KR101873071B1 - Mold release film and method for manufacturing mold release film - Google Patents

Abstract

An object of the present invention is to provide a release film which is excellent in releasability, has excellent followability with respect to the surface of a substrate, and can prevent the adhesive from flowing out during hot press forming.
The present invention relates to a release film having a surface layer, wherein the release treatment layer is observed only in a region from the surface of the surface layer to a thickness of 50 to 300 nm.

Description

TECHNICAL FIELD [0001] The present invention relates to a method for producing a release film and a release film,

The present invention relates to a release film which is excellent in releasability, has excellent followability with respect to the surface of a substrate, and can suppress the flow of an adhesive during hot press forming.

In the production process of a printed wiring board, a flexible printed board, a multilayer printed wiring board and the like, a release film is used when a copper clad laminate or a copper foil is hot-pressed on a substrate via a prepreg or a heat resistant film. Further, in the manufacturing process of the flexible printed circuit board, even when the cover-lay film is thermally press-bonded by the thermosetting adhesive or the thermosetting adhesive sheet to the flexible printed circuit board body having the copper circuit formed thereon, A release film is widely used.

With respect to the release film, for example, heat resistance that can withstand hot press molding, releasability to the printed wiring board and hot press plate, and ease of disposal are required. In addition, in order to improve the product yield at the time of hot press forming, non-pollution to the copper circuit is also important.

Conventionally, fluorine-based films, silicone-coated polyethylene terephthalate films, polymethylpentene films, and polypropylene films have been used as release films (for example, Patent Document 1).

However, the fluorine-based film is excellent in heat resistance, releasability, and non-staining property, and is expensive and difficult to burn when incinerating in a disposal process, and generates toxic gas. In addition, the silicone-coated polyethylene terephthalate film and the polymethylpentene film may cause contamination of the printed wiring board, particularly the copper circuit, due to migration of silicon or a low-molecular weight component in the constituent components, which may deteriorate the quality. In addition, the polypropylene film is poor in heat resistance and is also deficient in releasability.

A release film made of a polyester-based resin such as polybutylene terephthalate has also been studied. Such a release film is excellent in heat resistance, ease of disposal treatment and non-staining property, but there is room for improvement in releasability.

On the other hand, the applicant of the present invention invented a release film comprising a polyester resin and a predetermined amount of polypropylene as a release film excellent in non-staining property and excellent in releasability, and disclosed in Patent Document 2. Here, in order to further improve the releasability of the release film described in Patent Document 2, it is effective to subject the release film to a heat treatment as described in Patent Document 2.

However, such a heat treatment is carried out at a high temperature and also requires a long time, resulting in an increase in cost. In addition, the release film subjected to the heat treatment lowers the flexibility of the film as a whole, so that the followability (embeddability) with respect to the unevenness of the surface of the substrate is lowered. For example, voids are generated at the time of hot press forming, The adhesive agent formed on the coverlay film may flow out to the surface of the cover portion, and the plating process of the electrode portion may become an obstacle. Therefore, there is a demand for a release film having more excellent releasability without inhibiting the followability of the surface of the substrate to the unevenness.

Japanese Patent Application Laid-Open No. 5-283862 Japanese Laid-Open Patent Publication No. 2009-132806

An object of the present invention is to provide a release film which is excellent in releasability, has excellent followability to the surface of a substrate, and can suppress the flow of an adhesive during hot press forming.

The first invention of the present invention is a release film having a surface layer, wherein the release treatment layer is observed only in a region of 50 to 300 nm in thickness from the surface of the surface layer.

A second aspect of the present invention is a release film having a surface layer containing a polyester-based resin, characterized in that, in a region from the surface of the surface layer to a thickness of 1 mu m, a carbonyl group oriented in parallel to the surface of the carbonyl group contained in the polyester- Is 45% or more.

A third aspect of the present invention is a release film having a surface layer, wherein the surface layer has a surface roughness (Rz) of 250 to 450 nm, a surface roughness (Rsk) of +0.3 to +1.1 and a surface roughness (Rku) 11 < / RTI >

Hereinafter, the present invention will be described in detail.

The present inventors have found that the following three surface layers are used: (1) a surface layer in which a predetermined release treatment layer is observed, (2) a surface layer in which the ratio of carbonyl groups oriented parallel to the surface is in a predetermined range, and ) The release film having any of the surface layers in which the surface roughness Rz, the surface roughness Rsk and the surface roughness Rku satisfy a predetermined range can be subjected to hot press forming The present inventors have found that excellent releasability can be exhibited at the same time while suppressing the flow of the adhesive agent at the time of use.

The release film of the first invention of the present invention has a surface layer, and a release treatment layer is observed only in a region of 50 to 300 nm in thickness from the surface of the surface layer.

In the present specification, the release treatment layer means a layer having excellent releasability and having a different appearance as compared with other regions in the surface layer. Note that, in the present specification, the release treatment layer includes not only a case where the entire layer has a uniform appearance but also a case where the layer as a whole has a point having a part having a different appearance.

In the release-treated layer, different shapes are observed in comparison with other regions in the surface layer. The shape observed in the release treatment layer may be, for example, a striped shape parallel to the surface. The shape observed in the other region of the surface layer is not particularly limited, and examples thereof include a shape such as sand, vortex, etc., and a non-uniform shape other than these.

Figs. 1, 2 and 3 show cross-sectional views schematically showing a part of the surface layer of the release film of the first invention of the present invention. 1, 2 and 3, the upper side is the surface of the surface layer, that is, the surface of the release film. A part of the surface layer shown in Figs. 1, 2 and 3 has a release treatment layer 1 on the surface side in which a stripe shape parallel to the surface is observed. In Fig. 1, the other region 2 in the surface layer has a sand-like shape. In Fig. 2, the other region 2 'in the surface layer has a spiral shape. In Fig. 3, (2 ") have other uneven shapes.

The release treatment layer observed in this way is dense and acts as a barrier layer, so that when the surface layer is in contact with, for example, an epoxy adhesive, the penetration of the epoxy adhesive can be suppressed. Therefore, the release film of the first invention can exhibit excellent releasability.

The method of observing the release treatment layer is not particularly limited, but a method of observing a cross section obtained by cutting in the thickness direction using a microtome or the like with a transmission electron microscope is preferable. As a method for observing the release treatment layer, a method of observing a cross section obtained by cutting in the thickness direction using a microtome or the like with a polarizing microscope, an atomic force microscope, or the like may be used. The transmission electron microscope (TEM) is not particularly limited, and examples thereof include a Hitachi transmission electron microscope (Model H-9500, manufactured by Hitachi High-Technologies Corporation) and the like. The microtome is not particularly limited, and examples thereof include a slide stock microtome (type SM2000-R, manufactured by Ikeda Corporation).

