KR102667700B1 - Laminated films and methods for producing laminated films - Google Patents

Abstract

A laminated film is provided that can suppress cracking of the resin layer during peeling of the protective film and also suppress uneven curing of the resin layer. The laminated film according to the present invention is provided with a base material, a resin layer, and a protective film, and on one end side of the laminated film, the end faces of the base material and the protective film are each turned outward with respect to the end face of the resin layer. It protrudes, and on the other end side of the laminated film opposite to the one end side, the end surfaces of the base material, the resin layer, and the protective film are aligned, or the one end side and the one end side of the laminated film On both sides of the opposite end side, the end surfaces of the base material and the protective film each protrude outward with respect to the end face of the resin layer, and the base material and the end surface on the other end side are respectively protruded outward. The protruding distance of the protective film is smaller than the protruding distance between the base material and the protective film on the one end side.

Description

Laminated films and methods for producing laminated films

The present invention relates to a laminated film comprising a base material, a resin layer, and a protective film. Additionally, the present invention relates to a method for producing a laminated film comprising a base material, a resin layer, and a protective 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 to insulate the internal layers or to form an insulating layer located in the surface layer. In order to form the above insulating layer, a laminated film provided with a resin layer is used.

As an example of the laminated film, Patent Document 1 below discloses an adhesive sheet with a protective film comprising a support, a resin composition layer, and a protective film. When manufacturing this adhesive sheet with a protective film, a step of slitting (cutting) the adhesive sheet with a protective film is performed. In the example of Patent Document 1, both ends of the adhesive sheet with a protective film in the width direction are slit. For this reason, in the example of Patent Document 1, end surfaces on both sides of the support, the resin composition layer, and the protective film in the width direction are aligned.

Japanese Patent Publication No. 2016-74788

In a laminated film including a base material, a resin layer, and a protective film, the protective film peels when the resin layer is used. Additionally, the resin layer exposed by peeling off the protective film is adhered to an adherend such as a metal layer (for example, a laminate of a substrate and metal wiring, etc.), and the resin layer is cured by heating.

In conventional laminated films such as those described in Patent Document 1, cracks may occur in the resin layer when the protective film is peeled. Additionally, when using the laminated film, if the laminated film is heated in a heating oven or the like, the base material may be partially peeled off from the resin layer by hot air, causing curing unevenness in the resin layer.

An object of the present invention is to provide a laminated film that can suppress cracking of the resin layer during peeling of the protective film and can suppress uneven curing of the resin layer.

According to a broad aspect of the present invention, there is provided a substrate, a resin layer laminated on a surface of the substrate, and a protective film laminated on a surface of the resin layer opposite to the substrate side, wherein the resin layer is laminated on one end side of the laminated film. wherein the end surfaces of the base material and the protective film each protrude outward with respect to the end face of the resin layer, and on the other end side of the laminated film opposite to the end face, the base material and the The end surfaces of the resin layer and the protective film are aligned, or the base material and the protective film are aligned with the end surfaces of the resin layer on both one end side of the laminated film and the other end side opposite to the one end side. The end surfaces of each protrude outward, and the protrusion distance between the base material and the protective film on the other end side is such that the protrusion distance between the base material and the protective film on the one end side protrudes. A laminated film that is smaller than the distance is provided.

In a certain aspect of the laminated film according to the present invention, on one end side of the laminated film, the end surfaces of the base material and the protective film each protrude outward with respect to the end surface of the resin layer, and the end surfaces of the laminated film each protrude outward. On the other end side opposite to the one end, the end surfaces of the base material, the resin layer, and the protective film are aligned.

In a specific aspect of the laminated film according to the present invention, in the direction connecting the one end and the other end of the laminated film, when the size of the base material is W ₁ mm and the size of the resin layer is W ₂ mm , W ₂ /W ₁ is 0.9 or more and 0.999 or less.

In a specific aspect of the laminated film according to the present invention, in the direction connecting the one end and the other end of the laminated film, the dimension of the resin layer is W ₂ mm and the dimension of the protective film is W ₃ mm. At this time, W ₂ /W ₃ is 0.9 or more and 0.999 or less.

In a specific aspect of the laminated film according to the present invention, the resin layer contains an inorganic filler, a curing agent, and a thermosetting compound.

In a specific aspect of the laminated film according to the present invention, the content of the inorganic filler is 30% by weight or more in 100% by weight of the resin layer.

According to a broad aspect of the present invention, there is a method for producing the above-described laminated film, wherein a resin layer is disposed on the surface of a substrate so that the end surface of the substrate protrudes outward with respect to the end surface on the one end side of the resin layer. A first step, and a step of disposing a protective film on a surface of the resin layer opposite to the substrate side so that the end surface of the protective film protrudes outward with respect to the end surface of the one end side of the resin layer. 2 steps, wherein on one end of the laminated film corresponding to the one end of the resin layer, the end faces of the substrate and the protective film each protrude outward with respect to the end face of the resin layer, In addition, on the other end side of the laminated film opposite to the one end, the end surfaces of the substrate, the resin layer, and the protective film are aligned, or the other end surface of the laminated film is opposite to the one end. On both sides of the end side, the end surfaces of the substrate and the protective film each protrude outward with respect to the end surface of the resin layer, and the substrate and the protective film protrude outward on the other end side. A method for producing a laminated film is provided, which obtains a laminated film in which the protruding distance is smaller than the protruding distance between the base material and the protective film on the one end side.

In a specific aspect of the method for manufacturing a laminated film according to the present invention, the method for manufacturing a laminated film is, after the second step, on the other end side of the resin layer opposite to the one end side, the substrate and the Aligning the end surfaces of the resin layer and the protective film, or after the second step, on the other end side of the resin layer opposite to the one end side, the substrate and the protection film on the other end side. A third step is further provided to make the protruding distance of the film smaller than the protruding distance between the base material and the protective film on the one end side.

In a certain situation of the manufacturing method of the laminated film which concerns on this invention, in the said 3rd process, the said base material, the said resin layer, and the said protective film are slitted.

In a specific aspect of the method for manufacturing a laminated film according to the present invention, on the side of one end of the laminated film corresponding to the one end of the resin layer, the end surface of the base material and the protective film is relative to the end surface of the resin layer. A laminated film is obtained in which each of these protrudes outward and the end surfaces of the substrate, the resin layer, and the protective film are aligned on the other end side opposite to the one end of the laminated film.

The laminated film according to the present invention includes a base material, a resin layer laminated on the surface of the base material, and a protective film laminated on the surface of the resin layer opposite to the base material side. The laminated film according to the present invention has the following configuration (1) or (2). (1) On the one end side of the laminated film, the end surfaces of the substrate and the protective film each protrude outward with respect to the end surface of the resin layer, and the other end of the laminated film is opposite to the one end of the laminated film. On the side, the end surfaces of the base material, the resin layer, and the protective film are aligned. (2) On both one end side of the laminated film and the other end side opposite to the one end side, the end faces of the substrate and the protective film each protrude outward with respect to the end face of the resin layer, Moreover, the protruding distance between the substrate and the protective film on the other end side is smaller than the protruding distance between the substrate and the protective film on the one end side. Since the laminated film according to the present invention has the above structure, cracking of the resin layer during peeling of the protective film can be suppressed, and curing unevenness of the resin layer can also be suppressed.

1 is a cross-sectional view schematically showing a laminated film according to a first embodiment of the present invention.
Fig. 2 is a cross-sectional view schematically showing a laminated film according to a second embodiment of the present invention.
FIG. 3 is a cross-sectional view for explaining an example of a method for manufacturing a laminated film according to the first embodiment of the present invention.

