JP2009148896A - Laminated polyimide film and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a laminated polyimide film which is easy of forming a thin functional film layer and a very thin polyimide insulating layer on a flexible printed circuit board etc. <P>SOLUTION: A method for producing the laminated polyimide film comprises forming the thin functional film layer is on one surface of a polyimide film 0.5-10 μm in thickness, laminating a reinforcing backing film having an adhesive layer on one surface of the laminated polyimide film formed by laminating a reinforcing film on the upper surface of the thin functional film layer and of a very thin polyimide film, and forming the thin functional film layer on the surface on the side opposite to the reinforcing backing film lamination surface of the polyimide film. Next, the reinforcing film having an adhesive layer is laminated on the surface of the thin functional film layer, and the reinforcing backing film having the adhesive layer is peeled off. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a laminated polyimide film used in processing / manufacturing a multilayer printed circuit board (hereinafter referred to as multilayer board) and a method for manufacturing the same. More specifically, a functional thin film layer such as copper was formed on a polyimide film in which a reinforcing film having appropriate rigidity, thermal dimensional stability, and peelability suitable for handling an extremely thin polyimide film was laminated. The present invention relates to a laminated polyimide film. Furthermore, a polyimide film on which a reinforcing film having appropriate rigidity, thermal dimensional stability, and peelability is suitable for use in a flexible device manufacturing process in which solar cells, semiconductor circuits, sensors, and actuators are formed. About.

Along with technological advances in electronic devices such as mobile phones, the demand for thin multilayer substrates using films such as FPC (Flexible Printed Circuit), TAB (Tape Automated Bonding), and COF (Chip On Film) has increased rapidly. Furthermore, thinning of FPC and the like is progressing in response to the downsizing, weight reduction, and high density wiring of such devices. For this reason, thinning of a copper-clad film (CCL) for FPC or the like is also progressing at the same time, but this reduces the rigidity of the film itself and makes it difficult to process CCL.
As a method for improving workability when manufacturing an FPC or the like, a method of giving rigidity as a whole by attaching a reinforcing film in advance is used. At that time, a slightly tacky reinforcing film that can be easily handled at the time of processing and can be peeled and removed after the processing is finished is used. Conventionally, acrylic or rubber-based adhesive sheets have been used for this purpose. However, these sheets have a large adhesive force, and the adhesive force varies significantly with temperature and pressure. Depending on the processing conditions, it could not be used.
For example, in a flexible laminate with metal foil on only one side, coexistence of metal foil, thermoplastic polyimide layer, non-thermoplastic polyimide layer, and imidization accelerator to prevent warpage and decrease in production efficiency A flexible laminate (see Patent Document 1) obtained by laminating a polyimide resin backing layer obtained by converting the polyamic acid below in this order, and a polyester (A) and a polyimide ( A reinforcing polyester film containing B), having a thermal shrinkage rate of 0.25% or less, and a thermal expansion coefficient of 13 × 10 ⁻⁶ / ° C. to 50 × 10 ⁻⁶ / ° C. (see Patent Document 2) is proposed. Has been.
In addition, in the process of creating CCL, in the manufacturing methods other than the manufacturing method by casting on the copper foil, in particular, the handling of thin films by roll-to-roll is mostly performed, and the deposition and plating of copper thin films by sputtering Alternatively, application of adhesive, bonding of copper foil, thermocompression bonding, pressing, and the like correspond thereto. In these cases, it is necessary to transport the thin base film without wrinkles, distortion, or rubbing. In addition, even when a substrate is formed, depending on the thickness of the film, it may be difficult to cut, convey, and bond itself.

JP 2005-186274 A JP 2003-101166 A

  The present invention is excellent in handling of an ultrathin polyimide film laminated with a functional thin film layer, and can be easily and stably formed into a functional thin film layer laminated ultrathin polyimide layer when used in processing and manufacturing of FPC and the like. A laminated polyimide film is provided.

That is, this invention consists of the following structures.
1. A laminated polyimide film, wherein a functional thin film layer is formed on one surface of a polyimide film having a thickness of 0.5 to 10 μm, and a reinforcing film is laminated on the upper surface of the functional thin film layer.
2. 2. The laminated polyimide film as described in 1 above, wherein the polyimide film is a polyimide film mainly composed of polyimide benzoxazole obtained by condensation of aromatic tetracarboxylic acid anhydrides and diamines having a benzoxazole structure.
3. 3. The laminated polyimide film according to 1 or 2 above, wherein the functional thin film layer contains copper, nickel, or molybdenum as a main component and has a thickness of 100 nm to 10 μm.
4). 4. The laminated polyimide film according to any one of 1 to 3, wherein an adhesive layer or an adhesive layer is laminated on a surface opposite to the surface on which the functional thin film layer of the polyimide film is formed.
5. A reinforcing backing film having an adhesive layer is laminated on one side of the polyimide film, then a functional thin film layer is formed on the opposite side of the polyimide film reinforcing backing film laminate surface, and then the adhesive layer is formed on the functional thin film layer surface. The method for producing a laminated polyimide film according to any one of the above 1 to 4, wherein a reinforcing film having an adhesive layer is laminated, and then the reinforcing backing film having the adhesive layer is peeled off.

