JP2007314596A - Polyimide roll film, copper-clad laminate, circuit board and method for producing polyimide roll film - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a polyimide film that is useful as a substrate film of copper-clad laminate substrate (copper-clad laminate film) for a circuit board, has a small amount of foreign matter attached to a surface, is thin and has a high tensile modulus. <P>SOLUTION: The polyimide roll film has an attached amount of foreign matters having ≥2μm size of 100-100,000/m<SP>2</SP>, film thickness of 2-12.5 μm and a tensile modulus of ≥6 GPa. Especially the polyimide roll film comprises a polyimide containing a benzoxazole backbone as the residue of an aromatic diamine. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

The present invention relates to a polyimide roll film with a small amount of adhered foreign matter on the film surface.
More specifically, regarding a polyimide roll film having a small amount of adhering foreign matter on the surface of a thin film, which is very easy to be charged, easily adhering to floating foreign matters due to charging, and difficult to produce a roll film with a small amount of adhering foreign matters, Can be used as a substrate film for a metal layer laminated substrate with a metal layer such as copper, especially a copper clad laminate substrate, and can be used for a circuit board such as a flexible printed wiring board using this copper clad laminate substrate. The present invention relates to a polyimide roll film that can provide a polyimide film.

Ceramics have been used as the base material for electronic components. A base material made of ceramic has heat resistance, and can cope with a higher frequency band (reaching the GHz band) in recent information communication equipment. However, ceramics are not flexible and cannot be thinned, so the fields that can be used are limited. For this reason, studies have been made to use a film made of an organic material as a base material for an electronic component, and a film made of polyimide and a film made of polytetrafluoroethylene have been proposed. A film made of polyimide is excellent in heat resistance and has an advantage that the film can be thin because it is tough. Furthermore, a polyimide benzoxazole film made of polyimide having a benzoxazole ring in the main chain has been proposed as a polyimide film having a higher elastic modulus (see Patent Document 1). A printed wiring board using the polyimide benzoxazole film as a dielectric layer has also been proposed (see Patent Document 2 and Patent Document 3).
Japanese Patent Laid-Open No. 06-056792 Japanese National Patent Publication No. 11-504369 Japanese National Patent Publication No. 11-505184

As electronic parts such as LSIs become more dense, highly integrated, and circuit diversifies, foreign matter (particles) such as dust and metal impurities present on semiconductor wafers greatly affects product yield and product reliability. I got to do it. For example, foreign matters present on the surface (circuit pattern forming surface) of a semiconductor wafer cause circuit disconnection or short circuit during circuit formation. In addition, foreign matter present on the back side of the semiconductor wafer (opposite side of the circuit pattern surface) may cause the focus to be out of focus in the exposure process during circuit formation, and is transferred to the surface of the adjacent wafer for circuit breakage or short circuit. Cause.
In the LSI manufacturing process, we are striving to improve the level of cleanliness in the manufacturing process and the level of wafer cleaning technology. Various cleaning technologies have been proposed, and the cleaning process accounts for about 30% of the total process. It is a key point for improving yield and reliability. However, with recent increases in density and integration of LSIs, problems with conventional wafer cleaning methods have become apparent. There are two types of wafer cleaning methods: wet cleaning (with ultrapure water, chemicals, etc.) and dry cleaning (UV ozone, O ₂ plasma, etc.). In general, wet cleaning is frequently performed because of the balance of versatility and economy. Applies to The problem with wet cleaning is the reattachment of foreign matter removed from the wafer by cleaning to the wafer, and especially the foreign matter adhering to the backside of the wafer becomes a significant source of contamination. In addition, since the wet cleaning requires a drying process, there is a problem of wafer contamination in the drying process as well. As a cleaning method that compensates for the disadvantages of wet cleaning, the cleaning method is becoming more dry (UV ozone, O ₂ plasma, etc.), and it takes advantage of the advantages such as the reduction of reattachment of foreign substances and the elimination of the drying process. It has been found that cleaning does not show a sufficient removal capability against foreign substances and is not suitable for removing large amounts of contaminants.
There has been proposed a method for removing foreign substances adhering to the surface of a semiconductor wafer by adhering them to the adhesive layer surface of the tape using an adhesive tape. Since this method can be said to be a kind of dry cleaning, it can avoid the problem of reattachment of foreign matters in wet cleaning and the problem of contamination in the drying process, and can also be used for other dry cleaning such as UV ozone and O ₂ plasma. In comparison, it is expected that the foreign matter removal capability can be further enhanced (see Patent Documents 4 to 6).
JP-A-48-035771 Japanese Patent Laid-Open No. 01-135574 Japanese Patent Laid-Open No. 08-088205

These prior arts do not relate to a polyimide roll film that can provide a useful polyimide film with a small amount of foreign matter adhered to the surface, but relate to the removal of foreign matters in products such as LSIs. The removal of foreign matters in these products with a metal layer such as copper is easier than in the case of a film alone, for example, due to static electricity, and the problem of adhered foreign matters in an insulating polyimide film used as a substrate Is a bigger challenge.
In addition, as a method of removing decomposition products and dust attached to the surface of the polyimide film after treatment such as corona discharge treatment and plasma discharge treatment of the polyimide film, foreign matter attached to the film after discharge treatment of the polyimide film In this method, a first adhesive roller is disposed after the discharge device, and a polyimide film dust removal method is proposed in which the film after the discharge treatment is provided to the first roller (see Patent Document 7). This method is after the polyimide film is subjected to a specific treatment, and relates to a large foreign matter having a foreign matter size of 0.2 mm to 0.8 mm.
JP 2003-181945 A

    The present invention has been made against the background of such prior art problems. That is, the object of the present invention is to adhere to the surface of a polyimide film, particularly a thin polyimide film, which is very easy to be charged, to which floating foreign matters easily adhere due to charging, and to produce a roll film with a small amount of attached foreign matters. For polyimide roll film with a small amount of foreign matter, it can be used as a metal film laminated substrate with a metal layer such as copper, especially as a substrate film for copper clad laminate substrate, and used for circuit boards such as flexible printed wiring boards using this copper clad laminate substrate Another object of the present invention is to provide a useful polyimide film with a small amount of surface-attached foreign matter.