In addition, since the release film of the first present invention has a release treatment layer only in a region of 50 to 300 nm in thickness from the surface of the surface layer, the release film of the prior art, for example, Otherwise, even if the film has excellent releasability, the flexibility of the film as a whole can be maintained. Therefore, the release film of the first invention of the present invention has excellent followability with respect to the substrate surface, and the flow of the adhesive during hot press forming can be suppressed.

If the thickness of the release treatment layer is less than 50 nm from the surface of the surface layer, the surface layer can not sufficiently inhibit the penetration of the epoxy adhesive when it comes into contact with, for example, an epoxy adhesive, do. If the thickness of the release treatment layer exceeds 300 nm at the surface of the surface layer, the flexibility of the obtained release film is lowered and the followability to the substrate surface is lowered, and it is difficult to suppress the flow of the adhesive during hot press forming It becomes.

The thickness of the release treatment layer is preferably 70 nm or more on the surface of the surface layer, and preferably 250 nm or less on the surface of the surface layer.

The release film of the second invention has a surface layer containing a polyester-based resin.

In the release film of the second aspect of the present invention, the ratio of the carbonyl group oriented parallel to the plane of the carbonyl group contained in the polyester resin is 45% or more in the region from the surface of the surface layer to 1 탆 in thickness.

In the present specification, the ratio X of the carbonyl groups oriented parallel to the plane of the carbonyl group contained in the polyester resin is calculated by the following formula (1).

X = {A / (A + B)} x 100 (1)

In the formula (1), A represents a peak intensity of a carbonyl group oriented parallel to a plane obtained by an X-ray analysis, and B represents a peak of a carbonyl group oriented perpendicularly to the plane It represents strength. In the present specification, parallel or perpendicular to the plane means that the film is directed parallel or perpendicular to the surface of the release film.

The release film of the second invention can exhibit excellent releasability because the proportion of the carbonyl group oriented parallel to the surface is within the above range. This is presumably because the hydrophobicity of the surface of the surface layer is increased by increasing the proportion of the carbonyl group oriented parallel to the surface in the region from the surface of the surface layer to the thickness of 1 mu m.

In the release film of the second invention, since the region in which the ratio of the carbonyl groups oriented parallel to the plane is within the above range is the region from the surface of the surface layer to 1 mu m in thickness, for the purpose of improving the releasability, The flexibility of the entire film can be maintained even when the releasing film has excellent releasability. Therefore, the release film of the second invention of the present invention has excellent followability with respect to the substrate surface, and the flow of the adhesive during hot press forming can be suppressed.

If the proportion of the carbonyl group oriented parallel to the surface is less than 45%, the hydrophobicity of the surface of the surface layer is lowered, and the releasability of the resultant releasing film is lowered.

The ratio of the carbonyl group oriented parallel to the plane is preferably 55% or more.

The upper limit of the ratio of the carbonyl groups oriented parallel to the surface is not particularly limited and may be 100%, preferably 90% or less. When the ratio of the carbonyl groups oriented parallel to the surface exceeds 90%, for example, the energy amount of the friction treatment at the time of producing the release film becomes excessively large, so that damage such as wrinkles and scratches is caused in the resulting release film .

It is more preferable that the ratio of the carbonyl group oriented parallel to the surface is 70% or less.

As a method for carrying out the X-ray analysis, for example, a method of measuring the diffraction of X-rays incident on the surface of the surface layer (In-Plane) and the like can be given. The X-ray analysis apparatus for conducting the X-ray analysis is not particularly limited, and examples thereof include a horizontal X-ray diffraction apparatus (type Smart Lab, Rigaku Corporation) for evaluating thin films.

The release film of the third aspect of the present invention has a surface layer, and the surface layer has a lower surface roughness (Rz) of 250 nm. When the surface roughness (Rz) is less than 250 nm, the surface layer obtained becomes smooth, the contact area of the surface layer is increased, and the releasability is lowered. The lower limit of the surface roughness (Rz) is preferably 280 nm.

The upper limit of the surface roughness (Rz) is 450 nm. When the surface roughness (Rz) exceeds 450 nm, the obtained surface layer has increased irregularities, and when used for an adherend having high fluidity or flexibility such as an epoxy adhesive, the contact area with an adherend is increased , The releasability is deteriorated.

In the present specification, the surface roughness (Rz) is a surface roughness (Rz), which is the height of the top of the mountain from the highest peak to the fifth highest peak in the reference length L as Yp1, Yp2, Yp3, Yp4 and Yp5 Yv2, Yv3, Yv4, and Yv5, respectively, of the valley bottom from the bottom of the deep valley to the depth of the fifth valley, respectively. , The smaller the value, the smoother the surface as a whole.

The lower limit of the surface roughness (Rsk) of the surface layer is +0.3. If the surface roughness (Rsk) of the surface is less than +0.3, the convex component of the surface layer to be obtained decreases to increase the contact area of the surface layer, and the releasability is lowered or the appearance defect of the surface layer to be obtained occurs. The lower limit of the surface roughness Rsk is preferably +0.5, and more preferably the lower limit is +0.8.

Further, the upper limit of the degree of the surface roughness Rsk is +1.1. If the surface roughness (Rsk) of the surface exceeds 1.1, the surface layer of the obtained surface layer increases in convexity, and when used for an adherend having high fluidity or flexibility such as an epoxy adhesive, the contact area with the adherend is Which causes the releasability to deteriorate.

In the present specification, the surface roughness (Rsk) means a value obtained by the following formula (3) when the surface roughness of the surface layer is Rq and the height of the acid is Yi, and the positive value The convex component is larger with respect to the average line of the back surface, and a minus value means that the concave component is larger than the average line of the surface.

The lower limit of the surface roughness (Rku) of the surface layer is 5. If the surface roughness (Rku) is less than 5, the convex shape of the obtained surface layer becomes gentle, the contact area of the surface layer is increased, and the releasability is lowered. A preferable lower limit of the surface roughness (Rku) is 6, and a more preferable lower limit is 7.

The upper limit of the surface roughness (Rku) is 11. If the surface roughness (Rku) exceeds 11, the surface layer obtained becomes smooth, the contact area of the surface layer is increased, and the releasability is lowered.

In the present specification, the surface kurtosis (Rku) means a value obtained by the following formula (4) when the square-root mean roughness is Rq and the height of the acid is Yi with respect to the surface of the surface layer. , The convex shape becomes sharp and the portion flattening with respect to the average line increases. The smaller the value, the gentler the convex shape and the more flat the portion with respect to the average line decreases.

