more preferable that the thermal dimensional change rate from 23°C to 120°C in the TD direction (horizontal direction) is 3% or less, and the thermal dimensional change rate from 23°C to 170°C in the TD direction (horizontal direction) is 4% or less.

The thermal dimensional change rate from 23°C to 120°C in the TD direction (horizontal direction) is 3% or less, or the thermal dimensional change rate from 23°C to 170°C in the TD direction (horizontal direction) is 4% or less. Effectively suppress wrinkles during the hot pressing step. In this embodiment, the mechanism for more effectively suppressing the generation of wrinkles by using the thermal dimensional change rate in the transverse (TD) direction at the above-mentioned specific value is not yet clear, but it is presumed to be related to the following: For films with small thermal expansion/shrinkage, the thermal expansion/shrinkage of the release film for the process caused by heating/cooling during the process is suppressed.

For the release film of this embodiment, the thermal dimensional change rate from 23°C to 120°C in the TD direction (transverse direction) is preferably 2.5% or less, more preferably 2.0% or less, and even more preferably 1.5% or less . On the other hand, the thermal dimensional change rate from 23°C to 120°C in the TD direction (transverse direction) is preferably -5.0% or more.

The release film for the process of this embodiment preferably has a thermal dimensional change rate from 23°C to 170°C in the TD direction (transverse direction) of 3.5% or less, more preferably 3.0% or less, and even more preferably 2.0% or less . On the other hand, it is preferable that the thermal dimensional change rate of 23°C to 170°C in the TD direction (transverse direction) is -5.0% or more.

The release film for the process of the present invention preferably has a thermal dimensional change rate in the TD direction (transverse direction) and a thermal dimensional change rate in the MD direction (the longitudinal direction when the film is manufactured. Hereinafter, also referred to as "longitudinal direction") The sum is below the specified value.

That is, the sum of the thermal dimensional change rate of 23°C to 120°C in the transverse (TD) direction and the thermal dimensional change rate of 23°C to 120°C in the longitudinal (MD) direction of the release film for the above process is preferably 6 % Or less; On the other hand, the sum of the thermal dimensional change rate from 23°C to 120°C in the TD direction (transverse direction) and the thermal dimensional change rate from 23°C to 120°C in the longitudinal (MD) direction is preferably -5.0 %the above.

In the release film for the manufacturing process of this embodiment, the sum of the thermal dimensional change rate from 23°C to 120°C in the transverse (TD) direction and the thermal dimensional change rate from 23°C to 120°C in the longitudinal (MD) direction is 6 % Or less, can more effectively suppress the generation of wrinkles in the hot pressing step, etc.

In addition, the thermal dimensional change rate of 23°C to 170°C in the transverse (TD) direction and the thermal dimensional change rate of 23°C to 170°C in the longitudinal (MD) direction of the release film of the present invention is preferably 7% or less; on the other hand, the sum of the thermal dimensional change rate of 23°C to 170°C in the TD direction (transverse direction) and the thermal dimensional change rate of 23°C to 170°C in the longitudinal (MD) direction is preferably -5.0 %the above.

In the release film for the process of this embodiment, the sum of the thermal dimensional change rate from 23°C to 170°C in the transverse (TD) direction and the thermal dimensional change rate from 23°C to 170°C in the longitudinal (MD) direction is 7 % Or less, can more effectively suppress the generation of wrinkles in the hot pressing step, etc.

The thickness of the release film for the process of the present invention is not particularly limited as long as it can be made into a film and can be used as a release film, but it is usually 5 to 150 μm, preferably 15 to 100 μm, and more preferably 25 to 80μm.

The above-mentioned at least one side of the release film for the process of the present invention, as long as it satisfies the characteristics (1) The film recovery value R measured by the nanoindentation method at a test temperature of 180°C is R≧70(%), and its material There are no particular restrictions on the like, but it is preferably one containing polyester resin and/or polyamide resin in terms of achieving an appropriate film recovery property value R easily and inexpensively.

(polyester resin)

In the present invention, the preferably usable polyester resin may be a homopolyester or a copolymerized polyester. When a homopolyester is used, it is preferably obtained by polycondensation of an aromatic dicarboxylic acid and an aliphatic diol. Examples of aromatic dicarboxylic acids include terephthalic acid and 2,6-naphthalene dicarboxylic acid. As for the aliphatic diol, ethylene glycol, diethylene glycol, 1,4-cyclohexanedimethanol, and the like can be mentioned. As for the representative polyester, polyethylene terephthalate (PET), polybutylene terephthalate (PBT), etc. can be exemplified. On the other hand, the dicarboxylic acid component used in the copolymerized polyester includes isophthalic acid, phthalic acid, terephthalic acid, 2,6-naphthalenedicarboxylic acid, adipic acid, sebacic acid, One or two or more of acids, hydroxycarboxylic acids (for example, p-hydroxybenzoic acid, etc.). The glycol component includes one or two or more of ethylene glycol, diethylene glycol, propylene glycol, butanediol, 1,4-cyclohexanedimethanol, neopentyl glycol, and the like.