As a result of intensive studies, the present inventors have found that the above problems can be solved by the following means, and have reached the present invention.
That is, this invention consists of the following structures.
1. A polyimide roll film having an adhered foreign matter amount of 2 μm or more of 100 to 100,000 pieces / m ² , a winding length of 50 m or more, and a film width of 250 mm or more.
2. 1. The amount of adhering foreign matter of 5 μm or more is 100 to 10,000 / m ² . Polyimide roll film.
3. The first polyimide roll film deposition amount of foreign matters than 10μm is 100 to 1,000 pieces / ^{m 2.}
4). The polyimide roll film according to any one of 1 to 3, wherein the film has a thickness of 2 to 12.5 μm and a tensile elastic modulus of 6 GPa or more.
5). The polyimide roll film according to any one of 1 to 4, wherein the polyimide has a benzoxazole skeleton as a residue of an aromatic diamine.
6). 6. Copper-clad laminate produced using any of the polyimide films 1 to 5 above. A circuit board produced using the copper-clad laminate of 6 above.
8). The method for producing a polyimide roll film according to 1 to 5, wherein the number of particles in the winding atmosphere is 100 or less.
9. The manufacturing method of said 8 polyimide roll film whose charge amount of the film at the time of winding is 1 kV or less.
10. The manufacturing method of the polyimide roll film in any one of said 8-9 made to contact with an adhesion roll before winding up.
11. The manufacturing method of the said polyimide roll film in any one of said 8-10 which removes surface adhesion dust with a web cleaner before winding up.

The present invention is a polyimide roll film having a foreign matter amount of 2 μm or more of the present invention of 100 to 100,000 pieces / m ² , a winding length of 50 m or more and a film width of 250 mm or more, and a film thickness of 2 to 12. When using a polyimide roll film having a tensile modulus of 5 GPa or more and having a tensile modulus of 6 GPa or more, for example, on a circuit board manufactured using a copper-clad laminate, there is little foreign matter on the surface of the film within a certain value. Foreign matter existing on the forming surface may cause circuit disconnection or short circuit at the time of circuit formation, and foreign matter existing on the opposite side of the circuit forming surface may cause the focus to be out of focus in the exposure process at the time of circuit formation, and adjacent to it. Transfer to the surface of the wafer to cause circuit disconnection or short-circuit, etc., so that there are few quality problems, and the yield when manufacturing the circuit formed product. There have advantages such as improved industrial significance is extremely large. It is particularly suitable for thin polyimide films that are very easy to charge, and to which floating foreign matter easily adheres due to charging, and it is difficult to produce a roll film with a small amount of attached foreign matter. For example, a thin polyimide film of about 10 μm is suitable. However, because the tensile elastic modulus is more than a predetermined value, it can efficiently produce a copper-clad laminate that can be made into a light and short circuit board, and further use this to make a light and short circuit It can be an electronic component such as a substrate.

Hereinafter, the amount of adhering foreign matter of 2 μm or more of the present invention is 100 to 100,000 pieces / m ² , a polyimide roll film having a winding length of 50 m or more and a film width of 250 mm or more, and the film thickness as a preferred embodiment The polyimide roll film having a thickness of 2 to 12.5 μm and a tensile elastic modulus of 6 GPa or more will be described in detail.
The polyimide film in the polyimide roll film of the present invention is not particularly limited, but is preferably a polyimide film from polyimide obtained by a combination of the following aromatic diamines and aromatic tetracarboxylic acids (anhydrides). Is a preferred example.
A. A combination of an aromatic diamine having a benzoxazole structure and an aromatic tetracarboxylic acid (a combination of polyimides having a benzoxazole skeleton as a residue of the aromatic diamine).
B. A combination of an aromatic diamine having a diaminodiphenyl ether skeleton and an aromatic tetracarboxylic acid having a pyromellitic acid skeleton.
C. A combination of an aromatic diamine having a phenylenediamine skeleton and an aromatic tetracarboxylic acid having a biphenyltetracarboxylic acid skeleton.
D. A combination of one or more of the above ABCs.
In particular, A. A combination for producing a polyimide film having an aromatic diamine residue having a benzoxazole structure is preferred.
Benzene used in polyimide benzoxazole mainly composed of polyimide benzoxazole obtained by reacting aromatic diamines having a benzoxazole structure and aromatic tetracarboxylic anhydrides that can be particularly preferably used in the present invention. Examples of aromatic diamines having an oxazole structure include the following compounds.

Among these, amino (aminophenyl) benzoxazole isomers are preferable from the viewpoint of ease of synthesis. Here, “each isomer” refers to each isomer in which two amino groups of amino (aminophenyl) benzoxazole are determined according to the coordination position (eg, the above “formula 1” to “formula 4”). Each compound described in the above. These diamines may be used alone or in combination of two or more.
In the present invention, it is preferable to use 70 mol% or more of the aromatic diamine having the benzoxazole structure.

The present invention is not limited to the above items, and the following aromatic diamines may be used. Preferably, the diamines do not have the benzoxazole structure exemplified below as long as the total aromatic diamine is less than 30 mol%. It is a polyimide film using one or two or more in combination.
Examples of such diamines include 4,4′-bis (3-aminophenoxy) biphenyl, bis [4- (3-aminophenoxy) phenyl] ketone, and bis [4- (3-aminophenoxy) phenyl]. Sulfide, bis [4- (3-aminophenoxy) phenyl] sulfone, 2,2-bis [4- (3-aminophenoxy) phenyl] propane, 2,2-bis [4- (3-aminophenoxy) phenyl] -1,1,1,3,3,3-hexafluoropropane, m-phenylenediamine, o-phenylenediamine, p-phenylenediamine, m-aminobenzylamine, p-aminobenzylamine,

3,3'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 4,4'-diaminodiphenyl ether, 3,3'-diaminodiphenyl sulfide, 3,3'-diaminodiphenyl sulfoxide, 3,4'-diaminodiphenyl sulfoxide 4,4'-diaminodiphenyl sulfoxide, 3,3'-diaminodiphenyl sulfone, 3,4'-diaminodiphenyl sulfone, 4,4'-diaminodiphenyl sulfone, 3,3'-diaminobenzophenone, 3,4'- Diaminobenzophenone, 4,4′-diaminobenzophenone, 3,3′-diaminodiphenylmethane, 3,4′-diaminodiphenylmethane, 4,4′-diaminodiphenylmethane, bis [4- (4-aminophenoxy) phenyl] methane, 1 , 1-Bi [4- (4-aminophenoxy) phenyl] ethane, 1,2-bis [4- (4-aminophenoxy) phenyl] ethane, 1,1-bis [4- (4-aminophenoxy) phenyl] propane, 1 , 2-bis [4- (4-aminophenoxy) phenyl] propane, 1,3-bis [4- (4-aminophenoxy) phenyl] propane, 2,2-bis [4- (4-aminophenoxy) phenyl ]propane,

1,1-bis [4- (4-aminophenoxy) phenyl] butane, 1,3-bis [4- (4-aminophenoxy) phenyl] butane, 1,4-bis [4- (4-aminophenoxy) Phenyl] butane, 2,2-bis [4- (4-aminophenoxy) phenyl] butane, 2,3-bis [4- (4-aminophenoxy) phenyl] butane, 2- [4- (4-aminophenoxy) Phenyl] -2- [4- (4-aminophenoxy) -3-methylphenyl] propane, 2,2-bis [4- (4-aminophenoxy) -3-methylphenyl] propane, 2- [4- ( 4-aminophenoxy) phenyl] -2- [4- (4-aminophenoxy) -3,5-dimethylphenyl] propane, 2,2-bis [4- (4-aminophenoxy) -3,5-dimethylphen Le] propane, 2,2-bis [4- (4-aminophenoxy) phenyl] -1,1,1,3,3,3-hexafluoropropane,

