JP2007083459A - Surface-roughened film and its application - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a surface-roughened film which does not adversely affect the moldability of a surface contacting the film by preventing the occurrence of wrinkles in a release film used when, for example, a circuit board such as a flexible printed circuit board, and a prepreg of an epoxy resin, an unsaturated polyester resin, or the like are molded, or a copper-clad laminate is produced. <P>SOLUTION: In the surface-roughened thermoplastic resin film, the surface roughness (Ra) of a top level part is 0.25-15 μm, a surface in which grooves of 10-70 μm in average depth and 0.1-3 mm in average width are formed in an average pitch of 0.5-30 mm is provided on at least one side, its total thickness is 30-200 μm, and the average depth of the grooves is 10-70% of the total thickness. A method for producing the film is also disclosed. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a surface-roughened film suitable as a release film for use in pressure molding of a film or sheet-like laminate. More specifically, the present invention relates to a release film used when a coverlay is pressure-bonded with an adhesive to a flexible printed circuit board body on which an electric circuit is formed.

When forming a flexible printed board, a coverlay layer is provided on the board on which the electric circuit is formed. This coverlay is a thermosetting type on the single side when the print is formed on only one side of the substrate, and on both sides when the print is provided on the surface of the substrate or in multiple layers. The coverlay layer is bonded by a heat press using an adhesive.
In this case, a fluorine-based material such as polytetrafluoroethylene, tetrafluoroethylene-hexafluoropropylene copolymer, or polyvinyl fluoride is provided in the middle so that the cover lay and the press hot plate are not bonded during molding. Release films such as polymer films and polymethylpentene films are used.
Also, the electrical circuit (copper foil) surface formed on the substrate has a different height between the printed part and the non-printed part. There may be voids in the missing parts, and the encapsulated residual air may oxidize the copper circuit over time, significantly reducing the life of the electrical circuit.
Furthermore, the flexible printed circuit board does not cover the terminal area with a coverlay for electrical connection with other components, and the copper circuit of the connection area is exposed. The adhesive applied to the coverlay is melted by the hot press and often flows out onto the exposed copper circuit surface, covering the surface of the copper circuit with the adhesive and the subsequent electrical In some cases, poor connection was caused.
In this way, in order to prevent voids from being generated in the non-printed part, in order to prevent the exposed surface of the copper circuit from being contaminated (covered) by the molten adhesive, the mold release having both cushioning properties and release properties. It is also known to use film.
As such a release film, a release film in which a crystalline polymethylpentene layer is formed on both the inner and outer surfaces (Patent Document 1), and a release film in which the surface of the polymethylpentene layer is roughened with an embossing roll ( For example, Patent Document 2 and Patent Document 3) are already known.
However, even when a release film having a 10-point average roughness of 70 to 2000 nm specifically disclosed in the specification of Patent Document 3 is used, it is difficult to suppress the generation of wrinkles in the release film during molding. As a result, there is a possibility of adversely affecting the molding surface with which the release film contacts.

Japanese Patent No. 2619034 Japanese Patent Publication No. 6-2369 JP 2003-211602 A

  Accordingly, the inventors of the present invention used a wrinkle of a release film used when forming a circuit board such as a flexible printed circuit board, a prepreg such as polyimide, epoxy resin or unsaturated polyester resin, or manufacturing a copper-clad laminate. As a result of various investigations aimed at developing a surface roughened film that does not adversely affect the formability of the surface that it contacts by preventing occurrence, the purpose is achieved by providing specific irregularities on the surface of the film The present invention has been found to be suitable as a release film and has led to the present invention.

  In the present invention, the surface roughness (Ra) of the top flat portion is 0.25 to 15 μm, and grooves having an average depth of 10 to 70 μm and an average width of 0.1 to 3 mm on the surface have an average pitch of 0.5. It has a surface provided at ˜30 mm on at least one side, its total thickness is 30-200 μm, and the average depth of the groove is in the range of 10-70% of the total thickness The present invention relates to a roughened surface film made of a thermoplastic resin.