The polyester that can be preferably used in the present invention can be obtained by melt polymerization. However, since the amount of oligomers contained in the raw material can be reduced, the polyester that is chipped after melt polymerization is used for the process. The raw material obtained by solid phase polymerization is particularly good.

The amount of oligomer contained in the polyester is preferably 0.7% by weight or less, more preferably 0.5% by weight or less. When the amount of oligomers of the polyester is small, the amount of oligomers contained in the release film for the process of the present invention can be reduced to a particularly high degree, and even the effect of preventing the precipitation of oligomers on the surface of the film can be exerted to a particularly high degree.

In the case where the release film for the process contains polyester resin, the main purpose is to impart slipperiness, and particles can be blended in the polyester resin-containing layer. The type of particles to be formulated is not particularly limited as long as they are particles that can impart slipperiness. Specific examples include silica, calcium carbonate, magnesium carbonate, barium carbonate, calcium sulfate, calcium phosphate, and magnesium phosphate. , Kaolin, alumina, titanium oxide and other particles. In addition, heat-resistant organic particles described in Japanese Patent Publication No. 59-5216 and Japanese Patent Application Publication No. 59-217755 may also be used. Examples of other heat-resistant organic particles include thermosetting urea resin, thermosetting phenol resin, thermosetting epoxy resin, and benzoguanamine resin. Furthermore, in the polyester manufacturing step, it is also possible to use precipitated particles that partially precipitate and finely disperse a part of a metal compound such as a catalyst.

On the other hand, there is no particular limitation on the shape of the particles used, and any of spherical, massive, rod-shaped, flat-shaped, etc. can be used. In addition, there are no particular restrictions on its hardness, specific gravity, color, etc. These series of particles can be used in combination with more than two types according to needs.

In addition, the average particle size of the particles used is usually 0.01 to 3 μm, preferably 0.01 to 1 μm. When the average particle size is 0.01 μm or more, particle aggregation is suppressed, and sufficient dispersibility can be easily achieved; on the other hand, when the average particle size is 3 μm or less, the surface roughness of the film is suppressed within a certain practical limit.

Furthermore, the content of particles in the polyester layer is usually 0.001 to 5% by weight, preferably in the range of 0.005 to 3% by weight. When the particle content is 0.001% by weight or more, the smoothness of the film is sufficient. On the other hand, when the particle content is 5% by weight or less, sufficient transparency of the film is ensured.

The method of adding particles to the polyester layer is not particularly limited, and conventionally known methods can be adopted. For example, the polyester constituting each layer can be added at any stage, but it is preferable to perform the polycondensation reaction in the esterification stage or after the transesterification reaction is completed.

In addition, a kneading extruder with vents can be used to blend the slurry of particles dispersed in ethylene glycol or water with polyester raw materials, or a kneading extruder can be used to blend the material. Dry the particles and polyester raw materials.

(Polyamide resin)

In the present invention, the preferably usable polyamide resin may be an aliphatic polyamide resin or an aromatic polyamide resin, but more preferably an aliphatic polyamide resin.

Aliphatic polyamide resins can be produced by ring-opening polymerization of internal amines; polycondensation reaction of aliphatic diamine components and aliphatic dicarboxylic acid components; polycondensation of aliphatic amino carboxylic acids, etc.

Examples of aliphatic polyamides obtained by ring-opening polymerization of internal amides include polyamide 6, polyamide 11, polyamide 12, and polyamide 612. Examples of aliphatic polyamides obtained by polycondensation of aliphatic diamine components and aliphatic dicarboxylic acid components include polyamide 66, polyamide 610, polyamide 46, polyamide MXD6, and polyamide 6T , Polyamide 6I and Polyamide 9T, etc.

Among them, polyamide 6 or polyamide 66 is preferred; polyamide 66 is more preferred. This is because these polyamides can easily achieve the above-mentioned property (1), have a high melting point, a high modulus of elasticity, and are excellent in heat resistance and mechanical properties. In addition, since the adhesion to other layers is relatively good, it is also advantageous when forming a laminated film.