The laminated polyimide film of the present invention has a structure in which a functional thin film is laminated on a polyimide film, and a reinforcing film is laminated on the functional thin film. It is possible to reduce the occurrence of such problems.
Furthermore, when peeling the reinforcing film from the laminated polyimide film or when laminating with another substrate, an adhesive layer or an adhesive layer is formed on the side of the polyimide film opposite to the side on which the reinforcing film is attached. If laminated with a reinforcing film or substrate, the reinforcing film can be easily peeled off, and the occurrence of wrinkles and distortion of the polyimide film can be reduced, so that it has higher levels of heat resistance, flexibility and mechanical strength. Thus, an extremely thin polyimide layer can be formed easily and stably.
For this reason, it is industrially extremely useful as a functional film that can be used for electrical and electronic parts that require fineness, lightness, lightness, and thinness, such as thin FPC.

The laminated polyimide film of the present invention is required to have a thickness of 0.5 to 10 μm as a main constituent polyimide film. When the thickness of this polyimide film is less than 0.5 μm, a reinforcing backing When the laminated polyimide film of the present invention is produced by laminating the films, it is difficult to prevent wrinkles and distortion, and it is not preferable from the point of insulation of the polyimide film. On the other hand, when the thickness exceeds 10 μm, it is possible to carry with a conventional general apparatus in many cases without using a backing film, and there is little effect on lightness, lightness and thinning.
The tensile modulus of the polyimide film used in the present invention is preferably 3 GPa or more, more preferably 6 GPa or more, still more preferably 7 GPa or more, and particularly preferably 8 GPa or more. When it is less than 3 GPa, the handleability in the step of laminating and laminating the reinforcing film may be significantly reduced.
Moreover, although the upper limit of the tensile elasticity modulus of a polyimide film is not specifically limited, it is about 30 GPa from the point which maintains the minimum softness | flexibility on handling.
Moreover, it is preferable that the linear expansion coefficient (CTE) of a polyimide film is -3-20 ppm / degrees C. When the CTE is within this range, there is no distortion or wrinkle in high temperature exposure such as soldering, and the deviation from the linear expansion coefficient of the functional thin film is small.
In addition, when used in close proximity to a material having a small CTE such as Si or ceramics, the CTE in the vicinity of the CTE of the adjacent material is preferable, and the difference from the low CTE material is within ± 7 ppm / K. Is preferable, more preferably within ± 5 ppm / K, still more preferably within ± 3 ppm / K. When deviating from this range, the effect reduction becomes large.
Moreover, it is preferable that the thickness spot of a polyimide film is 20% or less, More preferably, it is 10% or less. If the thickness unevenness exceeds 20%, wrinkles may occur during the pasting operation, and uneven performance may be caused.

The most preferred embodiment of the polyimide film used in the present invention is mainly composed of polyimide benzoxazole obtained by reacting (aromatic) diamines having a benzoxazole structure with aromatic tetracarboxylic acids. .
The polyimide film used in the present invention was subjected to a ring-opening polyaddition reaction of diamines and aromatic tetracarboxylic acids in a solvent to obtain a polyamic acid solution, and then a green film was formed from the polyamic acid solution. It can be obtained later by dehydration condensation (imidization).
Although the polyimide film in this invention is not specifically limited, The combination of the following aromatic diamine and aromatic tetracarboxylic acid (anhydride) is mentioned as a preferable example.
A. A combination of an aromatic diamine having a benzoxazole structure and an aromatic tetracarboxylic acid.
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 two or more of the above A, B and C.
Among these, A. A polyimide film comprising a combination of a diamine having a benzoxazole structure and an aromatic tetracarboxylic acid is preferred.

  Specific examples of aromatic diamines having a benzoxazole structure used in polyimide films mainly composed of polyimide benzoxazole obtained by reacting diamines having a benzoxazole structure with aromatic tetracarboxylic acids include: The following are mentioned.

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%. Is a polyimide film using one kind or two or more kinds 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-bis [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) phenoxy] benzonitrile and hydrogen atom on aromatic ring in aromatic diamine A part or all of the above is a halogen atom, an alkyl group having 1 to 3 carbon atoms or an alkoxyl group, a cyano group or an alkyl group or an alkoxyl group in which some or all of the hydrogen atoms are substituted with a halogen atom and having 1 to 3 carbon atoms And aromatic diamines substituted with a halogenated alkyl group 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, the non-aromatic tetracarboxylic dianhydrides exemplified below may be used alone or in combination of two or more 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 polyamic acid is obtained by polycondensation (polymerization) of the diamines and aromatic tetracarboxylic acids (anhydrides) is one that dissolves both the raw material monomer and the resulting polyamic acid. Is not particularly limited, but a polar organic solvent is preferable, for example, N-methyl-2-pyrrolidone, N-acetyl-2-pyrrolidone, N, N-dimethylformamide, N, N-diethylformamide, N, N- Examples thereof include dimethylacetamide, dimethyl sulfoxide, hexamethylphosphoric amide, ethyl cellosolve acetate, diethylene glycol dimethyl ether, sulfolane, and halogenated phenols.
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.

