TWI834676B - Method for manufacturing laminated film and laminated structure - Google Patents

Abstract

The present invention provides a laminated film that can suppress natural peeling of a base film from an insulating resin layer during curing and can suppress peeling failure of the base film when peeling the base film from an insulating resin layer after curing. The laminated film of the present invention includes 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 relative to the end surface of the insulating resin layer, the end surface of the base film is the largest on the outside. When the peeling strength of the base film relative to the insulating resin layer is X gf/cm and the protrusion distance of the base film on the one end side is Y mm, Y/X is Above 0.5 and below 15.

Description

Method for manufacturing laminated film and laminated structure

The present invention relates to a laminated film including a base film and an insulating resin layer. Furthermore, the present invention relates to a method of manufacturing a laminated structure using the above-mentioned laminated film.

Conventionally, various resin compositions have been used to obtain electronic components such as semiconductor devices, laminated boards, and printed wiring boards. For example, in a multilayer printed wiring board, a resin composition is used to form an insulating layer for insulating internal layers or to form an insulating layer located on a surface portion. In order to form the above-described insulating layer, a laminated film including a base film and an insulating resin layer is used. The above-mentioned insulating resin layer is obtained by forming the above-mentioned resin composition into a film shape.

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

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

The following Patent Document 1 discloses a method for manufacturing a multilayer printed wiring board, which includes the following steps: in a state where an insulating layer and a plastic film are laminated on both sides or a single area of a circuit board, irradiating the insulating layer from the plastic film Carbon dioxide gas laser forms non-through holes with a top diameter of less than 100 μm. The above-mentioned insulating layer contains more than 35% by mass of inorganic filler.

The following Patent Document 2 discloses a manufacturing method of a circuit board including the following steps (A) to (F). (A) Step, which includes 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) involves thermally hardening 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. (C) Step: irradiate the plastic film support with laser to form a via hole with a top diameter of less than 40 μm in the insulating layer. (D) step, which performs slag removal treatment. (E) step, which peels off the plastic film support. (F) Step of forming a conductor layer on the surface of the insulating layer. [Prior technical literature] [Patent Document]

[Patent Document 1] WO2009/066759A1 [Patent Document 2] Japanese Patent Application Publication No. 2015-211085

[Problem to be solved by the invention]

In the conventional laminated film (laminated film including a base film and an insulating resin layer) as described in Patent Documents 1 and 2, the insulating resin layer is cured in a state where the base film and the insulating resin layer are laminated. In this case, the base film may naturally peel off from the insulating resin layer during hardening. When the above-mentioned natural peeling occurs, uneven hardening of the insulating resin layer may occur. Furthermore, in the conventional laminated films described in Patent Documents 1 and 2, when the base film is peeled off from the insulating resin layer after curing, the base film and the insulating resin layer may not be peeled off well and the base film may not be properly peeled off. 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 suppress the peeling failure of the base film when peeling off the insulating resin layer after curing. Furthermore, another 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 problems]

According to a broad aspect of the present invention, there is provided a laminated film, which includes a base film and an insulating resin layer laminated on the surface of the base film, and one end side of the laminated film is opposite to the end surface of the insulating resin layer. , the end surface of the above-mentioned base material film protrudes to the outside to the greatest extent, and the peeling strength of the above-mentioned base material film relative to the above-mentioned insulating resin layer is assumed to be When 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-mentioned X is 0.3 or more and 9 or less.

In a specific aspect of the laminated film of the present invention, 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 mean roughness Ra of the surface of the base film on the insulating resin layer side 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 ester compound, a maleimide compound or an active ester compound.

In a specific aspect of the laminated film of the present invention, the end surfaces of the base film and the insulating resin layer are aligned on the other end side of the laminated film opposite to the one end, or the end surfaces of the laminated film and the insulating resin layer are aligned with each other. The end surface of the above-mentioned base material film protrudes outward relative to the end surface of the above-mentioned insulating resin layer, and the protrusion distance of the above-mentioned base material film on the above-mentioned other end side is smaller than the above-mentioned end surface of the above-mentioned one end side. The protrusion 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 to 180°C 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, which includes a lamination step of using the above-mentioned laminated film, in a state where the above-mentioned base film and the above-mentioned insulating resin layer are laminated, and the above-mentioned insulating resin layer is laminated. The surface opposite to the above-mentioned base film is laminated on the lamination target member having the metal layer on the surface; and a via hole forming step is performed from the side of the above-mentioned base film in a state where the above-mentioned base film and the above-mentioned insulating resin layer are laminated The insulating resin layer is irradiated with laser to form via holes.

In a specific aspect of the manufacturing method of the laminated structure of the present invention, a hardening step of hardening the insulating resin layer is included between the lamination step and the via hole forming step. [Effects of the 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 outward to the maximum extent relative to the end surface of the insulating resin layer. In the laminated film of the present invention, when the peeling strength of the base film with respect to the insulating resin layer is X gf/cm, and the protrusion distance of the base film on the one end side is Y mm, Y /X is above 0.5 and below 15. Since the laminated film of the present invention has the above-mentioned structure, it can suppress the base film from being naturally peeled off from the insulating resin layer during curing, and can suppress the peeling failure of the base film when peeling off the base film 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 structure (0).

(0) On one end side of the laminated film, the end surface of the base film protrudes outward to the maximum extent relative to the end surface of the insulating resin layer. (Hereinafter, sometimes referred to as laminated film (0))

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

In the laminated film of the present invention, when the peeling strength of the base film with respect to the insulating resin layer is X gf/cm, and the protrusion 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, one end side has the largest protrusion distance among all ends, so the above distance Y is the maximum protrusion distance.

Since the laminated film of the present invention has the above-mentioned structure, it can suppress the base film from being naturally peeled off from the insulating resin layer during curing, and can suppress the peeling failure of the base film when peeling off the base film 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 off from the insulating resin layer after hardening.

In addition, the above-mentioned hardening time and the above-mentioned hardening time also include the pre-hardening time and the pre-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 off from the insulating resin layer from one end side after hardening.