The use of polyamide film with high melting point, high elastic modulus, excellent heat resistance and mechanical properties, can effectively suppress wrinkles, cracks, etc., so it is also suitable from the viewpoint of keeping the molded product and pressing equipment clean .

The melting point of the aliphatic polyamide measured by the DSC method is preferably 190°C or higher. By having a melting point above 190°C, it can effectively suppress wrinkles even when supplied to processes such as hot pressing at a higher temperature.

(Other resins)

The aforementioned polyester resin or polyamide resin may further contain other resins than polyester resin or polyamide resin. Preferable examples of other resins include: heat-resistant elastomers with excellent creep resistance to tensile stress and compressive stress at high temperatures, heat-resistant elastomers that are resistant to stress relaxation and have high elastic recovery.

With regard to such heat-resistant elastomers, in consideration of affinity with polyester resins or polyamide resins, thermoplastic polyamide-based elastomers, thermoplastic polyester-based elastomers, and the like are preferred.

Examples of thermoplastic polyamide-based elastomers include block copolymers in which polyamide is used as the hard segment and polyester or polyether is used as the soft segment. Examples of the polyamide constituting the hard segment include: polyamide 6, polyamide 66, polyamide 610, polyamide 612, polyamide 11, and the like. Examples of the polyether constituting the soft segment include: polyethylene glycol (PEG), polypropylene glycol (PPG), polytetramethylene glycol (PTMG), and the like.

Examples of thermoplastic polyester elastomers include: crystalline polymers composed of crystalline aromatic polyester units as hard segments, and amorphous polymers composed of polyether units or aliphatic polyester units As a soft segment block copolymer. Examples of crystalline polymers composed of crystalline aromatic polyester units constituting the hard segment include: polybutylene terephthalate (PBT), polybutylene naphthalate (PBN), and the like. Examples of amorphous polymers composed of polyether units constituting the soft segment include polytetramethylene ether glycol (PTMG) and the like. Examples of amorphous polymers composed of aliphatic polyester units constituting the soft segment include aliphatic polyesters such as polycaprolactone (PCL).

Specific examples of thermoplastic polyester elastomers include: a block copolymer of polybutylene terephthalate (PBT) and polytetramethylene ether glycol (PTMG); polybutylene terephthalate ( PBT) and polycaprolactone (PCL) block copolymer; polybutylene naphthalate (PBN) and aliphatic polyester block copolymer, etc.

The melting point of the thermoplastic polyamide-based elastomer and the thermoplastic polyester-based elastomer as measured by the DSC method is preferably 190°C or higher. Furthermore, even if the melting point of the thermoplastic elastomer does not reach 190°C, the thermoplastic elastomer can still be chemically crosslinked by crosslinking agents and crosslinking aids, or the thermoplastic elastomer can be chemically crosslinked by ultraviolet rays, electron rays, gamma rays, etc. Physically cross-link to improve creep resistance and elastic recovery at high temperatures.

The above-mentioned polyester resin or polyamide resin may further contain well-known additives within a range that does not impair the purpose of the present invention. The additives may be, for example, antistatic agents, antioxidants, heat-resistant stabilizers containing, for example, copper compounds, sliding agents such as calcium stearate and aluminum stearate, heat stabilizers, lubricants, dyes, pigments, etc. Any one or combination of additives.

(Polyester film layer, and polyamide film layer)

In the present invention, the above-mentioned polyester resin or polyamide resin preferably usable is usually used in the form of a stretched or unstretched film. That is, the release film for the process of the present invention preferably has an extended or non-extended polyester film layer, or an extended or non-extended polyamide film layer.

The thickness of the polyester film layer suitable for forming all or part of the release film for the process of the present invention is not particularly limited as long as it is within the range that can be made into a film, but it is usually 12 to 250 μm, preferably 25 to 188 μm, and more Preferably it is in the range of 38 to 125μm. In the case of a stretched polyester film, it is preferably 3 to 50 μm, more preferably 5 to 35 μm, and still more preferably 7 to 20 μm. In the case of a non-stretched polyester film, it is preferably 5 to 80 μm, more preferably 8 to 50 μm, and particularly preferably 10 to 35 μm.

The manufacturing method of the said polyester film is not specifically limited, It can manufacture suitably by a conventionally well-known method, However, when it is a stretched polyester film, it is preferable to manufacture it according to the guidelines described below, for example.