1,4-bis (3-aminophenoxy) benzene, 1,3-bis (3-aminophenoxy) benzene, 1,4-bis (4-aminophenoxy) benzene, 4,4′-bis (4-aminophenoxy) ) Biphenyl, bis [4- (4-aminophenoxy) phenyl] ketone, bis [4- (4-aminophenoxy) phenyl] sulfide, bis [4- (4-aminophenoxy) phenyl] sulfoxide, bis [4- ( 4-aminophenoxy) phenyl] sulfone, bis [4- (3-aminophenoxy) phenyl] ether, bis [4- (4-aminophenoxy) phenyl] ether, 1,3-bis [4- (4-aminophenoxy) ) Benzoyl] benzene, 1,3-bis [4- (3-aminophenoxy) benzoyl] benzene, 1,4-bis [4- (3 Aminophenoxy) benzoyl] benzene, 4,4′-bis [(3-aminophenoxy) benzoyl] benzene, 1,1-bis [4- (3-aminophenoxy) phenyl] propane, 1,3-bis [4- (3-aminophenoxy) phenyl] propane, 3,4'-diaminodiphenyl sulfide,

2,2-bis [3- (3-aminophenoxy) phenyl] -1,1,1,3,3,3-hexafluoropropane, bis [4- (3-aminophenoxy) phenyl] methane, 1,1 -Bis [4- (3-aminophenoxy) phenyl] ethane, 1,2-bis [4- (3-aminophenoxy) phenyl] ethane, bis [4- (3-aminophenoxy) phenyl] sulfoxide, 4,4 '-Bis [3- (4-aminophenoxy) benzoyl] diphenyl ether, 4,4'-bis [3- (3-aminophenoxy) benzoyl] diphenyl ether, 4,4'-bis [4- (4-amino-α) , Α-dimethylbenzyl) phenoxy] benzophenone, 4,4′-bis [4- (4-amino-α, α-dimethylbenzyl) phenoxy] diphenylsulfone, bis 4- {4- (4-aminophenoxy) phenoxy} phenyl] sulfone, 1,4-bis [4- (4-aminophenoxy) phenoxy-α, α-dimethylbenzyl] benzene, 1,3-bis [4- (4-aminophenoxy) phenoxy-α, α-dimethylbenzyl] benzene, 1,3-bis [4- (4-amino-6-trifluoromethylphenoxy) -α, α-dimethylbenzyl] benzene, 1,3 -Bis [4- (4-amino-6-fluorophenoxy) -α, α-dimethylbenzyl] benzene, 1,3-bis [4- (4-amino-6-methylphenoxy) -α, α-dimethylbenzyl Benzene, 1,3-bis [4- (4-amino-6-cyanophenoxy) -α, α-dimethylbenzyl] benzene,

3,3′-diamino-4,4′-diphenoxybenzophenone, 4,4′-diamino-5,5′-diphenoxybenzophenone, 3,4′-diamino-4,5′-diphenoxybenzophenone, 3, 3'-diamino-4-phenoxybenzophenone, 4,4'-diamino-5-phenoxybenzophenone, 3,4'-diamino-4-phenoxybenzophenone, 3,4'-diamino-5'-phenoxybenzophenone, 3,3 '-Diamino-4,4'-dibiphenoxybenzophenone, 4,4'-diamino-5,5'-dibiphenoxybenzophenone, 3,4'-diamino-4,5'-dibiphenoxybenzophenone, 3,3'- Diamino-4-biphenoxybenzophenone, 4,4′-diamino-5-biphenoxybenzophenone, 3,4 -Diamino-4-biphenoxybenzophenone, 3,4'-diamino-5'-biphenoxybenzophenone, 1,3-bis (3-amino-4-phenoxybenzoyl) benzene, 1,4-bis (3-amino- 4-phenoxybenzoyl) benzene, 1,3-bis (4-amino-5-phenoxybenzoyl) benzene, 1,4-bis (4-amino-5-phenoxybenzoyl) benzene, 1,3-bis (3-amino) -4-biphenoxybenzoyl) benzene, 1,4-bis (3-amino-4-biphenoxybenzoyl) benzene, 1,3-bis (4-amino-5-biphenoxybenzoyl) benzene, 1,4-bis (4-Amino-5-biphenoxybenzoyl) benzene, 2,6-bis [4- (4-amino-α, α-dimethylbenzyl) pheno Si] benzonitrile and some or all of the hydrogen atoms on the aromatic ring in the aromatic diamine are halogen atoms, alkyl groups having 1 to 3 carbon atoms or alkoxyl groups, cyano groups, or hydrogen atoms of alkyl groups or alkoxyl groups. Examples thereof include aromatic diamines substituted with a halogenated alkyl group having 1 to 3 carbon atoms partially or wholly substituted with a halogen atom or an alkoxyl group.

  The aromatic tetracarboxylic acids used in the present invention are, for example, aromatic tetracarboxylic anhydrides. Specific examples of the aromatic tetracarboxylic acid anhydrides include the following.

These tetracarboxylic dianhydrides may be used alone or in combination of two or more.
In the present invention, one or two or more non-aromatic tetracarboxylic dianhydrides exemplified below may be used in combination as long as they are less than 30 mol% of the total tetracarboxylic dianhydrides. Examples of such tetracarboxylic acid anhydrides include butane-1,2,3,4-tetracarboxylic dianhydride, pentane-1,2,4,5-tetracarboxylic dianhydride, and cyclobutanetetracarboxylic acid. Acid dianhydride, cyclopentane-1,2,3,4-tetracarboxylic dianhydride, cyclohexane-1,2,4,5-tetracarboxylic dianhydride, cyclohex-1-ene-2,3 5,6-tetracarboxylic dianhydride, 3-ethylcyclohex-1-ene-3- (1,2), 5,6-tetracarboxylic dianhydride, 1-methyl-3-ethylcyclohexane-3 -(1,2), 5,6-tetracarboxylic dianhydride, 1-methyl-3-ethylcyclohex-1-ene-3- (1,2), 5,6-tetracarboxylic dianhydride 1-ethylcyclohexane -(1,2), 3,4-tetracarboxylic dianhydride, 1-propylcyclohexane-1- (2,3), 3,4-tetracarboxylic dianhydride, 1,3-dipropylcyclohexane- 1- (2,3), 3- (2,3) -tetracarboxylic dianhydride, dicyclohexyl-3,4,3 ′, 4′-tetracarboxylic dianhydride,

Bicyclo [2.2.1] heptane-2,3,5,6-tetracarboxylic dianhydride, 1-propylcyclohexane-1- (2,3), 3,4-tetracarboxylic dianhydride, 1 , 3-Dipropylcyclohexane-1- (2,3), 3- (2,3) -tetracarboxylic dianhydride, dicyclohexyl-3,4,3 ′, 4′-tetracarboxylic dianhydride, bicyclo [2.2.1] Heptane-2,3,5,6-tetracarboxylic dianhydride, bicyclo [2.2.2] octane-2,3,5,6-tetracarboxylic dianhydride, bicyclo [2.2.2] Oct-7-ene-2,3,5,6-tetracarboxylic dianhydride and the like. These tetracarboxylic dianhydrides may be used alone or in combination of two or more.