Conventionally known conditions may be applied for the polymerization reaction for obtaining the polyamic acid (hereinafter also simply referred to as “polymerization reaction”). As a specific example, in a temperature range of 0 to 80 ° C., 10 Stirring and / or mixing continuously for 30 minutes. 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, by 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.

  100-500 degreeC is illustrated as a heating maximum temperature of a thermal ring closure method, Preferably it is 200-480 degreeC. When the maximum heating temperature is lower than this range, it is difficult to close the ring sufficiently. When the maximum heating temperature is higher than this range, deterioration proceeds and the composite tends to become brittle. A more preferable embodiment includes a two-stage heat treatment in which treatment is performed at 150 to 250 ° C. for 3 to 20 minutes and then treatment is performed at 350 to 500 ° C. for 3 to 20 minutes.

In the present invention, a method for obtaining a polyimide film having these thickness spots of 20% or less and a thickness of 7 μm or less is not particularly limited, but preferred methods include (1) aromatic tetracarboxylic acids and Polyamic acid obtained by reacting with aromatic diamines is cast and dried to obtain a precursor film (polyamic acid film), and the precursor film is formed at both end portions of the film in the width direction. Thickness to be imidized by a tenter method that grips the film with a number of clips or pierces with a number of pins provided on the pin sheet, and transports the film in a stretched state in the width and / or transport direction Is a polyimide film manufacturing method for obtaining a polyimide film having a thickness of 7 μm or less, and fills at both end portions in the width direction of the precursor film. Manufacture of polyimide film that is fixed by gripping and / or piercing the precursor (polyamic acid) film to be imidized and the easy-adhesive polyimide film provided with the adhesive layer on the narrow polyimide film. (2) A so-called precursor obtained by slitting a precursor film obtained by casting and drying a polyamic acid obtained by reacting an aromatic tetracarboxylic acid and an aromatic diamine with the narrow polyimide film. The method of said (1) which is a body film (green film) is mentioned.
Here, the thin film prepared separately is not particularly limited in the case of the precursor film or the easily adhesive polyimide film provided with the adhesive layer, but is the same as the precursor film to be processed. A diamine and the same tetracarboxylic acid are preferred, and apart from the polyimide film to be produced, the same polyamic acid solution is cast and dried to create another precursor film and slit in advance to prepare a narrow width A polyimide precursor film or a polyimide film obtained by imidizing the precursor film is preferable, and these can be prepared by slitting them as they are or by slitting them as easy-adhesive polyimide films provided with an adhesive layer. The width of the narrow film is preferably 20 to 80 mm. The thickness of the narrow film prepared separately is not particularly limited, but preferably the same thickness as the precursor film to be processed (manufactured as a polyimide film), and is 5 to 13 μm. If it is less than 5 μm, the reinforcing effect of the overlay tends to be reduced, and if it exceeds 13 μm, the reinforcing effect of the overlay tends to be difficult to reach the precursor film to be produced as a polyimide film.

Although it does not specifically limit as an adhesive agent used for the easily adhesive layer of a narrow polyimide film, There exist a thermoplastic adhesive and a thermosetting adhesive.
As the thermoplastic adhesive, an adhesive from a thermoplastic (thermocompression bonding) polyimide resin is preferable from the viewpoint of heat resistance and adhesiveness to a film, and as these thermoplastic (thermocompression bonding) polyimide resins, A thermoplastic polyimide resin that can be thermocompression bonded at a temperature of about 230 to 400 ° C. is preferred. As such a thermocompression bonding polyimide, preferably, as diamines,
APB: 1,3-bis (3-aminophenoxybenzene),
m-BP: 4,4′-bis (3-aminophenoxy) biphenyl,
DABP: 3,3′-diaminobenzophenone,
DANPG: at least one diamine selected from 1,3-bis (4-aminophenoxy) -2,2-dimethylpropane, and tetracarboxylic anhydride,
PMDA: pyromellitic dianhydride,
ODPS: 3,3 ′, 4,4′-diphenyl ether tetracarboxylic dianhydride,
BTDA: 3,3 ′, 4,4′-benzophenone tetracarboxylic dianhydride,
BPDA: 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride α-BPDA: 2,3,3 ′, 4′-biphenyltetracarboxylic dianhydride,
ODPA: 4,4′-oxydiphthalic dianhydride,
Polyimide obtained from at least one tetracarboxylic dianhydride selected from can be used. These can be used alone or in combination of two or more. Further, other diamines or tetracarboxylic acid anhydrides exemplified above can be used in combination within the range not exceeding 50 mol% of each of the diamines or tetracarboxylic acid anhydrides.
In addition, polyamide imide resins, polyether imide resins, polyester imide resins, and the like can be used alone or in appropriate combination.
Further, as long as the advantages of the present invention are not impaired, a thermosetting adhesive such as an epoxy-based or cyanate-based adhesive may be mixed with the thermoplastic adhesive of the present invention. The proportion of curable adhesive is at most 40%.