In the release film of the first aspect of the present invention, in order for the release treatment layer to be observed only in the region of 50 to 300 nm in thickness from the surface of the surface layer, it is preferable to subject the surface layer to surface treatment such as rubbing treatment Do. In order to keep the ratio of the carbonyl groups oriented parallel to the surface in the release film of the second invention within the above range, the surface roughness Rz or the like satisfying the above range in the release film of the third invention In order to impart the surface shape, it is also preferable to subject the surface layer to surface treatment such as rubbing treatment.

Although the friction treatment is not particularly limited, it is preferable that the friction energy treatment is performed such that the energy amount En (KJ) expressed by the following formula (5) is 50 to 500 KJ.

In the formula (5), Ar represents an area (m 2) of the friction processing apparatus subjected to friction processing, J represents a daily amount per unit time (KJ / min) for friction processing, W represents a width , And LS represents the line speed (m / min) of the film subjected to the rubbing treatment.

In the formula (5), the area Ar (m 2) of the rubbing treatment apparatus is the area of the film subjected to the friction treatment by the friction treatment apparatus.

The amount of energy J (KJ / min) per unit time for the rubbing treatment is calculated from the amount of load energy per unit time (the amount of load energy applied to the power source of the friction device caused by the application of pressure to the film by the friction device) And then multiplied by a number of times.

The width W (m) of the film subjected to the rubbing treatment is the width of the film subjected to the rubbing treatment by the friction device.

Further, the line speed LS (m / min) of the film subjected to the rubbing treatment is a speed at which the film passes through the friction device.

If the energy amount En (KJ) is less than 50 KJ, the mold-releasing treatment layer is not observed in the region of the thickness of 50 to 300 nm on the surface of the surface layer described above, or the ratio of the carbonyl groups oriented parallel to the surface Can not be made within the above range, or a surface shape such as a surface roughness (Rz) satisfying the above-described range can not be imparted. In such a case, excellent releasability can not be imparted to the resulting releasing film. If the energy amount En (KJ) exceeds 500 KJ, the resulting releasable film may have poor flexibility, or may suffer damage such as wrinkles and scratches, resulting in poor followability to the surface of the substrate, There is a case that the flow-out can not be sufficiently suppressed.

It is more preferable that the rubbing treatment is performed so that the upper limit of the energy amount En (KJ) expressed by the formula (5) is 300 KJ.

In the above-mentioned rubbing treatment, the fiber of the fabric used for the material of the surface of the friction material has a preferable lower limit of 1.0 g / d and a preferable upper limit of 5.0 g / d. If the tensile strength of the fiber is less than 1.0 g / d, the fibers are stretched and broken in the friction treatment, and the fibers may adhere to the resulting release film. If the tensile strength of the fiber exceeds 5.0 g / d, damage such as wrinkles, scratches, or the like occurs in the resulting release film, and the followability to the substrate surface is lowered to sufficiently suppress the flow of the adhesive during hot press forming There is a case that can not be. A more preferred upper limit of the tensile strength of the fibers is 3.0 g / d.

In the present specification, the tensile strength of a fiber means the tensile strength of one fiber obtained by a method in accordance with JIS-L-1095.

The fiber preferably has a lower limit of 1% and a preferred upper limit of 30% of elongation. If the elongation of the fibers is less than 1%, the fibers are elongated and broken in the friction treatment, and the fibers may adhere to the resulting release film. If the elongation of the fiber exceeds 30%, damage such as wrinkles or scratches may be caused in the resulting release film, and the followability to the substrate surface may decrease, and the flow of the adhesive during hot press forming can not be suppressed sufficiently There is a case. A more preferable upper limit of the elongation of the fibers is 29%.

In the present specification, the elongation of a fiber means the tensile elongation of one fiber obtained by a method in accordance with JIS-L-1095.

Specific examples of the fiber include PET, rayon, cotton, wool, acetate and the like. In particular, by performing the rubbing treatment, it is possible to further suppress damage to wrinkles, scratches, and the like caused in the release film, to obtain a release film excellent in followability to the surface of the substrate, Therefore, rayon and wool are preferable.

The fabric used for the material of the surface of the friction material has a preferable lower limit of friction coefficient of 0.1 and a preferable upper limit of 0.8. If the coefficient of friction of the fabric is less than 0.1, the releasability of the obtained release film may be lowered. When the coefficient of friction of the fabric exceeds 0.8, damage such as wrinkles and scratches is generated in the resulting releasing film, and the followability to the substrate surface is lowered and the flow of the adhesive during hot press forming can not be suppressed sufficiently . A more preferable lower limit of the friction coefficient of the fabric is 0.3, and a more preferable upper limit is 0.7.

In the present specification, the coefficient of friction of a fabric means a coefficient of friction of a fabric to a 2 mm polycarbonate sheet obtained by a method in accordance with JIS-K-7125.

The fabric preferably has a lower limit of elastic modulus of 0.1 MPa and a preferable upper limit of 4.0 MPa. If the elastic modulus of the fabric is less than 0.1 MPa, the releasability of the obtained release film may be lowered. If the elastic modulus of the fabric exceeds 4.0 MPa, damage such as wrinkles, scratches, or the like occurs in the resulting release film, and the followability to the substrate surface is lowered and the flow of the adhesive during hot press forming can not be suppressed sufficiently . A more preferable lower limit of the modulus of elasticity of the fabric is 0.7 MPa, and a more preferable upper limit is 3.9 MPa.

In the present specification, the modulus of elasticity of a fabric means the hardness of a fabric obtained by a method according to JIS-K-7127.

The fabric has a preferred lower limit of 1.5 N / 10 mm tensile strength and a preferred upper limit of 2.5 N / 10 mm. When the tensile strength of the fabric is less than 1.5 N / 10 mm, the fibers are stretched and broken in the friction treatment, and the fibers may adhere to the resulting release film. If the tensile strength of the fabric exceeds 2.5 N / 10 mm, damage to wrinkles, scratches, and the like may occur on the resulting release film, and the followability to the surface of the substrate may deteriorate to sufficiently inhibit the flow of the adhesive during hot press forming There is a case that can not be done. A more preferred lower limit of the tensile strength of the fabric is 1.6 N / 10 mm, a more preferred upper limit is 2.3 N / 10 mm, and a more preferred upper limit is 1.8 N / 10 mm.

In the present specification, the tensile strength of the fabric means the tensile strength of the fabric obtained by the method in accordance with JIS-K-7127.

The friction treatment apparatus for performing the friction treatment is not particularly limited, and for example, a polishing treatment apparatus (type YCM-150M, manufactured by Yamagata Machinery Co., Ltd.) and the like can be mentioned.

In the release film of the second aspect of the present invention, the surface layer contains a polyester resin. In the release films of the first and third inventions, the surface layer is not particularly limited, but preferably contains a polyester resin.

Hereinafter, matters common to the release films of the first, second, and third inventions will be described in detail. In the present specification, the term "release film" of the present invention refers to any of the release films of the first, second, and third inventions.