Hereinafter, the present invention will be described in detail.

The laminated film according to the present invention includes a base material, a resin layer, and a protective film. In the laminated film according to the present invention, the base material, the resin layer, and the protective film are laminated in this order. The resin layer is laminated on the surface of the substrate. The protective film is laminated on the surface of the resin layer opposite to the substrate side.

The laminated film according to the present invention has the following configuration (1) or (2).

(1) On the one end side of the laminated film, the end surfaces of the substrate and the protective film each protrude outward with respect to the end surface of the resin layer, and the other end of the laminated film is opposite to the one end of the laminated film. On the side, the end surfaces of the substrate, the resin layer, and the protective film are aligned. (Hereinafter, it may be referred to as the laminated film (1).)

(2) On both one end side of the laminated film and the other end side opposite to the one end side, the end faces of the substrate and the protective film each protrude outward with respect to the end face of the resin layer, In addition, the protruding distance between the base material and the protective film on the other end side is smaller than the protruding distance between the base material and the protective film on the one end side. (hereinafter referred to as laminated film (2) ) may be written)

Since the laminated film according to the present invention has the above structure, cracking of the resin layer during peeling of the protective film can be suppressed, and curing unevenness of the resin layer can also be suppressed. As a result, the insulation reliability of electronic components such as multilayer printed wiring boards manufactured using the laminated film according to the present invention can be improved.

In the laminated film according to the present invention, the end surfaces of the base material, the resin layer, and the protective film are aligned on the other end side of the laminated film, or the base material and the protective film are aligned on the other end side of the laminated film. The protruding distance is smaller than the protruding distance between the base material and the protective film on one end side. When the base material, the resin layer, and the end surfaces of the protective film are aligned on both one end and the other end of the laminated film, that is, in the case of a conventional laminated film, cracking of the resin layer occurs when the protective film is peeled off. This is easy to happen. For this reason, in the conventional laminated film, it is difficult to suppress cracking of the resin layer when the protective film is peeled. When the end surfaces of the base material, the resin layer, and the protective film are not aligned on both one end and the other end of the laminated film, depending on the protruding distance of the base material and the protective film with respect to the resin layer, Since uneven curing of the resin layer easily occurs, it is difficult to suppress uneven curing of the resin layer.

In the laminated film (1) according to the present invention, on one end side of the laminated film, the end surfaces of the substrate and the protective film each protrude outward with respect to the end surface of the resin layer. In the laminated film 1 according to the present invention, the end surfaces of the substrate, the resin layer, and the protective film are aligned on the other end side of the laminated film. In the laminated film (2) according to the present invention, on both one end side of the laminated film and the other end side opposite to the one end, the end surfaces of the substrate and the protective film are aligned with the end surfaces of the resin layer. Each one protrudes outward. In the laminated film (2) according to the present invention, the protruding distance between the substrate and the protective film on the other end side is the protruding distance between the substrate and the protective film on the one end side. It's smaller than Since the laminated film according to the present invention has the above structure, cracking of the resin layer during peeling of the protective film can be suppressed, and curing unevenness of the resin layer can also be suppressed. In addition, since the laminated film according to the present invention has the above-mentioned structure, the protective film can be easily peeled from one end side of the laminated film.

From the viewpoint of further suppressing cracking of the resin layer when peeling off the protective film and further suppressing uneven curing of the resin layer, among the laminated film (1) and the laminated film (2), the laminated film (1) is preferable. .

On the one end side of the laminated film 1, a method of causing the end surfaces of the base material and the protective film to protrude outward with respect to the end surface of the resin layer, respectively, is used when lamination of each layer in the laminated film 1. Another method is to shift the end surfaces.

On both the one end side of the laminated film 2 and the other end side opposite to the one end, the end faces of the substrate and the protective film are each protruded outward with respect to the end face of the resin layer. As a method, a method of shifting the end surfaces when lamination of each layer in the laminated film is mentioned. In the laminated film 2, the distance at which the end surfaces are shifted is adjusted.

As a method of aligning the end surfaces of the substrate, the resin layer, and the protective film on the other end side opposite to the one end of the laminated film 1, when lamination of each layer in the laminated film , a method of aligning the end surfaces, and a method of slitting the laminate of the base material, the resin layer, and the protective film.

A method of making the overhanging distance between the base material and the protective film on the other end side of the laminated film 2 smaller than the overhanging distance between the base material and the protective film on the one end side. Examples of this include the following methods. When lamination of each layer in a laminated film, the overhanging distance between the base material and the protective film on the other end side is defined as the overhanging distance between the base material and the protective film on the one end side. How to make it smaller. A method of slitting the substrate and protective film among the substrate, resin layer, and protective film.

The method for producing a laminated film according to the present invention has the following configurations (A) or (B). Manufacturing method (A) is a manufacturing method of the laminated film (1), and manufacturing method (B) is a manufacturing method of the laminated film (2). The manufacturing method of the laminated film (1) according to the present invention preferably has the following configuration (A). The manufacturing method of the laminated film (2) according to the present invention preferably has the following configuration (B).

(A) The manufacturing method of the laminated film (1) according to the present invention includes arranging a resin layer on the surface of a substrate so that the end surface of the substrate protrudes outward with respect to the end surface on the one end side of the resin layer. A first process is provided. The manufacturing method of the laminated film (1) according to the present invention is such that, on the surface of the resin layer opposite to the substrate side, the end face of the protective film is hollowed outward with respect to the end face of the one end side of the resin layer. A second step of arranging the protective film so that it sticks out is provided. In the method for manufacturing the laminated film (1) according to the present invention, on the side of one end of the laminated film corresponding to the one end of the resin layer, the end faces of the base material and the protective film are aligned with the end face of the resin layer. A laminated film is obtained, each protruding outward. In the method for manufacturing the laminated film (1) according to the present invention, the end surfaces of the substrate, the resin layer, and the protective film are aligned on the other end side opposite to the one end of the laminated film ( 1) gets

(B) The method for producing the laminated film (2) according to the present invention includes arranging a resin layer on the surface of a substrate so that the end surface of the substrate protrudes outward with respect to the end surface on the one end side of the resin layer. A first process is provided. In this first step, a resin layer is formed on the surface of the substrate so that the end surfaces of the substrate protrude outward with respect to both end surfaces of one end of the resin layer and the other end opposite to the one end. It is desirable to place The manufacturing method of the laminated film (2) according to the present invention is such that, on the surface of the resin layer opposite to the substrate side, the end face of the protective film is hollowed outward with respect to the end face of the one end side of the resin layer. A second step of arranging the protective film so that it sticks out is provided. In this second step, on the surface of the resin layer opposite to the substrate side, the ends of the protective film are applied to both end surfaces of the resin layer on the one end side and the other end side opposite to the one end side. It is desirable to arrange the protective film so that the side surface protrudes outward. In the method for manufacturing the laminated film (2) according to the present invention, the substrate and the protective film are connected to the end surface of the resin layer on both one end side of the laminated film and the other end side opposite to the one end side. A laminated film (2) with each end surface protruding outward is obtained. In the method for manufacturing the laminated film (2) according to the present invention, the protrusion distance between the substrate and the protective film on the other end side is the protrusion distance between the substrate and the protective film on the one end side. A laminated film (2) smaller than the distance shown is obtained.

The manufacturing method (A) of the laminated film according to the present invention is, after the second step, on the other end side opposite to the one end of the resin layer, the end surfaces of the base material, the resin layer, and the protective film are It is desirable to further provide a third process for alignment. In the method (A) for manufacturing a laminated film according to the present invention, in the second step, at the other end of the resin layer opposite to the one end, an end of the substrate, the resin layer, and the protective film is formed. You can align the sides.