In the present invention, when the precursor film is imidized (such as heat treatment) with a film end fixed tenter, the film end gripping at both ends in the width direction of the film can This is a tenter type that is composed of a large number of pins arranged on the pin sheet, and that conveys the film in a state of being stretched in the width direction and / or the conveying direction, with the pins being pierced at both ends of the film by a pressing brush roll In the polyimide film manufacturing method which has a process part, it is set as the preferable aspect that it is the state superimposed on the thin film prepared separately from the precursor film processed at the site | part stabbed with a pin. Further, in the present invention, when casting a polyamic acid solution on a support, by using a backup roll having a high roundness, the thickness unevenness at the time of coating is reduced, particularly the thickness unevenness in the MD direction is reduced. The roundness of the backup roll that can be expressed is expressed by the eccentric amount of the roll described below, and the eccentric amount (μm) is preferably 3 or less, and particularly preferably 2 or less.
The effect of reducing thickness unevenness on the film by reinforcing the pin portion is effective in suppressing thickness unevenness in the TD direction. The thickness spots are obtained by the following formula.
Thickness unevenness (%) = ((maximum thickness−minimum thickness) / average thickness) × 100
In these methods, a method of controlling the eccentric amount of the backup roll of the coater to 3 (μm) or less, preferably 2 (μm) or less is preferable. The measurement of the eccentric amount of the backup roll is a value obtained by abutting a dial gauge on the end surface of the backup roll and measuring the displacement amount of the gauge at the left end surface, the right end surface, and the center portion of the backup roll. More specifically, the dial gauge uses a capacitance type dial gauge (manufactured by Ozaki Mfg. Co., Ltd., trade name PEACOCK, model DG-205, measurement range 25 mm, minimum display amount 0.001 mm, accuracy 0.003 mm).
The dial gauge is fixed to the roll frame with a magnetic chuck. Eccentricity measurement is repeated 6 times for each portion divided into 8 in the circumferential direction. The measurement should be performed in an environment where temperature and humidity are stable and there is no vibration. The roll driving speed is 1 m / min.
Measurement is performed both with and without film. When there is a film, the film tension is about 100N.
Control of the eccentric amount of the backup roll is performed by removing the plating of the backup roll when the eccentric amount is large, and performing the control of the eccentric amount through at least the processes of cutting and polishing, and polishing the backup roll when the eccentric amount is small. Perform machining to control the amount of eccentricity.
The material of the backup roll is preferably carbon steel for mechanical structure (STKM, S45C).
Hard chrome plating is good for the surface treatment of the backup roll. The diameter of the roll is preferably about φ200 to 400. As the bearing, it is preferable to use a bearing having a dimensional accuracy and a rotational accuracy of the grade 4 or higher of the accuracy grade specified in JIS B1514.

  The shape of the high part in the pin sheet which has a part higher than the pin base installed outside with respect to the width direction of the pin sheet as a preferred embodiment of the present invention is not particularly limited, and the pin base is a surface in which the pin is implanted It is only necessary to have a function that the film is higher in position and the film does not contact the pin base. For example, only the outer side in the width direction of the pin sheet (the outer position in the width direction in which the pin is not implanted) is higher. It may be a base that contacts the film only, or may be a pin sheet in which the pin base is inclined outward in the width direction. For example, in the case of a base, the shape and size of the base are: Preferably, (1) the height of the base is lower in the range of 3 to 8 mm than the tip of the pin, more preferably lower in the range of 4 to 6 mm, and the height of the base is 3 from the tip of the pin. If the height is less than m, the depth of the pin piercing both ends of the film is shallow, and the frequency of the film coming off from the pin during the subsequent heat treatment process is increased, which is not preferable. If the thickness is lower than 8 mm, the resistance becomes large when the film is removed from the pin sheet after the heat treatment, which leads to tearing of both end portions of the worst film. (2) The height of the base is higher in the range of 0.5 to 5 mm than the base on which the pins are installed, more preferably in the range of 2 to 3 mm, and the film on the pin sheet During gripping, the pin insertion depth of the film by the holding brush roll is stably determined, and a direct heat transfer suppression effect from the pin sheet to the film gripping portion is manifested. As a result, the temperature between the film center and the gripping portion is exhibited. The difference is reduced, and the difference in breaking strength during film conveyance is reduced. As a result, troubles such as film breakage during peeling of the film from the pin sheet in the tenter and after the heat treatment in the tenter can be reduced. On the other hand, if the height of the base is less than 1 mm from the pedestal on which the pins are installed, the direct heat transfer suppression effect from the pin sheet to the film gripping portion is reduced. The temperature difference with the gripping part becomes large, and the difference in breaking strength during film conveyance becomes large, resulting in troubles such as film breakage in the tenter, which is not preferable. If it is higher than 5 mm than the pedestal, it is not preferable because it promotes contamination of the pin sheet itself in the heat treatment step. Further, (3) it is preferable that the periphery of the table is chamfered, and if the chamfering is not performed, the film in contact with the periphery of the table is not preferable. Also, (4) providing a cavity in the pedestal on which the pins are installed has a direct heat transfer suppression effect from the pin sheet to the film gripping part, resulting in a temperature difference between the film center part and the gripping part. Is reduced, and the difference in breaking strength during film conveyance is reduced, resulting in prevention of troubles such as film breakage in the tenter.

