TW202000472A - Laminate film and method for manufacturing laminate structure - Google Patents

Abstract

Provided is a laminate film in which it is possible to suppress spontaneous peeling of a base material film from an insulating resin layer during curing, and in which it is possible to suppress peeling defects in the base material film when the base material film is being peeled from the insulating resin layer after curing. The laminate film according to the present invention comprises a base material film and an insulating resin layer laminated on the obverse surface of the base material film, the laminate film being such that: at one end side of the laminate film, an end surface of the base material film juts farthest outward relative to an end surface of the insulating resin layer; and Y/X is 0.5-15, where X gf/cm is the peel strength of the base material film relative to the insulating resin layer, and Y mm is the distance by which the base material film juts out at the one end side.

Description

Laminated film and method for manufacturing laminated structure

The present invention relates to a laminated film provided with a base film and an insulating resin layer. In addition, the present invention relates to a method for manufacturing a laminated structure using the above-mentioned laminated film.

Previously, various resin compositions have been used to obtain electronic components such as semiconductor devices, laminates, and printed wiring boards. For example, in a multilayer printed wiring board, a resin composition is used in order to form an insulating layer for insulating interlayers inside, or to form an insulating layer located in a surface layer portion. In order to form the said insulating layer, the laminated film provided with a base film and an insulating resin layer is used. The insulating resin layer is obtained by forming the resin composition into a film.

In the manufacturing method of a multilayer printed wiring board, etc., there is a case where the insulating resin layer is cured or pre-cured in a state where the base film and the insulating resin layer are laminated to form an insulating layer (hardened layer or pre-cured layer) ), and then, the substrate film is peeled off from the cured or pre-cured insulating resin layer.

An example of such a manufacturing method is described in Patent Documents 1 and 2 below.

The following Patent Document 1 discloses a method for manufacturing a multilayer printed wiring board, which includes the steps of: irradiating the insulating layer from the plastic film with the insulating layer and the plastic film on both sides or a single area of the circuit board A carbon dioxide gas laser forms a non-through hole with a tip diameter of 100 μm or less. The insulating layer contains 35% by mass or more of an inorganic filler.

The following Patent Document 2 discloses a method of manufacturing a circuit board having the following steps (A) to (F). (A) Step of laminating a resin sheet with a support including a plastic film support and a resin composition layer bonded to the plastic film support on the inner substrate in such a manner that the resin composition layer is bonded to the inner substrate . Step (B), which is to thermally harden the resin composition layer to form an insulating layer, and the adhesion strength between the insulating layer and the plastic film support is 2 gf/cm to 18 gf/cm. In step (C), a laser is irradiated from the plastic film support to form a via hole with a tip diameter of 40 μm or less in the insulating layer. Step (D), which carries out the scum removal treatment. (E) Step, which peels off the plastic film support. Step (F), which forms a conductor layer on the surface of the insulating layer. [Prior Technical Literature] [Patent Literature]

[Patent Literature 1] WO2009/066759A1 [Patent Document 2] Japanese Patent Laid-Open No. 2015-211085

[Problems to be solved by the invention]

In the previous laminated film (laminated film provided with a base film and an insulating resin layer) as described in Patent Documents 1 and 2, the insulating resin layer is cured with the base film and the insulating resin layer laminated In this case, the base film may naturally peel from the insulating resin layer during curing. When the above natural peeling occurs, the insulating resin layer may be unevenly cured. In addition, in the previous laminated films described in Patent Documents 1 and 2, when the base film is peeled from the insulating resin layer after curing, the base film and the insulating resin layer may not be peeled off satisfactorily and the base film rupture.

An object of the present invention is to provide a laminated film that can suppress the natural peeling of the base film from the insulating resin layer during curing, and can suppress the peeling failure of the base film when the base film is peeled from the insulating resin layer after curing. In addition, an object of the present invention is to provide a method for manufacturing a laminated structure using the above-mentioned laminated film. [Technical means to solve the problem]

According to a broad aspect of the present invention, there is provided a laminated film including a base film and an insulating resin layer laminated on the surface of the base film, and on one end side of the laminated film, with respect to the end surface of the insulating resin layer , The end surface of the base film protrudes to the maximum extent, the peeling strength of the base film with respect to the insulating resin layer is set to X gf/cm, and the extension distance of the base film on the one end side is When it is set to Y mm, Y/X is 0.5 or more and 15 or less.

In a specific aspect of the laminated film of the present invention, the above X is 0.3 or more and 9 or less.

In a specific aspect of the laminated film of the present invention, the above Y is 0.5 or more and 20 or less.

In a specific aspect of the laminated film of the present invention, the thickness of the base film is 25 μm or more.

In a specific aspect of the laminated film of the present invention, the arithmetic average roughness Ra of the surface of the base film on the side of the insulating resin layer is 5 nm or more and less than 400 nm.

In a specific aspect of the laminated film of the present invention, the insulating resin layer contains an epoxy compound, an inorganic filler, and a hardener.

In a specific aspect of the laminated film of the present invention, the hardener contains a phenol compound, a cyanate compound, a maleimide compound or an active ester compound.

In a specific aspect of the laminated film of the present invention, on the other end side of the laminated film opposite to the one end, the end surfaces of the base film and the insulating resin layer are aligned, or on the one end side of the laminated film and the The two opposite ends of the one end are opposite to the end face of the insulating resin layer, the end face of the base material film extends outward, and the extension distance of the base material film of the other end side is smaller than that of the one end side The extension distance of the base film.

In a specific aspect of the laminated film of the present invention, the minimum melt viscosity of the insulating resin layer in a temperature range of 60°C or more and 180°C or less is 5 mPa·s or more.

In a specific aspect of the laminated film of the present invention, the insulating resin layer is preferably used to form an insulating layer on a multilayer printed wiring board.

According to a broad aspect of the present invention, there is provided a method for manufacturing a laminated structure, comprising: a laminating step, using the laminated film, in a state where the base film and the insulating resin layer are laminated, the insulating resin layer The surface area layer on the opposite side of the base material film is on the object to be laminated having a metal layer on the surface; and a via hole forming step from the base material film side with the base material film and the insulating resin layer laminated The insulating resin layer is irradiated with laser light to form via holes.

In a specific aspect of the method for manufacturing a laminated structure of the present invention, a curing step for curing the insulating resin layer is provided between the laminating step and the via hole forming step. [Effect of invention]

The laminated film of the present invention includes a base film and an insulating resin layer laminated on the surface of the base film. In the laminated film of the present invention, on one end side of the laminated film, the end surface of the base film protrudes to the outside with respect to the end surface of the insulating resin layer. In the laminated film of the present invention, when the peel strength of the base film with respect to the insulating resin layer is X gf/cm, and the extension distance of the base film on the one end side is Y mm, Y /X is 0.5 or more and 15 or less. Since the laminated film of the present invention has the above-mentioned configuration, it is possible to suppress the natural peeling of the base film from the insulating resin layer during curing, and to suppress the peeling failure of the base film when the base film is peeled from the insulating resin layer after curing.

Hereinafter, the present invention will be described in detail.

The laminated film of the present invention includes a base film and an insulating resin layer laminated on the surface of the base film.

The laminated film of the present invention has the following configuration (0).

(0) On one end side of the laminated film, the end surface of the base film protrudes to the outside with respect to the end surface of the insulating resin layer to the greatest extent. (Hereinafter, sometimes referred to as a laminated film (0))

In the laminated film of the present invention, the extension distance of one end side is the largest among all the ends.

In the laminated film of the present invention, when the peel strength of the base film with respect to the insulating resin layer is X gf/cm, and the extension distance of the base film on the one end side is Y mm, Y /X (the ratio of Y to X) is 0.5 or more and 15 or less.

In the laminated film of the present invention, the extension distance of one end side is the largest among all the ends, so the above-mentioned distance Y is the distance of the greatest extension.

Since the laminated film of the present invention has the above-mentioned configuration, it is possible to suppress the natural peeling of the base film from the insulating resin layer during curing, and to suppress the peeling failure of the base film when the base film is peeled from the insulating resin layer after curing. The laminated film of the present invention can suppress cracking of the base film when the base film is peeled from the insulating resin layer after curing.

In addition, the above-mentioned hardening time and after the hardening also include the pre-hardening time and the post-hardening time.

In the laminated film of the present invention, since one end side of the base film protrudes, the base film can be peeled from the insulating resin layer from one end side after curing.

Since the laminated film of the present invention has the above-mentioned structure, it is possible to suppress the natural peeling of the base film from the insulating resin layer during pre-curing, and it is also possible to suppress the peeling of the base film from the insulating resin layer after pre-curing. bad.

In addition, since the laminated film of the present invention has the above-mentioned structure, it is possible to suppress the natural peeling of the base film from the insulating resin layer when the substrate is transported or when laser irradiation for forming a via hole is performed.

Examples of the structure included in the above structure (0) include the following structure (1) and the following structure (2). The laminated film of the present invention may also have the following configuration (1) or the following configuration (2). The laminated film of the present invention may have the following structure (1) or the following structure (2).