The method (B) for producing a laminated film according to the present invention is, after the second step, on the other end side of the resin layer opposite to the one end side, the substrate and the protective film on the other end side. It is preferable to further provide a third step of making the protruding distance smaller than the protruding distance between the base material and the protective film on the one end side. In the method (B) for manufacturing a laminated film according to the present invention, in the second step, the protruding distance between the substrate and the protective film on the other end side is adjusted to the distance between the substrate and the protective film on the one end side. It may be smaller than the protruding distance of the protective film.

From the viewpoint of further flattening the end surface on the other end side of the laminated film 1, the protruding distance between the base material and the protective film on the other end side of the laminated film 2 is determined by From the viewpoint of making it even smaller than the protruding distance between the base material and the protective film on the negative side, it is preferable to make the following slits. In the third step, it is preferable to slit the resin layer. In the third step, it is preferable to slit the substrate, the resin layer, and the protective film.

In the laminated film according to the present invention, the protective film peels when the resin layer is used. An adherend such as a metal layer (for example, a laminate of a substrate and metal wiring, etc.) is generally laminated on the surface of the resin layer after peeling the protective film.

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

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

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

The laminated film 1 includes a base material 4, a resin layer 2, and a protective film 3. The protective film 3 is laminated on the first surface 2a of the resin layer 2. The base material 4 is laminated on the second surface 2b of the resin layer 2 opposite to the first surface 2a.

In the direction connecting one end 1a and the other end 1b of the laminated film 1, the size of the base material 4 is larger than the size of the resin layer 2. The size of the protective film 3 is larger than the size of the resin layer 2. In the direction connecting one end 1a and the other end 1b of the laminated film 1, the size of the resin layer 2 is smaller than the size of the base material 4. The size of the resin layer 2 is smaller than the size of the protective film 3.

On the one end 1a side of the laminated film 1, the end surfaces of the base material 4 and the protective film 3 each protrude outward with respect to the end surface of the resin layer 2. At one end 1a of the laminated film 1, the end surfaces of the base material 4 and the resin layer 2 are not aligned, and the end surfaces of the resin layer 2 and the protective film 3 are aligned. It is not done. The end surface of the laminated film 1 on the one end 1a side has a concave shape in which the resin layer 2 portion is concave. On the one end 1a side of the laminated film 1, there is a portion where the resin layer 2 is not laminated on the substrate 4, and the resin layer 2 is not laminated on the protective film 3. There are parts that are not there.

On the other end 1b side of the laminated film 1, the end surfaces of the base material 4, the resin layer 2, and the protective film 3 are aligned.

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

The laminated film 1A includes a base material 4A, a resin layer 2A, and a protective film 3A. The protective film 3A is laminated on the first surface 2Aa of the resin layer 2A. The base material 4A is laminated on the second surface 2Ab of the resin layer 2A opposite to the first surface 2Aa.

In the direction connecting one end 1Aa and the other end 1Ab of the laminated film 1A, the size of the substrate 4A is larger than the size of the resin layer 2A. The size of the protective film 3A is larger than the size of the resin layer 2A. In the direction connecting one end 1Aa and the other end 1Ab of the laminated film 1A, the size of the resin layer 2A is smaller than the size of the substrate 4A. The size of the resin layer 2A is smaller than the size of the protective film 3A.

On the one end 1Aa side of the laminated film 1A, the end surfaces of the base material 4A and the protective film 3A each protrude outward with respect to the end surface of the resin layer 2A. In one end 1Aa of the laminated film 1A, the end surfaces of the base material 4A and the resin layer 2A are not aligned, and the end surfaces of the resin layer 2A and the protective film 3A are aligned. It is not done. The end surface of the laminated film 1A on the one end 1Aa side has a concave shape in which the resin layer 2A portion is concave. On the one end 1Aa side of the laminated film 1A, there is a portion where the resin layer 2A is not laminated on the substrate 4A, and the resin layer 2A is not laminated on the protective film 3A. There are parts that are not there.

On the other end 1Ab side of the laminated film 1A, the end surfaces of the base material 4A and the protective film 3A each protrude outward with respect to the end surface of the resin layer 2A. At the other end 1Ab of the laminated film 1A, the end surfaces of the base material 4A and the resin layer 2A are not aligned, and the end surfaces of the resin layer 2A and the protective film 3A are aligned. It is not done. The end surface of the laminated film 1A on the other end 1Ab side has a concave shape in which the resin layer 2A portion is concave. On the other end 1Ab side of the laminated film 1A, there is a portion where the resin layer 2A is not laminated on the substrate 4A, and the resin layer 2A is not laminated on the protective film 3A. There are parts that are not there.

The protruding distance between the substrate 4A and the protective film 3A on the other end 1Ab side of the laminated film 1A is the distance between the substrate 4A and the protective film 3A on the one end 1Aa side. ) is smaller than the overhanging distance.

FIG. 3 is a cross-sectional view for explaining an example of a method for manufacturing a laminated film according to the first embodiment of the present invention. Figure 3 is a cross-sectional view for explaining an example of the method (A) for manufacturing the laminated film.

The laminated film 1 shown in FIG. 1 is shown, for example, in FIG. 3(a), FIG. 3(b-1) or FIG. 3(b-2), and FIG. 3(c). It can be obtained through each process. By partially changing each process shown in Figure 3(a), Figure 3(b-1) or Figure 3(b-2), and Figure 3(c), the laminated film shown in Figure 2 You can also get (1A).

As shown in Figure 3 (a), on the surface of the base material 4, a resin layer is formed so that the end surface of the base material 4 protrudes outward with respect to the end surface on the one end side of the resin layer 2. Place (2) (first process). In Figure 3 (a), the resin layer 2 is arranged so that the end surface of the base material 4 protrudes outward with respect to the end surface on the other end side opposite to the one end of the resin layer 2. I'm doing it. The resin layer 2 may be arranged so that the end surface of the resin layer 2 on the other end side is aligned with the end surface of the base material 4.

When disposing the resin layer 2, the resin composition for forming the resin layer 2 may be applied on the surface of the base material 4, and the resin composition may be formed into a film to form the resin layer.

When forming a resin layer using the resin composition, it is preferable to dry the resin composition. The temperature during drying is preferably 80°C or higher, more preferably 100°C or higher, preferably 160°C or lower, and more preferably 140°C or lower. By drying, the solvent in the resin composition can be volatilized. It is preferable that the resin layer 2 is a B stage film.

Next, as shown in FIG. 3(b-1) or FIG. 3(b-2), on the surface opposite to the base material 4 side of the resin layer 2, The protective film 3 is disposed so that the end surface of the protective film 3 protrudes outward with respect to the end surface on the one end side (second process).

In both FIG. 3(b-1) and FIG. 3(b-2), the base material 4 and the resin layer 2 are protected on the other end side opposite to the one end of the resin layer 2. The end faces of the film 3 are not aligned. In FIG. 3(b-1), the resin layer 2 is formed so that the end surface of the protective film 3 protrudes outward with respect to the end surface of the other end opposite to the one end of the resin layer 2. ) is being placed. In Figure 3 (b-2), the resin layer 2 is disposed so that the end surface of the protective film 3 is inside with respect to the end surface on the other end side opposite to the one end of the resin layer 2. I'm doing it. In the second step, the end surfaces of the base material, the resin layer, and the protective film may be aligned on the other end side opposite to the one end side of the resin layer 2.