In a polyimide film manufacturing apparatus in which a base is installed on the outer side with respect to the width direction of the pin sheet, the pin is made of a material having a melting point or a softening point of 150 ° C. or more and an elastic modulus of 4 GPa or more when the pins pierce both side ends. It is also a preferred embodiment to use means for piercing the film end into the pin with a member provided with a brush made of bristle material.
Further, in this presser brush roll, the member of the presser brush roll that comes into contact with a portion higher than the pin base installed outside in the width direction is higher in rigidity than the member in the inner part in the width direction, Specifically, it is more preferable that the member installed on the outer side in the width direction of the pressing brush roll is a metal wire brush-shaped member or a metal cylindrical member.
Although it does not specifically limit as a member provided with the brush which consists of a bristle material which has melting | fusing point or a softening point 150 degreeC or more and whose elasticity modulus is 4 GPa or more, The brush roll provided with the brush on the cylindrical plane periphery can use it preferably.
A brush made of a bristle material having a melting point or softening point of 150 ° C. or more and an elastic modulus of 4 GPa or more has the properties, so that the film can be pierced uniformly and its function is deteriorated even when used for a long time. The amount is extremely small, and when the material having no physical properties is used, the above two points cannot be satisfied at the same time.
A brush made of a bristle material having a melting point or softening point of 150 ° C. or higher and an elastic modulus of 4 GPa or higher is not particularly limited as long as it has this physical property. For example, a high elastic polymer fiber, Carbon fibers, glass fibers and the like can be mentioned, and polymer materials such as polymer fibers are more preferable, and aromatic polyamides such as Cornex (manufactured by Teijin) are preferred.

The gripping portion of the pin tenter according to the present invention is composed of a large number of pins arranged on each pin sheet as shown in, for example, FIGS. 1 and 2, and a film is formed by arranging a large number of these individual pin sheets. Before the precursor film to be conveyed and processed as shown in FIG. 2 is pierced into the pin of the pin sheet, it is overlapped with a thin film prepared separately on both sides thereof, and a pressing brush You can pierce the pin with a roll.
In the present invention, as a preferred embodiment, a cooling means is provided at a position immediately before the film heat treatment is finished and the pin or pin sheet turns and returns to the position where film gripping is started. When the film is sufficiently cooled and the film is pierced at both ends by the pins, the film holding uniformity is maintained, and the holes are enlarged or broken in the width direction or the conveying direction of the film at the holes where the pins are entrapped. Is suppressed. As the cooling means, either air cooling or water cooling may be used, and a refrigerant other than air or water may be used. From the viewpoint of cooling efficiency, it is preferable to use a liquid refrigerant. Further, considering that the tenter itself is heated above the ignition point of a general organic solvent, it is most preferable to use a cooling means based on water cooling specifications.

By providing this cooling means, when the pin and the pin sheet start gripping both ends of the film and start conveyance, the pin etc. is maintained at a high temperature when it is heated to a high temperature such as one end heat treatment temperature such as 450 ° C. and there is no cooling means. In the piercing of both ends of the film with this high-temperature pin, it is difficult to maintain uniformity of film gripping, and the hole expands or breaks in the film width direction or the conveyance direction at the hole where the pin is bitten. Can easily occur, and problems such as an increase in distortion in the entire film and an increase in film thickness unevenness can be solved to some extent.
Furthermore, in the present invention, as a preferred embodiment, in the pin arrangement of the pin tenter, the individual pins arranged on the innermost side in the film width direction during film conveyance are mutually different from each other in the individual pin sheet in the film conveyance direction. It is preferable that the pin sheets are all arranged at equal intervals.

  Further, in the present invention, when the precursor film is imidized (such as heat treatment) with a film end fixed type tenter, the film end gripping at both side ends in the width direction of the film is constituted by a number of clips. In the polyimide film manufacturing method having a tenter type processing unit that transports the film in a state of being stretched in the width direction and / or the transport direction, the clip is made by gripping both side edges of the film, A preferred mode is that the precursor film to be treated and a thin film prepared separately are overlapped.

In the present invention, when the precursor film is subjected to imidization (such as heat treatment) with a film end fixing type tenter, film end gripping at both end portions in the width direction of the film is performed, and many clips are endless. In the polyimide film manufacturing method having a clip tenter-type processing unit that transports the film in a state of being stretched in the width direction and / or the transport direction, each clip being held between both ends of the film. It is a preferred embodiment that the portion sandwiched between the two is a state where the precursor film to be processed and the thin film prepared separately are overlaid.
In the present invention, the clip portion of the end fixing tenter for heat-treating the polyimide film is not particularly limited as long as it is a known clip portion, but preferably uses a breathable heat-resistant material for the clip portion, The form and properties are not particularly limited, but preferably a breathable heat-resistant material that is a porous object or fiber aggregate having a thermal decomposition temperature of 400 ° C. or lower is used. Porous ceramics can be used as the breathable heat-resistant material in the present invention. There is no particular restriction on the material of the ceramic itself, and it is sufficient to use a single material or a plurality of materials such as alumina, calcia, magnesia, silica, etc. The porosity indicating the degree of porosity is preferably 30% or more by volume ratio, preferably 40% or more. Is more preferably 50% or more. When the degree of porosity is lower than this range, free emission of volatile components from the polymer film is prevented. On the other hand, if it exceeds 90%, the ceramic itself becomes brittle and becomes impractical. Similarly, as the porous body, foamed cement, gypsum, glass, metal, and other inorganic solids such as phosphates, carbonates, sulfates, and metal acid salts can be used.
As the breathable heat-resistant material in the present invention, an aggregate of inorganic fibers can be used. As the inorganic fibers used in the present invention, carbon fibers, alumina wool, glass wool, asbestos, various glass fibers, and the like can be used. These may be woven, non-woven, or thick like felt.
An aggregate of metal fibers can be used as the breathable heat-resistant material in the present invention. As the metal species, a stainless steel material having excellent corrosion resistance is preferable.
An aggregate of heat-resistant polymer fibers can be used as the breathable heat-resistant material in the present invention. As the heat resistant polymer fiber, aromatic polyamide fiber, polyimide fiber, polybenzoxazole fiber, polybenzothiazole fiber, polybenzimidazole fiber, polyimide benzoxazole fiber, or the like can be used.