  In the present invention, the surface roughness (Ra) of the top flat portion is less than 0.25 μm, and grooves having an average depth of 30 to 70 μm and an average width of 0.1 to 3 mm on the surface have an average pitch of 0.1. It has a surface provided at 5 to 30 mm on at least one side, its total thickness is 30 to 200 μm, and the average depth of the groove is in the range of 10 to 70% of the total thickness. The present invention relates to a surface roughened film made of a thermoplastic resin.

  In the present invention, the surface roughness (Ra) is set to a range of 0.25 to 15 μm on at least one surface of the thermoplastic resin film, the average depth is 10 to 70 μm, and the average width is The present invention relates to a method for producing a roughened surface film characterized by using in combination a groove forming step (b) in which grooves having a range of 0.1 to 3 mm are formed in an average pitch of 0.5 to 10 mm.

  In the present invention, the surface roughness (Ra) is set to a range of 0.25 to 15 μm on at least one surface of the thermoplastic resin film, the average depth is 10 to 70 μm, and the average width is A method for producing a roughened surface film, wherein a groove forming step (b) for forming grooves in a range of 0.1 to 3 mm in a lattice shape with an average pitch in a range of 0.5 to 10 mm is used.

  Further, in the present invention, grooves having an average depth of 30 to 70 microns and an average width of 0.1 to 3 mm are formed on the surface of a thermoplastic resin film having a surface roughness of less than Ra = 0.25 with an average pitch of 0.5 to 0.5 mm. It is related with the manufacturing method of the surface roughening film characterized by giving the groove | channel formation process (b) which forms a groove | channel so that it may exist in the range of 10 mm to the at least single side | surface of the said film.

  In the present invention, the surface roughness (Ra) is set to a range of 0.25 to 15 μm on at least one surface of the thermoplastic resin film, the average depth is 10 to 70 μm, and the average width is Surface roughening using a groove forming step (b) for forming grooves in the range of 0.1 to 3 mm with an average pitch in the range of 0.5 to 10 mm is performed, or the surface roughness Ra = 0 In the case of a thermoplastic resin film of less than .25, grooves having an average depth of 30 to 70 microns and an average width of 0.1 to 3 mm are formed so that the average pitch is in the range of 0.5 to 10 mm. It is related with the manufacturing method of the surface roughening film characterized by performing the process (b) of groove | channel formation.

  Further, in the present invention, the surface roughness of the down recess is Ra = 0.25 to 15 μm, the average height is 10 to 70 μm, and the average width of the portion (foot portion) in contact with the down recess is 0.1 to 3 mm. A surface roughening film characterized in that a groove having convex portions for groove formation is provided with an average pitch in the range of 0.5 to 10 mm, and at least one surface of the thermoplastic resin film is roughened and grooves are formed. It relates to a manufacturing method.

  The roughened surface film of the present invention can suppress generation of wrinkles when used as a release film and is suitable as a release film having appropriate cushioning properties.

According to one aspect of the present invention, at least one surface of the surface roughened film of the present invention has a surface roughness Ra = 0.25 to 15 μm at the top flat portion of the surface, and the surface Are provided with grooves having an average depth of 10 to 70 μm and an average width of 0.1 to 3 mm with an average pitch of 0.5 to 30 mm. According to another aspect of the present invention, when the surface roughness (Ra) of the top flat portion of at least one surface of the surface roughened film is less than 0.25 μm, the average depth on the surface is increased. Grooves with a length of 30 to 70 μm and an average width of 0.1 to 3 mm are provided with an average pitch of 0.5 to 30 mm.
The surface roughened film of the present invention may be a single layer film, but is composed of three layers such as a surface layer // intermediate layer // back surface layer, or a surface layer // intermediate layer // second surface layer. It is desirable.

  As the thermoplastic resin (A) used for the surface layer, the surface has a flexibility that allows the roughened pattern to be easily transferred and roughened on the surface at a temperature below the melting point, and is capable of curing a prepreg or the like. Although it will not specifically limit if it is a thermoplastic resin which can endure the temperature at the time, 4-methyl-1- pentene type polymer (A) is suitable.