First of all, it is preferable to use the polyester resin described above, and the molten sheet extruded from the mold is cooled and solidified by a cooling roll to obtain an unstretched sheet. At this time, in order to improve the flatness of the sheet, it is necessary to improve the adhesion between the sheet and the rotating cooling drum, and it is preferable to adopt an electrostatic adhesion method and/or a liquid coating adhesion method. Then, the resulting unstretched sheet is preferably stretched in a biaxial direction. In the successive biaxial stretching, the unstretched sheet is stretched in one direction by a roll or a tenter stretcher. The stretching temperature is usually 70 to 120°C, preferably 80 to 110°C, and the stretching ratio is usually 2.5 to 7 times, preferably 3.0 to 6 times. Furthermore, it can extend in a direction perpendicular to the extension direction of the first stage. The stretching temperature is usually 70 to 170°C, and the stretching ratio is usually 3.0 to 7 times, preferably 3.5 to 6 times. Then, continue the heat treatment at a temperature of 180 to 270°C and under tension or under 30% relaxation to obtain a biaxially oriented film. In the above-mentioned stretching, a method of stretching in one direction in two or more stages can be used. At this time, it is preferable to perform so that the stretching magnifications in the two directions finally fall into the above-mentioned ranges.

In addition, regarding the production of the polyester film in this embodiment, the simultaneous biaxial stretching method may also be used. At the same time, the biaxial stretching method is a method in which the aforementioned unstretched sheet is stretched and oriented in the machine direction and the width direction at the same time under a temperature control of usually 70 to 120°C, preferably 80 to 110°C. In terms of stretching magnification, The area magnification is usually 4 to 50 times, preferably 7 to 35 times, and more preferably 10 to 25 times. Then, continue to heat treatment at a temperature of 170 to 250° C. under tension or under 30% relaxation to obtain a stretched oriented film. Regarding the simultaneous biaxial stretching device using the aforementioned stretching method, conventionally known stretching methods such as a screw method, a pantograph method, and a linear drive method can be suitably used.

Furthermore, when the polyester film layer has a coating layer provided on its surface, the stretching step of the polyester film may be performed by a so-called coating stretching method (inline coating) that treats the surface of the film. ). When the coating layer is provided on the polyester film by the coating stretching method, the coating can be applied at the same time as the stretching, and the thickness of the coating layer can be thinned according to the stretching ratio, and the desired coating layer can be produced efficiently The polyester film layer.

The thickness of the polyamide film suitable for forming all or part of the release film for the process of the present invention is not particularly limited as long as the film can be formed, but it is usually 12 to 250 μm, preferably 25 to 188 μm, and more Preferably it is in the range of 38 to 125μm. In the case of a stretched polyamide film, it is preferably 3 to 50 μm, more preferably 5 to 35 μm, and still more preferably 7 to 20 μm. In addition, in the case of a non-extended polyamide film, it is preferably 5 to 80 μm, more preferably 8 to 50 μm, and particularly preferably 10 to 35 μm.

The manufacturing method of the above-mentioned polyamide film is not particularly limited, and can be suitably manufactured by a conventionally known method. In the case of a stretched polyamide film, it is preferably manufactured according to the following description, for example.

The stretched polyamide film can be obtained by, for example, extruding a polyamide resin and forming it into a film shape (protoembryo) and then stretching it. When extruding the polyamide resin, the polyamide resin can be extruded separately, or the polyamide resin can be used by dry blending with other resins such as thermoplastic polyamide elastomers. It can also be used in advance. Those who melt and knead with a single-shaft or twin-shaft extruder.

When manufacturing a biaxially stretched polyamide film, then, it is preferable to stretch the resulting unstretched film in a biaxial direction. In the sequential biaxial stretching, the unstretched sheet is stretched in one direction by a roll or a tenter stretcher. The stretching temperature is usually 30 to 220°C, preferably 50 to 210°C, and the stretching ratio is usually 1.5 to 4.5 times, preferably 2.5 to 4.0 times. Furthermore, it can extend in a direction perpendicular to the extension direction of the first stage. The stretching temperature is usually 30 to 220°C, and the stretching ratio is usually 1.5 to 4.5 times, preferably 2.5 to 4.0 times.

Then, heat treatment is performed at a temperature of 190 to 210° C. to obtain a biaxially stretched polyamide film. In the above-mentioned stretching, a method of stretching in one direction in two or more stages can be used. At this time, it is preferable to perform so that the stretching magnifications in the two directions finally fall into the above-mentioned ranges.