  The solvent used when the polyamic acid is obtained by reacting (polymerizing) the aromatic diamine with the aromatic tetracarboxylic acid (anhydride) dissolves both the monomer as a raw material and the polyamic acid to be produced. Although it will not specifically limit if it is a thing, A polar organic solvent is preferable, for example, N-methyl-2-pyrrolidone, N-acetyl-2-pyrrolidone, N, N-dimethylformamide, N, N-diethylformamide, N, N -Dimethylacetamide, dimethyl sulfoxide, hexamethylphosphoric amide, ethyl cellosolve acetate, diethylene glycol dimethyl ether, sulfolane, halogenated phenols and the like. These solvents can be used alone or in combination. The amount of the solvent used may be an amount sufficient to dissolve the monomer as a raw material. As a specific amount used, the mass of the monomer in the solution in which the monomer is dissolved is usually 5 to 40% by mass, The amount is preferably 10 to 30% by mass.

The polymerization reaction conditions for obtaining the polyamic acid may be conventionally known conditions. As a specific example, stirring and / or continuous in an organic solvent at a temperature range of 0 to 80 ° C. for 10 minutes to 30 hours. Mixing may be mentioned. If necessary, the polymerization reaction may be divided or the temperature may be increased or decreased. In this case, the order of adding both monomers is not particularly limited, but it is preferable to add aromatic tetracarboxylic acid anhydrides to the solution of aromatic diamines. The mass of the polyamic acid in the polyamic acid solution obtained by the polymerization reaction is preferably 5 to 40% by mass, more preferably 10 to 30% by mass, and the viscosity of the solution is measured with a Brookfield viscometer (25 ° C.). From the viewpoint of the stability of liquid feeding, it is preferably 10 to 2000 Pa · s, and more preferably 100 to 1000 Pa · s. The reduced viscosity (ηsp / C) of the polyamic acid in the present invention is not particularly limited, but is preferably 3.0 dl / g or more, and more preferably 4.0 dl / g or more.
Vacuum defoaming during the polymerization reaction is effective for producing a high-quality polyamic acid organic solvent solution. Moreover, you may perform superposition | polymerization by adding a small amount of terminal blockers to aromatic diamines before a polymerization reaction. Examples of the end capping agent include compounds having a carbon-carbon double bond such as maleic anhydride. The amount of maleic anhydride used is preferably 0.001 to 1.0 mol per mol of aromatic diamine.

  As an imidization method by high-temperature treatment, a conventionally known imidation reaction can be appropriately used. For example, using a polyamic acid solution that does not contain a ring-closing catalyst or a dehydrating agent, the imidization reaction proceeds by subjecting it to a heat treatment (so-called thermal ring-closing method), or a polycyclic acid solution containing a ring-closing catalyst and a dehydrating agent In particular, a chemical ring closing method in which an imidization reaction is performed by the action of the above ring closing catalyst and a dehydrating agent can be given.

  The method for obtaining the polyimide film of the present invention is applied in a known method in which a green film which is a precursor of a polyimide film is selected and carried out by selecting predetermined drying conditions and predetermined high temperature imidization conditions. For example, a polyimide roll film manufacturing method is a solution manufacturing process in which an aromatic diamine and an aromatic tetracarboxylic acid (anhydride) are reacted to obtain a polyamic acid solution, and this polyamic acid solution is used as an endless stainless steel belt or polyester. A drying process of casting on a support such as a film and drying on the support to obtain a self-supporting green film, an imidization process for imidizing this green film, and a polyimide roll film that winds up the imidized film The winding process and the polyimide film that takes each of these processes In the production method, as a preferred embodiment, there is a production method of a polyimide roll film in which the number of particles in the atmosphere in the winding process is set to 100 or less, and the charge amount of the film in the winding process is 1 kV or less. It is a manufacturing method, and is a manufacturing method of a polyimide roll film in which an imidized polyimide film is brought into contact with an adhesive roll before the winding process, and the number of particles in the winding atmosphere is 100 or less in a clean booth. This is a method for producing a polyimide roll film in which dust adhered to the surface is removed by a web cleaner before winding.

The polyimide film of the present invention is a polyimide roll film having a foreign matter amount of 2 μm or more of 100 to 100,000 pieces / m ² , a winding length of 50 m or more, and a film width of 250 mm or more, and a preferred embodiment of 5 μm. It is a polyimide roll film whose amount of adhering foreign matter is 100 to 10,000 pieces / m ² , and is a polyimide roll film whose amount of adhering foreign matter of 10 μm or more is 100 to 1,000 pieces / m ² , It is a polyimide roll film having a thickness of 2 to 12.5 μm and a tensile elastic modulus of 6 GPa or more.
In a polyimide roll film having an adhered foreign matter amount of 2 μm or more of 100 to 100,000 pieces / m ² , a winding length of 50 m or more and a film width of 250 mm or more, a more preferable value of the attached foreign matter amount of 2 μm or more is 100 ˜20,000 pieces / m ² .
Moreover, the value of the amount of adhering foreign matter of 5 μm or more is more preferably 100 to 3,500 / m ² . Further, a more preferable value of the amount of adhered foreign matter of 10 μm or more is 100 to 300 / m ² .