It is more preferable that the tenter of the present invention formed by sandwiching the film end gripping with a plurality of clips has means for cooling so that the temperature of the gripping portion where the clip is in contact with the film is less than 180 ° C.
Hereinafter, the clip cooling means will be described in detail. A tenter using such a clip as a fixing means is called a clip tenter. Clip tenter clips are often combined with drive chains and installed as endless tracks. As for the drive chain of the clip tenter, a type that passes through the inside of the processing furnace is known for both reciprocation, and a type that the return path passes through the inside of the processing furnace is known. It is preferable to apply to. In the case of such a type, the entire apparatus can be made compact.
As shown in FIG. 3, in a processing chamber that receives a treatment such as heat treatment, a number of clip blocks in which clips are arranged are arranged at both ends of the film, and these clips hold and convey both ends of the film, In the processing chamber, the clips run parallel to each other at both ends of the film, and the film is heat-treated while being kept at a very high temperature. At least in this processing chamber, the clip is also exposed to the high temperature, and the film is heat-treated. After the process is completed, the film is turned again to hold the film again at the original position.
In the present invention, the cooling of the clip and the clip block is preferably performed between the return path of the drive chain on the inlet side of the processing furnace and the clipping zone.

In the conventional tenter type transfer device, when these clips grip the both ends of the film and start to transfer, one end is heated to a heat treatment temperature of 490 ° C., for example, 490 ° C., and there is no cooling means or temperature control means, and temperature variation is maintained at a high temperature. In the gripping of both ends of the film by the clip, the film gripping uniformity is difficult to be maintained, film thickness spots and cracks are likely to occur in the vicinity of the portion sandwiched between the clips, and the film breaks easily due to the expansion of the cracks. Furthermore, the distortion of the whole film increases and the film thickness unevenness increases. Therefore, in the present invention, a cooling means is provided at a position immediately before the clip is turned after the film heat treatment is finished and returns to the position where film gripping is started, and the clip is sufficiently cooled and temperature controlled at the time of starting film gripping. Therefore, uniformity of film gripping by the clip can be maintained, tearing in the vicinity of the clip, distortion reduction in the entire film, and reduction in film thickness unevenness can be achieved.
As a cooling means in the present invention, either air cooling or water cooling may be used, and a refrigerant other than air or water may be used. From the viewpoint of cooling efficiency, it is preferable to use a liquid refrigerant. Further, considering that the tenter itself is heated above the ignition point of a general organic solvent, it is most preferable to use a cooling means based on water cooling specifications. In order to prevent dew condensation in the vicinity of the cooling part, it is preferable to control the dew point of the cold air when air is used as the atmosphere and the refrigerant.
Furthermore, in the present invention, it is preferable that a means for measuring the temperature of the clip portion and a control system for controlling the degree of cooling according to the measurement result are provided. As the temperature measuring means, a known means such as a thermocouple or a radiation thermometer can be used. The control system may use normal negative feedback control.

As the reinforcing film used in the present invention, polyimide film, polyamideimide film, polyethylene naphthalate film, polyphenylene sulfide film, aramid film, liquid crystal polymer film, fluororesin film, polycarbonate film, polyester film, acetate film, polyolefin, There is no particular limitation as long as the heat resistance, mechanical strength, and the like of aluminum foil are above a certain level. Further, from the gist of the present invention, the water absorption of the reinforcing film is preferably 0.5% or less, and the linear expansion coefficient thereof is preferably 50 ppm / ° C. or less, more preferably 30 ppm / ° C. or less. .
These films preferably have an adhesive layer in order to be laminated on the functional thin film layer. It is preferable to select the adhesive layer so that the adhesive strength between the adhesive layer and the functional thin film layer is 1.0 N / cm or less. A pressure-sensitive adhesive layer that adheres well to the reinforcing film and has the above-mentioned pressure-sensitive adhesive strength is preferable for the functional thin film layer. The adhesive strength of the adhesive layer is more preferably 0.5 N / cm or less, and still more preferably 0.2 N / cm or less. As a minimum of adhesive strength, 0.04 N / cm or more is preferred. If it is less than 0.04 N / cm, peeling may occur in the process.
The adhesive layer is thought to cause glue transfer to the functional thin film layer on the polyimide film due to pressure, heat, etc. during various processes, but it is desirable that this glue transfer is small. After peeling, slight glue transfer is removed by mechanical processing such as plasma processing such as atmospheric pressure plasma, vacuum plasma, reactive plasma, microwave plasma, photocleaning, functional thin film etching chemical treatment, polishing and grinding. If possible, levels that are not at all observed by ESCA are not required.
In addition, said reinforcement film is used also as a backing film for reinforcement of the polyimide film before forming a functional thin film layer on a polyimide film. The reinforcing backing film laminated with the polyimide film through the adhesive layer is formed on the functional thin film layer surface after the functional thin film layer is formed on the polyimide film surface (the surface on which the reinforcing backing film is not laminated). Since the reinforcing film is laminated, the reinforcing backing film becomes unnecessary and is peeled off.