In addition, regarding the production of the polyamide film in this embodiment, the simultaneous biaxial stretching method can be used. At the same time, the biaxial stretching method is a method in which the aforementioned unstretched polyamide film is usually stretched and oriented in the machine direction and the width direction at a temperature of 30 to 220°C, preferably 50 to 210°C, at the same time. As for the magnification, the area magnification is usually measured from 1.5 to 20 times, preferably 5 to 15 times, and more preferably 8 to 12 times. Then, heat treatment is continued at a temperature of 190 to 210° C. to obtain a stretched oriented polyamide film. Regarding the simultaneous biaxial stretching device using the aforementioned stretching method, conventionally known stretching methods such as a screw method, a pantograph method, and a linear drive method can be suitably used.

(Multilayer film)

The process of the present invention may be a single-layer film or a multilayer film with two or more layers as long as it does not violate the purpose of the present invention.

In the case of a multilayer film with more than two layers, at least one surface of at least one layer located on the outermost layer has the following characteristics: (1) The film recovery value R measured by the nanoindentation method at a test temperature of 180°C is R≧ 70(%).

The material of each film constituting the multilayer film with more than two layers is not particularly limited, but it is preferable to have the above (1) film recovery value R measured by the nanoindentation method at a test temperature of 180°C is R≧70( %) at least one layer contains polyester resin and/or polyamide resin.

The layer other than at least one layer having the characteristics of (1) above may be a layer containing polyester resin and/or polyamide resin, or a layer containing resins other than such resins, for example, containing such A layer made of thermoplastic resin other than resin. More specifically, it may be a layer containing, for example, polyphenylene sulfide resin (PPS resin), polysulfide resin (PSF resin), polyether sulfide resin (PES resin), polyether ether ketone resin ( PEEK resin), polyimide resin (PI resin), polyimide imide resin (PAI resin), polyether imide resin (PEI resin), polyethylene naphthalate resin (PEN resin), Polyacetal resin (POM resin), polycarbonate resin (PC resin), polyphenylene ether resin (PPE resin), polybutylene terephthalate resin (PBT resin), polyethylene terephthalate resin (PET resin), cyclic polyolefin resin (COP resin), parallel polystyrene resin (SPS resin), polymethylpentene resin (PMP resin), polymethyl methacrylate resin (PMMA resin), poly Vinyl resin (PE resin), polypropylene resin (PP resin), polystyrene resin (PS resin), polyvinyl acetate resin (PVAc resin), acrylonitrile butadiene styrene resin (ABS resin) or acrylonitrile benzene Vinyl resin (AS resin) or a combination of these, etc.

In the above aspect, the method of laminating two or more resin layers is not particularly limited, and conventionally known methods can be suitably used, such as laminating layers containing polyester resin and/or polyamide resin and layers made of other resins. In the case of the layer, the polyester resin and/or polyamide resin can be co-extruded with other resins to obtain a multilayer film (original embryo film) and stretch it. Alternatively, a stretched film containing a polyester resin and/or a polyamide resin and a stretched film made of other resins obtained separately may be laminated by thermocompression bonding, an adhesive, an adhesive layer, or the like. When you want to co-extrude polyester resin and/or polyamide resin with other resins to obtain the original embryo film, you can use the usual T-die method, cylindrical die method (inflation method) and other film forming methods .

There are no particular restrictions on the adhesive, the adhesive when laminating by the adhesive layer, and the resin used for the adhesive layer, as long as it is a resin that can improve the adhesion between the two layers. Epoxy compounds can be appropriately selected and used. , Isocyanate compounds, acrylic compounds and urethane compounds are representative adhesives. In addition, it is also possible to use polyester resin, polyamide resin, or other resins, or resins the same or similar to the aforementioned plural resins, to be grafted and modified with unsaturated carboxylic acids and/or their anhydrides.之resin.

Regarding the unsaturated carboxylic acid and/or its anhydride that can be used as the grafting monomer, examples include unsaturated compounds having at least one carboxylic acid group with 3 to 20 carbon atoms, and those having at least one carboxylic acid anhydride group. As for the unsaturated compound, the unsaturated group includes a vinyl group, an vinylene group, an unsaturated cyclic hydrocarbon group, and the like. Specifically, examples include: unsaturated monocarboxylic acids such as acrylic acid and methacrylic acid; maleic acid, fumaric acid, itaconic acid, citraconic acid, allyl succinic acid, mesaconic acid, glutaconic acid, Nadic acid TM, methyl nadic acid, tetrahydrophthalic acid, methylhexahydrophthalic acid and other unsaturated dicarboxylic acids; maleic anhydride, itaconic anhydride, citraconic anhydride, allyl succinic anhydride , Glutaredic anhydride, Nadic anhydride TM, methyl Nadic anhydride, tetrahydrophthalic anhydride, methyl tetrahydrophthalic anhydride and other unsaturated dicarboxylic acid anhydrides. These can be used individually by 1 type or in combination of 2 or more types. Among them, maleic acid, maleic anhydride, nadic acid and nadic acid anhydride are preferred.