Since the laminated film of the present invention has the above-mentioned structure, it can suppress the natural peeling of the base film from the insulating resin layer during pre-hardening, and can also suppress the peeling of the base film when peeling off the base film from the insulating resin layer after pre-hardening. bad.

Furthermore, since the laminated film of the present invention has the above-mentioned structure, it can suppress the base film from being naturally peeled off from the insulating resin layer during transportation of the substrate or during laser irradiation for forming via holes.

Examples of the structures included in the above-mentioned structure (0) include the following structure (1), the following structure (2), and the like. 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 configuration (1), or may have the following configuration (2).

(1) On one end side of the laminated film, the end surface of the base film protrudes to the outside as much as possible with respect to the end surface of the insulating resin layer. 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 laminated film (1))

(2) On one end side of the laminated film, the end surface of the base film protrudes to the outside as much as possible with respect to the end surface of the insulating resin layer. On the other end side of the laminated film opposite to the one end, the end surface of the base film protrudes outward relative to the end surface of the insulating resin layer. The protruding distance of the base film on the other end side is equal to or smaller than the protruding distance of the base film on the one end side. (Hereinafter, sometimes referred to as laminated film (2))

The above-mentioned one end and the above-mentioned other end refer to the two opposite ends in the laminated film.

In the above-mentioned structure (2), the protrusion distance of the above-mentioned base material film on the above-mentioned other end side is the same as the protrusion distance of the above-mentioned base material film on the above-mentioned one end side, or is smaller than the distance over which the above-mentioned base material film protrudes on the above-mentioned one end side. .

In the case where the end faces of the base film and the insulating resin layer are aligned at all ends of the laminated film, that is, in the case of the previous laminated film, the base film is easily peeled off naturally from the insulating resin layer during hardening. In addition, in the case of the previous laminated film, when the base film is peeled off from the insulating resin layer after hardening, the base film is easily cracked. Therefore, it is difficult for the conventional laminated film to suppress the natural peeling of the base film from the insulating resin layer during curing, and it is difficult to suppress the rupture of the base film when peeling off 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 failure of the base film when peeling off 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 preferred.

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 as much as possible with respect to the end surface of the insulating resin layer. On the other end side of the laminated film opposite to the one end, the end surface of the base film protrudes outward relative to the end surface of the insulating resin layer. The protrusion distance of the base film on the other end side is smaller than the protrusion distance of the base film on the one end side. (Hereinafter, sometimes referred to as laminated film (2A))

In the laminated film of the present invention, let the peeling strength of the base film relative to the insulating resin layer be X gf/cm, and let the protrusion distance of the base film on the one end side be Y mm. Therefore, in the laminated films (2) and (2A), the above-mentioned Y represents the larger of the distances in which the end surfaces of the above-mentioned base film respectively project outward relative to the end surfaces of the above-mentioned insulating resin layer.

Y/X (the ratio of Y to ) is above 0.5 and below 15. If the above-mentioned Y/X is less than 0.5, the base film will easily peel off naturally from the insulating resin layer during hardening. If the Y/X exceeds 15, when the base film is peeled off from the insulating resin layer after curing, the base film and the insulating resin layer cannot be peeled off satisfactorily, 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 failure of the base film when peeling off the insulating resin layer after curing, the above-mentioned Y/X is preferably 0.7. or above, more preferably 1.0 or more, more preferably 13 or less, 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 failure of the base film when peeling off the insulating resin layer after curing, the above-mentioned X is preferably 0.3 or more. And preferably it is 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 off the insulating resin layer after curing, the above-mentioned Y is preferably 0.5 or more. And preferably it is 20 or less.

The peel strength (i.e., below gf/cm. If the peeling strength is equal to or higher than the lower limit, the base film can be suppressed from being naturally peeled off from the insulating resin layer during transportation of the substrate, and the base film can also be suppressed from being insulated even during laser irradiation for forming via holes. The resin layer peels off naturally. If the peel strength is equal to or less than the upper limit, the peel strength can be increased, and the roughness after the desmear treatment can be suppressed from increasing.

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

The protruding 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 protruding distance of the base film on the one end side is more than the above lower limit, the base film can be well peeled off from the insulating resin layer after curing using an automatic peeling device, and the laminated film can be removed during the production of the laminated film. When one end or the other end is cut, cracking or rupture of the insulating resin layer can be suppressed. If the protruding distance of the base film on the one end side is less than the upper limit, the base film can be suppressed from being naturally peeled off from the insulating resin layer during transportation of the laminated film, and the manufacturing cost can be suppressed.

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

An example of a method for causing the end surface of the base film to protrude outward from the end surface of the insulating resin layer on one end side of the laminated films (0) and (1) is to laminate the base film and the insulating layer. A method of staggering the surface of the resin layer.

As a method of extending the end surface of the base film to the outside with respect to the end surface of the insulating resin layer on both one end side of the laminated film (2) and the other end side opposite to the one end, there can be enumerated: A method of staggering the end faces when laminating the above-mentioned base film and the above-mentioned insulating resin layer. In the laminated film (2), adjust the staggered distance of the end faces.

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 can be cited. A method of aligning end faces when laminating the above-mentioned base film and the above-mentioned insulating resin layer; and a laminate of the above-mentioned base film and the above-mentioned insulating resin layer, or a laminate of the above-mentioned base film, the above-mentioned insulating resin layer, and the above-mentioned protective film Method of cutting into long strips.

As a method for making the protruding distance of the substrate film on the other end side of the laminated film (2A) smaller than the protruding distance of the substrate film on the one end side, the following methods can be listed. A method for making the protruding distance of the substrate film on the other end side smaller than the protruding distance of the substrate film on the one end side when laminating the substrate film and the insulating resin layer. A method for cutting the substrate film in the substrate film and the insulating resin layer into long strips. A method for cutting the substrate film and the protective film in the substrate film, the insulating resin layer and the protective film into long strips.