The polyester resin is not particularly limited. By using the above-mentioned polyester-based resin, the resulting release film can exhibit excellent mechanical performance, particularly excellent mechanical performance in a temperature range of about 170 DEG C, which is usually subjected to hot press forming. Further, by using the polyester-based resin, the obtained release film is economically advantageous in reducing the environmental load in incineration treatment. In addition, since the polyester-based resin has few low-molecular-weight components, the obtained release film is excellent in non-staining property, and plating defects occur in the electrode portion of the flexible printed circuit board due to bleeding out of low- And the like can be suppressed.

As the polyester-based resin, for example, a crystalline aromatic polyester resin is preferable.

The crystalline aromatic polyester resin is not particularly limited, and examples thereof include a crystalline aromatic polyester resin obtained by reacting an aromatic dicarboxylic acid or an ester-forming derivative thereof with a low molecular weight aliphatic diol.

As the crystalline aromatic polyester resin, a crystalline aromatic polyester resin obtained by reacting an aromatic dicarboxylic acid or an ester-forming derivative thereof with a low molecular weight aliphatic diol and a high molecular weight diol (hereinafter referred to as " a polyether skeleton Quot; crystalline aromatic polyester resin having in the main chain "), a crystalline aromatic polyester resin obtained by reacting an aromatic dicarboxylic acid or an ester-forming derivative thereof with a low molecular weight aliphatic diol is dissolved in a caprolactone monomer , A crystalline aromatic polyester resin obtained by ring-opening polymerization of caprolactone (hereinafter also referred to as " crystalline aromatic polyester resin having a polycaprolactone skeleton in its main chain "), and the like.

Among them, in comparison with a case where a crystalline aromatic polyester resin obtained by reacting an aromatic dicarboxylic acid or an ester-forming derivative thereof with a low molecular weight aliphatic diol is used, the obtained release film is excellent in flexibility and releasability while maintaining heat resistance , A crystalline aromatic polyester resin having a polyether skeleton in its main chain and a crystalline aromatic polyester resin having a polycaprolactone skeleton in its main chain are preferable.

Examples of the aromatic dicarboxylic acid or ester-forming derivative thereof include terephthalic acid, isophthalic acid, orthophthalic acid, naphthalene dicarboxylic acid, paraphenylene dicarboxylic acid, dimethyl terephthalate, dimethyl isophthalate, dimethyl orthophthalate, Dimethyl naphthalene dicarboxylate, dimethyl paraphenylene dicarboxylate, and the like. These may be used alone, or two or more of them may be used in combination.

Examples of the low molecular weight aliphatic diol include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, neopentyl glycol, 1,6-hexanediol, 1,4-cyclohexanedimethanol, and the like. These may be used alone, or two or more of them may be used in combination.

Examples of the high molecular weight diol include polyethylene glycol, polypropylene glycol, polytetramethylene glycol, polyhexamethylene glycol and the like. These may be used alone, or two or more of them may be used in combination.

Specific examples of the crystalline aromatic polyester resin include polyethylene terephthalate, polybutylene terephthalate, polyhexamethylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, terephthalic acid butanediol-polytetramethylene glycol Terephthalic acid butanediol-polycaprolactone copolymer, and the like. These may be used alone, or two or more of them may be used in combination. Among them, polybutylene terephthalate is preferable because the resulting release film is excellent in non-staining property and crystallinity.

It is preferable that the crystalline aromatic polyester resin has a melting point of 200 DEG C or more as measured using a differential scanning calorimeter.

Generally, since the heat press molding is carried out at a temperature of less than 200 占 폚, by using such a resin having a high melting point, the obtained release film can not be melted even during hot press forming and can be releasable. As a differential scanning calorimeter, for example, DSC 2920 (manufactured by TA Instrument) can be mentioned.

If the melting point of the crystalline aromatic polyester resin measured using a differential scanning calorimeter is less than 200 占 폚, the resultant releasing film may be deteriorated in heat resistance and may be melted at the time of hot press forming. It is more preferable that the crystalline aromatic polyester resin has a melting point of 220 캜 or higher as measured using a differential scanning calorimeter.

The crystalline aromatic polyester resin having a melting point of 200 ° C or higher as measured using the differential scanning calorimeter is not particularly limited and includes, for example, polyethylene terephthalate, polybutylene terephthalate, polyhexamethylene terephthalate, polyethylene naphthalate, poly Butylene naphthalate, terephthalic acid butanediol-polytetramethylene glycol copolymer, and the like. These may be used alone, or two or more of them may be used in combination. Of these, polybutylene terephthalate is preferable because the obtained release film is excellent in non-staining property and crystallinity.

The surface layer may contain a stabilizer. The stabilizer is not particularly limited, and examples thereof include hindered phenol-based antioxidants and heat stabilizers.

The hindered phenol-based antioxidant is not particularly limited, and examples thereof include 1,3,5-trimethyl-2,4,6-tris (3,5-di-t-butyl- 3,9-bis {2- [3- (3-t-butyl-4-hydroxy-5-methylphenyl) propionyloxy] -1,1- dimethylethyl} -2,4,8,10-tetra Oxaspiro [5,5] undecane, and the like.

The heat stabilizer is not particularly limited and includes, for example, tris (2,4-di-t-butylphenyl) phosphite, trilauryl phosphite, 2-t- -Hydroxyphenyl) -p-cumenebis (p-nonylphenyl) phosphite, dimyristyl 3,3'-thiodipropionate, distearyl 3,3'-thiodipropionate, pentaerythritol Styryltetrakis (3-laurylthiopropionate), ditridecyl 3,3'-thiodipropionate, and the like.

The surface layer may contain additives such as fibers, an inorganic filler, a flame retardant, an ultraviolet absorber, an antistatic agent, an inorganic substance, and a higher fatty acid salt within a range not hindering the effect of the present invention.

The fibers may be inorganic fibers or organic fibers. The inorganic fibers are not particularly limited, and examples thereof include glass fibers, carbon fibers, boron fibers, silicon carbide fibers, alumina fibers, amorphous fibers and silicon-titanium-carbon fibers. The organic fibers are not particularly limited, and examples thereof include aramid fibers and the like.

The inorganic filler is not particularly limited, and examples thereof include calcium carbonate, titanium oxide, mica, talc and the like.

The flame retardant is not particularly limited, and examples thereof include hexabromocyclododecane, tris- (2,3-dichloropropyl) phosphate, and pentabromophenyl allyl ether.

The ultraviolet absorber is not particularly limited, and examples thereof include pt-butylphenyl salicylate, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-methoxy- , 4,5-trihydroxybutyrophenone, and the like.

The antistatic agent is not particularly limited, and examples thereof include N, N-bis (hydroxyethyl) alkylamine, alkylallylsulfonate, alkylsulfanate and the like.