(1) On one end side of the laminated film, the end surface of the base film protrudes to the outside with respect to the end surface of the insulating resin layer to the greatest extent. On the other end side of the laminated film opposite to the one end, the end surfaces of the base film and the insulating resin layer are aligned. (Hereinafter, sometimes referred to as a laminated film (1))

(2) On one end side of the laminated film, the end surface of the base film protrudes to the outside with respect to the end surface of the insulating resin layer to the greatest extent. On the other end side of the laminated film opposite to the one end, the end face of the base film protrudes outward with respect to the end face of the insulating resin layer. The extension distance of the base film on the other end side is equal to or shorter than the extension distance of the base film on the one end side or less than the extension distance of the base film on the one end side. (Hereinafter, sometimes referred to as a laminated film (2))

The one end and the other end refer to opposite ends in the laminated film.

In the above configuration (2), the distance from which the base film on the other end side protrudes is the same as the distance from which the base film on the one end side protrudes, or is smaller than the distance that the base film on the one end side protrudes .

In all the ends of the laminated film, when the base film is aligned with the end surface of the insulating resin layer, that is, in the case of the previous laminated film, the base film is easily peeled off from the insulating resin layer when cured. Moreover, in the case of the previous laminated film, the base film is likely to crack when the base film is peeled from the insulating resin layer after curing. Therefore, the previous laminated film is difficult to suppress the natural peeling of the base film from the insulating resin layer during curing, and it is difficult to suppress the cracking of the base film when the base film is peeled from the insulating resin layer after curing.

From the viewpoint of further suppressing the natural peeling of the base film from the insulating resin layer during curing, and further suppressing the peeling defects of the base film when peeling the base film from the insulating resin layer after curing, the laminated film (1) and the laminated film Among (2), the laminated film (1) is preferable.

The laminated film (2) preferably has the following structure (2A).

(2A) On one end side of the laminated film, the end surface of the base film protrudes to the outside with respect to the end surface of the insulating resin layer to the greatest extent. On the other end side of the laminated film opposite to the one end, the end face of the base film protrudes outward with respect to the end face of the insulating resin layer. The extension distance of the base film on the other end side is smaller than the extension distance of the base film on the one end side. (Hereinafter, sometimes referred to as a laminated film (2A))

In the laminated film of the present invention, the peel strength of the base film with respect to the insulating resin layer is X gf/cm, and the extension distance of the base film on the one end side is Y mm. Therefore, in the build-up films (2) and (2A), the above Y represents a greater distance of the end surfaces of the base film extending outward from the end surfaces of the insulating resin layer.

From the viewpoint of suppressing the natural peeling of the base film from the insulating resin layer during curing and suppressing the peeling failure of the base film when the base film is peeled from the insulating resin layer after curing, Y/X (Y to X ratio ) Is 0.5 or more and 15 or less. If the above-mentioned Y/X is less than 0.5, the base film easily peels off from the insulating resin layer during curing. If the above Y/X exceeds 15, the base film and the insulating resin layer cannot be peeled off well when the base film is peeled from the insulating resin layer after curing, and the base film is easily broken.

From the viewpoint of further suppressing the natural peeling of the base film from the insulating resin layer during curing, and further suppressing the peeling defect of the base film when peeling the base film from the insulating resin layer after curing, the above Y/X is preferably 0.7 The above is more preferably 1.0 or more, and preferably 13 or less, and more preferably 11 or less.

From the viewpoint of further suppressing the natural peeling of the base film from the insulating resin layer during curing, and further suppressing the peeling defects of the base film when peeling the base film from the insulating resin layer after curing, the above X is preferably 0.3 or more, And it is preferably 9 or less.

From the viewpoint of further suppressing the natural peeling of the base film from the insulating resin layer during curing and further suppressing the peeling failure of the base film when peeling the base film from the insulating resin layer after curing, the above Y is preferably 0.5 or more, And it is preferably 20 or less.

The peel strength (ie, X) of the base film with respect to the insulating resin layer is preferably 0.3 gf/cm or more, more preferably 0.5 gf/cm or more, and preferably 9 gf/cm or less, more preferably 7 Below gf/cm. If the peel strength is above the lower limit or more, the substrate film can be naturally peeled from the insulating resin layer when the substrate is transported, and the substrate film can also be inhibited from self-insulating even during laser irradiation for forming via holes The resin layer peels off naturally. If the peel strength is equal to or lower than the upper limit, the peel strength can be increased, and the roughness after the removal of the dross can be suppressed from increasing.

The peel strength of the base film with respect to the insulating resin layer can be measured using a tensile tester ("AG-5000B" manufactured by Shimadzu Corporation) at a crosshead speed of 5 mm/min.

The extension distance (ie, Y) of the base film on the one end side is preferably 0.5 mm or more, more preferably 1 mm or more, and preferably 20 mm or less, more preferably 15 mm or less. If the extension distance of the base film on the one end side is more than the above lower limit, an automatic peeling device can be used to peel the base film from the insulating resin layer after curing, and when the laminated film is manufactured, the laminated film When one end or the other end is cut, it can suppress the cracking or cracking of the insulating resin layer. If the extension distance of the base film on the one end side is equal to or less than the upper limit, the base film can be naturally peeled from the insulating resin layer during the transport of the build-up film, and the manufacturing cost can be suppressed.

Regarding the above-mentioned laminated film, it is preferable to deposit a protective film on the surface of the insulating resin layer opposite to the side of the base film.

As a method of extending the end face of the base material film outward from the end face of the insulating resin layer on one end side of the laminated films (0) and (1), the lamination of the base material film and the insulation The method of staggering the end faces of the resin layer.

As a method of extending the end surface of the base material film outward from the end surface of the insulating resin layer on both the one end side of the build-up film (2) and the other end side opposite to the one end, A method of staggering the end faces when stacking the base film and the insulating resin layer. In the laminated film (2), the offset distance of the end face is adjusted.

As a method of aligning the end surfaces of the base material, the insulating resin layer, and the protective film on the other end side of the laminated film (1) opposite to the one end, the following method may be mentioned. A method of aligning the end surfaces when laminating the base film and the insulating resin layer; and a laminate of the base film and the insulating resin layer, or a laminate of the base film, the insulating resin layer, and the protective film The method of cutting long bars.

As a method of making the extension distance of the base material film on the other end side of the build-up film (2A) smaller than the extension distance of the base material film on the one end side, the following method may be mentioned. When laminating the base film and the insulating resin layer, a method of making the extension distance of the base film on the other end side smaller than the extension distance of the base film on the one end side. A method for cutting a base film in a base film and an insulating resin layer into long strips. Method for cutting the base film and the protective film among the base film, the insulating resin layer and the protective film into long strips.

The method for manufacturing a laminated film of the present invention preferably has the following structure (A) or (B). The manufacturing methods (A) and (B) are methods for manufacturing the laminated film (0). The manufacturing method (A) is a manufacturing method of a laminated film (1), and the manufacturing method (B) is a manufacturing method of a laminated film (2). The manufacturing method of the laminated film (1) preferably has the following structure (A). The manufacturing method of the laminated film (2) preferably has the following structure (B).

(A) The manufacturing method of the laminated film (1) includes the first step: disposing the insulating resin on the surface of the base film so that the end face of one end side of the insulating resin layer extends outward from the end surface of the base film Floor. The method for manufacturing the build-up film (1) preferably includes a second step: disposing a protective film on the surface of the insulating resin layer opposite to the base film side. In the manufacturing method of the build-up film (1), one end side of the build-up film corresponding to the one end of the insulating resin layer, with respect to the end face of the insulating resin layer, the end face of the base film extends outward Laminated film. In the manufacturing method of the build-up film (1), a build-up film (1) obtained on the other end side of the build-up film opposite to the one end and in which the base film and the end surface of the insulating resin layer are aligned.

(B) The manufacturing method of the laminated film (2) includes the first step: disposing the insulating resin on the surface of the base material film so that the end surface of one end side of the insulating resin layer extends outward from the end surface of the base material film Floor. In the first step, it is preferable that the end surface of the base film protrudes outward with respect to one end side of the insulating resin layer and the other end side opposite to the one end on the surface of the base film Configure insulating resin layer. The manufacturing method of the build-up film (2) preferably includes a second step: disposing a protective film on the surface of the insulating resin layer opposite to the base film side. In the manufacturing method of the build-up film (2), obtained on both the one end side of the build-up film and the other end side opposite to the one end, the end face of the base film protrudes outward with respect to the end face of the insulating resin layer Laminated film (2). In the manufacturing method of the build-up film (2), a build-up film (2) in which the extension distance of the base film on the other end side is smaller than the extension distance of the base film on the one end side is obtained.

The manufacturing method (A) of the laminated film of the present invention preferably further includes a third step: after the second step, on the other end side of the insulating resin layer opposite to the one end, the base film, the above The end surfaces of the insulating resin layer and the protective film are aligned. In the manufacturing method (A) of the laminated film of the present invention, in the second step, the base film, the insulating resin layer and the above may be formed on the other end side of the insulating resin layer opposite to the one end The end faces of the protective film are aligned.