The measurement of the amount of adhered foreign matter in the present invention is as follows.
All measurements were carried out on a class 100 clean bench installed in a clean room of class 1000 or lower. When actually measured, the number of particles of 0.3 μm or less in the working atmosphere was 5 or less, and particles of 0.3 μm or more were not included.
(1) Adjustment method of measurement dispersion medium Dispersion for measurement by filtering 1 L (liter) of ion-exchanged water using a chemical circulation filtration device (manufactured by Rion) equipped with a filter having a pore diameter of 0.1 μm. The medium was adjusted. When the number of particles contained in 10 ml of this solution was measured using a liquid fine particle counter (manufactured by Rion, KL-11-A), no particles of 2 μm or more were contained.
(2) Adjustment of measuring container The container used for the measurement was a clean-packed screw clean bottle. The dispersion medium for measurement was put in a clean bottle and the inside of the container was thoroughly washed, and then 100 ml of the dispersion medium for measurement was added and sonication was performed (28 kHz, 1 minute). When the number of particles contained in 10 ml of this solution was measured using a liquid fine particle counter (manufactured by Rion Co., Ltd., KL-11-A), no number of 2 μm or more was contained. The container washed by the above method was used for the measurement.
(3) Measurement of surface adhering foreign matter In a clean bench of class 100, the roll film was rolled out by 5 m, and the central part of the film inside the roll was cut out to 100 mm ² with a cutter as a film for evaluation (sampling film). Thereafter, 100 mL (milliliter) of the measurement dispersion medium and 10 sampled films were placed in the clean screw bottle described above. By performing ultrasonic treatment for 3 minutes at a frequency of 28 kHz, the adhered foreign matter was dispersed in pure water. Using a liquid fine particle counter (Lion Co., Ltd., KL-11-A), the number of particles of 2 μm or more contained in 10 ml of this solution was measured, and the number obtained according to the following formula was taken as the number per 1 m ² of film. .
Surface foreign matter amount per 1 m ² (number) = (measured number of particles / measured area (100 mm × 100 mm)) × 100 (conversion coefficient).

In the preferred embodiment of the polyimide roll film of the present invention, the adhered foreign matter amount of 2 μm or more is 100 to 100,000 pieces / m ² , the winding length is 50 m or more, and the film width is 250 mm or more, the film thickness is 2 to 2 mm. It is the said polyimide roll film whose 12.5 micrometers and tensile elasticity modulus are 6 GPa or more.
Since the thickness of the film is 2 to 12.5 μm, it is possible to contribute to the lightness and thinness of electronic components such as circuit boards, and in these thin polyimide films, it is extremely difficult to reduce the amount of adhered foreign matter. The effect of reducing the amount of adhering foreign matter becomes extremely remarkable.
In addition, the tensile modulus is preferably 6 GPa or more in the state, and if it is less than 6 GPa, even if the amount of adhered foreign matter can be satisfied, defects such as wrinkles and partial breakage of the film are likely to occur, and film production Efficiency is extremely poor.

The measurement of the tensile elastic modulus and the tensile strength at break of the polyimide film is carried out by measuring the polyimide film to be measured in the MD direction (long film flow direction, vertical direction) and TD direction (long film width direction, horizontal direction), respectively. A specimen cut into a strip of 100 mm × 10 mm is used as a test piece, and a tensile tester (manufactured by Shimadzu Corp., Autograph (trade name) model name AG-5000A) is used, and the tensile speed is 50 mm / min and the distance between chucks is 40 mm. In each of the MD direction and the TD direction, the tensile elastic modulus, tensile breaking strength, and tensile breaking elongation are measured.
The tear propagation resistance is measured in accordance with the tear propagation resistance measurement method defined in JIS P8116. Further, the tear propagation resistance value is proportional to the film thickness, and converted into a thickness of 1.0 mm.

Next, a copper-clad laminate using the above-described polyimide roll film (polyimide benzoxazole roll film) film and printed circuit board of a circuit board will be described.
The copper-clad laminate is a substantially flat substrate having a structure in which a copper metal layer is laminated on at least one surface of a polyimide film as an insulating substrate. The copper metal layer to be laminated may be a metal layer for a circuit intended to form a circuit by processing such as etching, or heat radiation etc. together with an insulating plate without any post processing. It may be a metal layer used for the purpose.

For example, as a printed wiring board, FPC, TAB carrier tape, and the like are preferable because the characteristics of the polyimide film of the present invention that the amount of adhering foreign matter is small can be utilized. The metal laminated on at least one surface of the polyimide film is not particularly limited, and preferably copper, aluminum, stainless steel, or the like. The method of laminating is not particularly limited, and a method of attaching a metal plate to a polyimide film using an adhesive, a method of forming a film by applying a polyamic acid solution to the metal plate as a support and imidizing as described above A method of forming a metal layer on a polyimide film using a dry film forming method (vacuum coating technique) such as vapor deposition, sputtering, or ion plating, or a metal layer on a polyimide film by a wet plating method such as electroless plating or electroplating. The method of forming etc. are mentioned.
A metal layer can be laminated on at least one surface of the polyimide benzoxazole film by using these methods alone or in combination.

EXAMPLES Hereinafter, although an Example and a comparative example are shown and this invention is demonstrated more concretely, this invention is not limited by a following example. In addition, the evaluation method of the physical property in the following examples is as follows.
1. Reduced viscosity of polyamic acid (ηsp / C)
A solution dissolved in N-methyl-2-pyrrolidone so that the polymer concentration was 0.2 g / dl was measured at 30 ° C. using an Ubbelohde type viscosity tube.
2. The thickness of the film was measured using a micrometer (Finereuf, Millitron (trade name) 1254D).

3. Measurement of tensile modulus, tensile breaking strength, etc. of polyimide film A test piece was prepared by cutting a polyimide film to be measured into strips of 100 mm × 10 mm in the MD direction and TD direction, respectively. Using a tensile tester (manufactured by Shimadzu Corp., Autograph (trade name) model name AG-5000A) under the conditions of a tensile speed of 50 mm / min and a distance between chucks of 40 mm, the tensile modulus and tension in each of the MD and TD directions. The breaking strength and tensile breaking elongation were measured. When there is no MD or TD annotation, the value in the MD direction is indicated.

4). Measurement of the amount of foreign matter adhering to the surface of the polyimide film This operation was performed on a class 100 clean bench installed in a clean room of class 1000 or less. When actually measured, the number of particles of 0.3 μm or less in the working atmosphere was 5 or less, and particles of 0.3 μm or more were not included.
(1) Method for adjusting dispersion medium The dispersion medium for measurement was adjusted by filtering 1 L of ion-exchanged water using a chemical circulation filtration device (manufactured by Rion) equipped with a filter having a pore size of 0.1 μm. When the number of particles contained in 10 ml of this solution was measured using a liquid fine particle counter (manufactured by Rion, KL-11-A), no particles of 2 μm or more were contained.
(2) Adjustment of measuring container The container used for the measurement was a clean-packed screw clean bottle. The dispersion medium for measurement was put in a clean bottle and the inside of the container was thoroughly washed, and then 100 ml of the dispersion medium was added and sonication was performed (28 kHz, 1 minute). When the number of particles contained in 10 ml of this solution was measured using a liquid fine particle counter (manufactured by Rion Co., Ltd., KL-11-A), no more than 2 μm was included. The container washed by the above method was used for the measurement.
(3) Measurement of surface adhering foreign matter amount In a clean bench of class 100, the roll film was rolled out by 5 m, and the central part of the film inside the roll was cut out to 100 mm ² using a cutter. Thereafter, 100 ml of the dispersion medium and 10 sampled films were placed in the clean screw bottle described above. By performing ultrasonic treatment for 3 minutes at a frequency of 28 kHz, the adhered foreign matter was dispersed in pure water. Using a liquid fine particle counter (Lion Co., Ltd., KL-11-A), the number of particles of 2 μm or more contained in 10 ml of this solution was measured, and the number obtained according to the following formula was taken as the number per 1 m ² of film. .
The number of surface foreign matters per 1 m ² = (measured number of particles / measured area (100 mm × 100 mm)) × 100 (conversion coefficient).