The method of arranging the protective film on the surface opposite to the substrate side of the resin layer is preferably carried out by lamination. In this case, the temperature during lamination is preferably 70°C or lower, more preferably 65°C or lower. The lower limit of the temperature during lamination is not particularly limited, but is usually 20°C or 25°C. Additionally, the pressure during lamination is preferably 0.01 MPa or more, more preferably 0.02 MPa or more, preferably 1.0 MPa or less, and more preferably 0.8 MPa or less.

In Figure 3 (b-1) and Figure 3 (b-2), on the other end side opposite to the one end of the resin layer 2, the base material 4, the resin layer 2, and the protective film The end faces of (3) are not aligned. For this reason, as shown in Figure 3 (c), on the other end side of the resin layer 2 opposite to the above-mentioned one end, the base material 4, the resin layer 2, and the protective film 3 A process of aligning the end surfaces is performed (third process). For example, at the slit position By doing so, the end surfaces of the base material 4, the resin layer 2, and the protective film 3 can be easily aligned. As a result, the laminated film 1 shown in FIG. 1 can be obtained.

The laminated film preferably has a MD (Machine Direction) direction and a TD (Transverse Direction) direction. The MD direction is the flow direction of the laminated film during production of the laminated film, for example, the longitudinal direction. The TD direction is a direction perpendicular to the flow direction of the laminated film during production of 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. It is preferable that the one end and the other end of the laminated film are opposite ends in the width direction of the laminated film.

In the direction of connecting the one end and the other end of the laminated film according to the present invention, the size of the base material is W ₁ mm, the size of the resin layer is W ₂ mm, and the size of the protective film is W ₃ mm. do. In the laminated film according to the present invention, W ₁ is usually larger than W ₂ and W ₃ is larger than W ₂ . The laminated film according to the present invention usually satisfies W ₁ >W ₂ and satisfies W ₃ >W ₂ .

W ₂ /W ₁ (ratio of the resin layer dimension to the substrate dimension) is preferably 0.9 or more, more preferably 0.92 or more, further preferably 0.94 or more, and particularly preferably 0.96 or more. W ₂ /W ₁ (ratio of the resin layer dimension to the substrate dimension) 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 and below the above upper limit, cracking of the resin layer during peeling of the protective film can be further suppressed, and curing unevenness of the resin layer can be further suppressed.

W ₂ /W ₃ (ratio of the resin layer dimension to the protective film dimension) is preferably 0.9 or more, more preferably 0.92 or more, further preferably 0.94 or more, and particularly preferably 0.96 or more. W ₂ /W ₃ (ratio of the resin layer dimension to the protective film dimension) 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 ₃ is more than the above lower limit and below the above upper limit, cracking of the resin layer during peeling of the protective film can be further suppressed, and curing unevenness of the resin layer can be further suppressed.

W ₃ /W ₁ (ratio of the protective film dimension to the substrate dimension) is preferably 0.997 or greater, more preferably 0.998 or greater, further preferably 0.999 or greater, and particularly preferably 1.0 or greater. W ₃ /W ₁ (ratio of the protective film dimension to the substrate dimension) is preferably 1.01 or less, more preferably 1.009 or less, further preferably 1.008 or less, particularly preferably 1.007 or less. If W ₃ /W ₁ is more than the above lower limit and below the above upper limit, cracking of the resin layer during peeling of the protective film can be further suppressed, and curing unevenness of the resin layer can be further suppressed.

In the above-mentioned laminated film (1) and the above-mentioned laminated film (2), the distance over which the substrate protrudes on one end side is greater than 0 mm, preferably 3 mm or more, preferably 15 mm or less, more preferably is less than 10 mm. In the laminated film (1) and the laminated film (2), the distance over which the protective film protrudes at one end is greater than 0 mm, preferably 3 mm or more, preferably 15 mm or less, more preferably Typically, it is less than 10 mm. If the overhanging distance is less than or equal to the upper limit, cracking of the resin layer during peeling of the protective film can be further suppressed, and curing unevenness of the resin layer can be further suppressed.

In the laminated film 2, the absolute value of the difference between the distance where the substrate protrudes on the other end side and the distance where the substrate protrudes on the one end side exceeds 0 mm, preferably 3. It is mm or more, more preferably 5 mm or more, and even more preferably 10 mm or more. In the laminated film 2, the absolute value of the difference between the protruding distance of the protective film on the other end side and the protruding distance of the protective film on one end side is preferably greater than 0 mm. is 3 mm or more, more preferably 5 mm or more, and even more preferably 10 mm or more. If the absolute value of the difference is more than the above lower limit, cracking of the resin layer during peeling of the protective film can be further suppressed, and curing unevenness of the resin layer can be further suppressed.

In the laminated film 2, the distance over which the substrate protrudes at the other end is greater than 0 mm, preferably 10 mm or less, more preferably 5 mm or less, and still more preferably 1 mm or less. . In the laminated film 2, the distance over which the protective film protrudes on the other end is greater than 0 mm, preferably 10 mm or less, more preferably 5 mm or less, and even more preferably 1 mm or less. am. If the overhanging distance is less than or equal to the upper limit, cracking of the resin layer during peeling of the protective film can be further suppressed, and curing unevenness of the resin layer can be further suppressed.

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

(write)

Examples of the substrate include metal foil, polyester resin films such as polyethylene terephthalate film and polybutylene terephthalate film, olefin resin films such as polyethylene film and polypropylene film, and polyimide film. The surface of the substrate may be subjected to mold release treatment as needed. The base material may be a metal foil or a resin film. The base material is preferably a resin film. When using metal foil as the base material, it is preferable that the metal foil is copper foil.

From the viewpoint of improving the operability of the laminated film and improving the lamination properties of the resin layer, the thickness of the substrate is preferably 5 μm or more, more preferably 10 μm or more, preferably 75 μm or less, More preferably, it is 60㎛ or less.

(resin layer)

The resin layer is laminated on the surface of the substrate. The resin layer preferably contains an inorganic filler described later, a curing agent described later, and a thermoplastic compound described later.

Hereinafter, details of each component used in the resin layer will be described.

[Inorganic filler]

The resin layer preferably contains an inorganic filler. By using an inorganic filler, the dimensional change due to heat of the cured product of the resin layer is reduced. Additionally, the surface roughness of the surface of the cured product of the resin layer becomes smaller, and the adhesive strength between the cured product and the metal layer increases. As for the said inorganic filler, only one type may be used, and two or more types may be used together.

In a conventional laminated film, if the resin layer contains an inorganic filler, cracking of the resin layer is likely to occur when the protective film is peeled. However, in the laminated film according to the present invention, even when the resin layer contains an inorganic filler, cracking of the resin layer during peeling of the protective film can be effectively suppressed.

Examples of the inorganic filler include silica, 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 cured product, further increasing the adhesive strength between the cured product and the metal layer, forming finer wiring on the surface of the cured product, and providing good insulation reliability by the cured product, The inorganic filler is preferably silica or alumina, more preferably silica, and even more preferably fused silica. By using silica, the coefficient of thermal expansion of the cured product is further lowered, the surface roughness of the surface of the cured product is effectively reduced, and the adhesive strength between the cured product and the metal layer is effectively increased. The shape of the silica is preferably spherical.

From the viewpoint of advancing the curing of the resin regardless of the curing environment, effectively increasing the glass transition temperature of the cured product, and effectively reducing the thermal expansion coefficient of the cured product, it is preferable that the inorganic filler is spherical silica.

The average particle diameter of the inorganic filler is preferably 10 nm or more, more preferably 50 nm or more, even more preferably 100 nm or more, preferably 5 μm or less, more preferably 3 μm or less, even more preferably It is 1㎛ or less, especially preferably 0.5㎛ or less. If the average particle size of the inorganic filler is equal to or greater than the lower limit and equal to or smaller than the upper limit, the adhesive strength between the cured product and the metal layer increases further.