The manufacturing method (B) of the laminated film of the present invention preferably further includes a third step: after the second step, on the other end side of the insulating resin layer opposite to the one end, the base on the other end side The projecting distance of the material film is smaller than the projecting distance of the base film on the one end side.

From the viewpoint of further flattening the end surface on the other end side of the laminated film (1), the extension distance of the base film on the other end side of the laminated film (2) is further smaller than the extension of the base film on the one end side From the standpoint of distance, it is preferable to cut the long bar in the following manner. Preferably, the insulating resin layer is cut into long strips in the third step. Preferably, in the third step, the base film, the insulating resin layer, and the protective film are cut into long strips.

In the laminated film of the present invention, a adherend such as a metal layer is usually laminated on the surface of the insulating resin layer (for example, a laminate of a substrate and a metal wiring, etc.). When the laminated film includes a protective film, the protective film is peeled off when the insulating resin layer is used in the laminated film. After the protective film is peeled off, the surface of the above-mentioned insulating resin layer is usually laminated with an adherend such as a metal layer (for example, a laminate of a substrate and a wiring as a metal, etc.).

Hereinafter, the present invention will be specifically described with reference to the drawings.

Fig. 1 is a cross-sectional view showing a laminated film according to a first embodiment of the present invention. Fig. 1 is a cross-sectional view showing the above-mentioned laminated film (1).

The laminated film 1 has one end 1a and the other end 1b opposite to the one end 1a. One end 1a and the other end 1b of the laminated film 1 are the ends on opposite sides.

The laminated film 1 includes a base film 2 and an insulating resin layer 3. The insulating resin layer 3 is laminated on the first surface 2a of the base film 2.

In the direction connecting the one end 1 a and the other end 1 b of the laminated film 1, the size of the base film 2 is larger than the size of the insulating resin layer 3. In the direction connecting the one end 1 a and the other end 1 b of the laminated film 1, the size of the insulating resin layer 3 is smaller than the size of the base film 2.

On one end 1 a side of the laminated film 1, the end surface of the base film 2 protrudes outward with respect to the end surface of the insulating resin layer 3. At one end 1a of the laminated film 1, the base film 2 and the end surface of the insulating resin layer 3 are not aligned. On the first end 1 a side of the laminated film 1, there is a portion where the insulating resin layer 3 is not laminated on the first surface 2 a of the base film 2.

On the one end 1a side of the laminated film 1, the projecting distance of the base film 2 is Y mm.

On the other end 1b side of the laminated film 1, the base film 2 and the end surface of the insulating resin layer 3 are aligned.

2 is a cross-sectional view showing a laminated film according to a second embodiment of the present invention. Fig. 2 is a cross-sectional view showing the above-mentioned laminated film (2).

The laminated film 1A has one end 1Aa and the other end 1Ab opposite to the one end 1Aa. One end 1Aa and the other end 1Ab of the laminated film 1A are the ends on opposite sides.

The laminated film 1A includes a base film 2A and an insulating resin layer 3A. The insulating resin layer 3 is laminated on the first surface 2Aa of the base film 2A.

In the direction connecting the one end 1Aa and the other end 1Ab of the laminated film 1A, the size of the base film 2A is larger than the size of the insulating resin layer 3A. In the direction connecting the one end 1Aa and the other end 1Ab of the laminated film 1A, the size of the insulating resin layer 3A is smaller than the size of the base film 2A.

On one end 1Aa side of the laminated film 1A, the end surface of the base film 2A protrudes outward with respect to the end surface of the insulating resin layer 3A. At one end 1Aa of the laminated film 1A, the end surface of the base film 2A and the insulating resin layer 3A are not aligned. On the first end 1Aa side of the laminated film 1A, there is a portion where the insulating resin layer 3A is not laminated on the first surface 2Aa of the base film 2A.

On the other end 1Ab side of the laminated film 1A, the end surface of the base film 2A protrudes outward with respect to the end surface of the insulating resin layer 3A. At the other end 1Ab of the laminated film 1A, the end surfaces of the base film 2A and the insulating resin layer 3A are not aligned. On the other end 1Ab side of the laminated film 1A, there is a portion where the insulating resin layer 3A is not laminated on the first surface 2Aa of the base film 2A.

The projecting distance of the base film 2A on the other end 1Ab side of the laminated film 1A is smaller than the projecting distance of the base film 2A on the one end 1Aa side.

On the side of one end 1Aa of the laminated film 1A, the projecting distance of the base film 2A is Y mm.

The laminated film preferably has an MD (Machine Direction, vertical) direction and a TD (Transverse Direction, horizontal) direction. The MD direction is the traveling direction of the laminated film when the laminated film is manufactured, and is, for example, the longitudinal direction. The TD direction is a direction orthogonal to the traveling direction of the laminated film when manufacturing the laminated film, and is a direction orthogonal to the thickness direction of the laminated film. When the laminated film has an MD direction and a TD direction, the TD direction is the width direction. The one end and the other end of the laminated film are preferably opposite side ends of the laminated film in the width direction.

In the direction of the laminated film of the present invention connecting the one end and the other end, the size of the base film is set to W ₁ mm, and the size of the insulating resin layer is set to W ₂ mm. In the laminated film of the present invention, W ₁ is usually larger than W ₂ . The laminated film of the present invention usually satisfies W ₁ >W ₂ .

W ₂ /W ₁ (the ratio of the size of the insulating resin layer to the size of the base film) is preferably 0.9 or more, more preferably 0.92 or more, still more preferably 0.94 or more, and particularly preferably 0.96 or more. W ₂ /W ₁ (the ratio of the size of the insulating resin layer to the size of the base film) is preferably 0.999 or less, more preferably 0.998 or less, further preferably 0.997 or less, and particularly preferably 0.996 or less. If W ₂ /W ₁ is more than the above lower limit, an automatic peeling device can be used to peel off the base film from the insulating resin layer after curing, and when manufacturing the laminated film, when one end or the other end of the laminated film is cut It can suppress the cracking or cracking of the insulating resin layer. When W ₂ /W ₁ is equal to or less than the above upper limit, the base film can be suppressed from peeling off from the insulating resin layer naturally during the transport of the laminated film, and the base film can be used efficiently, so that the manufacturing cost can be suppressed.

Hereinafter, the details of each layer constituting the laminated film of the present invention will be described.

(Substrate film) Examples of the base film include metal foils, polyester resin films such as polyethylene terephthalate films and polybutylene terephthalate films, olefin resin films such as polyethylene films and polypropylene films, and Polyimide film, etc. The surface of the above-mentioned base film can also be demolded if necessary. The base film may be a metal foil or a resin film. The base film is preferably a resin film. When a metal foil is used as the base film, the metal foil is preferably a copper foil.

From the viewpoint of further suppressing peeling defects, the base film is preferably subjected to release treatment. From the viewpoint of further suppressing the natural peeling accompanying the movement of polysiloxane, the above-mentioned release treatment is preferably a non-mobile release treatment of polysiloxane. Furthermore, the non-mobile silicone mold release treatment means a mold release treatment that does not contain silicone, or a mold release treatment that is performed in such a way that the silicone does not move to the insulating resin layer side.

From the viewpoint of improving the handleability of the laminated film and improving the lamination of the insulating resin layer, the thickness of the base film is preferably 25 μm or more, more preferably 30 μm or more, and preferably 75 less than 50 μm, more preferably 50 μm or less. From the viewpoint of further suppressing natural peeling, the thickness of the base film is preferably 75 μm or less, and more preferably 50 μm or less. From the viewpoint of further suppressing peeling defects, the thickness of the base film is preferably 25 μm or more.

The arithmetic mean roughness Ra of the surface of the base film on the side of the insulating resin layer is preferably 5 nm or more, more preferably 10 nm or more, and preferably 400 nm or less, more preferably less than 400 nm, and further It is preferably below 300 nm. If the arithmetic average roughness is above the lower limit and below the upper limit, the natural peeling of the base film from the insulating resin layer during curing can be further suppressed, and further suppressed when the base film is peeled from the insulating resin layer after curing. Poor peeling.

The above arithmetic average roughness Ra is measured using a non-contact surface roughness meter in the VSI (Vertical Scanning Interferometry) contact mode, with a 50x lens and the measurement range set to 95.6 μm×71.7 μm .

(Insulating resin layer) The insulating resin layer is laminated on the surface of the base film. The insulating resin layer preferably contains the following epoxy compound, the following inorganic filler, and the following hardener.

[Epoxy compound] The insulating resin layer preferably contains an epoxy compound. As the above-mentioned epoxy compound, previously known epoxy compounds can be used. The above-mentioned epoxy compound refers to an organic compound having at least one epoxy group. Only one kind of the epoxy compound may be used, or two or more kinds may be used in combination.