5). Method for evaluating appearance of copper-clad laminate film The copper-clad laminate film was slit to 48 mm with a rewinder equipped with a rotary blade. The appearance of the obtained copper-clad laminate film was observed from the polyimide substrate side using an optical microscope. The measurement visual field performed this operation with respect to 100 samples, and evaluated the presence or absence of the defect of the interface of an imide and a copper layer. A defect shows the black spot seen in the interface whose magnitude | size is 10 micrometers or more. The number of samples with confirmed defects is shown in the table.

6). Shape Evaluation of Comb Pattern A slit roll of a copper clad laminate film was processed into a comb pattern having a pitch of 10 μm (line width 5 μm, space width 5 μm) using a ferric chloride solution 40 ° Be (Baume). The pattern shape of 10 pieces of the comb pattern portion was evaluated by SEM. Samples with a line drawn uniformly were good, and samples with irregularities on the line due to foreign matter were regarded as abnormal.

7). Insulation durability test of comb pattern Insulation reliability test was conducted in a constant temperature and humidity chamber of 85 ° C and 85% RH in a clean room. A bias of 60 V was applied to the comb-shaped pattern adjusted in step 1, and the insulation resistance value was measured. The time until the insulation resistance value reached 1 × 10 ⁴ Ω or less was measured. When the insulation resistance value after the lapse of 1000 hours was 1 × 10 ⁴ Ω or more, it was judged that the insulation durability was good, and the following was judged as defective.

8). Measurement of the amount of particles in the winding atmosphere The amount of suspended dust in the atmosphere of the winding film was measured using an air particle counter (KC-01D1 manufactured by Lion Co., Ltd.). The measurement position was carried out at a position 50 mm away from the wound film.

9. Measurement of electrification amount of take-up film Using a precision electrostatic meter (STATIION-DS3 Co., Ltd., CID), the charge amount of the polyimide film being taken up was measured. The maximum charge amount value during winding was described as the charge amount during winding.

[Polymerization of polyamic acid solution (1)]
The inside of a reaction vessel equipped with a nitrogen introduction tube, a thermometer, and a stirring rod was purged with nitrogen, and then 500 parts by mass of 5-amino-2- (p-aminophenyl) benzoxazole was charged. Subsequently, after adding 5000 mass parts of N-methyl-2-pyrrolidone and making it melt | dissolve completely, 485 mass parts of pyromellitic dianhydrides were added. Next, 1000 ppm of colloidal silica was mixed with 50 parts by mass of N-methyl-2-pyrrolidone separately distilled, added after stirring for 15 minutes with a homogenizer, and then stirred for 48 hours at a reaction temperature of 25 ° C. A tonic polyamic acid solution (1) was obtained. Ηsp / C of the obtained solution was 4.1 dl / g.

[Polymerization of polyamic acid solution (2)]
The inside of a reaction vessel equipped with a nitrogen introduction tube, a thermometer, and a stirring rod was purged with nitrogen, and then 545 parts by mass of pyromellitic anhydride and 500 parts by mass of 4,4′diaminodiphenyl ether were dissolved in 5000 parts by mass of dimethylacetamide. Next, 1000 ppm of colloidal silica was mixed with 50 parts by mass of N-methyl-2-pyrrolidone separately distilled, added after stirring for 15 minutes with a homogenizer, and then stirred for 48 hours at a reaction temperature of 25 ° C. A tonic polyamic acid solution (2) was obtained. The obtained solution had a ηsp / C of 3.0 dl / g.

[Polymerization of polyamic acid solution (3)]
After replacing the inside of the reaction vessel equipped with a nitrogen introduction tube, a thermometer, and a stirring rod with nitrogen, 545 parts by mass of 3,3′-4,4′biphenyltetracarboxylic acid anhydride and 500 parts by mass of paraphenylenediamine were 5000 parts by mass. In dimethylacetamide. Next, 1000 ppm of colloidal silica was mixed with 50 parts by mass of N-methyl-2-pyrrolidone separately distilled, stirred for 15 minutes with a homogenizer, and then stirred for 48 hours at a reaction temperature of 25 ° C. A tonic polyamic acid solution (3) was obtained. The solution obtained had a ηsp / C of 3.5 dl / g.

[Polymerization of polyamic acid solution (4)]
The inside of a reaction vessel equipped with a nitrogen introduction tube, a thermometer and a stirring rod was purged with nitrogen, 5000 parts by mass of dimethylacetamide was added, and 545 parts by mass of pyromellitic acid anhydride and 500 parts by mass of paraphenylenediamine were added and dissolved. Next, 1000 ppm of colloidal silica was mixed with 50 parts by mass of N-methyl-2-pyrrolidone separately distilled, added after stirring for 15 minutes with a homogenizer, and then stirred for 48 hours at a reaction temperature of 25 ° C. A tonic polyamic acid solution (4) was obtained. The solution obtained had a ηsp / C of 3.1 dl / g.

Example 1
The above polyamic acid solution (1) was coated on a stainless steel belt using a T-type die. The lip gap of the die was 280 μm. Next, the polyamic acid film having a self-supporting property obtained by drying at 90 ° C. for 60 minutes is peeled off from the stainless steel belt, and then in a continuous drying furnace at 170 ° C. for 3 minutes and then for about 20 seconds. The temperature is raised to 450 ° C., heated at 450 ° C. for 7 minutes, then cooled to room temperature in 5 minutes, an adhesive roll (butyl rubber roll: manufactured by Nagata Corporation) and an ultrasonic dust cleaner (blowout) A polyimide roll film having a thickness of 10 μm was wound up by a winder equipped with a pressure of 12 KPa (manufactured by Shinko Co., Ltd.), a static eliminator, and a clean booth. The winding mechanism is shown in FIG. Table 1 shows the amount of charge on the film during winding, the number of particles in the winding environment, and Table 2 shows the evaluation results of the film.
The obtained polyimide roll film is mounted on a continuous sputtering apparatus, and the frequency is 13.56 MHz, the output is 400 W, the gas pressure is 0.8 Pa, and the target is a nickel-chromium (chromium content: 10%) alloy, in an argon atmosphere. A nickel-chromium alloy film having a thickness of 50 mm was formed at a rate of 10 mm / second by RF sputtering. Subsequently, copper was vapor-deposited at a rate of 100 liters / second to form a copper thin film having a thickness of 0.3 μm. Then, using this film copper sulfate plating bath, a thick copper plating layer having a thickness of 5 μm was formed on the copper thin film to obtain a metallized polyimide film (copper-clad laminate film).
Table 3 shows the appearance evaluation of the obtained copper-clad laminate film, the shape evaluation of the comb pattern, and the insulation durability test result of the comb pattern.