The resin used for the intermediate layer is not particularly limited as long as it has a deformation temperature capable of being melted and deformed to follow the shape of the surface layer upon curing of a prepreg or the like. In addition, it is desirable that the prepreg or the like does not contaminate due to the melting at that time, protruding from the surface layer. An example of such a resin is a soft olefin polymer (B).
Furthermore, various thermoplastic resins such as polyolefin resin such as polypropylene, polyester, polyamide, and polycarbonate are used for the back surface layer. Each polymer will be described below.

4-methyl-1-pentene polymer (A)
The 4-methyl-1-pentene polymer (A) used in the present invention is a homopolymer of 4-methyl-1-pentene or 4-methyl-1-pentene and other α-olefins such as ethylene and propylene. , 1-butene, 1-hexene, 1-octene, 1-decene, 1-tetradecene, 1-octadecene and the like, and a copolymer with an α-olefin having 2 to 20 carbon atoms, usually 4-methyl-1- A crystalline polymer mainly composed of 4-methyl-1-pentene containing 85 mol% or more of pentene, preferably having a melting point (Tm) of 200 ° C. or higher. Among them, the polymer is in the range of 200 to 235 ° C.
The melt flow rate (MFR; load: 5 Kg, temperature: 260 ° C.) of the 4-methyl-1-pentene polymer (A) is not particularly limited as long as it has a film-forming ability. It is in the range of 200 g / 10 min. A polymer having a melt flow rate of less than 0.5 g / 10 min has a high melt viscosity and poor moldability, while a polymer having a melt flow rate of more than 200 g / 10 min has a low melt viscosity and poor moldability. Tend to be low.

Soft olefin polymer (B)
The soft olefin polymer (B) forming the intermediate layer of the roughened surface film of the present invention is usually an olefin polymer having a Vicat softening temperature in the range of 40 to 140 ° C. Specific examples of the soft olefin polymer (B) include ethylene homopolymers or ethylene and propylene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1 A copolymer of one or more α-olefins such as octene, a copolymer of propylene and one or more α-olefins such as ethylene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene; Examples thereof include a polymer, a copolymer of acrylic acid ester such as acrylate together with ethylene or a methacrylic acid ester such as methyl methacrylate, a copolymer of ethylene and acrylic acid or methacrylic acid, or a partially ion-crosslinked product thereof. Such a soft olefin polymer (B) may be a composition of one kind or two or more kinds, and as long as the soft olefin polymer (B) is a main component, an amorphous or low crystalline ethylene. Propylene random copolymers, ethylene / 1-butene random copolymers, ethylene / α-olefin random copolymers such as ethylene / 1-hexene random copolymers, propylene / ethylene random copolymers, propylene / 1-butene Random copolymer, propylene / ethylene / 1-butene random copolymer, propylene / α-olefin random copolymer such as propylene / 1-butene / 4-methyl-1-pentene random copolymer It may be a thing.

Surface Roughened Film When the surface roughened film of the present invention is a single layer, at least one surface thereof is adjusted to the specific surface roughness and the specific groove is formed. Moreover, when the surface roughening film of this invention is comprised from a surface layer // intermediate layer // back surface layer, only a surface layer roughens the said specific surface. Furthermore, when the surface roughened film of the present invention is composed of a surface layer // intermediate layer // second surface layer, only the surface layer, or the surface layer and the second surface layer, as necessary. Both are roughened as described above.
The surface roughened film of the present invention has a total thickness of 40 to 200 μm, preferably in the range of 50 to 180 μm. Moreover, in the case of a single layer, it is 40-200 micrometers normally. In the case of a multilayer film, the thickness of the surface layer is usually 10 to 40 μm, preferably 15 to 30 μm, and the thickness of the intermediate layer is usually 30 to 160 μm, preferably 40 to 120 μm. Moreover, the thickness of a back surface layer is 10-60 micrometers normally, Preferably it is 20-50 micrometers.