As the average particle diameter of the inorganic filler, the value of the median diameter (d50) equal to 50% is adopted. The average particle size can be measured using a laser diffraction scattering type particle size distribution measuring device.

It is preferable that the said inorganic filler is spherical, and it is more preferable that it is spherical silica. In this case, the surface roughness of the surface of the cured product is effectively reduced, and the adhesive strength between the cured product 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 inorganic filler is preferably surface-treated, more preferably surface-treated with a coupling agent, and even more preferably surface-treated with a silane coupling agent. As a result, the surface roughness of the surface of the roughened cured product is further reduced, the adhesive strength between the cured product and the metal layer is further increased, further finer wiring is formed on the surface of the cured product, and further improved inter-wiring insulation reliability and Interlayer insulation reliability can be imparted to the cured product.

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

In 100% by weight of the resin layer, the content of the inorganic filler is preferably 30% by weight or more, more preferably 40% by weight or more, further preferably 50% by weight or more, particularly preferably 60% by weight or more, Most preferably, it is 70% by weight or more, 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 more than the above lower limit and less than the above upper limit, the surface roughness of the surface of the cured product becomes smaller, the adhesive strength between the cured product and the metal layer is further increased, and further finer wiring is formed on the surface of the cured product. do. Moreover, if the content of this inorganic filler is sufficient, it is possible to lower the coefficient of thermal expansion of the cured product and improve smear removal properties. When the content of the inorganic filler is more than the above lower limit, the dielectric loss tangent is effectively lowered. If the content of the inorganic filler is below the upper limit, cracking of the resin layer during peeling of the protective film can be suppressed more effectively.

[Thermosetting compound]

The resin layer preferably contains a thermosetting compound. The thermosetting compound is not particularly limited. As the thermosetting compound, conventionally known thermosetting compounds can be used.

Examples of the thermosetting compounds include styrene compounds, phenoxy compounds, oxetane compounds, epoxy compounds, episulfide compounds, (meth)acrylic compounds, phenol compounds, amino compounds, unsaturated polyester compounds, polyurethane compounds, silicone compounds, and polyimides. Compounds, etc. can be mentioned. As for the said thermosetting compound, only 1 type may be used, and 2 or more types may be used together.

The thermosetting compound is preferably an epoxy compound. The epoxy compound refers to an organic compound having at least one epoxy group. As for the said thermosetting compound and the said epoxy compound, only 1 type may be used, and 2 or more types may be used together.

Examples of the epoxy compounds include bisphenol A-type epoxy compounds, bisphenol F-type epoxy compounds, bisphenol S-type epoxy compounds, phenol novolak-type epoxy compounds, biphenyl-type epoxy compounds, biphenyl novolak-type epoxy compounds, biphenol-type epoxy compounds, Naphthalene type epoxy compound, fluorene type epoxy compound, phenol aralkyl type epoxy compound, naphthol aralkyl type epoxy compound, dicyclopentadiene type epoxy compound, anthracene type epoxy compound, epoxy compound with adamantane skeleton, tricyclodecane Examples include epoxy compounds having a skeleton, naphthylene ether type epoxy compounds, and epoxy compounds having a triazine nucleus in the skeleton.

From the viewpoint of further increasing the adhesive strength between the cured product and the metal layer, the epoxy compound preferably has an aromatic skeleton, preferably has a biphenyl skeleton, and is preferably a biphenyl-type epoxy compound.

It is more preferable that the molecular weight of the epoxy compound is 1000 or less. In this case, when the resin layer is laminated on the substrate, the inorganic filler can be uniformly present.

The molecular weight of the epoxy compound and the molecular weight of the curing agent described later mean the molecular weight that can be calculated from the structural formula when the epoxy compound or curing agent is not a polymer and when the structural formula of the epoxy compound or curing agent can be specified. Additionally, when the epoxy compound or curing agent is a polymer, it means the weight average molecular weight.

The content of the thermosetting compound (epoxy compound when the thermosetting compound is an epoxy compound) in 100% by weight of the resin layer is preferably 10% by weight or more, more preferably 20% by weight or more, and preferably 70% by weight. Below, more preferably 65% by weight or less, further preferably 60% by weight or less, particularly preferably 55% by weight or less. If the content is more than the lower limit and less than the upper limit, the adhesive strength between the insulating layer and the metal layer can be further increased.

[Hardener]

The resin layer preferably contains a curing agent. The curing agent is not particularly limited. As the curing agent, a conventionally known curing agent can be used. Only one type of the said hardening|curing agent may be used, and two or more types may be used together.

As the curing agent, cyanate ester compound (cyanate ester curing agent), phenol compound (phenol curing agent), amine compound (amine curing agent), thiol compound (thiol curing agent), imidazole compound, phosphine compound, acid anhydride, active ester compound. and dicyandiamide. When the thermosetting compound is an epoxy compound, the curing agent preferably has a functional group capable of reacting with the epoxy group of the epoxy compound.

Examples of the cyanate ester compound include novolak-type cyanate ester resin, bisphenol-type cyanate ester resin, and a prepolymer obtained by partially trimerizing these. Examples of the novolak-type cyanate ester resin include phenol novolak-type cyanate ester resin and alkylphenol-type cyanate ester resin. Examples of the bisphenol-type cyanate ester resin include bisphenol A-type cyanate ester resin, bisphenol E-type cyanate ester resin, and tetramethylbisphenol F-type cyanate ester resin.

Commercially available products of the cyanate ester compound include phenol novolak-type cyanate ester resin (“PT-30” and “PT-60” manufactured by Lonza Japan), and a prepolymer in which bisphenol-type cyanate ester resin is trimerized (manufactured by Lonza Japan). “BA-230S”, “BA-3000S”, “BTP-1000S”, and “BTP-6020S”).

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

Commercially available products of the above phenolic compounds include novolak-type phenol (“TD-2091” manufactured by DIC), biphenyl novolac-type phenol (“MEH-7851” manufactured by Meiwa Kasei), and aralkyl-type phenol compound (Meiwa Kasei). “MEH-7800”), and phenol having an aminotriazine skeleton (“LA1356” and “LA3018-50P” manufactured by DIC).

From the viewpoint of further lowering the dielectric loss tangent, it is preferable that the curing agent contains an active ester compound. The active ester compound refers to a compound that contains at least one ester bond in the structure and has aromatic rings bonded to both sides of the ester bond. Preferred examples of the active ester compound include compounds represented by the following formula (1).

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

In the formula (1), examples of the combination of X1 and . Additionally, examples of the combination of X1 and X2 include a combination of a naphthalene ring that may have a substituent and a naphthalene ring that may have a substituent.

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

The molecular weight of the curing agent is preferably 1000 or less. In this case, when the resin layer is laminated on the substrate, the inorganic filler can be uniformly present.

Among 100% by weight of components excluding the inorganic filler in the resin layer, the total content of the thermosetting compound and the curing agent, and the total content of the epoxy compound and the curing agent, are preferably 75% by weight or more, more preferably Preferably it is 80% by weight or more, preferably 99% by weight or less, and more preferably 97% by weight or less. If the total content of the thermosetting compound and the curing agent, and the total content of the epoxy compound and the curing agent are more than the lower limit and less than the upper limit, a better cured product can be obtained and the melt viscosity can be adjusted, so the inorganic filler The dispersibility becomes good. Additionally, during the curing process, the resin layer can be prevented from spreading to unintended areas. Additionally, dimensional changes due to heat in the cured product can be further suppressed. In addition, if the total content of the thermosetting compound and the curing agent, and the total content of the epoxy compound and the curing agent are more than the above lower limit, the melt viscosity will not be too low, and the insulating film will not be excessive in unintended areas during the curing process. It tends to be difficult to spread. In addition, if the total content of the thermosetting compound and the curing agent, and the total content of the epoxy compound and the curing agent are below the upper limit, embedding into holes or irregularities of the circuit board becomes easy, and the inorganic filler is unevenly present. It tends to be difficult to do.