The manufacturing method of the laminated film of this invention preferably has the following structure (A) or (B). The manufacturing methods (A) and (B) are methods of manufacturing the laminated film (0). The manufacturing method (A) is a manufacturing method of the laminated film (1), and the manufacturing method (B) is a manufacturing method of the 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 of arranging insulating resin on the surface of the base film so that the end surface of the base film protrudes outward relative to the end surface of one end side of the insulating resin layer. layer. The manufacturing method of the laminated film (1) preferably includes a second step of arranging a protective film on the surface of the insulating resin layer opposite to the base film side. In the manufacturing method of the laminated film (1), on one end side of the laminated film corresponding to the one end of the insulating resin layer, the end surface of the base film protrudes outward with respect to the end surface of the insulating resin layer. Laminated film. In the manufacturing method of the laminated film (1), the laminated film (1) is obtained in which the end surfaces of the base film and the insulating resin layer are aligned on the other end side of the laminated film opposite to the one end.

(B) The manufacturing method of the laminated film (2) includes the first step of arranging an insulating resin on the surface of the base film in such a manner that the end surface of the base film protrudes outward relative to the end surface of one end side of the insulating resin layer. layer. In the first step, it is preferable that the end surface of the base film protrudes outward relative to one end side of the insulating resin layer and both end surfaces of the other end side opposite to the one end. Install an insulating resin layer. The manufacturing method of the laminated film (2) preferably includes a second step of arranging a protective film on the surface of the insulating resin layer opposite to the base film side. In the manufacturing method of the laminated film (2), it is obtained that the end surface of the base film protrudes outward relative to the end surface of the insulating resin layer on both one end side of the laminated film and the other end side opposite to the one end. The laminated film (2). In the manufacturing method of the laminated film (2), a laminated film (2) in which the protrusion distance of the base film on the other end side is smaller than the protrusion 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 above-mentioned second step, on the other end side of the above-mentioned insulating resin layer opposite to the above-mentioned one end, the above-mentioned base film, the above-mentioned 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 insulating resin layer may be placed on the other end side of the insulating resin layer opposite to the one end. Align the ends of the protective film.

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

From the viewpoint of further flattening the end surface of the other end side of the laminated film (1), the protrusion distance of the base film on the other end side of the laminated film (2) is further smaller than the protrusion distance of the base film on the one end side. From the perspective of distance, it is preferable to cut into long strips 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, an adherend such as a metal layer is usually laminated on the surface of the insulating resin layer (for example, a laminated body such as a substrate and metal wiring). When the above-mentioned laminated film is provided with a protective film, the protective film is peeled off when using the insulating resin layer in the above-mentioned laminated film. An adherend such as a metal layer (for example, a laminate of a substrate and metal wiring, etc.) is usually laminated on the surface of the insulating resin layer after the protective film is peeled off.

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

FIG. 1 is a cross-sectional view showing a laminated film according to the 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 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 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 . The size of the insulating resin layer 3 is smaller than the size of the base film 2 in the direction connecting one end 1 a and the other end 1 b of the laminated film 1 .

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

The protruding distance of the base film 2 on one end 1a side of the laminated film 1 is Y mm.

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

FIG. 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 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 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 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 relative to the end surface of the insulating resin layer 3A. At one end 1Aa of the laminated film 1A, the end surfaces of the base film 2A and the insulating resin layer 3A are not aligned. On one 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 relative 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 protrusion distance of the base film 2A on the other end 1Ab side of the laminated film 1A is smaller than the protrusion distance of the base film 2A on the one end 1Aa side.

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

The laminated film preferably has an MD (Machine Direction) direction and a TD (Transverse Direction) direction. The MD direction is the traveling direction of the laminated film when manufacturing the laminated film, 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 opposite ends in the width direction of the laminated film.

In the direction connecting the one end and the other end of the laminated film of the present invention, the size of the base film is W ₁ mm, and the size of the insulating resin layer is 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, further preferably 0.94 or more, 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, particularly preferably 0.996 or less. If W ₂ /W ₁ is more than the above lower limit, the base film can be well peeled off from the insulating resin layer after curing using an automatic peeling device. Also, when producing a laminated film, one end or the other end of the laminated film can be cut. Can inhibit cracking or cracking of the insulating resin layer. When W ₂ /W ₁ is less than the above upper limit, the base film can be suppressed from being naturally peeled off from the insulating resin layer during transportation of the laminated film, and the base film can be used efficiently, so 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 foil, 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 may also be subjected to demoulding treatment if necessary. The above-mentioned base film may be a metal foil or a resin film. The above-mentioned base film is preferably a resin film. When a metal foil is used as the base film, the metal foil is preferably copper foil.

From the viewpoint of further suppressing peeling defects, the base film is preferably subjected to a release treatment. From the viewpoint of further suppressing natural peeling accompanying the movement of polysilicone, the above-described mold release treatment is preferably a non-migration mold release treatment of polysilicone. In addition, the release treatment of polysilicone non-migration means the release treatment of not containing polysilicone, or the release treatment of processing so that polysilicone will not move to the said insulating resin layer side.

From the viewpoint of improving the operability of the laminated film and improving the lamination properties of the insulating resin layer, the thickness of the base film is preferably 25 μm or more, more preferably 30 μm or more, and more preferably 75 μm or more. μm or less, 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, 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 above-mentioned base film on the above-mentioned insulating resin layer side 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 preferably Preferably, it is below 300 nm. If the above-mentioned arithmetic mean roughness is not less than the above-mentioned lower limit and below the above-mentioned upper limit, 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 being peeled off from the insulating resin layer after curing. Poor peeling.

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

(Insulating resin layer) The above-mentioned insulating resin layer is laminated on the surface of the base film. The above-described 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, a conventionally known epoxy compound can be used. The above-mentioned epoxy compound refers to an organic compound having at least one epoxy group. Only one type of the above-mentioned epoxy compound may be used, or two or more types may be used in combination.

Examples of the above epoxy compounds include bisphenol A type epoxy compounds, bisphenol F type epoxy compounds, bisphenol S type epoxy compounds, phenolic novolac type epoxy compounds, biphenyl type epoxy compounds, bisphenol type epoxy compounds, Phenol-type epoxy compounds, biphenol-type epoxy compounds, naphthalene-type epoxy compounds, quinol-type epoxy compounds, phenol aralkyl type epoxy compounds, naphthol aralkyl type epoxy compounds, dicyclopentadien Alkene 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 𠯤 nuclei on the skeleton Epoxy compounds, etc.