Manufacturing method of surface roughening film The surface roughening film of this invention can be manufactured with the following shaping | molding methods, for example.
That is, a film surface roughening step (a) in which the surface layer has a surface roughness Ra = 0.25 to 15 μm, and grooves having an average width of 0.5 to 3 mm, particularly 0.5 to 2 mm, have an average pitch of 0. Groove forming step for forming grooves in the range of 5 to 30 mm, in particular 0.5 to 10 mm, in particular 0.5 to 5 mm, in particular, grooves formed of square lattice-shaped recesses (b) By using together, it is possible to produce a surface roughened film in which the generation of wrinkles is suppressed.
Moreover, according to the suitable aspect of the manufacturing method of this invention, the average width | variety is 0.5-3 mm in the film whose surface roughness is less than Ra = 0.25, and the groove | channel of 0.5 to 2 mm is especially used. Groove forming step for forming grooves having an average pitch of 0.5 to 30 mm, particularly 0.5 to 10 mm, especially 0.5 to 5 mm, and in particular, square lattice-shaped recesses on at least one side of the film (b) The surface roughened film in which the generation of wrinkles is suppressed can be produced.
According to another aspect of the present invention, the surface roughness of the down portion (embossed recess) is Ra = 0.25 to 15 μm, the average height is 10 to 70 μm, and the portion in contact with the down portion (foot portion) Forming grooves on at least one side using a roll having an average width of 0.5 to 3 mm, in particular 0.5 to 2 mm of groove forming convex portions having an average pitch of 0.5 to 30 mm. Thus, it is possible to produce a surface roughened film in which the generation of wrinkles is suppressed.

Each method will be described below.
In the case of a single layer film composed of 4-methyl-1-pentene polymer (A), only the following groove forming step (b) or the roughening step (b) and groove forming step (b) ) Can be used together to produce a surface roughened film.
In the case of a three-layer film, the surface layer (I), the intermediate layer (II) and the back layer (III-a) are formed using a film forming machine equipped with a three-layer T-die, and this surface A surface roughened film is produced by applying only the following surface roughening step (ii) or using both the surface roughening step (ii) and the groove forming step (b) on the surface on the layer (I) side. be able to.
Further, the surface layer (I), the intermediate layer (II) and the second surface layer (III-b) were molded using a film molding machine equipped with a T-die having a three-layer structure. A surface roughened film can be produced by applying the step of forming grooves (b) together with the surface roughening step (ii) or the step of roughening (b).

  The roughening step (b) and the groove forming step (b) are performed on at least one side of these single layer films, or in the case of the surface layer (I), the intermediate layer (II) and the back layer (III-a), In the case of the surface layer (I), the intermediate layer (II) and the second surface layer (III-b) on the surface of the surface layer (I), if necessary, only the surface layer (I) is present or further It is also applied to the surface of the second surface layer ((III-b)).

The roughening step (A) is a step of pressing the surface layer using an embossing roll having a roughened surface. Thereby, the surface roughness of the surface layer is roughened within a range of Ra = 0.25 to 15 μm.
The groove forming step (b) is performed such that, for example, a groove having an average width of 0.1 to 3 mm is provided on the film in a range of an average pitch of 0.5 to 30 mm. Is a step of pressing a roll having an average pitch in the range of 5 to 50 mm against the surface of the film to provide specific grooves in the film. The groove provided in the film may be either linear or curved. It may be a square lattice such as a square or rhombus, a shape in which small circles are periodically overlapped, a triangular lattice, a hexagonal lattice, or a deformed lattice, but a square lattice, especially a square lattice. It has a simple shape and is effective in suppressing wrinkles.

In a roll provided with a convex part for providing a specific groove in the film, the convex part is
Usually, the cross section is an isosceles trapezoid or the upper base of the isosceles trapezoid protrudes in a crescent shape or a semicircular shape, and the convex height is usually about 30 μm to 5 mm. Moreover, the width | variety of the part (base part) which contact | connects the roll of this convex part is about 0.5-30 mm normally, for example, when making a groove | channel into a grid | lattice form, these convex parts also become a grid | lattice form.