The inorganic material is not particularly limited, and examples thereof include barium sulfate, alumina, silicon oxide and the like.

The higher fatty acid salt is not particularly limited, and examples thereof include sodium stearate, barium stearate, sodium palmitate and the like.

The surface layer may contain a thermoplastic resin and a rubber component in order to modify the properties of the surface layer.

The thermoplastic resin is not particularly limited, and examples thereof include polyolefin, modified polyolefin, polystyrene, polyvinyl chloride, polyamide, polycarbonate, polysulfone, polyester and the like.

The rubber component is not particularly limited, and examples thereof include natural rubber, styrene-butadiene copolymer, polybutadiene, polyisoprene, acrylonitrile-butadiene copolymer, ethylene-propylene copolymer (EPM, EPDM), polychloroprene, butyl rubber , Acryl rubber, silicone rubber, urethane rubber, olefin thermoplastic elastomer, styrene thermoplastic elastomer, vinyl chloride thermoplastic elastomer, ester thermoplastic elastomer and amide thermoplastic elastomer.

The surface layer may also contain an inorganic compound having a large aspect ratio.

By containing an inorganic compound having a large aspect ratio, the obtained release film can exhibit improved releasability at high temperatures and can inhibit bleed-out of additives, low-molecular-weight water and the like contained in the release film to the surface of the release film, The cleanability at the time of press forming is improved.

The inorganic compound having a high aspect ratio is not particularly limited, and for example, a layered silicate such as clay and a layered multiple ash such as hydrotalcite can be cited.

The surface layer preferably has a crystallinity of 25% or less. If the degree of crystallinity exceeds 25%, the resulting releasable film may be deteriorated in followability. The crystallinity of the surface layer is more preferably 20 to 23%.

In the present specification, the degree of crystallization means a value obtained from a peak intensity ratio between a crystalline portion and an amorphous portion obtained by an X-ray diffraction method.

The surface layer may be subjected to heat treatment in order to further improve the heat resistance, dimensional stability and releasability of the obtained release film within a range not hindering the effect of the present invention.

The heat treatment method is not particularly limited. For example, a method of passing a film between rolls heated to a constant temperature, a method of heating a film by a heater, and the like are preferable.

The heat treatment temperature is not particularly limited as long as it is not lower than the glass transition temperature of the resin contained in the surface layer of the polyester resin or the like but not higher than the melting point. The lower limit is preferably 120 占 폚, and the upper limit is preferably 200 占 폚. If the heat treatment temperature is less than 120 캜, the effect of improving the releasability due to the heat treatment may hardly be obtained. If the heat treatment temperature exceeds 200 캜, the surface layer tends to be deformed at the time of heat treatment, and a release film may not be produced. A more preferable lower limit of the heat treatment temperature is 170 占 폚, and a more preferable upper limit is 190 占 폚.

The thickness of the surface layer is not particularly limited, but the lower limit is preferably 5 占 퐉, and the upper limit is preferably 20 占 퐉. If the thickness of the surface layer is less than 5 占 퐉, the surface layer is impaired in strength and may be broken at the time of hot press forming or peeling off of the release film. When the thickness of the surface layer exceeds 20 m, flexibility of the resultant releasing film is lowered, and the followability to the substrate surface is lowered, so that the flow of the adhesive during hot press forming can not be suppressed sufficiently. A more preferable lower limit of the thickness of the surface layer is 10 mu m, and a more preferable upper limit is 15 mu m.

The release film of the present invention may be a single-layer film or a plurality of layers of two or more layers as long as the film has the surface layer.

The release film of the present invention may have an intermediate layer in the case of a plurality of films.

The intermediate layer preferably contains a polyolefin-based resin having a melting point of not lower than 60 ° C and lower than 130 ° C as measured using a differential scanning calorimeter.

By using the polyolefin-based resin, the resulting intermediate layer starts to soften near the temperature at which the adhesive of the coverlay film starts melting, and thus the release film having such an intermediate layer has excellent followability to the surface of the substrate. For example, It is possible to sufficiently follow the flexible printed circuit board having a minute copper circuit pitch such as the following, and the flow of the adhesive can be suppressed.

When the melting point measured using a differential scanning calorimeter of the above polyolefin resin is less than 60 ° C, when the temperature of the atmosphere becomes 50 to 60 ° C during storage of the release film, the above-mentioned intermediate layer resin melts and seeps out and causes blocking . If the melting point of the polyolefin-based resin measured using a differential scanning calorimeter is 130 캜 or higher, the resulting releasable film may have poor followability to the substrate surface. The melting point of the polyolefin-based resin measured using a differential scanning calorimeter is more preferably 65 ° C or more and 100 ° C or less.

Specific examples of the polyolefin resin include polyethylene, low density polyethylene, linear low density polyethylene, polypropylene, ethylene-methyl methacrylate copolymer, ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer , Ethylene-acrylic acid copolymer, and the like. These may be used alone, or two or more of them may be used in combination. Of these, low-density polyethylene, linear low-density polyethylene, ethylene-methyl methacrylate copolymer and ethylene-vinyl acetate copolymer are preferable.

The intermediate layer preferably further contains a resin having a melting point of 130 ° C or higher as measured using a differential scanning calorimeter.

When a resin having a low softening temperature such as a polyolefin resin having a melting point of 60 ° C or more and less than 130 ° C as measured using the differential scanning calorimeter is used for the intermediate layer, The resin seeps out from the intermediate layer and may contaminate the printed wiring board, hot press plate, and the like. On the other hand, by using a resin having a melting point of 130 DEG C or higher, which is measured by using the above differential scanning calorimeter, it is possible to inhibit the resin from leaking out of the intermediate layer generated at the end of the release film during hot press forming. The resin having a melting point of not lower than 130 占 폚 as measured using the above differential scanning calorimeter is not particularly limited, and examples thereof include polypropylene, crystalline aromatic polyester resin and the like.

When the intermediate layer contains a resin having a melting point of 130 ° C or higher as measured using the differential scanning calorimeter, the blending amount of such a resin is not particularly limited, but a preferable lower limit is 5 wt% and a preferable upper limit is 50 wt% in the intermediate layer. If the blending amount of the resin having a melting point of 130 캜 or higher as measured by the above differential scanning calorimeter is less than 5% by weight, the effect of suppressing the resin from leaking out from the intermediate layer generated at the end portion of the release film during hot press forming is sufficiently obtained . If the blending amount of the resin having a melting point of 130 캜 or higher as measured using the differential scanning calorimeter exceeds 50% by weight, the resulting releasable film may have poor followability to the substrate surface.

The intermediate layer may contain additives such as fibers, an inorganic filler, a flame retardant, an ultraviolet absorber, an antistatic agent, an inorganic substance and a higher fatty acid salt in the same manner as the surface layer.