Examples of the epoxy compound include bisphenol A epoxy compounds, bisphenol F epoxy compounds, bisphenol S epoxy compounds, phenol novolac epoxy compounds, biphenyl epoxy compounds, and Phenolic novolac epoxy compound, biphenol epoxy compound, naphthalene epoxy compound, fusel epoxy compound, phenol aralkyl epoxy compound, naphthol aralkyl epoxy compound, dicyclopentane Ethylene-type epoxy compounds, anthracene-type epoxy compounds, epoxy compounds with adamantane skeleton, epoxy compounds with tricyclodecane skeleton, naphthyl ether-type epoxy compounds, and those with three cores on the skeleton Epoxy compounds, etc.

From the viewpoint of further improving the bonding strength between the hardened product and the metal layer, the epoxy compound preferably has an aromatic skeleton, more preferably has a biphenyl skeleton, and further preferably is a biphenyl epoxy compound.

From the viewpoint of further improving the bonding strength between the hardened product and the metal layer, the content of the epoxy compound in 100% by weight of the insulating resin layer is preferably 10% by weight or more, more preferably 20% by weight or more, preferably 70% by weight or less, more preferably 65% by weight or less, further preferably 60% by weight or less, particularly preferably 55% by weight or less.

The molecular weight of the epoxy compound is more preferably 1,000 or less. In this case, when the insulating resin layer is laminated on the base film, the inorganic filler can be uniformly present.

With regard to the molecular weight of the epoxy compound and the molecular weight of the following hardener, when the epoxy compound or hardener is not a polymer, and when the structural formula of the epoxy compound or hardener can be specified, it means that The molecular weight calculated by the structural formula. In addition, when the epoxy compound or the hardener is a polymer, it means the weight average molecular weight.

[Inorganic filler] The insulating resin layer preferably contains an inorganic filler. By using an inorganic filler, the dimensional change of the hardened product due to heat becomes small. Furthermore, the surface roughness of the surface of the hardened product is further reduced, and the bonding strength between the hardened product and the metal layer is increased.

In the previous laminate film, if the insulating resin layer contains an inorganic filler, the base film may naturally peel off from the insulating resin layer during curing, and then the base film may not be peeled from the insulating resin layer after curing. The material film and the insulating resin layer peel well, and the base material film is easily broken. However, in the laminated film of the present invention, even in the case where the insulating resin layer contains an inorganic filler, the natural peeling of the base film from the insulating resin layer during curing can be further suppressed, and the base film can be further suppressed from Defective peeling of the base film when the insulating resin layer is peeled off.

Examples of the inorganic filler include silicon dioxide, talc, clay, mica, hydrotalcite, alumina, magnesium oxide, aluminum hydroxide, aluminum nitride, and boron nitride.

From the viewpoint of reducing the surface roughness of the surface of the hardened product, further improving the bonding strength of the hardened product and the metal layer, and forming further fine wiring on the surface of the hardened product, and giving the hardened product better insulation reliability The above-mentioned inorganic filler is preferably silica or alumina, more preferably silica, and further preferably fused silica. By using silicon dioxide, the thermal expansion rate of the hardened product is further lowered, and the surface roughness of the surface of the hardened product is effectively reduced, and the bonding strength between the hardened product and the metal layer is effectively increased. The shape of silicon dioxide is preferably spherical.

From the viewpoints that the curing of the resin does not depend on the curing environment, the glass transition temperature of the cured product is effectively increased, and the thermal linear expansion coefficient of the cured product is effectively reduced, the inorganic filler is preferably spherical silica.

The average particle diameter of the inorganic filler is preferably 10 nm or more, more preferably 50 nm or more, further preferably 100 nm or more, and preferably 5 μm or less, more preferably 3 μm or less, and still more preferably 1 Below μm, particularly preferably below 0.5 μm. If the average particle diameter of the inorganic filler is not less than the lower limit and not more than the upper limit, the strength of adhesion between the cured product and the metal layer further increases.

As the average particle diameter of the inorganic filler, a value of 50% of the median diameter (d50) is adopted. The above average particle diameter can be measured using a laser diffraction scattering particle size distribution measuring device. When the insulating resin layer contains two or more types of inorganic fillers, the average particle diameter of the inorganic filler is measured on the entire inorganic filler contained in the insulating resin layer. The average particle diameter of the inorganic filler can also be measured using the resin composition or inorganic filler used to obtain the insulating resin layer.

The inorganic filler is preferably spherical, and more preferably spherical silica. In this case, the surface roughness of the surface of the hardened product is effectively reduced, and the bonding strength between the hardened product and the metal layer is effectively increased. In the case where the inorganic filler is spherical, the aspect ratio of the inorganic filler is preferably 2 or less, and more preferably 1.5 or less.

The inorganic filler is preferably surface-treated, more preferably a surface-treated product based on a coupling agent, and further preferably a surface-treated product based on a silane coupling agent. As a result, the surface roughness of the surface of the roughened and hardened material is further reduced, the bonding strength of the hardened material and the metal layer is further increased, and further fine wiring can be formed on the surface of the hardened material, and further good Wiring room insulation reliability and interlayer insulation reliability.

Examples of the coupling agent include a silane coupling agent, a titanium coupling agent, and an aluminum coupling agent. Examples of the silane coupling agent include methacrylic silane, acrylic silane, amino silane, imidazole silane, vinyl silane, and epoxy silane.

The content of the inorganic filler in 100% by weight of the insulating resin layer is preferably 30% by weight or more, more preferably 40% by weight or more, and still more preferably 50% by weight or more, particularly preferably 60% by weight or more, most preferably 70% by weight or more. In 100% by weight of the insulating resin layer, the content of the inorganic filler is preferably 90% by weight or less, more preferably 85% by weight or less, further preferably 83% by weight or less, and particularly preferably 80% by weight or less. If the content of the inorganic filler is above the above lower limit and below the above upper limit, the surface roughness of the surface of the cured product further becomes smaller, the bonding strength of the cured product and the metal layer further becomes higher, and further fineness is formed on the surface of the cured product Of wiring. Furthermore, if the content of the inorganic filler is reduced, the thermal expansion rate of the cured product can be reduced, and the slag removability can be improved. If the content of the inorganic filler is above the lower limit, the dielectric loss tangent is effectively reduced. If the content of the inorganic filler is below the upper limit, the cracking of the insulating resin layer when the protective film is peeled off can be further effectively suppressed.

[hardener] The insulating resin layer preferably contains a hardener. The hardener is not particularly limited. As the above-mentioned hardener, a conventionally known hardener can be used. Only one kind of the above hardener may be used, or two or more kinds may be used in combination.

Examples of the hardener include cyanate compounds (cyanate hardeners), phenol compounds (phenolic hardeners), amine compounds (amine hardeners), thiol compounds (thiol hardeners), imidazole compounds, Phosphine compounds, acid anhydrides, dicyandiamide, carbodiimide compounds (carbodiimide hardeners), maleimide diimide compounds (maleimide diimide hardeners), active ester compounds, etc. . The hardener preferably has a functional group capable of reacting with the epoxy group of the epoxy compound.

From the viewpoint of further reducing the dielectric loss tangent, the hardener preferably contains a cyanate compound, a phenol compound, a maleimide compound, an active ester compound, or a carbodiimide compound. From the viewpoint of further suppressing the natural peeling of the base film from the insulating resin layer during curing, and further suppressing the peeling failure of the base film when the base film is peeled from the insulating resin layer after curing, the above curing agent preferably contains phenol Compounds, cyanate compounds, maleimide compounds or active ester compounds. The above-mentioned hardener may also contain a phenol compound, a cyanate ester compound or an active ester compound.

The cyanate compound may be a cyanate compound (cyanate hardener). Examples of the cyanate compound include novolak type cyanate resin, bisphenol type cyanate resin, and prepolymers obtained by trimerization of a part of these. Examples of the novolak-type cyanate resins include phenol-based novolak-type cyanate resins and alkylphenol-type cyanate resins. Examples of the bisphenol cyanate resin include bisphenol A cyanate resin, bisphenol E cyanate resin, and tetramethyl bisphenol F cyanate resin.

Examples of commercially available products of the cyanate compounds include phenolic novolak type cyanate resins ("PT-30" and "PT-60" manufactured by Lonza Japan) and bisphenol type cyanate resins. Prepolymers ("BA-230S", "BA-3000S", "BTP-1000S" and "BTP-6020S" manufactured by Lonza Japan, etc.), etc.

Examples of the phenol compounds include novolac phenol, biphenol phenol, naphthalene phenol, dicyclopentadiene phenol, aralkyl phenol, and dicyclopentadiene phenol.

Examples of commercially available products of the above phenol compounds include novolac type phenol ("TD-2091" manufactured by DIC Corporation), biphenol novolac type phenol ("MEH-7851" manufactured by Minghe Chemical Industry Co., Ltd.), and aralkyl groups Type phenol compounds ("MEH-7800" manufactured by Meiwa Chemical Industry Co., Ltd.) and phenols with an amine tri-framework ("LA1356" and "LA3018-50P" manufactured by DIC), etc.