(Example 2)
The above polyamic acid solution (1) was coated on a stainless steel belt using a T-type die. The die lip gap was 210 μm. Next, the polyamic acid film having a self-supporting property obtained by drying at 90 ° C. for 60 minutes is peeled off from the stainless steel belt, and then in a continuous drying furnace at 170 ° C. for 3 minutes and then for about 20 seconds. The temperature is raised to 450 ° C., heated at 450 ° C. for 7 minutes, then cooled to room temperature in 5 minutes, an adhesive roll (butyl rubber roll: manufactured by Nagata Corporation) and an ultrasonic dust cleaner (blowout) A polyimide roll film having a thickness of 7.5 μm was wound by a winder provided with a pressure of 12 KPa (manufactured by Shinko Co., Ltd.), a static eliminator, and a clean booth. The winding mechanism is shown in the figure. Table 1 shows the amount of charge on the film during winding, the number of particles in the winding environment, and Table 2 shows the evaluation results of the film.
The obtained polyimide roll film is mounted on a continuous sputtering apparatus, and the frequency is 13.56 MHz, the output is 400 W, the gas pressure is 0.8 Pa, and the target is a nickel-chromium (chromium content: 10%) alloy, in an argon atmosphere. A nickel-chromium alloy film having a thickness of 50 mm was formed at a rate of 10 mm / second by RF sputtering. Subsequently, copper was vapor-deposited at a rate of 100 liters / second to form a copper thin film having a thickness of 0.3 μm. Then, using this film copper sulfate plating bath, a thick copper plating layer having a thickness of 5 μm was formed on the copper thin film to obtain a metallized polyimide film (copper-clad laminate film).
Table 3 shows the appearance evaluation of the obtained copper-clad laminate film, the shape evaluation of the comb pattern, and the insulation durability test result of the comb pattern.

(Example 3)
The above polyamic acid solution (3) was coated on a stainless steel belt using a T-type die. The lip gap of the die was 280 μm. Next, the polyamic acid film having a self-supporting property obtained by drying at 90 ° C. for 60 minutes is peeled off from the stainless steel belt, and then in a continuous drying furnace at 170 ° C. for 3 minutes and then for about 20 seconds. The temperature is raised to 450 ° C., heated at 450 ° C. for 7 minutes, then cooled to room temperature in 5 minutes, an adhesive roll (butyl rubber roll: manufactured by Nagata Corporation) and an ultrasonic dust cleaner (blowout) A polyimide roll film having a thickness of 10 μm was wound up by a winder equipped with a pressure of 12 KPa (manufactured by Shinko Co., Ltd.), a static eliminator, and a clean booth. The winding mechanism is shown in the figure. Table 1 shows the amount of charge on the film during winding, the number of particles in the winding environment, and Table 2 shows the evaluation results of the film.
The obtained polyimide roll film is mounted on a continuous sputtering apparatus, and the frequency is 13.56 MHz, the output is 400 W, the gas pressure is 0.8 Pa, and the target is a nickel-chromium (chromium content: 10%) alloy, in an argon atmosphere. A nickel-chromium alloy film having a thickness of 50 mm was formed at a rate of 10 mm / second by RF sputtering. Subsequently, copper was vapor-deposited at a rate of 100 liters / second to form a copper thin film having a thickness of 0.3 μm. Then, using this film copper sulfate plating bath, a thick copper plating layer having a thickness of 5 μm was formed on the copper thin film to obtain a metallized polyimide film (copper-clad laminate film).
Table 3 shows the appearance evaluation of the obtained copper-clad laminate film, the shape evaluation of the comb pattern, and the insulation durability test result of the comb pattern.

Example 4
The above polyamic acid solution (4) was coated on a stainless steel belt using a T-type die. The lip gap of the die was 280 μm. Next, the polyamic acid film having a self-supporting property obtained by drying at 90 ° C. for 60 minutes is peeled off from the stainless steel belt, and then in a continuous drying furnace at 170 ° C. for 3 minutes and then for about 20 seconds. The temperature is raised to 450 ° C., heated at 450 ° C. for 7 minutes, then cooled to room temperature in 5 minutes, an adhesive roll (butyl rubber roll: manufactured by Nagata Corporation) and an ultrasonic dust cleaner (blowout) A polyimide roll film having a thickness of 10 μm was wound up by a winder equipped with a pressure of 12 KPa (manufactured by Shinko Co., Ltd.), a static eliminator, and a clean booth. The winding mechanism is shown in the figure. Table 1 shows the amount of charge on the film during winding, the number of particles in the winding environment, and Table 2 shows the evaluation results of the film.
The obtained polyimide roll film is mounted on a continuous sputtering apparatus, and the frequency is 13.56 MHz, the output is 400 W, the gas pressure is 0.8 Pa, and the target is a nickel-chromium (chromium content: 10%) alloy, in an argon atmosphere. A nickel-chromium alloy film having a thickness of 50 mm was formed at a rate of 10 mm / second by RF sputtering. Subsequently, copper was vapor-deposited at a rate of 100 liters / second to form a copper thin film having a thickness of 0.3 μm. Then, using this film copper sulfate plating bath, a thick copper plating layer having a thickness of 5 μm was formed on the copper thin film to obtain a metallized polyimide film (copper-clad laminate film).
Table 3 shows the appearance evaluation of the obtained copper-clad laminate film, the shape evaluation of the comb pattern, and the insulation durability test result of the comb pattern.

(Comparative Example 1)
The above polyamic acid solution (2) was coated on a stainless steel belt using a T-type die. The lip gap of the die was 1400 μm. Next, the polyamic acid film having a self-supporting property obtained by drying at 90 ° C. for 60 minutes is peeled off from the stainless steel belt, and then in a continuous drying furnace at 170 ° C. for 3 minutes and then for about 20 seconds. The temperature is raised to 450 ° C., heated at 450 ° C. for 7 minutes, then cooled to room temperature in 5 minutes, an adhesive roll (butyl rubber roll: manufactured by Nagata Corporation) and an ultrasonic dust cleaner (blowout) A polyimide roll film having a thickness of 50 μm was wound up by a winder equipped with a pressure 12 KPa (manufactured by Shinko Co., Ltd.), a static eliminator, and a clean booth. The winding mechanism is shown in the figure. Table 1 shows the amount of charge on the film during winding, the number of particles in the winding environment, and Table 2 shows the evaluation results of the film.
The obtained polyimide roll film is mounted on a continuous sputtering apparatus, and the frequency is 13.56 MHz, the output is 400 W, the gas pressure is 0.8 Pa, and the target is a nickel-chromium (chromium content: 10%) alloy, in an argon atmosphere. A nickel-chromium alloy film having a thickness of 50 mm was formed at a rate of 10 mm / second by RF sputtering. Subsequently, copper was vapor-deposited at a rate of 100 liters / second to form a copper thin film having a thickness of 0.3 μm. Then, using this film copper sulfate plating bath, a thick copper plating layer having a thickness of 5 μm was formed on the copper thin film to obtain a metallized polyimide film (copper-clad laminate film).
Table 3 shows the appearance evaluation of the obtained copper-clad laminate film, the shape evaluation of the comb pattern, and the insulation durability test result of the comb pattern.