The thickness of the intermediate layer is not particularly limited, but a preferable lower limit is 10 占 퐉, and a preferable upper limit is 200 占 퐉. If the thickness of the intermediate layer is less than 10 mu m, the intermediate layer is too thin, and when the intermediate layer is softened at the time of hot press forming, a point at which the intermediate layer does not partially exist is generated and the press pressure can not be uniformly applied to the substrate There is a case. When the thickness of the intermediate layer is more than 200 占 퐉, the intermediate layer is thicker than necessary, so that the resin can not be inhibited from exuding from the intermediate layer generated at the end of the film during hot press forming. A more preferable lower limit of the thickness of the intermediate layer is 20 占 퐉, and a more preferable upper limit is 100 占 퐉.

It is preferable that the dimensional change ratio when the release film of the present invention is pressed at 170 캜 under a load of 3 MPa for 60 minutes is 1.5% or less. If the dimensional change rate exceeds 1.5%, the circuit pattern of the flexible printed circuit board may be damaged at the time of hot press forming. The dimensional change ratio is more preferably 1.0% or less.

In addition, the release film of the present invention preferably has a dimensional change ratio of the width direction of the release film (hereinafter referred to as TD) and the longitudinal direction (hereinafter referred to as MD) in the same direction. In the case where dimensional changes in the longitudinal and transverse directions are different from each other (for example, MD) is contracted and the other (for example, TD) is elongated, The pattern may be damaged.

The use of the release film of the present invention is not particularly limited. For example, the release film of the present invention can be produced by hot-pressing a copper clad laminate or copper foil on a substrate via a prepreg or a heat resistant film, When a substrate or a multilayer printed wiring board is manufactured, it is preferable to use it to prevent adhesion between the hot press plate and the obtained printed wiring board, the flexible printed board, or the multilayer printed wiring board.

Further, the release film of the present invention is characterized in that, when a coverlay film is adhered to a substrate on which a copper circuit is formed via a thermosetting adhesive by hot press forming, and a flexible printed substrate is produced, It is also preferable to use them to prevent adhesion of the film or adhesion of the coverlay films.

It is also preferable that the release film of the present invention is used for preventing the adhesion between the molding die and the mold resin when the mold for semiconductor is manufactured by hot press molding.

The method for producing the release film of the present invention is not particularly limited, but it is preferable to form a film having the surface layer and then subject the surface layer to a surface treatment such as the rubbing treatment described above, Specifically, for example, the surface of the surface layer is subjected to a friction treatment with a friction material, and the material of the surface of the friction material is a fabric composed of fibers having a tensile strength of 1.0 to 5.0 g / d, It is preferable that the treatment is carried out such that the energy amount En (KJ) expressed by the formula (5) is 50 to 500 KJ.

The method for producing the film of the release film of the present invention is not particularly limited and includes, for example, a method of producing a film by a water-cooled or air-cooled coextrusion inflation method, a coextrusion T die method, A lamination method by a lamination method, a method of dry-laminating a film to be the surface layer, a film to be an intermediate layer, a solvent casting method, and a hot press forming method. Among them, when the release film of the present invention is a plurality of films, it is preferable that the film is produced by the co-extrusion T die method because the thickness control of each layer is excellent.

In the solvent casting method, for example, an anchor layer is subjected to undercoating treatment on a film to be an intermediate layer, and then a resin composition serving as a surface layer in which the polyester resin or the like is dissolved in a solvent is coated on the anchor layer , The coating film is uniformly heated and dried to form a surface layer.

Further, in the hot press forming method, for example, the film serving as the surface layer and the film serving as the intermediate layer are superposed and hot-pressed.

According to the present invention, it is possible to provide a release film which is excellent in releasability, has excellent followability with respect to the surface of a substrate, and can prevent the adhesive from flowing out during hot press forming.

1 is a cross-sectional view schematically showing a part of a surface layer of a release film of the first invention of the present invention.
2 is a cross-sectional view schematically showing a part of the surface layer of the release film of the first invention of the present invention.
3 is a cross-sectional view schematically showing a part of the surface layer of the release film of the first invention of the present invention.
4 is an image obtained by observing a cross section obtained by cutting a release film obtained in Example 1 in the thickness direction using a microtome by a transmission electron microscope.
5 is an image obtained by observing a cross section obtained by cutting a release film obtained in Example 2 in the thickness direction using a microtome by a transmission electron microscope.
6 is an image obtained by observing a cross section obtained by cutting a release film obtained in Example 3 in the thickness direction using a microtome by a transmission electron microscope.
7 is an image obtained by observing a cross section obtained by cutting a thickness direction of a release film obtained in Example 5 using a microtome by a transmission electron microscope.
8 is an image obtained by observing a cross section obtained by cutting a release film obtained in Comparative Example 1 in the thickness direction using a microtome by a transmission electron microscope.

Hereinafter, embodiments of the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.

In the following Examples and Comparative Examples, " TORESI " manufactured by Toray Industries, Inc. and TETRON manufactured by Teijin Fibers Corporation, which are used as materials for the surface of the friction material, are PET.

(Example 1)

Polybutylene terephthalate (Nova Duran 5010 R5, manufactured by Mitsubishi Engineering Plastics, melting point 224 ° C) was used as the crystalline aromatic polyester resin for the surface layer, and linear low density polyethylene (excelene FX (Trade name: CX5501, manufactured by Sumitomo Chemical Co., Ltd., melting point: 66 占 폚) and an ethylene-methyl methacrylate copolymer (Aclift (WH401, manufactured by Sumitomo Chemical Co., melting point: 86 占 폚) and polypropylene Extrusion molding machine, and co-extruded from T die to obtain a film having a surface layer thickness of 10 mu m and an intermediate layer thickness of 80 mu m. The melting point was measured using a differential scanning calorimeter (DSC 2920, manufactured by TA Instrument).

The surface of the obtained surface layer of the film was subjected to surface treatment using a friction treatment apparatus (polishing apparatus, type YCM-150M, manufactured by Yamagata Machinery Co., Ltd.) using a friction material having a fabric made of fibers shown in Table 1 as a surface material, (KJ), thereby obtaining a release film.

The amount of energy per day is calculated as follows: the area Ar (m 2) subjected to the friction treatment by the friction device, the quantity J (KJ / min) per unit time for friction treatment, the width W The line speed LS (m / min) was calculated by applying the equation (5).

The obtained release film was observed with a transmission electron microscope (TEM) (Model H-9500, manufactured by Hitachi High-Technologies Corporation) to obtain a cross section obtained by cutting in the thickness direction using a sliding microtome (type SM2000R, manufactured by Ikeda Corporation) , The release treatment layer was observed only in the region from the surface of the surface layer to the thickness (nm) shown in Table 1. An image observed by a transmission electron microscope in Example 1 is shown in Fig. The crystallinity (%) of the surface layer was calculated from the peak intensity ratio between the crystalline portion and the amorphous portion obtained by the X-ray diffraction method.