Among 100% by weight of components excluding the inorganic filler in the resin layer, the content of the curing agent is preferably 30% by weight or more, more preferably 40% by weight or more, preferably 70% by weight or less, and more preferably 70% by weight or less. Typically, it is 60% by weight or less. If the content of the curing agent is more than the lower limit and less than the upper limit, a better cured product is obtained and the dielectric loss tangent is effectively lowered.

[Thermoplastic resin]

The resin layer preferably contains a thermoplastic resin. Examples of the thermoplastic resin include polyvinyl acetal resin and phenoxy resin. As for the said thermoplastic resin, only 1 type may be used, and 2 or more types may be used together.

From the viewpoint of effectively lowering the dielectric loss tangent and effectively increasing adhesion to metal wiring, regardless of the curing environment, it is preferable that the thermoplastic resin is a phenoxy resin. By using the phenoxy resin, deterioration of the embedding properties of the resin layer into holes or irregularities of the circuit board and unevenness of the inorganic filler are suppressed. In addition, since the melt viscosity can be adjusted by using the phenoxy resin, the dispersibility of the inorganic filler improves, and it becomes difficult for the resin layer to spread into unintended areas during the curing process. The phenoxy resin is not particularly limited. As the phenoxy resin, conventionally known phenoxy resins can be used. As for the said phenoxy resin, only 1 type may be used, and 2 or more types may be used together.

Examples of the phenoxy resin include, for example, a phenoxy resin having a skeleton such as 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 imide skeleton. etc. can be mentioned.

Commercially available products of the phenoxy resin include, for example, "YP50", "YP55", and "YP70" manufactured by Nippon Chemical Co., Ltd., and "1256B40", "4250", and "4256H40" manufactured by Mitsubishi Chemical Corporation. “4275”, “YX6954BH30”, and “YX8100BH30”, etc. can be mentioned.

From the viewpoint of obtaining a resin layer with even more 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 in terms of polystyrene measured by gel permeation chromatography (GPC).

The content of the thermoplastic resin and the phenoxy resin is not particularly limited. Among 100% by weight of components excluding the inorganic filler in the resin layer, the content of the thermoplastic resin (if the thermoplastic resin is a phenoxy resin, the content of the phenoxy resin) is preferably 1% by weight or more, more preferably It is 5% by weight or more, preferably 30% by weight or less, and more preferably 15% by weight or less. If the content of the thermoplastic resin is more than the lower limit and less than the upper limit, the embedding property of the resin layer into 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 resin layer becomes easier, and an even better insulating layer is obtained. If the content of the thermoplastic resin is below the upper limit, the coefficient of thermal expansion of the cured product is further lowered. The surface roughness of the surface of the cured product is further reduced, and the adhesive strength between the cured product and the metal layer is further increased.

[Curing accelerator]

The resin layer preferably contains a curing accelerator. The curing speed is further accelerated by the use of the curing accelerator. By quickly curing the resin layer, the crosslinked structure in the cured product becomes uniform, the number of unreacted functional groups decreases, and as a result, the crosslinking density increases. The curing accelerator is not particularly limited, and conventionally known curing accelerators can be used. As for the said hardening accelerator, only 1 type may be used, and 2 or more types may be used together.

Examples of the curing 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-phenyl. -4-methylimidazole, 1-benzyl-2-methylimidazole, 1-benzyl-2-phenylimidazole, 1,2-dimethylimidazole, 1-cyanoethyl-2-methylimidazole Sol, 1-cyanoethyl-2-ethyl-4-methylimidazole, 1-cyanoethyl-2-undecylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-cyano Ethyl-2-undecylimidazolium trimellitate, 1-cyanoethyl-2-phenylimidazolium trimellitate, 2,4-diamino-6-[2'-methylimidazolyl-(1' )]-ethyl-s-triazine, 2,4-diamino-6-[2'-undecylimidazolyl-(1')]-ethyl-s-triazine, 2,4-diamino-6 -[2'-ethyl-4'-methylimidazolyl-(1')]-ethyl-s-triazine, 2,4-diamino-6-[2'-methylimidazolyl-(1') ]-Ethyl-s-triazine isocyanuric acid adduct, 2-phenylimidazoleisocyanuric acid adduct, 2-methylimidazoleisocyanuric acid adduct, 2-phenyl-4,5-dihyde Roxymethylimidazole, 2-phenyl-4-methyl-5-dihydroxymethylimidazole, etc. are mentioned.

Examples of the phosphorus compound include triphenylphosphine.

Examples of the amine compounds include diethylamine, triethylamine, diethylenetetramine, triethylenetetramine, and 4,4-dimethylaminopyridine.

Examples of the organometallic compounds include zinc naphthenate, cobalt naphthenate, tin octylate, cobalt octylate, cobalt(II) bisacetylacetonate, and cobalt(III) trisacetylacetonate.

The content of the curing accelerator is not particularly limited. Among 100% by weight of components excluding the inorganic filler in the resin layer, the content of the curing accelerator is preferably 0.005% by weight or more, more preferably 0.01% by weight or more, preferably 5% by weight or less, more preferably It is 3% by weight or less. If the content of the curing accelerator is equal to or greater than the lower limit and equal to or lower than the upper limit, the resin layer is efficiently cured. If the content of the curing accelerator is in a more preferable range, the storage stability of the resin layer is further improved, and a better cured product is obtained.

[solvent]

The resin layer does not contain or contains a solvent. Additionally, the solvent may be used to obtain a slurry containing the inorganic filler. Only one type of the said solvent may be used, and two or more types may be used together.

Examples of the solvent include acetone, methanol, ethanol, butanol, 2-propanol, 2-methoxyethanol, 2-ethoxyethanol, 1-methoxy-2-propanol, 2-acetoxy-1-methoxypropane, toluene, Examples include xylene, methyl ethyl ketone, N,N-dimethylformamide, methyl isobutyl ketone, N-methyl-pyrrolidone, n-hexane, cyclohexane, cyclohexanone, and mixtures of naphtha.

It is preferable that most of the solvent is removed when molding the resin layer. Therefore, the boiling point of the solvent is preferably 200°C or lower, more preferably 180°C or lower. The content of the solvent in the resin layer is not particularly limited. The content of the solvent can be appropriately changed to the extent that the layer shape of the resin layer can be maintained.

[Other ingredients]

For the purpose of improving impact resistance, heat resistance, resin compatibility and workability, etc., the resin layer contains a leveling agent, a flame retardant, a coupling agent, a colorant, an antioxidant, an ultraviolet ray deterioration inhibitor, an antifoaming agent, a thickener, and a thixotropy imparting agent. And other thermosetting resins other than the above thermosetting compounds may be added.

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

Examples of the other thermosetting resins include polyphenylene ether resin, divinylbenzyl ether resin, polyarylate resin, diallyl phthalate resin, polyimide resin, benzoxazine resin, benzoxazole resin, bismaleimide resin, and acrylate resin. etc. can be mentioned.