The active ester compound refers to a compound containing at least one ester bond in the structure, and an aromatic ring bonded to both sides of the ester bond. The active ester compound is obtained, for example, by a condensation reaction of a carboxylic acid compound or a thiocarboxylic acid compound with a hydroxyl compound or a thiol compound. Examples of the active ester compound include compounds represented by the following formula (1).

[Chemical 1]

In the above formula (1), X1 and X2 each represent a group containing an aromatic ring. Preferred examples of the aromatic ring-containing group include a benzene ring which may have a substituent, a naphthalene ring which may have a substituent, and the like. Examples of the substituents include hydrocarbon groups. The carbon number of the hydrocarbon group is preferably 12 or less, more preferably 6 or less, and still more preferably 4 or less.

Examples of the combination of X1 and X2 include a combination of a benzene ring that may have a substituent and a benzene ring that may have a substituent, and a combination of a benzene ring that may have a substituent and a naphthalene ring that may have a substituent. Furthermore, as a combination of X1 and X2, the combination of the naphthalene ring which may have a substituent and the naphthalene ring which may have a substituent is mentioned.

The active ester compound is not particularly limited. Examples of commercially available products of the active ester compounds include "HPC-8000-65T", "EXB9416-70BK", "EXB8100-65T", and "EXB-8000L-65MT" manufactured by DIC Corporation.

The carbodiimide compound has a structural unit represented by the following formula (2). In the following formula (2), the right end portion and the left end portion are bonded to other bases.

[Chem 2]

In the above formula (2), X represents an alkylene group, a group bonded with a substituent on the alkylene group, a cycloalkyl group, a group bonded with a substituent on the cycloalkyl group, an aryl group, or A group having a substituent bonded to the arylene group, p represents an integer of 1 to 5. When there are multiple Xs, the multiple Xs may be the same or different.

In a preferred form, at least one X is an alkylene group, a group bonded with a substituent on the alkylene group, a cycloalkyl group, or a group bonded with a substituent on the cycloalkyl group.

Examples of commercially available products of the above carbodiimide compounds include "Carbodilite V-02B", "Carbodilite V-03", "Carbodilite V-04K", "Carbodilite V-07", and "Carbodilite V-07" manufactured by Nisshinbo Chemical Company. "Carbodilite V-09", "Carbodilite 10M-SP" and "Carbodilite 10M-SP (revised)", and "Stabaxol P", "Stabaxol P400" and "Hykasil 510" manufactured by Rhein Chemie.

As the above-mentioned maleimide diimide compound, a previously known maleimide diimide compound can be used. As for the maleimide compound, only one type may be used, or two or more types may be used in combination.

The maleimide diimide compound may be a bismaleimide diimide compound.

Examples of the maleimide diimide compound include N-phenyl maleimide diimide, N-alkylbismaleimide diimide, and the like.

The maleimide diimide compound preferably has a skeleton derived from a diamine compound other than dimer diamine or a triamine compound other than trimer triamine.

The maleimide compound may have an aromatic ring or may not have an aromatic ring. The maleimide compound preferably has an aromatic ring.

In the maleimide diimide compound, it is preferable that a nitrogen atom and an aromatic ring are bonded to the maleimide diimide skeleton.

From the viewpoint of further improving the thermal dimensional stability of the cured product, the content of the maleimide compound is preferably 0.5% by weight or more in 100% by weight of components other than the solvent in the insulating resin layer, It is more preferably 1% by weight or more, and preferably 15% by weight or less, and more preferably 10% by weight or less.

The content of the maleimide compound in 100% by weight of the insulating resin layer except for the inorganic filler and the solvent is preferably 2.5% by weight or more, more preferably 5% by weight or more, and more preferably It is 7.5% by weight or more, and preferably 50% by weight or less, and more preferably 35% by weight or less. If the content of the maleimide compound is above the lower limit and below the upper limit, the thermal dimensional stability of the cured product can be further improved.

From the viewpoint of effectively exerting the effects of the present invention, the molecular weight of the maleimide compound is preferably 500 or more, more preferably 1000 or more, and more preferably less than 30,000, more preferably less than 20,000 .

Regarding the molecular weight of the maleimide diimide compound, when the maleimide diimide compound is not a polymer and the structural formula of the maleimide diimide compound can be specified, it means Refers to the molecular weight that can be calculated from the structural formula. In addition, when the molecular weight of the maleimide diimide compound is a polymer when the maleimide diimide compound is a polymer, it means that polystyrene is measured by gel permeation chromatography (GPC) Weight-average molecular weight in terms of conversion.

Examples of the commercially available products of the maleimide diimide compound include "BMI-4000" and "BMI-5100" manufactured by Daiwa Chemical Industry Co., Ltd., and "BMI-3000" manufactured by Designer Molecules Inc. Wait.

The molecular weight of the hardener is preferably 1,000 or less. In this case, when the insulating resin layer is laminated on the base film, the inorganic filler can be uniformly present.

In 100% by weight of the components other than the inorganic filler in the insulating resin layer, the total content of the epoxy compound and the hardener is preferably 75% by weight or more, more preferably 80% by weight or more, and is preferably 99% by weight or less, more preferably 97% by weight or less. If the total content of the epoxy compound and the hardener is above the lower limit and below the upper limit, a further good cured product can be obtained, and since the melt viscosity can be adjusted, the dispersibility of the inorganic filler becomes good. Furthermore, the insulating resin layer can be prevented from wetting and spreading to unintended areas during the hardening process. Furthermore, the dimensional change of the hardened product due to heat can be further suppressed. In addition, if the total content of the epoxy compound and the hardener is more than the lower limit, the melt viscosity will not become too low, and the insulating film becomes difficult to overwet and diffuse to the unintended area during the hardening process tendency. In addition, if the total content of the epoxy compound and the hardener is equal to or less than the upper limit, it is easy to embed holes or irregularities in the circuit board, and the inorganic filler tends to be unevenly present.

The content of the hardener is preferably 30% by weight or more, more preferably 40% by weight or more, and preferably 70% by weight or less in 100% by weight of the components other than the inorganic filler in the insulating resin layer It is preferably 60% by weight or less. If the content of the hardener is above the lower limit and below the upper limit, a further good hardened product is obtained, and the dielectric loss tangent is effectively reduced.

[Thermoplastic resin] The insulating resin layer preferably contains a thermoplastic resin. Examples of the thermoplastic resin include polyimide resin, polyvinyl acetal resin, and phenoxy resin. Only one type of the thermoplastic resin may be used, or two or more types may be used in combination.

In terms of effectively reducing the dielectric loss tangent without relying on a hardening environment and effectively improving the adhesion of metal wiring, the thermoplastic resin is preferably a phenoxy resin. By using a phenoxy resin, it is possible to suppress the deterioration of the embedding property of the insulating resin layer with respect to the holes or irregularities of the circuit board and the unevenness of the inorganic filler. Moreover, by using a phenoxy resin, the melt viscosity can be adjusted, so the dispersibility of the inorganic filler becomes good, and it becomes difficult for the insulating resin layer to wet and diffuse to unintended areas during the curing process. The phenoxy resin is not particularly limited. As the above-mentioned phenoxy resin, a conventionally known phenoxy resin can be used. Only one type of the phenoxy resin may be used, or two or more types may be used in combination.

Examples of the phenoxy resin include benzene having a bisphenol A skeleton, a bisphenol F skeleton, a bisphenol S skeleton, a biphenyl skeleton, a novolac skeleton, a naphthalene skeleton, and an imide skeleton. Oxygen resin, etc.

Examples of the commercially available products of the phenoxy resin include: "YP50", "YP55", and "YP70" manufactured by Nippon Steel & Sumitomo Chemical Co., Ltd.; and "1256B40", "4250", and "" manufactured by Mitsubishi Chemical Corporation. "4256H40", "4275", "YX6954BH30" and "YX8100BH30" etc.

From the viewpoint of obtaining an insulating resin layer having further excellent storage stability, the weight average molecular weight of the thermoplastic resin is preferably 5,000 or more, more preferably 10,000 or more, preferably 100,000 or less, and more preferably 50,000 or less.

The above-mentioned weight average molecular weight of the above thermoplastic resin means the weight average molecular weight in terms of polystyrene measured by gel permeation chromatography (GPC).

The content of the thermoplastic resin and the phenoxy resin is not particularly limited. In the insulating resin layer, the content of the thermoplastic resin (the content of the phenoxy resin when the thermoplastic resin is a phenoxy resin) is preferably 1% by weight in 100% by weight of the components other than the inorganic filler. The above is more preferably 5% by weight or more, and is preferably 30% by weight or less, and more preferably 15% by weight or less. If the content of the thermoplastic resin is not less than the lower limit and not more than the upper limit, the embedding property of the insulating resin layer into the holes or irregularities of the circuit board becomes good. If the content of the thermoplastic resin is more than the above lower limit, the formation of the insulating resin layer is further facilitated, and a further good insulating layer can be obtained. If the content of the thermoplastic resin is equal to or lower than the upper limit, the thermal expansion coefficient of the cured product will further decrease. The surface roughness of the surface of the hardened product is further reduced, and the subsequent strength of the hardened product and the metal layer is further increased.