The thickness of the reinforcing film used in the present invention is not limited, but a polyimide film or a polyester film having a thickness of about 12 to 200 μm is preferable from the gist of the present invention. These reinforcing films are preferably laminated with an adhesive layer having a high heat-resistant adhesive function. The adhesive layer is formed of an adhesive such as vinyl chloride, acrylic, or urethane. Further, the TOC elution amount from the reinforcing film is desirably 450 ppm or less, and the thermal shrinkage rate of the reinforcing film is desirably 0.7% or less.
The reinforcing film is laminated on the polyimide film via the adhesive layer by, for example, pressure welding or thermocompression bonding.

Functional thin film layers formed on the polyimide film include oxide thin films such as ITO (indium / tin oxide), metal thin films such as copper, nickel, molybdenum, tungsten, gold, silver, chromium, titanium, and aluminum. Semiconductor thin films such as silicon, germanium, TiO ₂ , strontium titanate, calcium titanate, magnesium titanate. Capacitor materials such as alumina, MgO, steatite, BaTi4O ₉ , BaTiO ₃ , BaTiO ₃ + CaZrO ₃ , BaSrCaZrTiO ₃ , Ba (TiZr) O ₃ , PMN-PT PFN-PFW, PbNb ₂ O ₆ , Pb _0.5 Be _0.5 Nb ₂ Piezoelectric materials such as O ₆ , PbTiO ₃ , BaTiO ₃ , PZT, 0.855PZT-.95PT-0.5BT, 0.873PZT-0.97PT-0.3BT, PLZT, etc. A thin film having a main component is preferably applicable.
When copper is the main component, the copper thin film contains a small amount of other elements, or between the film and the copper thin film, Cr, Ta, Ti, Hf, Mo, W, Re, Ni-Cr, SiCr, TiCr Cu—Mn—NiPd—Ag, Pd—Au—Fe, Cr—SiO, Cr—MgF ₂ , Au—SiO, tantalum nitride or partial tantalum nitride, titanium nitride, or partial titanium nitride. Of these, Ni—Cr, Ni—Co—Cr, and more preferably, 99.9% or more NiCr target for sputtering is used. These include metals, oxides such as ITO, Si, and Al, and composite oxide thin films sandwiched between them as an underlayer.

  The thickness of such a NiCr intermediate layer is required to be at least as small as the copper particles do not substantially penetrate into the polyimide layer by heat treatment at 150 ° C. for 24 hours in the atmosphere (diffusion suppression effect). About 50 nm is preferable. If the film thickness is too thin, the copper particles penetrate into the polyimide layer under such conditions, and the diffusion suppressing layer is not effective. Moreover, if it is too thick, it takes time to form the NiCr intermediate layer, which is not preferable in terms of production efficiency.

  The method of forming the thin film is not particularly limited, but is a dry thin film forming method such as vapor deposition, sputtering, ion plating, MBE, plasma CVD, MOCVD, aerosol deposition method, formation of nano ink thin film by ink jet printing, plating, sol gel Methods, coatings and the like can be preferably applied. A sputtering method excellent in thin film adhesion and thin film controllability is a particularly preferable method. The sputtering method is not particularly limited, and methods such as DC magnetron sputtering, high-frequency magnetron sputtering, and ion beam sputtering are effectively used. Industrially, direct current sputtering is simple and sufficient film quality can be obtained.

  As a form of the thin film in the present invention, in addition to being laminated with a uniform thickness on the entire surface of the polyimide film, when there are moderate irregularities on the surface, or when a pattern for expressing the function is formed Is also included.

  As a method of obtaining the laminated polyimide film of the present invention, for example, a polyimide film in which a reinforcing backing film is laminated via an adhesive layer, on the surface opposite to the reinforcing backing film laminated surface of the polyimide film, It can be produced by forming the functional thin film layer, then laminating a reinforcing film having an adhesive layer on the surface of the functional thin film layer, and then peeling the reinforcing backing film having the adhesive layer.

  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 (or N, N-dimethylacetamide) so that the polymer concentration was 0.2 g / dl was measured at 30 ° C. with an Ubbelohde type viscosity tube. (When the solvent used for preparing the polyamic acid solution was N, N-dimethylacetamide, measurement was performed by dissolving the polymer using N, N-dimethylacetamide.)