In the method for producing a roughened surface film of the present invention, on at least one surface of the thermoplastic resin film,
A surface roughening step (a) in which the surface roughness (Ra) is in the range of 0.25 to 15 μm, and grooves having an average depth of 10 to 70 μm and an average width of 0.1 to 3 mm are provided with an average pitch of 0.1. In the case of surface roughening using a groove forming step (b) to be formed in a range of 5 to 10 mm or a thermoplastic resin film having a surface roughness of less than Ra = 0.25, the average depth A surface is provided with a groove forming step (b) in which grooves having a length of 30 to 70 microns and an average width of 0.1 to 3 mm are formed so that the average pitch is in the range of 0.5 to 10 mm. There is a method for producing a roughened film.

If the groove forming step (b) is performed without the roughening step (ii) or after the roughening step (ii), a specific groove is formed in the roughened top flat portion.
The grooves to be formed preferably have intersecting points, and in the case of a lattice shape, the number of intersecting points is desirably 10 to 1000 per unit area (25 cm ² ).
In the present invention, the surface roughening step (A) and the groove forming step (B) may be performed in one step as necessary. For example, the above-mentioned convex part is provided on the roll, and the down part (embossed concave part) other than the convex part of the roll is prepared so that the surface roughness is Ra = 0.25 to 15 μm, and the average height of the convex part is At least one surface of the film is formed by using a roll provided with groove forming convex portions having an average width of 0.5 to 5 mm and an average width of 0.5 to 5 mm at a portion (foot portion) in contact with the down portion at 10 to 70 μm. By pressing with a roll, the method for producing a roughened surface film of the present invention can be performed in one step.

  The average depth of the grooves provided in the surface roughened film of the present invention is desirably in the range of 10 to 70%, particularly 30 to 60% of the total thickness of the surface roughened film. If it is less than 10%, the prevention of wrinkles cannot be suppressed so much. If it exceeds 70%, the generation of wrinkles cannot be suppressed, but the generation of wrinkles tends to increase.

EXAMPLES Next, although this invention is demonstrated through an Example, this invention is not limited by these Examples.
In addition, the average depth of a groove | channel is the distance from the surface (average surface which averaged the unevenness | corrugation) where the surface roughness of the top flat part is Ra = 0.25-15 micrometers to the bottom part (deepest part) of a groove | channel. It is a measured value (an average value obtained by measuring arbitrary five points in a groove portion of a unit area (25 cm ² )).
In addition, the average width of the groove is the width at the portion where the extension line of the wall surface of the groove intersects the surface (average surface averaged with unevenness) where the surface roughness of the top flat portion is Ra = 0.25 to 15 μm. An average value obtained by measuring five arbitrary points in a groove portion having a unit area (25 cm ² ) as a measured value).
Furthermore, the average pitch is obtained by arbitrarily drawing the line segment of the unit name (50 mm) in the X-direction and the Y-direction orthogonal to the surface roughened film, and the Y-direction. The number of times each line segment intersects with the groove was determined, and the average value obtained by measuring any five points in the unit area (25 cm ² ), which was a value determined by the following equation. In the case of a lattice shape, either the X-direction or the Y-direction is placed in parallel to the straight line of the lattice.
Average pitch (mm) = 100 mm / (number of times the line segment in the X-direction intersects the groove) +100 mm / (number of times the line segment in the Y-direction intersects the groove)

When the specific roughening and the specific groove are provided on both surfaces of the surface roughened film, the effect of the present invention can be obtained when the surface of at least one surface falls within the specific range.
Various test methods and evaluation methods in the present invention are as follows.

(1) Surface roughness (central surface average roughness SRa; μm)
The surface roughness of the film was measured using a surface roughness measuring instrument Surfcom 120A type manufactured by Tokyo Seimitsu Co., Ltd. in an atmosphere of temperature: 23 ° C. and relative humidity: 50% (cutoff value 0, 80 mm, measurement length). 10 mm).

(2) Wrinkle test As shown in FIG. 1, the test piece of the surface roughened film was sandwiched between aluminum plates, subjected to heat treatment at 170 ° C. for 30 minutes, rapidly cooled, and the test piece was visually observed for wrinkles. .