[Hardening accelerator] The insulating resin layer preferably contains a hardening accelerator. By using the above hardening accelerator, the hardening speed is further increased. By rapidly curing the insulating resin layer, the cross-linked structure in the cured product becomes uniform, and the number of unreacted functional groups decreases, resulting in a high cross-link density. The above curing accelerator is not particularly limited, and a conventionally known curing accelerator can be used. Only one kind of the above curing accelerator may be used, or two or more kinds may be used in combination.

Examples of the hardening accelerator include imidazole compounds, phosphorus compounds, amine compounds, and organometallic compounds.

Examples of the imidazole compounds include 2-undecylimidazole, 2-heptadecylimidazole, 2-methylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, and 2-benzene 4-methylimidazole, 1-benzyl-2-methylimidazole, 1-benzyl-2-phenylimidazole, 1,2-dimethylimidazole, 1-cyanoethyl-2-methylimidazole , 1-cyanoethyl-2-ethyl-4-methylimidazole, 1-cyanoethyl-2-undecylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-cyanoethyl- 2-undecylimidazolium trimellitate, 1-cyanoethyl-2-phenylimidazolium trimellitate, 2,4-diamino-6-[2'-methylimidazolyl -(1')]-ethylmestris, 2,4-diamino-6-[2'-undecylimidazolyl-(1')]-ethylmestris, 2,4- Diamino-6-[2'-ethyl-4'-methylimidazolyl-(1')]-ethylmestris, 2,4-diamino-6-[2'-methylimidazole基-(1')]-ethyl homotricyanate adduct, 2-phenylimidazole isocyanurate adduct, 2-methylimidazole isocyanurate adduct, 2-phenyl-4,5-dihydroxymethylimidazole, 2-phenyl-4-methyl-5-dihydroxymethylimidazole, etc.

Examples of the phosphorus compound include triphenylphosphine.

Examples of the above-mentioned amine compounds include diethylamine, triethylamine, diethylidenetetraamine, triethylideneamine, 4,4-dimethylaminopyridine, and the like.

Examples of the above-mentioned organometallic compounds include zinc naphthenate, cobalt naphthenate, tin octoate, cobalt octoate, cobalt (II) diacetone acetone, and cobalt (III) triacetone acetone.

The content of the hardening accelerator is not particularly limited. In the insulating resin layer, the content of the above-mentioned hardening accelerator is preferably 0.005 wt% or more, more preferably 0.01 wt% or more, and preferably 5 wt% or less, in 100 wt% of the components other than the inorganic filler in the insulating resin layer It is preferably 3% by weight or less. If the content of the curing accelerator is more than the lower limit and less than the upper limit, the insulating resin layer is cured efficiently. If the content of the above-mentioned hardening accelerator is in a more preferable range, the storage stability of the insulating resin layer further becomes higher, and a further good hardened product can be obtained.

[Solvent] The insulating resin layer does not contain or contains a solvent. Moreover, the said solvent can also be used for obtaining the slurry containing the said inorganic filler. Only one type of the above solvents may be used, or two or more types may be used in combination.

Examples of the solvent include acetone, methanol, ethanol, butanol, 2-propanol, 2-methoxyethanol, 2-ethoxyethanol, 1-methoxy-2-propanol, 2-acetyl Oxy-1-methoxypropane, toluene, xylene, methyl ethyl ketone, N,N-dimethylformamide, methyl isobutyl ketone, N-methyl-pyrrolidone, n-hexane , Cyclohexane, cyclohexanone and naphtha as a mixture.

Most of the solvents are preferably removed when the insulating resin layer is molded. Therefore, the boiling point of the above solvent is preferably 200°C or lower, and more preferably 180°C or lower. The content of the solvent in the insulating resin layer is not particularly limited. The content of the above-mentioned solvent can be appropriately changed to such an extent that the layer shape of the above-mentioned insulating resin layer can be maintained.

[Other ingredients] For the purpose of improving impact resistance, heat resistance, resin compatibility and workability, etc., leveling agents, flame retardants, coupling agents, colorants, antioxidants, and UV resistance can also be added to the above-mentioned insulating resin layer Agents, defoamers, tackifiers, thixotropy-imparting agents and other thermosetting resins other than epoxy compounds.

Examples of the coupling agent include a silane coupling agent, a titanium coupling agent, and an aluminum coupling agent. Examples of the silane coupling agent include vinyl silane, amino silane, imidazole silane, and epoxy silane.

Examples of the above other thermosetting resins include polyphenylene ether resins, divinyl benzyl ether resins, polyarylate resins, diallyl phthalate resins, polyimide resins, benzo resins, Benzoazole resin and acrylate resin etc.

As a method of obtaining the above-mentioned insulating resin layer, the following methods and the like can be mentioned. Extrusion molding method: Use an extruder to melt and knead the material used to form the insulating resin layer. After extrusion, the material is formed into a film shape by a T-die or a round die. Casting method: The material used to form the insulating resin layer containing a solvent is cast to form a film. Other previously known film forming methods. Alternatively, a material for forming an insulating resin layer may be laminated on the base film, and heated and dried to obtain an insulating resin layer. In terms of being able to cope with thinning, the extrusion molding method or the casting molding method is preferable. The film includes sheets.

The material used to form the insulating resin layer is formed into a film shape, so that the curing by heat does not excessively progress, for example, heating and drying at 50°C to 150°C for 1 to 10 minutes, thereby obtaining a B-stage film The insulating resin layer.

The film-like insulating resin layer obtainable by the drying step as described above is called a B-stage film. The above B-stage film is in a semi-hardened state. The semi-hardened product is not completely hardened, and can be further hardened.

The insulating resin layer is preferably a B-stage film.

The minimum melting viscosity of the insulating resin layer (in the case where the insulating resin layer is a B-stage film is B-stage film) in the temperature range of 60°C or more and 180°C or less is preferably 5 mPa·s or more. It is preferably 10 mPa·s or more. If the above-mentioned minimum melt viscosity is above the above-mentioned lower limit, it can prevent the resin from oozing out into unintended areas during lamination and pressure processing, and can effectively suppress the peeling failure when peeling the base film after curing, and furthermore, it can also be effective To suppress natural peeling. The upper limit of the minimum melt viscosity of the insulating resin layer (the B-stage film when the insulating resin layer is a B-stage film) in a temperature range of 60°C or more and 180°C or less is not particularly limited. The minimum melting viscosity of the insulating resin layer (the B-stage film when the insulating resin layer is a B-stage film) in the temperature range of 60°C or more and 180°C or less may be 200 mPa·s or less. It can be 150 mPa·s or less, 100 mPa·s or less, or 75 mPa·s or less.

The temperature at the above minimum melt viscosity is preferably 140°C or lower, and more preferably 130°C or lower. If the temperature at the lowest melt viscosity is below the upper limit, the natural peeling accompanying the shrinkage of the base film can be effectively suppressed.

The above-mentioned minimum melt viscosity is obtained by using a rheometer device (for example, "AR-2000" manufactured by TA Instruments) at a frequency of 6.28 rad/sec, a starting temperature of 60°C, a heating rate of 5°C/min, and a strain of 21.8% It is determined by measuring the dynamic viscoelasticity.

From the viewpoint of further improving the lamination of the insulating resin layer (in the case where the insulating resin layer is a B-stage film, the B-stage film), and further suppressing uneven curing of the insulating resin layer, the above-mentioned insulating resin layer The thickness is preferably 5 μm or more, more preferably 10 μm or more, and preferably 200 μm or less, and more preferably 100 μm or less.

(Protection film) The laminated film preferably has a protective film laminated on a surface of the insulating resin layer opposite to the base film side.

Examples of the material of the protective film include polyolefins such as polypropylene and polyethylene, and polyethylene terephthalate. The material of the protective film is preferably polyolefin, and more preferably polypropylene.

From the viewpoint of further improving the protection of the insulating resin layer, the thickness of the protective film is preferably 5 μm or more, more preferably 10 μm or more, and preferably 75 μm or less, more preferably 60 μm or less.

(Other details of laminated film) The laminated film of the present invention can be preferably used to form an insulating layer on a multilayer printed wiring board. The above-mentioned insulating resin layer can be preferably used for forming an insulating layer on a multilayer printed wiring board. The insulating layer can be formed by the insulating resin layer of the laminated film of the present invention.

As an example of the multilayer printed wiring board, a multilayer printed wiring board including a circuit board, a plurality of insulating layers laminated on the circuit board, and a metal layer disposed between the plurality of insulating layers may be mentioned. At least one of the insulating layers is formed of the insulating resin layer. The insulating layer in contact with the circuit board may be formed of the insulating resin layer. The insulating layer disposed between the two insulating layers may be formed of the insulating resin layer. The insulating layer farthest from the circuit board may also be formed of the insulating resin layer. A metal layer may be disposed on the outer surface of the plurality of insulating layers away from the insulating layer of the circuit board.