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

From the viewpoint of further improving the bonding strength between the hardened material 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, and preferably 70% by weight or less, more preferably 65% by weight or less, still more preferably 60% by weight or less, particularly preferably 55% by weight or less.

The molecular weight of the above-mentioned 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.

Regarding the molecular weight of the epoxy compound and the molecular weight of the following hardener, when the epoxy compound or the hardener is not a polymer, and when the structural formula of the epoxy compound or the hardener can be specified, it means that it can be derived from the molecular weight of the epoxy compound or the hardener. Molecular weight calculated from structural formula. In addition, when the epoxy compound or hardener is a polymer, it means the weight average molecular weight.

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

In the conventional laminated film, if the insulating resin layer contains an inorganic filler, the base film may naturally peel off from the insulating resin layer during hardening. Furthermore, when the base film is peeled off from the insulating resin layer after hardening, the base film may not be able to be peeled off. The material film and the insulating resin layer are well peeled off, but the base film is easily broken. However, in the laminated film of the present invention, even when the insulating resin layer contains an inorganic filler, the base film can be further suppressed from being naturally peeled off from the insulating resin layer during curing, and the base film can be further suppressed from being peeled off after curing. Poor peeling of the base film when the insulating resin layer peels off.

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

From the perspective of reducing the surface roughness of the surface of the hardened object, further improving the bonding strength between the hardened object and the metal layer, forming further finer wiring on the surface of the hardened object, and imparting better insulation reliability to the hardened object. , the above-mentioned inorganic filler is preferably silica or alumina, more preferably silica, and further preferably fused silica. By using silica, the thermal expansion coefficient of the hardened material is further reduced, the surface roughness of the surface of the hardened material is effectively reduced, and the bonding strength between the hardened material and the metal layer is effectively increased. The shape of silicon dioxide is preferably spherical.

From the viewpoint of hardening the resin without relying on the hardening environment, effectively increasing the glass transition temperature of the hardened material, and effectively reducing the thermal expansion coefficient of the hardened material, the above-mentioned inorganic filler is preferably spherical silica.

The average particle diameter of the above-mentioned 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 further preferably 1 μm or less, preferably 0.5 μm or less. If the average particle diameter of the inorganic filler is equal to or greater than the aforementioned lower limit and equal to or less than the aforementioned upper limit, the bonding strength between the cured material and the metal layer becomes higher.

As the average particle diameter of the above-mentioned inorganic filler, a value that becomes the 50% median diameter (d50) is used. 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 size of the inorganic fillers is measured based on the entire inorganic filler included 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 above-mentioned inorganic filler is preferably spherical, more preferably spherical silica. In this case, the surface roughness of the surface of the hardened object is effectively reduced, and the bonding strength between the hardened object and the metal layer is effectively increased. When the inorganic filler is spherical, the aspect ratio of the inorganic filler is preferably 2 or less, more preferably 1.5 or less.

The above-mentioned inorganic filler is preferably surface-treated, more preferably surface-treated based on a coupling agent, and even more preferably surface-treated based on a silane coupling agent. Thereby, the surface roughness of the surface of the roughened hardened object is further reduced, the bonding strength between the hardened object and the metal layer is further increased, further fine wiring can be formed on the surface of the hardened object, and further good texture is imparted to the hardened object. Insulation reliability between wiring and interlayer insulation reliability.

Examples of the coupling agent include silane coupling agents, titanium coupling agents, aluminum coupling agents, and the like. Examples of the silane coupling agent include methacrylic silane, acrylic silane, aminosilane, imidazolesilane, vinylsilane, and epoxysilane.

In 100% by weight of the above-mentioned insulating resin layer, the content of the above-mentioned inorganic filler is preferably 30% by weight or more, more preferably 40% by weight or more, further preferably 50% by weight or more, especially 60% by weight or more, most preferably It is more than 70% by weight. 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, particularly preferably 80% by weight or less. If the content of the above-mentioned inorganic filler is above the above-mentioned lower limit and below the above-mentioned upper limit, the surface roughness of the surface of the hardened object will be further reduced, the bonding strength between the hardened object and the metal layer will be further increased, and the formation on the surface of the hardened object will be further finer. of wiring. Furthermore, if the content of the inorganic filler is this, the thermal expansion coefficient of the cured material can be reduced and the slag removability can be improved. If the content of the above-mentioned inorganic filler is equal to or higher than the above-mentioned lower limit, the dielectric loss tangent becomes effectively low. If the content of the inorganic filler is below the upper limit, 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 above-mentioned hardening agent is not particularly limited. As the hardening agent, a conventionally known hardening agent can be used. Only one type of the above-mentioned hardening agent may be used, or two or more types may be used in combination.

Examples of the hardener include cyanate ester compounds (cyanate ester hardeners), phenol compounds (phenol hardeners), amine compounds (amine hardeners), thiol compounds (mercaptan hardeners), imidazole compounds, Phosphine compounds, acid anhydrides, dicyandiamide, carbodiimide compounds (carbodiimide hardener), maleimide compounds (maleimide hardener), and 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 ester 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 peeling the base film from the insulating resin layer after curing, the curing agent preferably contains phenol. compounds, cyanate ester 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 above-mentioned cyanate ester compound may be a cyanate ester compound (cyanate ester hardener). Examples of the cyanate ester compound include novolac-type cyanate ester resin, bisphenol-type cyanate ester resin, and prepolymers obtained by trimerizing a part of these. Examples of the novolak-type cyanate ester resin include phenolic novolak-type cyanate ester resins, alkylphenol-type cyanate ester resins, and the like. Examples of the bisphenol-type cyanate ester resin include bisphenol A-type cyanate ester resin, bisphenol E-type cyanate ester resin, tetramethylbisphenol F-type cyanate ester resin, and the like.