(Examples 2 to 5)

A release film was obtained in the same manner as in Example 1 except that the material and the amount of energy per day (KJ) of the surface of the friction material were changed as shown in Table 1.

The obtained release film was observed with a transmission electron microscope (TEM) (Model H-9500, manufactured by Hitachi High-Technologies Corporation) to obtain a cross section obtained by cutting in the thickness direction using a sliding microtome (type SM2000R, manufactured by Ikeda Corporation) , The release treatment layer was observed only in the region from the surface of the surface layer to the thickness (nm) shown in Table 1. An image observed by a transmission electron microscope in Example 2 is shown in Fig. 5, an image observed by a transmission electron microscope in Example 3 is shown in Fig. 6, an image observed by a transmission electron microscope in Example 5 is shown 7. Further, the crystallinity (%) of the surface layer was calculated in the same manner as in Example 1.

(Comparative Example 1)

A release film was obtained in the same manner as in Example 1 except that no rubbing treatment was carried out.

The obtained release film was observed with a transmission electron microscope (TEM) (Model H-9500, manufactured by Hitachi High-Technologies Corporation) to obtain a cross section obtained by cutting in the thickness direction using a sliding microtome (type SM2000R, manufactured by Ikeda Corporation) , No release treatment layer was observed. An image observed by a transmission electron microscope is shown in Fig. Further, the crystallinity (%) of the surface layer was calculated in the same manner as in Example 1.

(Comparative Examples 2 to 3)

A release film was obtained in the same manner as in Example 1 except that the material and the amount of energy (KJ) of the surface of the friction material were changed as shown in Table 2.

The obtained release film was observed with a transmission electron microscope (TEM) (Model H-9500, manufactured by Hitachi High-Technologies Corporation) to obtain a cross section obtained by cutting in the thickness direction using a sliding microtome (type SM2000R, manufactured by Ikeda Corporation) , The release treatment layer was observed only in the region from the surface of the surface layer to the thickness (nm) shown in Table 2. Further, the crystallinity (%) of the surface layer was calculated in the same manner as in Example 1.

(Example 6)

Polybutylene terephthalate (Nova Duran 5010 R5, manufactured by Mitsubishi Engineering Plastics, melting point 224 ° C) was used as the crystalline aromatic polyester resin for the surface layer, and linear low density polyethylene (excelene FX (Trade name: CX5501, manufactured by Sumitomo Chemical Co., Ltd., melting point: 66 占 폚) and an ethylene-methyl methacrylate copolymer (Aclift (WH401, manufactured by Sumitomo Chemical Co., melting point: 86 占 폚) and polypropylene , And the mixture was fed into a coextrusion molding machine and co-extruded from a T die to obtain a film having a surface layer thickness of 10 mu m and an intermediate layer thickness of 80 mu m. The melting point was measured using a differential scanning calorimeter (DSC 2920, manufactured by TA Instrument).

Using the friction treatment apparatus (polishing apparatus, type YCM-150M, manufactured by Yamagata Machinery Co., Ltd.) using the friction material having the fabric made of the fiber shown in Table 3 as the surface material of the obtained surface layer of the film, (KJ), thereby obtaining a release film.

The amount of energy per day is calculated as follows: the area Ar (m 2) subjected to the friction treatment by the friction device, the quantity J (KJ / min) per unit time for friction treatment, the width W The line speed LS (m / min) was calculated by applying the equation (5).

X-ray analysis was performed on the surface of the obtained release film surface layer to a thickness of 1 mu m using a horizontal thin film X-ray diffraction apparatus (type Smart Lab, Rigaku Corporation) The percentage (%) of the oriented carbonyl group was determined.

The ratio (%) of the carbonyl group oriented parallel to the plane is determined by the peak intensity A of the carbonyl group oriented parallel to the plane obtained by the X-ray analysis and the peak intensity B of the carbonyl group oriented perpendicularly to the plane , And (1), respectively. Further, the crystallinity (%) of the surface layer was calculated in the same manner as in Example 1.

(Examples 7 to 9)

A release film was obtained in the same manner as in Example 6 except that the material and the amount of energy (KJ) of the surface of the friction material were changed as shown in Table 3.

X-ray analysis was performed on the surface of the obtained release film surface layer to a thickness of 1 mu m using a horizontal thin film X-ray diffraction apparatus (type Smart Lab, Rigaku Corporation) The percentage (%) of the oriented carbonyl group was determined. In addition, the crystallinity (%) of the surface layer was calculated in the same manner as in Example 6.

(Comparative Example 4)

A release film was obtained in the same manner as in Example 6 except that no rubbing treatment was carried out.

X-ray analysis was performed on the surface of the obtained release film surface layer to a thickness of 1 mu m using a horizontal thin film X-ray diffraction apparatus (type Smart Lab, Rigaku Corporation) The percentage (%) of the oriented carbonyl group was determined. In addition, the crystallinity (%) of the surface layer was calculated in the same manner as in Example 6.

(Example 10)

Polybutylene terephthalate (Nova Duran 5010 R5, manufactured by Mitsubishi Engineering Plastics, melting point 224 ° C) was used as the crystalline aromatic polyester resin for the surface layer, and linear low density polyethylene (excelene FX (Trade name: CX5501, manufactured by Sumitomo Chemical Co., Ltd., melting point: 66 占 폚) and an ethylene-methyl methacrylate copolymer (Aclift (WH401, manufactured by Sumitomo Chemical Co., melting point: 86 占 폚) and polypropylene , And the mixture was fed into a coextrusion molding machine and co-extruded from a T die to obtain a film having a surface layer thickness of 10 mu m and an intermediate layer thickness of 80 mu m. The melting point was measured using a differential scanning calorimeter (DSC 2920, manufactured by TA Instrument).

The surface layer of the obtained film was treated with a friction treatment apparatus (type YCM-150M, manufactured by Yamagata Kikai Co., Ltd.) and a friction material having a surface textile material so that the energy amount (KJ) To obtain a release film having a surface roughness Rz of the surface layer of 250 nm, a surface roughness Rsk of +0.80 and a surface roughness Rku of 8. The surface roughness (Rz), surface roughness (Rsk) and surface roughness (Rku) of the surface layer were calculated using the above formulas (2), (3) and (4), respectively. Further, the crystallinity (%) of the surface layer was calculated in the same manner as in Example 1.

(Example 11)

The surface roughness Rz of the surface layer was 250 nm, the surface roughness Rsk was +0.30, the surface roughness (Rz) of the surface layer was 3.0 nm, the surface roughness And a release film having a kurtosis (Rku) of 5 was obtained. The crystallinity (%) of the surface layer was calculated in the same manner as in Example 10.