(Manufacturing method of laminated structure) The method for manufacturing a laminated structure of the present invention includes a laminating step: using the laminated film, and in a state where the base film and the insulating resin layer are laminated, a surface area layer of the insulating resin layer on the opposite side of the base film On the object to be laminated with a metal layer on the surface. The manufacturing method of the laminated structure of the present invention includes a via hole forming step of forming a via hole by irradiating the insulating resin layer with laser light from the base film side with the base film and the insulating resin layer stacked.

Since the manufacturing method of the laminated structure of the present invention has the above-mentioned structure, it is possible to suppress the natural peeling of the base film from the insulating resin layer in the curing step.

(Stacking step) In the manufacturing method of the laminated structure of the present invention, the above-mentioned laminated film is used, and in the state where the above-mentioned base film and the above-mentioned insulating resin layer are laminated, the surface area of the insulating resin layer opposite to the above-mentioned base film is layered on The object to be laminated with a metal layer on the surface.

In the layering step, when the layered film is provided with the protective film, the protective film is peeled off, and the surface area layer of the insulating resin layer exposed by the peeling is placed on the layered object member having a metal layer on the surface.

The above lamination step is preferably performed by lamination. The temperature during the above lamination is preferably 80°C or higher, and preferably 120°C or lower.

(Hardening step) The manufacturing method of the laminated structure of the present invention preferably includes a hardening step of hardening the insulating resin layer.

In the manufacturing method of the laminated structure of the present invention, it is preferable to harden the insulating resin layer. In the above curing step, the insulating resin layer is cured to form a cured product. The hardening of the insulating resin layer in the hardening step may be pre-hardening. The above-mentioned hardened products also include pre-hardened products that can be further hardened. In the curing step, the insulating resin layer may be pre-cured to obtain a B-stage film.

The above hardening step is preferably performed by heating. The above heating temperature is preferably 130°C or higher, and preferably 200°C or lower. The above heating time is preferably 30 minutes or more, and preferably 120 minutes or less.

In order to form fine irregularities on the surface of the cured product obtained by pre-curing the insulating resin layer, it is preferable to roughen the cured product. Preferably, the hardened product is subjected to swelling treatment before the roughening treatment. The cured product is preferably subjected to swelling treatment after pre-curing and before roughening treatment, and then hardened after roughening treatment. However, the hardened product need not be subjected to swelling treatment.

As a method of the above swelling treatment, for example, a method of treating the hardened material with an aqueous solution of a compound mainly composed of ethylene glycol or the like or an organic solvent dispersion solution or the like can be used. The swelling liquid used for swelling treatment usually contains an alkali as a pH adjuster or the like. The swelling liquid preferably contains sodium hydroxide. Specifically, for example, the swelling treatment is performed by using a 40% by weight aqueous ethylene glycol solution or the like to treat the cured product at a treatment temperature of 30°C to 85°C for 1 to 30 minutes. The temperature of the swelling treatment is preferably in the range of 50°C to 85°C. If the temperature of the swelling treatment is too low, the swelling treatment takes a long time, and the bonding strength between the hardened product and the metal layer tends to be low.

For the roughening treatment, for example, a chemical oxidizing agent such as a manganese compound, chromium compound, or persulfate compound can be used. These chemical oxidants are used as aqueous solutions or organic solvent dispersion solutions after adding water or organic solvents. The roughening liquid used for the roughening treatment usually contains an alkali as a pH adjuster or the like. The roughening liquid preferably contains sodium hydroxide.

Examples of the above-mentioned manganese compound include potassium permanganate and sodium permanganate. Examples of the chromium compound include potassium dichromate and potassium chromate. Examples of the persulfate compound include sodium persulfate, potassium persulfate, and ammonium persulfate.

The arithmetic average roughness Ra of the surface of the hardened product is preferably 5 nm or more, more preferably 10 nm or more, and preferably 400 nm or less, more preferably less than 400 nm, more preferably 300 nm or less, and more preferably It is less than 300 nm, particularly preferably less than 200 nm, and most preferably less than 150 nm. In this case, the bonding strength between the hardened material and the metal layer becomes higher, and further fine wiring is formed on the surface of the insulating layer. Furthermore, conductor loss can be suppressed, and signal loss can be suppressed low.

(Steps for forming via holes) In the manufacturing method of the laminated structure of the present invention, in a state where the base film and the insulating resin layer are stacked, a laser is irradiated from the base film side to the insulating resin layer to form a via hole.

Examples of the laser used in the above-mentioned via formation step include CO ₂ laser and UV (Ultraviolet) laser.

From the viewpoint of using a general-purpose polyethylene terephthalate (PET) film as a substrate, the above-mentioned laser is preferably a CO ₂ laser. On the other hand, when UV laser is used as the laser, it is preferable to use polyethylene naphthalate (PEN) film, a film containing an ultraviolet absorber, and the like.

The diameter of the formed via hole is not particularly limited, but it is preferably 80 μm or less. The diameter of the via hole may be 10 μm or more, 30 μm or more, or 60 μm or more.

(Steps of removing slag) The manufacturing method of the laminated structure of the present invention preferably includes a step of removing the dross inside the via hole by the dross removal process (the dross removal step) after the via hole formation step. By including the above-mentioned scum removal step, it is possible to effectively remove the slag which is the resin residue from the resin component formed in the above-mentioned via formation step.

In the above slag removal step, for example, a chemical oxidizing agent such as a manganese compound, a chromium compound, or a persulfate compound is used. These chemical oxidants are used as aqueous solutions or organic solvent dispersion solutions after adding water or organic solvents. The dross removal treatment liquid used in the dross removal step usually contains alkali. The slag removal treatment liquid preferably contains sodium hydroxide.

The above-mentioned scum removal step can also be used as a roughening treatment step for roughening the surface of the insulating resin layer.

(Stripping step) The manufacturing method of the laminated structure of the present invention preferably includes a step (peeling step) of peeling the base film from the insulating resin layer after the scum removal step.

The above peeling step is preferably performed using an automatic peeling device.

Since the manufacturing method of the laminated structure of the present invention includes the above-mentioned structure, the peeling failure of the base film can be suppressed in the peeling step.

(Other steps) The manufacturing method of the laminated structure of the present invention preferably includes each step of a plating step and a formal hardening step. The plating step is performed after the peeling step by plating treatment on the insulating resin layer exposed by peeling. A metal layer is formed on the surface. The above-mentioned main hardening step is after the above-mentioned plating step, and further hardens the insulating resin layer.

Hereinafter, the present invention will be specifically described by citing examples and comparative examples. The present invention is not limited to the following embodiments.

(Substrate film) Base film A (polyethylene terephthalate (PET) film ("25X" manufactured by LINTEC), thickness 25 μm, width 550 mm, arithmetic average roughness Ra30 nm on the surface of the insulating resin layer) Base film B (polyethylene terephthalate (PET) film ("386501" manufactured by LINTEC), thickness 38 μm, width 550 mm, arithmetic average roughness Ra30 nm on the surface of the insulating resin layer) Base film C (polyethylene terephthalate (PET) film ("PLD386502" manufactured by LINTEC), thickness 38 μm, width 550 mm, arithmetic average roughness Ra7 nm on the surface of the insulating resin layer)

The above arithmetic average roughness was measured using a non-contact surface roughness meter ("WYKONT3300" manufactured by Veeco Instruments) in a VSI contact mode with a 50x lens and the measurement range set to 95.6 μm×71.7 μm . In addition, the threshold is set to 1%, and the above arithmetic average roughness under the conditions of median filtering (window: 5 size) and tilt correction is measured at 10 randomly selected measurement positions, and the average of the measured values is used value.

(Material used to form the insulating resin layer) The material for forming the insulating resin layer is prepared in the following manner.

Materials used to form the insulating resin layer A: Prepare 69.3 parts by weight of cyclohexanone slurry (solid content 70% by weight) of vinyl silane-treated silica ("SOC2" manufactured by Admatechs). To this slurry, 5.6 parts by weight of a biphenyl type epoxy compound ("NC3000H" manufactured by Nippon Kayaku Co., Ltd.), 5.3 parts by weight of a bisphenol F type epoxy compound ("830S" manufactured by DIC Corporation), and a fusel ring Oxygen compound ("OGSOL PG-100" manufactured by Osaka Gas Chemicals) 2.0 parts by weight. Using a stirrer, stirring at 1200 rpm for 60 minutes, it was confirmed that the undissolved matter disappeared. Thereafter, 1.6 parts by weight of a phenolic novolac hardener ("H4" manufactured by Meiwa Chemical Co., Ltd.) and a toluene mixed solution (solid content 65) of an active ester hardener ("HPC-8000-65T" manufactured by DIC Corporation) were added. 13% by weight), stirring at 1200 rpm for 60 minutes, and it was confirmed that the undissolved matter disappeared. A methyl ethyl ketone and cyclohexanone mixed solution (solid content 30% by weight) of bisphenol acetophenone skeleton phenoxy resin ("YX6954" manufactured by Mitsubishi Chemical Corporation) was prepared. Furthermore, 3.6 parts by weight of the mixed solution (solid content 30% by weight), 0.3 parts by weight of 2-ethyl-4-methylimidazole ("2E4MZ" manufactured by Shikoku Chemical Industry Co., Ltd.), and a leveling agent (Nanmoto Chemical Co., Ltd.) Manufactured "LS-480") 0.1 parts by weight. Stir at 1200 rpm for 30 minutes to obtain a material (varnish) for forming the insulating resin layer A.