In addition, the grafting rate is usually less than 20% by weight, preferably 0.1 to 5% by weight, and more preferably 0.5 to 2% by weight. By making the grafting amount within the above-mentioned range, the above-mentioned graft-modified resin can achieve sufficient adhesiveness without impairing the mechanical properties, stability, etc. of the resin. The graft-modified resin can be produced by a known graft polymerization method such as a solution method and a melt-kneading method. Among them, a solution method that can be obtained in the form of a solution is preferred.

The release film for the manufacturing process of the present invention can be easily and fully removed from the copper foil with high roughness even under severe conditions such as hot pressing with higher temperature and pressure than the previous conditions, or hot pressing for a longer time. It can be used in processes involving peeling from metal surfaces with large surface roughness and roughened metal surfaces, such as the manufacturing process of metal/resin laminates such as multilayer printed wiring boards.

When the release film for the process of the present invention is used in the manufacturing process of a metal/resin laminate, the release film for the process of the present invention has (1) measured by the nanoindentation method at a test temperature of 180°C The film recoverability value R is R≧70(%). At least one side of the characteristic is in contact with the roughened metal foil layer, and hot-pressed, and then the release film for the process is peeled from the metal foil layer .

The surface roughness of copper foil layers such as single-sided copper-clad laminate plates and double-sided copper-clad laminate plates, which become the material of multilayer printed wiring boards, usually Rz is 1.0 to 6.5 μm, typically 1.5 to 4.0 μm. The process of the present invention The release film is particularly suitable for peeling from the metal surface of the copper foil layer with such surface roughness.

Hereinafter, taking the manufacture of a 5-layer printed wiring board as an example, the use of the release film for the process of the present invention in the manufacture of a multilayer printed wiring board will be described.

After the copper foil layer 2 and the copper foil layer 3 of the double-sided copper-clad laminate composed of the copper foil layer 2 and the copper foil layer 3 and the hardened glass fiber-epoxy composite insulator 1 are formed with printed wiring patterns, The copper foil layer 2 and the copper foil layer 3 are subjected to blackening treatment, etching treatment using an organic acid-based etching treatment agent, and the like. The etching treatment such as blackening treatment is a treatment to roughen the surface of the copper foil, which can improve the adhesion with the adhesive prepreg.

Then, the adhesive prepreg 6 is used to perform the first multi-layer buildup between the above-mentioned substrate and the copper foil layer 7. At this time, the release film 4 corresponding to the process of the present invention is placed on the outer side of the copper foil layer 2, and the release film 5 corresponding to the process of the present invention is also placed on the outer side of the copper foil layer 7. Heating and pressurizing caused by hot pressing are performed in the direction (Figure 2). The conditions of heating and pressurization are preferably, for example, 190°C, pressure 30 kg/cm ² , and time 40 minutes.

After heating and pressing, the release films 4 and 5 for the process of the present invention can be easily peeled off, and it is also effective to prevent scratches on the surfaces of the copper foil layers 2 and 7 (Fig. 3).

Furthermore, as shown in Figure 4, the laminated board composed of the copper foil layer 11, the copper foil layer 9 and the hardened glass fiber-epoxy composite insulator 10 will be compared with the previously produced copper foil layer 2, copper A three-layer substrate composed of the foil layer 3 and the copper foil layer 7 is subjected to the second multi-layer lamination using the adhesive prepreg 8. The release film 5 and the release film 4 are placed on the outer side of the copper foil layer 11 and the copper foil layer 2, and they are heated and pressurized to perform lamination integration. The heating and pressurizing conditions are preferably set to, for example, 190°C, pressure 30 kg/cm ² , and time 40 minutes.

After heating and pressurizing, the release films 4 and 5 for the process of the present invention can be easily peeled off, and it can also effectively suppress the scratches on the surfaces of the copper foil layers 2 and 11 (Figure 5).

Above, although the manufacture of a 5-layer printed wiring board is taken as an example to illustrate the use of the release film for the process of the present invention in the manufacture of a multilayer printed wiring board, the release film for the process of the present invention is also suitable for use in addition to this Manufacturing of multilayer printed wiring boards with other configurations. In addition, it is not limited to multilayer printed wiring boards, but can also utilize its excellent peelability from rough surfaces and is suitable for use in the manufacture of metal/resin laminates, etc., for heating and pressurizing members with high roughness metal surfaces. In the manufacturing process.