(Example 12)

Except that the daily energy amount KJ was changed as shown in Table 4 and the friction material treated as the surface material was subjected to a friction treatment with a friction material made of wool as the surface material A release film having surface roughness Rz of the surface layer of 380 nm, surface roughness Rsk of +0.85 and surface roughness Rku of 7 was obtained in the same manner as in Example 10. The crystallinity (%) of the surface layer was calculated in the same manner as in Example 10.

(Example 13)

The surface roughness Rz of the surface layer was 430 (mass%) in the same manner as in Example 10, except that the woven fabric made of wool was rubbed with a rubbing treatment material having a surface material instead of the rubbing treatment material having the surface material (Rsk) of +1.10 and a surface roughness (Rku) of 11 was obtained. The crystallinity (%) of the surface layer was calculated in the same manner as in Example 10.

(Comparative Example 5)

A release film having a surface roughness (Rz) of 200 nm, a surface roughness (Rsk) of +0.50 and a surface roughness (Rku) of 3 was obtained in the same manner as in Example 10 except that no rubbing treatment was carried out . The crystallinity (%) of the surface layer was calculated in the same manner as in Example 10.

(Comparative Example 6)

Except that the amount of energy per day (KJ) was changed as shown in Table 4 and the friction material treated with a cloth made of a cotton material was subjected to a friction treatment with a friction material having a surface material made of PET, A release film having a surface roughness (Rz) of 258 nm, a surface roughness (Rsk) of -0.34 and a surface roughness (Rku) of 3 was obtained in the same manner as in Example 10. The crystallinity (%) of the surface layer was calculated in the same manner as in Example 10.

(Comparative Example 7)

Except that the amount of energy per day (KJ) was changed as shown in Table 4 and the friction material treated with a cloth made of a cotton material was subjected to a friction treatment with a friction material having a surface material made of PET, A release film having a surface roughness (Rz) of 280 nm, a surface roughness (Rsk) of +0.29 and a surface roughness (Rku) of 3 was obtained in the same manner as in Example 10. The crystallinity (%) of the surface layer was calculated in the same manner as in Example 10.

(Comparative Example 8)

Except that the daily energy amount KJ was changed as shown in Table 4 and the friction material treated as the surface material was subjected to a friction treatment with a friction material made of wool as the surface material A release film having a surface roughness Rz of the surface layer of 240 nm, a surface roughness Rsk of +0.25 and a surface roughness Rku of 4 was obtained in the same manner as in Example 10. The crystallinity (%) of the surface layer was calculated in the same manner as in Example 10.

(Comparative Example 9)

Except that the daily energy amount KJ was changed as shown in Table 4 and the friction material treated as the surface material was subjected to a friction treatment with a friction material made of wool as the surface material A release film having a surface roughness (Rz) of 460 nm, a surface roughness (Rsk) of +1.15 and a surface roughness (Rku) of 12 was obtained in the same manner as in Example 10. The crystallinity (%) of the surface layer was calculated in the same manner as in Example 10.

(evaluation)

The release films obtained in the examples and comparative examples were evaluated as follows. The results are shown in Tables 1 to 4.

(1) Dissimilarity (peeling force)

The surface of the obtained release film was overlapped with the epoxy adhesive surface of a coverlay film (CISV-2535, manufactured by Nikkan Kogyo Co., Ltd.) cut to a width of 200 mm and the surface was covered with a slide type vacuum heater press (MKP-3000v-MH- Manufactured by Fuji Photo Film Co., Ltd.) under a pressure of 30 kgf at 180 占 폚 for 6 minutes, and then cured at 23 占 폚 and 50% RH for 1 day. Thereafter, an evaluation sample having a width of 30 mm and a length of 150 mm was cut out from the sample after curing, and the evaluation sample was subjected to a peeling test at a peeling speed of 500 mm / min using Tensilon (STA-1150, manufactured by A & The peel force (N / 30 mm) was measured at a peel angle of 180 °.

(2) Followability (landfillability)

(20 cm x 20 cm, polyimide thickness: 25 m, copper foil: 18 m, hereinafter referred to as "CCL"), a coverlay film (20 cm x 20 cm, polyimide thickness: 12 m, 15 mu m), and the obtained release films were stacked in this order from below and pressed at 160 DEG C under a pressure of 30 kg / cm < 2 > for 30 minutes using a vacuum press to produce FPC evaluation samples comprising CCL and coverlay film Respectively. In the coverlay film, a pattern (200 μm pitch, 100 μm pitch) for evaluating adhesive flow-out was prepared in advance.

Thereafter, the FPC evaluation sample and the release film were taken out, and the length of the flowing adhesive was measured by observing the hole for evaluating the amount of adhesive on the coverlay film with a microscope. The case where the length of the flowing adhesive agent was less than 10 탆 was evaluated as ⊚, the case of not less than 10 탆 and less than 20 탆 as ∘, the case of not less than 20 탆 and less than 30 탆 as △, and the case of not less than 30 탆 as x.

Industrial availability

According to the present invention, it is possible to provide a release film which is excellent in releasability, excellent in followability to the surface of a substrate, and capable of suppressing the flow of an adhesive during hot press forming.

1: release treatment layer
2, 2 ', 2'': other regions in the surface layer

Claims (8)

As a release film having a surface layer containing a polyester-based resin,
Wherein a ratio of a carbonyl group oriented parallel to the plane of the carbonyl group contained in the polyester resin is 45% or more in a region from the surface of the surface layer to a thickness of 1 占 퐉. As a release film having a surface layer,
Wherein the surface layer has a surface roughness (Rz) of 250 to 450 nm, a surface roughness (Rsk) of +0.3 to +1.1, and a surface roughness (Rku) of 5 to 11. 3. The method of claim 2,
Wherein the surface layer contains a polyester-based resin. The method according to claim 1, 2, or 3,
And the surface layer has a crystallinity of 25% or less. The method according to claim 1, 2, or 3,
When a copper clad laminate or a copper foil is hot-pressed on a substrate via a prepreg or a heat resistant film to produce a printed wiring board, a flexible printed board or a multilayer printed wiring board, a hot press plate, a printed wiring board obtained, Or to prevent adhesion of the multilayered printed circuit board. The method according to claim 1, 2, or 3,
When a coverlay film is adhered to a substrate having a copper circuit formed thereon by hot press forming via a thermosetting adhesive and the flexible printed board is manufactured, adhesion of the hot press plate and the coverlay film, Wherein the release film is used to prevent adhesion between the substrates. The method according to claim 1, 2, or 3,
Characterized in that it is used for preventing adhesion between a molding die and a mold resin when the mold for semiconductor is manufactured by hot press molding. delete

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