(Comparative Example 2)
The above polyamic acid solution (2) was coated on a stainless steel belt using a T-type die. The lip gap of the die was 280 μm. Next, the polyamic acid film having a self-supporting property obtained by drying at 90 ° C. for 60 minutes is peeled off from the stainless steel belt, and then in a continuous drying furnace at 170 ° C. for 3 minutes and then for about 20 seconds. The temperature is raised to 450 ° C., heated at 450 ° C. for 7 minutes, then cooled to room temperature in 5 minutes, an adhesive roll (butyl rubber roll: manufactured by Nagata Corporation) and an ultrasonic dust cleaner (blowout) Attempt to wind up a polyimide roll film with a thickness of 10 μm using a winder equipped with a pressure remover and a clean booth. The film could not be wound up.

(Comparative Example 3)
A polyimide film was obtained in the same manner as in Example 1 except that a clean booth and a static eliminator were not used in the winding mechanism. Table 1 shows the amount of charge on the film during winding, the number of particles in the winding environment, and Table 2 shows the evaluation results of the film.
The obtained polyimide roll film is mounted on a continuous sputtering apparatus, and the frequency is 13.56 MHz, the output is 400 W, the gas pressure is 0.8 Pa, and the target is a nickel-chromium (chromium content: 10%) alloy, in an argon atmosphere. A nickel-chromium alloy film having a thickness of 50 mm was formed at a rate of 10 mm / second by RF sputtering. Subsequently, copper was vapor-deposited at a rate of 100 liters / second to form a copper thin film having a thickness of 0.3 μm. Then, using this film copper sulfate plating bath, a thick copper plating layer having a thickness of 5 μm was formed on the copper thin film to obtain a metallized polyimide film (copper-clad laminate film).
Table 3 shows the appearance evaluation of the obtained copper-clad laminate film, the shape evaluation of the comb pattern, and the insulation durability test result of the comb pattern.

(Comparative Example 4)
A polyimide film was obtained in the same manner as in Example 1 except that the winding mechanism did not use a static eliminating device, an adhesive roll, or an ultrasonic removing device. Table 1 shows the amount of charge on the film during winding, the number of particles in the winding environment, and Table 2 shows the evaluation results of the film.
The obtained polyimide roll film is mounted on a continuous sputtering apparatus, and the frequency is 13.56 MHz, the output is 400 W, the gas pressure is 0.8 Pa, and the target is a nickel-chromium (chromium content: 10%) alloy, in an argon atmosphere. A nickel-chromium alloy film having a thickness of 50 mm was formed at a rate of 10 mm / second by RF sputtering. Subsequently, copper was vapor-deposited at a rate of 100 liters / second to form a copper thin film having a thickness of 0.3 μm. Then, using this film copper sulfate plating bath, a thick copper plating layer having a thickness of 5 μm was formed on the copper thin film to obtain a metallized polyimide film (copper-clad laminate film).
Table 3 shows the appearance evaluation of the obtained copper-clad laminate film, the shape evaluation of the comb pattern, and the insulation durability test result of the comb pattern.

A polyimide film from a polyimide roll film having an amount of adhered foreign matter of 2 μm or more obtained by the present invention of 100 to 100,000 pieces / m ² , a winding length of 50 m or more, and a film width of 250 mm or more is, for example, this film Is used as a circuit board made of copper-clad laminate, the foreign matter on the surface of the film is within a certain value and is small. This may cause disconnection or shorting of the circuit, and foreign matter existing on the opposite side of the circuit formation surface may cause the focus to go out of focus in the exposure process during circuit formation. The circuit board has few quality problems with respect to the cause of damage and short circuit, and the yield is improved when manufacturing a circuit-formed product. Has, industrial significance is extremely large. It is particularly suitable for thin polyimide films that are very easy to charge, and to which floating foreign matter easily adheres due to charging, and it is difficult to produce a roll film with a small amount of attached foreign matter. For example, a thin polyimide film of about 10 μm is suitable. However, because the tensile elastic modulus is more than a predetermined value, it can efficiently produce a copper-clad laminate that can be made into a light and short circuit board, and further use this to make a light and short circuit It can be used as an electronic component such as a substrate, can be further improved in productivity, and is very easy to improve the product yield, so that it is expected to greatly contribute to the industry.

The outline of the polyimide roll film manufacturing apparatus of this invention is shown.

Explanation of symbols

1: Heat treatment furnace 2: Conveying film 3: Adhesive roll 4: Web cleaner 5: Electrification machine 6: Conveying roll 7: Imide winding film 8: Clean booth: Class 100

Claims (11)

A polyimide roll film having an adhered foreign matter amount of 2 μm or more of 100 to 100,000 pieces / m ² , a winding length of 50 m or more, and a film width of 250 mm or more. The polyimide roll film according to claim 1, wherein the amount of adhered foreign matter of 5 μm or more is 100 to 10,000 pieces / m ² . The polyimide roll film according to claim 1, wherein the amount of adhering foreign matter of 10 μm or more is 100 to 1,000 pieces / m ² .   The polyimide roll film according to claim 1, wherein the film has a thickness of 2 to 12.5 μm and a tensile elastic modulus of 6 GPa or more.   The polyimide roll film according to any one of claims 1 to 4, wherein the polyimide has a benzoxazole skeleton as a residue of aromatic diamines.   A copper-clad laminate produced using the polyimide film according to claim 1.   The circuit board produced using the copper clad laminated board of Claim 6.   The method for producing a polyimide roll film according to claim 1, wherein the number of particles in the winding atmosphere is 100 or less.   The method for producing a polyimide roll film according to claim 8, wherein the charge amount of the film at the time of winding is 1 kV or less.   The manufacturing method of the polyimide roll film in any one of Claims 8-9 made to contact with an adhesion roll before winding up.   The manufacturing method of the polyimide roll film in any one of Claims 8-10 which removes surface adhesion dust with a web cleaner before winding up in the clean booth whose number of particles of winding-up atmosphere is class 100 or less.

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