Methods for obtaining the resin layer include the following methods. An extrusion molding method in which materials for forming a resin layer are melted and kneaded using an extruder, extruded, and then molded into a film using a T die or circular die. A casting molding method that casts a material to form a solvent-containing resin layer and molds it into a film. Other conventionally known film forming methods. Additionally, the resin layer can also be obtained by laminating the materials for forming the resin layer on the substrate and heating and drying them. Since it can accommodate thinning, the extrusion molding method or casting molding method is preferable. Film includes sheets.

The material for forming the resin layer is molded into a film and dried by heating at 50°C to 150°C for 1 to 10 minutes to the extent that heat curing does not proceed too much, to obtain a resin layer that is a B stage film. You can.

The film-shaped resin layer obtained through the above-described drying process is called a B-stage film. The B stage film is in a semi-cured state. The semi-cured product is not completely hardened, and hardening may proceed further.

It is preferable that the resin layer is a B stage film.

From the viewpoint of further improving the lamination properties of the resin layer (when the resin layer is a B stage film, the B stage film) and further suppressing uneven curing of the resin layer, the thickness of the resin layer is preferably It is 5㎛ or more, more preferably 10㎛ or more, preferably 200㎛ or less, more preferably 100㎛ or less.

(protective film)

The protective film is laminated on the surface of the resin layer opposite to the substrate side.

Materials for 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 resin layer, the thickness of the protective film is preferably 5 μm or more, more preferably 10 μm or more, preferably 75 μm or less, and more preferably 60 μm or less. am.

(Other details of laminated film)

The laminated film according to the present invention is suitably used to form an insulating layer in a multilayer printed wiring board. An insulating layer can be formed with the resin layer of the laminated film according to the present invention.

An example of a multilayer printed wiring board is 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. At least one of the insulating layers is formed by the resin layer. The insulating layer in contact with the circuit board may be formed by the resin layer. An insulating layer disposed between two insulating layers may be formed by the resin layer. The insulating layer furthest from the circuit board may be formed by the resin layer. Among the plurality of insulating layers, a metal layer may be disposed on the outer surface of the insulating layer spaced apart from the circuit board.

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

The following substrates and protective films were prepared.

(write)

Polyethylene terephthalate (PET) film (“AL5” manufactured by Lintec, thickness 38 ㎛, width 550 mm)

(protective film)

Protective film (“Alpan MA-411” manufactured by Oji Ftex, thickness 15㎛, width 550mm)

(Material for forming the resin layer)

Materials for forming a resin layer were prepared as follows.

Materials for forming the resin layer:

107 parts by weight of cyclohexanone slurry (solid content: 70% by weight) of aminophenylsilane-treated silica (“SOC2” manufactured by Admatex) was prepared. In this slurry, 11 parts by weight of a biphenyl type epoxy compound (“NC3000H” manufactured by Nippon Kayaku Co., Ltd.), 5 parts by weight of a bisphenol A-type epoxy compound (“850S” manufactured by DIC Corporation), 7.9 parts by weight of cyclohexanone, and methyl ethyl. 7.7 parts by weight of ketone was added. Using a stirrer, the mixture was stirred at 1200 rpm for 60 minutes, and it was confirmed that undissolved substances had disappeared. After that, 11 parts by weight of a methyl ethyl ketone mixed solution (solid content: 50% by weight) of an aminotriazine-modified phenol novolak curing agent (“LA-1356” manufactured by DIC) and a phenol novolak curing agent (“H4” manufactured by Maywa Kasei Corporation). ) 3 parts by weight were added, stirred at 1200 rpm for 60 minutes, and it was confirmed that undissolved substances had disappeared. After that, a mixed solution of bisphenol acetophenone skeleton phenoxy resin (“YX6954” manufactured by Mitsubishi Chemical Corporation) in methyl ethyl ketone and cyclohexanone (solid content: 30% by weight) was prepared. 2.5 parts by weight of the mixed solution (solid content 30% by weight), 0.1 part by weight of 2-ethyl-4-methylimidazole (“2E4MZ” manufactured by Shikoku Kasei Industries, Ltd.), and a leveling agent (“LS-” manufactured by Kusumoto Kasei Corporation) 480") 0.01 parts by weight was further added. It was stirred at 1200 rpm for 30 minutes to obtain a material (varnish) for forming a resin layer.

(Example 1)

Process of disposing a resin layer on the surface of a substrate:

Using a die coater, the material (varnish) for forming the obtained resin layer was applied onto the substrate to a width of 410 mm, excluding a range of 70 mm from both ends in the width direction of the substrate, and then applied at an average temperature of 100 mm. It was dried at ℃ for 3 minutes to volatilize the solvent. In this way, a resin layer with a thickness of 40 μm and a width of 410 mm was formed on the substrate.

Process of placing a protective film on the surface of the resin layer:

The protective film was heat laminated on the surface opposite to the base material side of the resin layer at a pressure of 0.4 MPa and a temperature of 50°C, and then wound into a roll to obtain a laminate of the base material, the resin layer, and the protective film.

Process of aligning one end surface in the width direction of the laminate:

A slitter was placed at a position of 84 mm inward from one end (the other end) in the width direction of the obtained laminate, and at a position of 66 mm inward from the end (one end) opposite to the other end. was used to slit at a speed of 10 m/min, and the end surface of the base material, the end surface of the resin layer, and the end surface of the protective film on the other end side were aligned. In this way, a laminated film in which the width direction dimension (W ₁ ) of the substrate is 400 mm, the width direction dimension (W ₂ ) of the resin layer is 396 mm, and the width direction dimension (W ₃ ) of the protective film is 400 mm. got it

(Example 2)

Process of disposing a resin layer on the surface of a substrate:

A resin layer was formed in the same manner as in Example 1.

Process of placing a protective film on the surface of the resin layer:

In the same manner as in Example 1, a laminate of the base material, the resin layer, and the protective film was obtained.

Process of aligning the other end surface of the laminated film:

A slitter was placed at a position of 120 mm inward from one end (the other end) in the width direction of the obtained laminate, and at a position of 30 mm inward from the end (one end) opposite to the other end. was used to slit at a speed of 10 m/min, and the end surface of the base material, the end surface of the resin layer, and the end surface of the protective film on the other end side were aligned. In this way, a laminated film in which the width direction dimension (W ₁ ) of the substrate is 400 mm, the width direction dimension (W ₂ ) of the resin layer is 360 mm, and the width direction dimension (W ₃ ) of the protective film is 400 mm. got it

(Example 3)

Process of disposing a resin layer on the surface of a substrate:

A resin layer was formed in the same manner as in Example 1.

Process of placing a protective film on the surface of the resin layer:

In the same manner as in Example 1, a laminate of the base material, the resin layer, and the protective film was obtained.

Process of aligning one end surface in the width direction of the laminate:

A slitter was placed at a position of 140 mm inward from one end (the other end) in the width direction of the obtained laminate, and at a position of 10 mm inward from the end (one end) opposite to the other end. was used to slit at a speed of 10 m/min, and the end surface of the base material, the end surface of the resin layer, and the end surface of the protective film on the other end side were aligned. In this way, a laminated film in which the width direction dimension (W ₁ ) of the substrate is 340 mm, the width direction dimension (W ₂ ) of the resin layer is 400 mm, and the width direction dimension (W ₃ ) of the protective film is 400 mm. got it

(Comparative Example 1)

Process of disposing a resin layer on the surface of a substrate:

A resin layer was formed in the same manner as in Example 1.

Process of placing a protective film on the surface of the resin layer:

In the same manner as in Example 1, a laminate of the base material, the resin layer, and the protective film was obtained.