(Example)
Examples 1-12, Comparative Examples 1-6
Poly-4-methyl-pentene resin (Mitsui Chemicals, melting point 235 ° C, TPX grade MX-020), ethylene-ethyl acrylate copolymer (ethyl acrylate copolymer content 21 wt%, density 0.93 g / cm 3, MFR 45 g / 10 min, melting point 84 ° C. (Mitsui DuPont Polychemical, Evaflex) -EEA A725)) and a surface layer of a three-layer film (25 μm // 70 μm // 25 μm) consisting of a second surface layer made of poly-4-methyl-pentene resin (TPI manufactured by Mitsui Chemicals) Alternatively, both the following surface roughening step and groove forming step were performed on both the surface layer and the second surface layer.

・ Roughening process (I-1)
Three layers with the surface roughened by pressing the above three layer film with a mat (heated to 120 ° C.) and having a rough surface (diameter 100 mm, width 350 mm) at a linear pressure of 75 kg / cm. A film was obtained. In addition, as a roll having a rough surface, a deep mat finish roll (Rz = 24 to 30) (hereinafter referred to as a deep mat) provided with relatively deep unevenness and a shallow mat finish provided with relatively shallow unevenness. Any of rolls (Rz = 31 to 40) (hereinafter referred to as a shallow mat) was used.

・ Groove formation process (b-1)
Press the linear pressure of 75 kg / cm with the roll (diameter: 100 mm, width: 350 mm) having specific protrusions heated to 80 ° C. to the three-layer film after the roughening step (ii-1), Lattice grooves having an average depth of 15 μm or 50 μm, an average width of 2 mm, and an average pitch of 10 mm or 23 mm were provided.

In addition, the average roughness of the three-layer film surface layer before the treatment in which neither of these steps (I-1) nor the step (B-1) is performed, the above roughening step (E1) and the groove formation. The average roughness of the surface layer of the three surface-roughened films obtained by using the step (B-1) is as follows (unit: μm).
Before treatment After treatment with shallow mat After treatment with deep mat Ra 0.082 0.639 0.949
Rmax 0.744 7.359 11.71
Rx 0.506 4.114 7.090

Table 1 (single side) and Table 2 (both sides) show the evaluation results of the wrinkle test of the obtained surface roughened film. The determination of wrinkles was as follows.
X = 0 → ○
X ≦ 10mm → △
X> 10mm → ×

  The surface roughening film of the present invention is used as a release film for substrates such as single-sided printed wiring boards, double-sided printed wiring boards, and multilayer printed wiring boards. Especially, it is suitable as a release film at the time of shaping | molding of a flexible printed wiring board. Such a release film for producing a flexible printed circuit board can suppress generation of wrinkles, and can improve excellent productivity without contaminating these substrates.

FIG. 1 is a cross-sectional view of an essential part showing a pressing method for a wrinkle test. FIG. 2A is a front view showing an example in which only one surface of the surface roughening film of the present invention is surface roughened, and the grooves are formed in a square lattice shape. A cross-sectional view taken along line l in FIG. 2a is shown in FIG. 2b. FIG. 3 shows the average groove depth (h), average groove width (w), average pitch (p), and total thickness (d) in an example in which only one surface of the surface roughened film of the present invention is surface roughened. FIG. FIG. 4 is a partial cross-sectional view showing an average width (w) of grooves when the cross-sectional shape of the groove is an inverted triangle or an inverted trapezoidal shape in an example in which only one surface is roughened.