Commercially available products of the cyanate ester compound include phenolic novolak-type cyanate ester resins ("PT-30" and "PT-60" manufactured by Lonza Japan) and bisphenol-type cyanate ester resins. Trimerized prepolymers ("BA-230S", "BA-3000S", "BTP-1000S" and "BTP-6020S" manufactured by Lonza Japan), etc.

Examples of the phenol compound include novolak-type phenol, biphenol-type phenol, naphthalene-type phenol, dicyclopentadiene-type phenol, aralkyl-type phenol, dicyclopentadiene-type phenol, and the like.

Commercially available products of the above-mentioned phenolic compound include: novolak-type phenol ("TD-2091" manufactured by DIC Corporation), biphenyl novolak-type phenol ("MEH-7851" manufactured by Meiwa Kasei Co., Ltd.), aralkyl phenol compounds ("MEH-7800" manufactured by Meiwa Kasei Co., Ltd.), and phenols with an amino triskeleton skeleton ("LA1356" and "LA3018-50P" manufactured by DIC Corporation), etc.

Active ester compounds refer to compounds that contain at least one ester bond in the structure and have aromatic rings bonded to both sides of the ester bond. The active ester compound is obtained, for example, by the condensation reaction of a carboxylic acid compound or a thiocarboxylic acid compound and a hydroxy compound or a thiol compound. Examples of active ester compounds 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. Preferable 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 substituent include hydrocarbon groups. The number of carbon atoms in the hydrocarbon group is preferably 12 or less, more preferably 6 or less, still more preferably 4 or less.

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

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

The above carbodiimide compound has a structural unit represented by the following formula (2). In the following formula (2), the right end part and the left end part are the bonding parts with other groups.

[Chemicalization 2]

In the above formula (2), A group having a substituent bonded to an aryl group, and p represents an integer from 1 to 5. When there are multiple X's, the multiple X's may be the same or different.

In a preferred embodiment, at least one X is an alkylene group, a group having a substituent bonded to the alkylene group, a cycloalkylene group, or a group having a substituent bonded to the cycloalkylene group.

Commercially available products of the carbodiimide compound include "Carbodilite V-02B", "Carbodilite V-03", "Carbodilite V-04K", "Carbodilite V-07", "Carbodilite V-07" manufactured by Nisshinbo Chemical Co., Ltd. Carbodilite V-09", "Carbodilite 10M-SP" and "Carbodilite 10M-SP (modified)", as well as "Stabaxol P", "Stabaxol P400" and "Hykasil 510" manufactured by Rhein Chemie.

As the above-mentioned maleimide compound, a conventionally known maleimide compound can be used. Only one type of the above-mentioned maleimide compound may be used, or two or more types may be used in combination.

The above-mentioned maleimide compound may be a bismaleimine compound.

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

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

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

In the above maleimide compound, it is preferable that a nitrogen atom and an aromatic ring are bonded to the maleimine 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. More preferably, it is 1 weight% or more, and more preferably, it is 15 weight% or less, More preferably, it is 10 weight% or less.

In 100% by weight of components other than inorganic fillers and solvents in the above-mentioned insulating resin layer, the content of the above-mentioned maleimide compound is preferably 2.5% by weight or more, more preferably 5% by weight or more, and still more preferably The content is 7.5% by weight or more, preferably 50% by weight or less, and more preferably 35% by weight or less. If the content of the maleimide compound is above the above lower limit and below the above 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 1,000 or more, more preferably less than 30,000, more preferably less than 20,000. .

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

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

The molecular weight of the above-mentioned 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 the above-mentioned insulating resin layer, the total content of the above-mentioned epoxy compound and the above-mentioned hardener is preferably 75% by weight or more, more preferably 80% by weight or more, and preferably 100% by weight of components other than the above-mentioned inorganic filler. 99% by weight or less, more preferably 97% by weight or less. If the total content of the above-mentioned epoxy compound and the above-mentioned hardening agent is not less than the above-mentioned lower limit and below the above-mentioned upper limit, a further good cured product can be obtained, and the melt viscosity can be adjusted, so the dispersibility of the inorganic filler becomes good. This can prevent the insulating resin layer from wetting and spreading to unintended areas during the curing process. Furthermore, dimensional change of the hardened material due to heat can be further suppressed. Furthermore, if the total content of the above-mentioned epoxy compound and the above-mentioned hardener is more than the above-mentioned lower limit, the melt viscosity will not become too low, and the insulating film will become difficult to excessively wet and spread to unintended areas during the curing process. tendency. Moreover, if the total content of the above-mentioned epoxy compound and the above-mentioned hardener is less than the above-mentioned upper limit, it becomes easier to fit into the holes or unevenness of the circuit board, and further, there is a tendency that the inorganic filler becomes less likely to exist non-uniformly.

In 100% by weight of components other than the above-mentioned inorganic filler in the above-mentioned insulating resin layer, the content of the above-mentioned hardener is preferably 30% by weight or more, more preferably 40% by weight or more, and more preferably 70% by weight or less, and more Preferably, it is less than 60% by weight. If the content of the curing agent is equal to or greater than the aforementioned lower limit and equal to or less than the aforementioned upper limit, a further excellent cured 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, phenoxy resin, and the like. Only one type of the above-mentioned thermoplastic resin may be used, or two or more types may be used in combination.

From the viewpoint of effectively reducing the dielectric loss tangent without relying on a hardening environment and effectively improving the adhesion of metal wiring, the above-mentioned thermoplastic resin is preferably a phenoxy resin. By using phenoxy resin, it is possible to suppress the deterioration of the insulating resin layer's ability to fit into the holes or unevenness of the circuit board and the non-uniformity of the inorganic filler. In addition, by using phenoxy resin, the melt viscosity can be adjusted, so the dispersibility of the inorganic filler becomes good, and the insulating resin layer becomes difficult to wet and spread to unintended areas during the curing process. The above-mentioned 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 above-mentioned 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-type skeleton, a bisphenol F-type skeleton, a bisphenol S-type skeleton, a biphenyl skeleton, a novolak skeleton, a naphthalene skeleton, and an amide imine skeleton. Oxygen-based resins, etc.