By using the release film for the manufacturing process of the present invention, a multilayer printed wiring board can be manufactured with high quality, low cost, and high production efficiency. This kind of multilayer printed wiring board can be suitable for the mounting of electronic parts, and it is suitable for mounting on electrical and electronic equipment used in information processing equipment, displays, communication equipment, and transportation equipment.

(Example)

Hereinafter, the present invention will be explained in more detail with examples, but the present invention is not limited thereto.

In the following examples/comparative examples, the evaluation of physical properties/characteristics is performed by the following methods.

(Film recovery value R obtained by nanoindentation at 180℃)

At the measurement temperature of 180℃, use a nanoindenter to press a triangular pyramid diamond indenter (Berkovich indenter) with an edge angle of 115° into the film measurement surface with a maximum indentation load of 2mN, and then remove the load to measure the maximum indentation load. (2mN) press-in depth, after unloading (0mN) press-in depth. The ratio of the indentation depth at the maximum indentation load (2mN) to the indentation depth after the load is unloaded (0mN) is calculated according to the following formula as the film restorability value R.

Film restorability value R=Press-in depth after unloading/Press-in depth at maximum press-in load

(Hardness obtained by nanoindentation at 180℃)

Calculate according to the following formula. At a measurement temperature of 180°C, a triangular pyramid diamond indenter (Berkovich indenter) with an edge angle of 115° is pressed into the measuring surface of the film with a maximum indentation load of 2mN using a nanoindenter, and the load is removed The maximum press-in load (F _max ) and press-in depth (h _c ) at the time.

Hardness H=F _max /(23.96×h _c ² )

(Releasability)

The process release film was used in the manufacture of hot-pressed copper-clad laminates. After the pressure was released and cooled, the process release film was subjected to tension by hand to try to peel. The peelability was evaluated based on the following criteria.

○: When tension is applied after the pressure is released, the release film for the process is easily peeled from the surface of the copper foil layer.

×: The release film for the process is closely attached to the surface of the copper foil layer and cannot be peeled off by hand.

[Example 1]

A biaxially stretched PET (polyethylene terephthalate) film (manufactured by UNITIKA Co., Ltd., product name: EMBLET PET12) with a film thickness of 12 μm was used as a release film for the process.

The recoverability value R of the biaxially stretched PET film measured by the nanoindentation method at a test temperature of 180°C is 70.8%, and the hardness H measured by the nanoindentation method at a test temperature of 180°C is 111.0MPa .

Use of copper-clad laminate: FR4 (glass epoxy/copper foil 18μm double-sided, 250×200mm×0.2mmt), and organic acid etchant (manufactured by MEC Co., Ltd., product name: MEC V-Bond BO -7790V) A copper-clad laminate that has been etched so that the surface roughness of the copper foil becomes Ra: 2μm. Between the copper-clad laminated board and the copper-clad laminated board, the resin layer (following the prepreg) is superimposed, and the release film for the process is further arranged on the top and bottom, and the temperature is 180°C, 25kg, 60°C. Hot press in minutes to confirm the peelability of the film from the copper foil.

When the pressure is released and tension is applied by hand after cooling, the release film for the process is easily peeled from the copper foil layer.

[Example 2]

A biaxially stretched nylon film (manufactured by Xingren Film & Chemicals Co., Ltd., product name: BONYL RX) with a film thickness of 15 µm was used as a release film for the process.

The recoverability value R of the biaxially stretched nylon membrane measured by the nanoindentation method at a test temperature of 180°C is 77.7%, and the hardness H measured by the nanoindentation method at a test temperature of 180°C is 58.7MPa .

It was used in the manufacturing process of the laminated board under the same conditions as in Example 1.

When the pressure is released and tension is applied after cooling, the release film is easily peeled from the copper foil layer.

[Example 3]

Use commercially available PBT (polybutylene terephthalate) resin (Tm=224°C, IV=1.2, [manufactured by Mitsubishi Engineering-Plastics Co., Ltd., trade name: NOVADURAN 5020]), with a screw diameter of 40 mm The T-die film forming machine of the extruder, under the conditions of resin temperature of 250℃, chilled roll temperature of 80℃, and air chamber static pressure of 440mmHG, produces a 20μm non-stretched PBT film and uses it as a process Use release film.