Explanation of symbols

1, 9 ... Stainless steel hot plate 2, 8 ... 10 newspaper sheets 3, 5, 7 ... Aluminum foil (thickness 100 μm)
4, 6 ... Surface roughening film d ... Total thickness h ... Average depth p of groove ... Average pitch t ... Top flat part w ... Average width of groove

Claims (16)

  The surface roughness (Ra) of the top flat portion is 0.25 to 15 μm, and grooves having an average depth of 10 to 70 μm and an average width of 0.1 to 3 mm are provided on the surface with an average pitch of 0.5 to 30 mm. A thermoplastic resin characterized in that the surface has at least one surface, the total thickness is 30 to 200 μm, and the average depth of the groove is in the range of 10 to 70% of the total thickness Surface roughening film.   The surface roughness (Ra) of the top flat portion is less than 0.25 μm, and grooves having an average depth of 30 to 70 μm and an average width of 0.1 to 3 mm are provided on the surface with an average pitch of 0.5 to 30 mm. The thermoplastic resin is characterized in that the surface has at least one surface, the total thickness is 30 to 200 μm, and the average depth of the groove is in the range of 10 to 70% of the total thickness. Surface roughening film.   The surface roughening film according to claim 1, wherein the grooves are lattice-shaped grooves.   The surface roughening film according to any one of claims 1 to 3, wherein the thermoplastic resin comprises a 4-methyl-1-pentene polymer (A).   The surface roughened film according to claim 4, wherein the 4-methyl-1-pentene polymer (A) is a polymer having a melting point (Tm) in the range of 200 to 235 ° C.   The surface roughening film according to any one of claims 1 to 5, comprising a layer (I) constituting a surface comprising a 4-methyl-1-pentene polymer (A). Consists of a layer (I), an intermediate layer (II) and a second surface layer (III-a) or back layer (III-b) constituting the surface comprising a 4-methyl-1-pentene polymer (A) The surface roughening film according to any one of claims 1 to 6. The surface-roughened film according to claim 7, comprising an intermediate layer made of a soft olefin polymer (B).   The surface roughened film according to claim 8, wherein the soft olefin polymer (B) is one or more copolymers selected from an α-olefin copolymer and an ethylene / vinyl compound copolymer.   The surface roughened film according to any one of claims 1 to 9, wherein the surface roughened film is a release film for producing a flexible printed circuit board.   At least one side of the thermoplastic resin film is a roughening step (a) in which the surface roughness (Ra) is in the range of 0.25 to 15 μm, the average depth is 10 to 70 μm, and the average width is 0.1 to 3 mm. A method for producing a roughened surface film, which is used in combination with a step (b) for forming a groove having an average pitch of 0.5 to 10 mm.   At least one side of the thermoplastic resin film is a roughening step (a) in which the surface roughness (Ra) is in the range of 0.25 to 15 μm, the average depth is 10 to 70 μm, and the average width is 0.1 to 3 mm. A method for producing a roughened surface film, which is used in combination with a step (c) of forming a groove having a mean pitch of 0.5 to 10 mm in a lattice shape.   Grooves having an average depth of 30 to 70 microns and an average width of 0.1 to 3 mm are in the range of an average pitch of 0.5 to 10 mm on the surface of the thermoplastic resin film having a surface roughness of less than Ra = 0.25. A method for producing a surface roughened film, wherein the groove forming step (b) for forming grooves is performed on at least one side of the film.   At least one side of the thermoplastic resin film is a roughening step (a) in which the surface roughness (Ra) is in the range of 0.25 to 15 μm, the average depth is 10 to 70 μm, and the average width is 0.1 to 3 mm. A surface roughening is performed in combination with a groove forming step (b) for forming grooves in the range of 0.5 to 10 mm in average pitch, or the surface roughness of the surface is less than Ra = 0.25. In the case of a resin film, a groove forming step for forming grooves having an average depth of 30 to 70 microns and an average width of 0.1 to 3 mm so that the average pitch is in the range of 0.5 to 10 mm (B) A method for producing a roughened surface film, comprising:   A groove-forming convex portion having a surface roughness Ra of 0.25 to 15 μm, an average height of 10 to 70 μm, and an average width of a portion (base) contacting the down concave portion of 0.1 to 3 mm. A method for producing a roughened surface film, characterized by performing roughening and groove formation on at least one surface of a thermoplastic resin film using a roll provided with an average pitch of 0.5 to 10 mm. The surface roughening film according to claim 3, wherein the intersecting points of the grooves are in a range of 10 to 1000 pieces / 25 cm ² .

Images