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

From the viewpoint of obtaining an insulating resin layer with 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 weight average molecular weight of the thermoplastic resin represents the weight average molecular weight measured by gel permeation chromatography (GPC) in terms of polystyrene.

The contents of the above-mentioned thermoplastic resin and the above-mentioned phenoxy resin are not particularly limited. In 100% by weight of components other than the above-mentioned inorganic filler in the insulating resin layer, the content of the above-mentioned thermoplastic resin (the content of the phenoxy resin when the above-mentioned thermoplastic resin is a phenoxy resin) is preferably 1% by weight. More preferably, it is 5 weight% or more, More preferably, it is 30 weight% or less, More preferably, it is 15 weight% or less. When the content of the thermoplastic resin is equal to or greater than the aforementioned lower limit and equal to or less than the aforementioned upper limit, the embedding property of the insulating resin layer into holes or unevenness of the circuit board becomes good. If the content of the thermoplastic resin is equal to or higher than the lower limit, the formation of the insulating resin layer becomes easier, and a better insulating layer can be obtained. If the content of the thermoplastic resin is equal to or less than the upper limit, the thermal expansion coefficient of the cured product will be further reduced. The surface roughness of the hardened object is further reduced, and the bonding strength between the hardened object and the metal layer is further increased.

[hardening accelerator] The insulating resin layer preferably contains a hardening accelerator. By using the above-mentioned hardening accelerator, the hardening speed is further accelerated. By rapidly hardening the insulating resin layer, the cross-linked structure in the hardened product becomes uniform, and the number of unreacted functional groups is reduced, resulting in a higher cross-link density. The above-mentioned hardening accelerator is not particularly limited, and conventionally known hardening accelerators can be used. Only one type of the above-mentioned hardening accelerator may be used, or two or more types may be used in combination.

Examples of the hardening accelerator include imidazole compounds, phosphorus compounds, amine compounds, organic metal compounds, and the like.

Examples of the imidazole compound include 2-undecylimidazole, 2-heptadecylimidazole, 2-methylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, and 2-benzene 1-4-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-Undecyl imidazolium trimellitate, 1-cyanoethyl-2-phenylimidazolium trimellitate, 2,4-diamino-6-[2'-methylimidazolyl -(1')]-ethyl mesosine, 2,4-diamino-6-[2'-undecyl imidazolyl-(1')]-ethyl mesosine, 2,4- Diamino-6-[2'-ethyl-4'-methylimidazolyl-(1')]-ethyl mesitylene, 2,4-diamino-6-[2'-methylimidazole Base-(1')]-ethyl mesostrimeric isocyanuric acid adduct, 2-phenylimidazole isocyanuric acid adduct, 2-methylimidazole isocyanuric acid adduct, 2-phenyl-4,5-dihydroxymethylimidazole and 2-phenyl-4-methyl-5-dihydroxymethylimidazole, etc.

Examples of the phosphorus compound include triphenylphosphine.

Examples of the amine compound include diethylamine, triethylamine, diethyltetramine, triethyltetramine, 4,4-dimethylaminopyridine, and the like.

Examples of the organic metal compound include zinc naphthenate, cobalt naphthenate, tin octoate, cobalt octoate, cobalt bisacetyl acetonate (II), cobalt triacetyl acetonate (III), and the like.

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

[Solvent] The above-mentioned insulating resin layer does not contain or contains a solvent. Moreover, the said solvent can also be used in order to obtain the slurry containing the said inorganic filler. Only one type of the above solvent 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, and 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, etc.

Most of the above solvents are preferably removed when the above insulating resin layer is formed. Therefore, the boiling point of the above solvent is preferably 200°C or lower, 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 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, 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, defoaming agents, tackifiers, thixotropic agents and other thermosetting resins other than epoxy compounds.

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

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

As a method of obtaining the above-described insulating resin layer, the following methods and the like can be cited. Extrusion molding method: Using an extruder, the material used to form the insulating resin layer is melted and kneaded. After extrusion, it is formed into a film shape using a T-shaped die or a circular die. Tape casting method: The material used to form the insulating resin layer containing the solvent is cast and formed into a film shape. Other previously known film forming methods. Alternatively, a material for forming an insulating resin layer may be laminated on a 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 tape casting method is preferred. Membranes include sheets.

A B-stage film can be obtained by molding the material used to form the insulating resin layer into a film shape, and heating and drying it at 50°C to 150°C for 1 to 10 minutes so that hardening by heat will not proceed excessively. 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 material is not completely hardened and can be further hardened.

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

The minimum melt viscosity of the above-mentioned insulating resin layer (when the above-mentioned insulating resin layer is a B-stage film, it is a B-stage film) in a temperature range of 60°C to 180°C is preferably 5 mPa·s or more, and is preferably 5 mPa·s or more. The best value is 10 mPa·s or more. If the minimum melt viscosity is above the above lower limit, the resin can be prevented from exuding to unintended areas during lamination and pressure processing, and peeling defects when peeling off the base film after hardening can be effectively suppressed. Furthermore, it can also be effectively suppressed. Prevents natural peeling. The upper limit of the minimum melt viscosity of the above-mentioned insulating resin layer (when the above-mentioned insulating resin layer is a B-stage film, it is a B-stage film) in a temperature range of 60°C to 180°C is not particularly limited. The minimum melt viscosity of the above-mentioned insulating resin layer (when the above-mentioned insulating resin layer is a B-stage film, it is a B-stage film) in a temperature range of 60°C to 180°C 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 minimum melt viscosity is preferably 140°C or lower, more preferably 130°C or lower. If the temperature at the minimum melt viscosity is below the upper limit, natural peeling accompanying shrinkage of the base film can be effectively suppressed.

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

From the viewpoint of further improving the lamination properties of the insulating resin layer (when the insulating resin layer is a B-stage film, the B-stage film) and further suppressing uneven hardening 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, more preferably 100 μm or less.

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

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

From the viewpoint of further improving the protective properties 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 the 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-described insulating resin layer can be preferably used to form an insulating layer on a multilayer printed wiring board. An insulating layer can be formed by the insulating resin layer of the laminated film of the present invention.