A slitter was placed at a position of 48 mm inward from one end (the other end) in the width direction of the obtained laminate, and at a position of 48 mm inward from the end (one end) opposite to the other end. It was slit at a speed of 10 m/min. In this way, the width direction dimension (W ₁ ) of the base material is 454 mm, the width direction dimension (W ₂ ) of the resin layer is 410 mm, and the width direction dimension (W ₃ ) of the protective film is 454 mm, and the lamination A laminated film was obtained in which both end surfaces in the width direction of the film were not aligned.

(Comparative Example 2)

Process of disposing a resin layer on the surface of a substrate:

A resin layer was formed in the same manner as in Example 1.

Process of placing a protective film on the surface of the resin layer:

In the same manner as in Example 1, a laminate of the base material, the resin layer, and the protective film was obtained.

Process of aligning both end surfaces in the width direction of the laminate:

A slitter was placed at a position of 75 mm inward from one end (the other end) in the width direction of the obtained laminate, and at a position of 75 mm inward from the end (one end) opposite to the other end. It was slit at a speed of 10 m/min. In this way, the width direction dimension of the base material (W ₁ ), the width direction dimension of the resin layer (W ₂ ), and the width direction dimension of the protective film (W ₃ ) are all 400 mm, and the width direction of the laminated film A laminated film was obtained in which both end surfaces were aligned.

(evaluation)

(1) Cracking of the resin layer when peeling off the protective film

After the obtained laminated film was cut to 500 mm in length (MD direction), the protective film was peeled. The exposed resin layer was observed with the naked eye, and cracking of the resin layer was evaluated.

[Criteria for judging cracks in the resin layer when peeling off the protective film]

○: There are no cracks in the resin layer.

×: There are cracks in the resin layer

(2) Non-uniform curing of the resin layer

After cutting the obtained laminated film to a length (MD direction) of 380 mm, the protective film was peeled. On the surface of the exposed resin layer, a glass epoxy substrate (“E679FGR” manufactured by Hitachi Chemical Company) was laminated to obtain a laminate of the substrate, the resin layer, and the glass epoxy substrate. Incidentally, the above laminate was prepared using a “batch type vacuum laminator MVLP-500IIA” manufactured by Meiki Seisakusho, with a laminating pressure of 0.4 MPa, a laminating temperature of 90°C, a laminating time of 20 seconds, a press pressure of 0.8 MPa, and a press temperature of 0.8 MPa. It was conducted under conditions of 90°C and a press time of 20 seconds.

The obtained laminate of the base material, the resin layer, and the glass epoxy substrate was placed in a heating oven (“SPHH-201” manufactured by ESPEC) and heated at a temperature of 170°C for 60 minutes to cure the resin layer. After heating, it was left to cool at room temperature, and then the base material was peeled off to obtain a laminate of the resin layer (cured product) and the glass epoxy substrate.

From the obtained laminate of the resin layer (cured product) and the glass epoxy substrate, using a microgrinder (“UC210” manufactured by Urawa Kogyo Co., Ltd.), both ends in the width direction of the resin layer (cured product) and the The resin layer (cured product) in the central part was cut to 20 mm in width x 100 mm in length x 0.04 mm in thickness, and three samples of the cured product were obtained.

Using "Q2000" manufactured by TA Instruments, the glass transition temperature Tg of the three obtained cured samples was measured under the conditions of a temperature increase rate of 3°C/min and a temperature range of -30°C to 250°C. In the obtained measurement results, the curing unevenness of the resin layer was evaluated by determining the difference between the maximum and minimum values of Tg of the three cured samples.

[Criteria for determining uneven curing of the resin layer]

○: The difference between the maximum and minimum Tg values is 5°C or less.

△: The difference between the maximum and minimum values of Tg is more than 5℃ and less than 15℃

×: The difference between the maximum and minimum values of Tg is 15°C or more.

The composition of the laminated film and the results are shown in Table 1 below.

1, 1A: Laminated film
1a, 1Aa: one end
1b, 1Ab: other end
2, 2A: Resin layer
2a, 2Aa: first surface
2b, 2Ab: second surface
3, 3A: Protective film
4, 4A: Description
X: Slit location

Claims (10)

With equipment,
A resin layer laminated on the surface of the substrate,
A protective film is laminated on a surface of the resin layer opposite to the substrate side,
On one end side of the laminated film, the end surfaces of the substrate and the protective film each protrude outward with respect to the end surface of the resin layer, and on the other end side of the laminated film opposite to the one end side, The end surfaces of the base material, the resin layer, and the protective film are aligned, or on both one end side of the laminated film and the other end side opposite to the one end side, with respect to the end face of the resin layer. and the end surfaces of the protective film each protrude outward, and the protruding distance between the base material and the protective film on the other end side is the distance between the base material and the protective film on the one end side. A laminated film that is smaller than the protruding distance. The method according to claim 1, wherein, on one end side of the laminated film, the end surfaces of the substrate and the protective film each protrude outward with respect to the end surface of the resin layer, and are opposite to the one end of the laminated film. A laminated film in which end surfaces of the base material, the resin layer, and the protective film are aligned on the other end side. The method according to claim 1 or 2, wherein in the direction connecting the one end and the other end of the laminated film, when the size of the base material is W ₁ mm and the size of the resin layer is W ₂ mm, W A laminated film where ₂ /W ₁ is 0.9 or more and 0.999 or less. The method according to claim 1 or 2, wherein in the direction connecting the one end and the other end of the laminated film, when the size of the resin layer is set to W ₂ mm and the size of the protective film is set to W ₃ mm, A laminated film wherein W ₂ /W ₃ is 0.9 or more and 0.999 or less. The laminated film according to claim 1 or 2, wherein the resin layer contains an inorganic filler, a curing agent, and a thermosetting compound. The laminated film according to claim 5, wherein the content of the inorganic filler is 30% by weight or more in 100% by weight of the resin layer. A method for producing the laminated film according to claim 1, comprising:
A first step of arranging a resin layer on the surface of a substrate so that the end surface of the substrate protrudes outward with respect to the end surface on one end of the resin layer;
A second step of arranging a protective film on a surface of the resin layer opposite to the substrate side so that the end surface of the protective film protrudes outward with respect to the end surface on the one end side of the resin layer, ,
After the second step, the end surfaces of the substrate, the resin layer, and the protective film are aligned on the other end side opposite to the one end of the resin layer, or after the second step, the end surfaces of the protective film are aligned. On the other end side of the stratum opposite to the one end side, the protruding distance between the base material and the protective film on the other end side is defined as the distance between the base material and the protective film on the one end side. A third process is provided to reduce the protruding distance,
On the one end side of the laminated film corresponding to the one end of the resin layer, the end surfaces of the substrate and the protective film each protrude outward with respect to the end surface of the resin layer, and the one end of the laminated film On the opposite end side, the end surfaces of the substrate, the resin layer, and the protective film are aligned, or on both one end side of the laminated film and the other end side opposite to the one end side, The end surfaces of the base material and the protective film each protrude outward with respect to the end surface of the resin layer, and the protrusion distance between the base material and the protective film on the other end side is the protrusion distance on the one end side. A method for producing a laminated film, wherein a laminated film is obtained that is smaller than the protruding distance between the base material and the protective film. The manufacturing method of a laminated film according to claim 7, wherein in the third step, the base material, the resin layer, and the protective film are slit. The method according to claim 7 or 8, wherein, on the side of one end of the laminated film corresponding to the one end of the resin layer, the end faces of the substrate and the protective film are each hollow outward with respect to the end face of the resin layer. A method for producing a laminated film, wherein a laminated film is obtained in which the end surfaces of the substrate, the resin layer, and the protective film are aligned on the other end side opposite to the one end of the laminated film. delete

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