The material used to form the insulating resin layer B: The active ester hardener ("HPC-8000-65T" manufactured by DIC Corporation) was changed to a phenolic novolac hardener ("MEH7851-H" manufactured by Meiwa Chemical Industry Co., Ltd.), and used to form an insulating resin layer The material of A is similarly obtained as the material (varnish) for forming the insulating resin layer B.

(Example 1) The steps of disposing the insulating resin layer on the surface of the base film: Using a die coater, apply the material used to form the insulating resin layer A to the substrate film A, except for the width of the substrate in the width direction of 20 mm from both ends, at a width of 510 mm After (varnish), it was dried at an average temperature of 100°C for 3 minutes to volatilize the solvent. In this way, an insulating resin layer A having a thickness of 40 μm and a width of 510 mm was formed on the base film A to obtain a laminate.

Steps to align one end face in the width direction of the laminate: Use a strip cutter at a position of 30 mm from one end (the other end) toward the inside in the width direction of the obtained laminate, and at a position 18 mm from the end (the other end) opposite to the other end Cut the strip at a speed of 10 m/min, and align the end surface of the base material film on the other end side with the end surface of the insulating resin layer. In this way, a laminated film obtained on one end side and with respect to the end surface of the insulating resin layer, the distance (Y) over which the end surface of the base film protrudes is 2 mm.

(Examples 2 to 16 and Comparative Examples 1 to 5) Change the type of the base film, the type of the insulating resin layer, and the distance (Y) that the end surface of the base film extends from the end surface of the laminated film relative to the end surface of the insulating resin layer as shown in Tables 1 to 3. Except for this, a laminated film was obtained in the same manner as in Example 1.

(Evaluation) (1) Peel strength of the base film relative to the insulating resin layer (X) The obtained laminated film was measured using a tensile tester ("AG-5000B" manufactured by Shimadzu Corporation) at a crosshead speed of 5 mm/min to measure the peel strength of the base film relative to the insulating resin layer (X).

(2)Y/X According to the distance (Y) at which the end face of the obtained laminated film with respect to the end face of the insulating resin layer, the end face of the base film protrudes, and the base film relative to the insulating resin layer measured in (1) above The peel strength (X) is calculated as Y/X.

(3) The lowest melt viscosity and the temperature at the lowest melt viscosity The base film was peeled from the obtained laminated film to obtain an insulating resin layer. For the obtained insulating resin layer, a rheometer device ("AR-2000" manufactured by TA Instruments) was used at a frequency of 6.28 rad/sec, a starting temperature of 60°C, a heating rate of 5°C/min, and a strain of 21.8% The dynamic viscoelasticity is measured below to find the lowest melt viscosity and the temperature at the lowest melt viscosity. The results are shown below.

Insulating resin layer A: minimum melt viscosity 98 mPa·s, temperature at minimum melt viscosity 137℃ Insulating resin layer B: minimum melt viscosity 50 mPa·s, temperature at minimum melt viscosity 128℃

(4) Natural peeling Stacking steps: Prepare a 340 mm × 510 mm CCL (Copper Clad Laminate) substrate ("E679FG" manufactured by Hitachi Chemical Industry Co., Ltd.) with an inner layer circuit formed by etching. The two surfaces of the CCL substrate were immersed in a copper surface roughening agent ("Mec Etch Bond CZ-8101" manufactured by MEC Corporation) to roughen the copper surface.

The obtained laminated film was cut into 325 mm × 502 mm, mounted on both sides of the above CCL substrate from the resin film side, and laminated using a diaphragm-type vacuum laminating machine ("MVLP-500" manufactured by Mingji Manufacturing Co., Ltd.) On both sides of the above CCL substrate, an uncured laminated sample A was obtained. The lamination was performed by depressurizing for 20 seconds, setting the air pressure to 13 hPa or less, pressurizing at 100°C for 20 seconds, and further pressurizing at 100°C and a pressure of 0.8 MPa for 40 seconds.

Hardening steps: The insulating resin layer is heated at a heating temperature of 180° C. for 30 minutes to pre-harden the insulating resin layer.

In the above hardening step, it is visually confirmed whether the base film is naturally peeled off from the insulating resin layer.

[Evaluation criteria for natural divestiture] ○: No natural peeling occurs △: Natural peeling occurs slightly ×: Natural peeling occurs

(5) Cracking of substrate film (defective peeling) After the evaluation of (4) natural peeling mentioned above, perform the following steps.

Steps for forming via holes: In a state where the base film and the insulating resin layer (B-stage film) are laminated and pre-cured, the insulating resin layer is irradiated with CO ₂ laser from the base film side (manufactured by Hitachi Via Mechanics) "LC-4KF212"), a via hole penetrating through the base film and the insulating resin layer is formed so that the diameter of the upper end of the via hole becomes 60 μm. In addition, the irradiation conditions of CO ₂ laser are set as follows.

[CO ₂ laser irradiation conditions] Processing mode peak (Burst) period 0.100 ms pulse width 0.018 ms pulse number 3 luminous circle 3.5 mm second iris 28 mm power 3.3 W

Stripping steps: The base film is peeled from the insulating resin layer.

In the above peeling step, it was visually confirmed whether the base film was broken.

[Evaluation criteria for substrate film rupture] ○: No cracking of the base film △: The substrate film is slightly broken ×: Cracking of the base film occurred

The structure of the laminated film and the results are shown in Tables 1 to 3 below.

[Table 1]

[Table 2]

[table 3]

1‧‧‧ laminated film 1A‧‧‧Lamination film 1Aa‧‧‧one end 1Ab‧‧‧The other end 1a‧‧‧ one end 1b‧‧‧The other end 2‧‧‧ Base film 2A‧‧‧Base film 2Aa‧‧‧1st surface 2a‧‧‧1st surface 3‧‧‧Insulating resin layer 3A‧‧‧Insulating resin layer Y‧‧‧Extending distance of the base film on one end of the laminated film

Fig. 1 is a cross-sectional view showing a laminated film according to a first embodiment of the present invention. 2 is a cross-sectional view showing a laminated film according to a second embodiment of the present invention.

Claims (12)

A laminated film comprising a base film and an insulating resin layer laminated on the surface of the base film, and On one end side of the laminated film, the end surface of the base film protrudes to the outside with respect to the end surface of the insulating resin layer, When the peel strength of the base film with respect to the insulating resin layer is X gf/cm, and the extension distance of the base film on the one end side is Y mm, Y/X is 0.5 or more and 15 or less. The laminated film according to claim 1, wherein X is 0.3 or more and 9 or less. The laminated film according to claim 1 or 2, wherein the above Y is 0.5 or more and 20 or less. The laminated film according to claim 1 or 2, wherein the thickness of the base film is 25 μm or more. The laminated film according to claim 1 or 2, wherein the arithmetic average roughness Ra of the surface of the base film on the side of the insulating resin layer is 5 nm or more and less than 400 nm. The laminated film according to claim 1 or 2, wherein the insulating resin layer contains an epoxy compound, an inorganic filler and a hardener. The laminated film according to claim 6, wherein the hardener contains a phenol compound, a cyanate compound, a maleimide compound or an active ester compound. The laminated film according to claim 1 or 2, wherein on the other end side of the laminated film opposite to the one end, the base film is aligned with the end surface of the insulating resin layer, or on the one end side of the laminated film and opposite to the one end On both sides of the other end side, with respect to the end surface of the insulating resin layer, the end surface of the base material film extends outward, and the extension distance of the base material film on the other end side is smaller than the base material film on the one end side The reach. The laminated film according to claim 1 or 2, wherein the minimum melting viscosity of the insulating resin layer in the temperature range of 60°C or more and 180°C or less is 5 mPa·s or more. The laminated film according to claim 1 or 2, wherein the above-mentioned insulating resin layer is used to form an insulating layer on a multilayer printed wiring board. A method for manufacturing a laminated structure, which includes: A lamination step using the laminated film according to any one of claims 1 to 10, in a state where the base film and the insulating resin layer are laminated, the surface of the insulating resin layer on the side opposite to the base film Laminated on the laminated object member with a metal layer on the surface; and In the step of forming a via hole, the insulating resin layer is irradiated with laser light from the base film side to form a via hole in a state where the base film and the insulating resin layer are stacked. The method for manufacturing a laminated structure according to claim 11 includes a hardening step for hardening the insulating resin layer between the stacking step and the via hole forming step.

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