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

(Method for manufacturing laminated structure) The manufacturing method of the laminated structure of the present invention includes a lamination step of using the above-mentioned laminated film, in a state where the above-mentioned base film and the above-mentioned insulating resin layer are laminated, and laminating the surface of the above-mentioned insulating resin layer opposite to the above-mentioned base film. On the laminated target component with a metal layer on the surface. The manufacturing method of the laminated structure of the present invention includes a via hole forming step: in a state where the base film and the insulating resin layer are laminated, irradiating the insulating resin layer with laser from the side of the base film to form a via hole.

Since the manufacturing method of the laminated structure of the present invention has the above-mentioned structure, the base film can be prevented from being naturally peeled off from the insulating resin layer in the above-mentioned hardening step.

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

In the lamination step, when the laminate film has the protective film, the protective film is peeled off, and the surface of the insulating resin layer exposed by peeling is laminated on the lamination target member having the metal layer on the surface.

The above-mentioned layering step is preferably performed by lamination. The temperature during lamination is preferably 80°C or higher and 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 this invention, it is preferable to harden the said insulating resin layer. In the above-mentioned curing step, the above-mentioned insulating resin layer is cured to form a cured product. The hardening of the insulating resin layer in the above hardening step may be pre-hardening. The above-mentioned hardened materials also include pre-hardened materials that can be further hardened. In the above-mentioned hardening step, the above-mentioned insulating resin layer may also be pre-hardened to obtain a B-stage film.

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

In order to form fine unevenness on the surface of the hardened material obtained by pre-hardening the insulating resin layer, it is preferable to perform a roughening process on the hardened material. It is preferable to subject the hardened material to swelling treatment before roughening treatment. For the hardened material, it is preferable to perform swelling treatment after preliminary hardening and before roughening treatment, and then harden it after roughening treatment. However, the hardened material does not need to be subjected to swelling treatment.

As the above-mentioned swelling treatment method, for example, a method can be used in which the hardened material is treated with an aqueous solution of a compound containing ethylene glycol or the like as a main component or an organic solvent dispersion solution. The swelling liquid used for swelling treatment usually contains a base as a pH adjuster or the like. The swelling liquid preferably contains sodium hydroxide. Specifically, for example, the above-mentioned swelling treatment is performed by using a 40% by weight ethylene glycol aqueous solution or the like to treat the hardened material at a treatment temperature of 30°C to 85°C for 1 to 30 minutes. The temperature of the above-mentioned swelling treatment is preferably in the range of 50°C to 85°C. If the temperature of the above-mentioned swelling treatment is too low, the swelling treatment will take a long time, and the bonding strength between the hardened material and the metal layer will tend to decrease.

For the roughening treatment, chemical oxidants such as manganese compounds, chromium compounds, and persulfate compounds can be used. These chemical oxidants are used as aqueous solutions or organic solvent dispersions 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 manganese compound include potassium permanganate, sodium permanganate, and the like. Examples of the chromium compound include potassium dichromate, potassium chromic anhydride, and the like. Examples of the persulfate compound include sodium persulfate, potassium persulfate, ammonium persulfate, and the like.

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

(via hole formation step) 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 laminated, a laser is irradiated from the side of the base film to the insulating resin layer to form a via hole.

Examples of the laser used in the via hole forming step include CO ₂ laser, UV (Ultraviolet, ultraviolet) laser, and the like.

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

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

(Glame removal step) The manufacturing method of the multilayer structure of the present invention preferably includes a step of removing the smear inside the via hole through a desmear process (a desmearing step) after the via hole forming step. By having the above-mentioned smear removal step, the smear, which is the residue of the resin from the resin component formed in the above-mentioned via hole forming step, can be effectively removed.

In the above desmearing step, chemical oxidants such as manganese compounds, chromium compounds, or persulfate compounds are used, for example. These chemical oxidants are used as aqueous solutions or organic solvent dispersions after adding water or organic solvents. The desmear treatment liquid used in the desmearing step usually contains alkali. The desmear treatment liquid preferably contains sodium hydroxide.

The above desmear removal step can also serve as a roughening step for roughening the surface of the insulating resin layer.

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

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

In the manufacturing method of the laminated structure of the present invention, since it has the above-mentioned structure, it is possible to suppress peeling defects of the base film in the above-mentioned peeling step.

(additional 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 to perform a plating treatment on the insulating resin layer exposed by the peeling after the peeling step. A metal layer is formed on the surface, and the formal hardening step is performed after the plating step to further harden the insulating resin layer.

Hereinafter, the present invention will be explained concretely by giving examples and comparative examples. The present invention is not limited to the following examples.

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

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

(Material used to form insulating resin layer) Materials for forming the insulating resin layer are prepared in the following manner.

Materials used to form the insulating resin layer A: 69.3 parts by weight of cyclohexanone slurry (solid content 70% by weight) of vinylsilane-treated silica ("SOC2" manufactured by Admatechs) was prepared. To this slurry were added 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 quinoa ring Oxygen compound ("OGSOL PG-100" manufactured by Osaka Gas Chemicals Co., Ltd.) 2.0 parts by weight. Use a mixer to stir at 1200 rpm for 60 minutes and confirm that undissolved matter disappears. Thereafter, 1.6 parts by weight of a phenolic novolac hardener ("H4" manufactured by Meiwa Kasei Co., Ltd.) and a toluene mixed solution (solid content 65%) of an active ester hardener ("HPC-8000-65T" manufactured by DIC Corporation) were added Weight%) 13 parts by weight, stir at 1200 rpm for 60 minutes, and confirm that the undissolved matter disappears. A mixed solution of methyl ethyl ketone and cyclohexanone (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 this 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 (Kusumoto Chemical Co., Ltd. Manufactured "LS-480") 0.1 part by weight. Stir at 1200 rpm for 30 minutes to obtain the material (varnish) used to form the insulating resin layer A.

Materials used to form insulating resin layer B: In addition to changing the active ester hardener ("HPC-8000-65T" manufactured by DIC Corporation) to a phenolic novolac hardener ("MEH7851-H" manufactured by Meiwa Kasei Co., Ltd.), it is used to form the insulating resin layer. The material (varnish) used to form the insulating resin layer B is obtained in the same manner as the material A.