The film recovery value R of the non-stretched PBT film measured by the nanoindentation method at a test temperature of 180°C is 78.3%, and the hardness H measured by the nanoindentation method at the test temperature of 180°C is also 68.0MPa.

It was used in the manufacturing process of the laminated board under the same conditions as in Example 1.

When the pressure is released and tension is applied after cooling, the release film is easily peeled from the copper foil layer.

[Example 4]

A non-stretch nylon film (manufactured by TORAY ADVANCED FILM Co., Ltd., product name: Rayfan NO1401) with a film thickness of 20 μm was used as a release film for the process.

The film recovery value R of the non-stretched nylon membrane measured by the nanoindentation method at a test temperature of 180°C is 76.6%, and the hardness H measured by the nanoindentation method at the test temperature of 180°C is also 81.9MPa.

It was used in the manufacturing process of the laminated board under the same conditions as in Example 1.

When tension is applied after the pressure is released, the release film is easily peeled from the copper foil layer.

[Comparative Example 1]

A biaxially stretched polyethylene terephthalate (PET) film (manufactured by TORAY ADVANCED FILM Co., Ltd., product name: Lumirror F865) with a film thickness of 16 μm was used as a release film for the process.

The recoverability value R of the biaxially stretched PET film measured by the nanoindentation method at a test temperature of 180°C is 68.5%, and the hardness H measured by the nanoindentation method at a test temperature of 180°C is 34.7MPa .

It was used in the manufacturing process of the laminated board under the same conditions as in Example 1.

Although tension was applied after the pressure was released, the release film adhered to the surface of the copper foil layer and could not be peeled off by hand.

The results are summarized in Table 1.

(Industrial availability)

The release film for the manufacturing process of the present invention can be easily and fully peeled off from the metal surface with high roughness even after the severe manufacturing process. Therefore, it is used in various fields of industry, especially in the manufacturing of multilayer printed wiring boards. It has a high degree of availability in the electrical and electronic industry.

1, 10‧‧‧Glass fiber-epoxy resin composite insulator

2, 3, 7, 9, 11‧‧‧Copper foil layer

4、5‧‧‧Release film

6, 8‧‧‧Next to prepreg

Claims (8)

A method for manufacturing a metal/resin laminate, comprising: contacting a metal foil layer subjected to roughening treatment on at least one side of a release film for the process with the following characteristics (1), and performing hot pressing; And the step of peeling the release film for the process from the metal foil layer, wherein the release film for the process contains a thermoplastic resin, and at least one side has the following (1) characteristics: (1) The film restorability value R measured by the nanoindentation method at a test temperature of 180℃ is: R≧70(%). The aforementioned film restorability value R is a triangular pyramid diamond with an edge angle of 115° using a nanoindenter The indenter is pressed into the measuring surface of the film with a maximum indentation load of 2mN and then the load is removed. The ratio of the indentation depth at the measured maximum indentation load (2mN) to the indentation depth after the load is unloaded (0mN), Calculated according to the following formula, film recovery value R(%)=(indentation depth after unloading/indentation depth at maximum indentation load)×100. The manufacturing method described in item 1 of the scope of the patent application, wherein the release film for the manufacturing process contains a thermoplastic resin, and at least one side has the following (2) characteristics: (2) at a test temperature of 180°C The hardness H measured by the nanoindentation method is: 130≧H≧40 (MPa). The aforementioned hardness H is determined by using a nanoindenter to indent a triangular pyramid diamond indenter with an edge angle of 115° at the maximum load. _{The maximum indentation load (F max} ) and the indentation depth (h _c ) when the load is unloaded after 2mN is pressed into the measuring surface of the film, calculated according to the following formula, hardness H=F _max /(23.96×h _c ² ). According to the manufacturing method described in claim 2, wherein, in the release film for the process, at least one side having the characteristics (1) and at least one side having the characteristics (2) are the same. The manufacturing method according to any one of items 1 to 3 in the scope of the patent application, wherein the release film for the process contains a polyester resin and/or a polyamide resin. The manufacturing method according to any one of items 1 to 3 in the scope of the patent application, wherein the release film for the process has an extended or non-extended polyester film layer, or an extended or non-extended polyamide膜层。 Film layer. According to the manufacturing method described in any one of items 1 to 3 in the scope of the patent application, the metal foil layer has a metal surface with a surface roughness Rz of 1.0 to 6.5 μm. The manufacturing method according to any one of items 1 to 3 in the scope of the patent application, wherein the metal/resin laminate system multilayer printed wiring board. An electrical and electronic device having a multilayer printed circuit board manufactured by the manufacturing method described in item 7 of the scope of patent application.

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