(Example 1) Steps for arranging an insulating resin layer on the surface of the base film: Using a die nozzle coater, apply the material used to form the insulating resin layer A on the base film A with a width of 510 mm, except for a range of 20 mm from both ends in the width direction of the base material. (varnish), it was dried at an average temperature of 100° C. for 3 minutes to evaporate the solvent. In this way, the 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 the end faces of the laminated body in the width direction: Use a slitting machine at a position 30 mm inward from one end (the other end) and a position 18 mm inward from the end (one end) opposite to the other end in the width direction of the obtained laminate. Cut into strips at a speed of 10 m/min, and align the end surface of the base film on the other end side with the end surface of the insulating resin layer. In this way, a laminated film was obtained in which the distance (Y) extending from the end surface of the base film to the end surface of the insulating resin layer on one end side was 2 mm.

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

(evaluate) (1) Peeling strength of the base film relative to the insulating resin layer (X) The obtained laminated film was measured using a tensile testing machine ("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 Based on the distance (Y) protruding from one end side of the obtained laminated film relative to the end surface of the insulating resin layer, the end surface of the base film, and the distance (Y) measured in the above (1) between the base film and the insulating resin layer Peel strength (X), calculate Y/X.

(3)The lowest melt viscosity and the temperature at which the lowest melt viscosity occurs The base film is peeled off 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 under the conditions of frequency 6.28 rad/sec, starting temperature 60°C, heating rate 5°C/min, and strain 21.8%. Measure the dynamic viscoelasticity under the conditions to find the minimum melt viscosity and the temperature at which the minimum melt viscosity occurs. The results are shown below.

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

(4)Natural peeling Layering steps: A 340 mm × 510 mm CCL (Copper Clad Laminate) substrate ("E679FG" manufactured by Hitachi Chemical Industries, Ltd.) with an inner circuit formed by etching was prepared. Both sides 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-mentioned CCL substrate from the resin film side, and laminated using a diaphragm-type vacuum laminating machine ("MVLP-500" manufactured by Meiki Seisakusho Co., Ltd.). Unhardened laminated sample A was obtained from both sides of the above-mentioned CCL substrate. Lamination was performed by depressurizing for 20 seconds to lower the air pressure to 13 hPa or less, pressurizing at 100°C for 20 seconds, and then pressurizing at 100°C and a pressure of 0.8 MPa for 40 seconds.

Hardening steps: The above-mentioned 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-mentioned hardening step, it is visually confirmed whether the base film is naturally peeled off from the insulating resin layer.

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

(5) Crack of base film (poor peeling) After evaluating the natural peeling in (4) above, perform the following steps.

Via hole formation step: 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 a CO ₂ laser (manufactured by Hitachi Via Mechanics Co., Ltd.) from the base film side. "LC-4KF212"), a via hole is formed that penetrates the base film and the insulating resin layer so that the upper end diameter 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 aperture 28 mm power 3.3 W

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

In the above-mentioned peeling step, whether the base film is cracked is visually confirmed.

[Evaluation criteria for substrate film rupture] ○: No cracking of the base film occurred △: Slight cracking of the base film occurs ×: Crack of base film occurs

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‧‧‧Laminated film 1Aa‧‧‧One end 1Ab‧‧‧The other end 1a‧‧‧One end 1b‧‧‧The other end 2‧‧‧Substrate film 2A‧‧‧Substrate film 2Aa‧‧‧1st surface 2a‧‧‧Surface 1 3‧‧‧Insulating resin layer 3A‧‧‧Insulating resin layer Y‧‧‧The protruding distance of the base film from one end of the laminated film

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

Claims (11)

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 face of the base film faces outward relative to the end face of the insulating resin layer. Maximum protrusion, when the peel strength of the above-mentioned base film with respect to the above-mentioned insulating resin layer is set to X gf/cm, and the protruding distance of the above-mentioned base film on the one end side is set to Y mm, Y/ It is 0.5 or more and 15 or less, and the arithmetic mean roughness Ra of the surface of the said base film on the said insulating resin layer side is 5 nm or more and less than 400 nm. The laminated film of Claim 1, wherein the above-mentioned X is 0.3 or more and 9 or less. For example, the laminated film of claim 1 or 2, wherein the above-mentioned Y is 0.5 or more and 20 or less. The laminated film of claim 1 or 2, wherein the thickness of the above-mentioned base film is 25 μm or more. The laminated film of claim 1 or 2, wherein the insulating resin layer contains an epoxy compound, an inorganic filler and a hardener. The laminated film of claim 5, wherein the hardener contains a phenol compound, a cyanate ester compound, a maleimide compound or an active ester compound. The laminated film of Claim 1 or 2, wherein the base film is aligned with the end surface of the insulating resin layer on the other end side of the laminated film opposite to the above-mentioned one end, or the above-mentioned one end side of the laminated film is aligned with the end surface opposite to the above-mentioned one end. On both sides of the other end side, relative to the end surface of the insulating resin layer, the end surface of the above-mentioned base material film protrudes outward, and the protrusion distance of the above-mentioned base material film on the above-mentioned other end side is smaller than the above-mentioned base material film on the one end side the extended distance. For example, the laminated film of claim 1 or 2, wherein the minimum melt viscosity of the above-mentioned insulating resin layer in the temperature range of above 60°C and below 180°C is 5mPa‧s or more. The laminated film according to claim 1 or 2, wherein the 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 in which the laminated film according to any one of claims 1 to 9 is used, and in a state where the above-mentioned base film and the above-mentioned insulating resin layer are laminated, the above-mentioned insulating resin is The surface of the layer opposite to the above-mentioned base film is laminated on a lamination target member having a metal layer on the surface; and a via hole forming step is performed in a state where the above-mentioned base film and the above-mentioned insulating resin layer are laminated, from the above-mentioned base material On the film side, the insulating resin layer is irradiated with laser to form via holes. The method of manufacturing a laminated structure according to claim 10, further comprising a hardening step of hardening the insulating resin layer between the lamination step and the via hole forming step.