2. The thickness and thickness unevenness of the polyimide film and the laminated polyimide film were measured using a micrometer (Minetron 1245D, manufactured by Fine Reef).
The measurement of thickness spots is as follows.
With respect to the width direction (TD), the entire width was measured at intervals of 1 cm in the width direction, and the average thickness, the maximum thickness, and the minimum thickness were calculated and calculated using the following formula.
About the longitudinal direction (MD), it measured for 5 m by a 5-cm space | interval of the longitudinal direction, the average thickness in the meantime, the maximum thickness, and the minimum thickness were taken out, and it calculated using the following Formula.
Thickness unevenness (%) = ((maximum thickness−minimum thickness) / average thickness) × 100
3. Polyimide film tensile modulus, tensile breaking strength and tensile breaking elongation The polyimide film to be measured is cut into strips of 100 mm × 10 mm in the flow direction (hereinafter also referred to as MD direction) and in the width direction (hereinafter also referred to as TD direction). The test piece was used as a test piece. Using a tensile tester (manufactured by Shimadzu Corp., Autograph (registered trademark) 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.

4). Melting point and glass transition temperature of polyimide film For the polyimide film to be measured, differential scanning calorimetry (DSC) is performed under the following conditions, and the melting point (melting peak temperature Tm) and glass transition point (Tg) are based on JIS K 7121. Asked.
Device name: DSC3100S manufactured by MAC Science
Pan ： Aluminum pan (non-airtight)
Sample mass: 4mg
Temperature rising start temperature: 30 ° C
Temperature rising end temperature: 600 ° C
Temperature increase rate: 20 ° C / min
Atmosphere: Argon

5. Linear expansion coefficient (CTE) of polyimide film
For the polyimide film to be measured, the stretch rate in the MD direction and the TD direction is measured under the following conditions, and the stretch rate / temperature at intervals of 90 to 100 ° C., 100 to 110 ° C.,. Measurement was performed up to 400 ° C., and an average value of all measured values from 100 ° C. to 350 ° C. was calculated as CTE (average value).
Device name: TMA4000S manufactured by MAC Science
Sample length; 10mm
Sample width: 2 mm
Temperature rise start temperature: 25 ° C
Temperature rising end temperature: 400 ° C
Temperature increase rate: 5 ° C / min
Atmosphere: Argon

6). Water absorption rate of the film The water absorption rate of the film was determined by cutting the film into about 10 cm × 10 cm and testing it, drying the test piece in a dry oven at 150 ° C. for 1 hour, and immediately measuring its mass to obtain an initial value. The test piece was put in ion exchange water at 25 ° C. for 24 hours, and then water droplets on the surface were sufficiently wiped off and reweighed to obtain a water absorption value. The water absorption was determined from the following formula.
Water absorption rate = 100 × (water absorption value−initial value) / (initial value) [mass%]

7). Judgment of film bulge Check if there are air bubbles and cavities between the adhesive layer of the reinforcing backing film and the polyimide film. What was seen was set as x.

8). Judgment of adhesive layer transfer After peeling off the reinforcing backing film, visually determine whether the adhesive layer has completely moved to the reinforcing backing film side, and the adhesive layer has completely moved to the reinforcing backing film side. ○, the case where the adhesive layer was not completely transferred to the reinforcing backing film side but remained on the polyimide film side was evaluated as x.

9. Judgment of peeled condition When the reinforcing backing film is peeled off, the polyimide film is visually checked for abnormalities such as wrinkles and distortion, and those with almost no abnormalities such as wrinkles and distortion are found. A case where a slight abnormality was observed was evaluated as x, and a case where a large amount of abnormality such as Δ, wrinkles and distortion was observed.
10. Adhesive strength Measured according to JIS Z0237 at a tensile speed of 300 mm / min and a peeling angle of 180 °.

[Reference Example 1]
(Preparation of polyamic acid solution)
Nitrogen introduction tube, thermometer, vessel wetted part equipped with stirring rod, and infusion pipe were replaced with nitrogen in the reaction vessel of austenitic stainless steel SUS316L, and then 5-amino-2- (p-aminophenyl) ) Snowtex (registered trademark) DMAC-ST30 (Nissan Chemical Co., Ltd.) obtained by adding 223 parts by mass of benzoxazole and 4416 parts by mass of N, N-dimethylacetamide and completely dissolving it, and then dispersing colloidal silica in dimethylacetamide 40.5 parts by mass (including 8.1 parts by mass of silica) and 217 parts by mass of pyromellitic dianhydride are added and stirred at a reaction temperature of 25 ° C. for 24 hours. A was obtained. The reduced viscosity (ηsp / C) of this polyamic acid was 4.0 dl / g.

[Reference Example 2]
(Preparation of polyamic acid solution)
The liquid contact part of the vessel equipped with a nitrogen introduction tube, a thermometer, a stirring rod, and the pipe for infusion were substituted with nitrogen in the reaction vessel made of austenitic stainless steel SUS316L, and then 200 parts by mass of diaminodiphenyl ether was added. Next, 4170 parts by mass of N-methyl-2-pyrrolidone was added and completely dissolved, and then Snowtex (registered trademark) DMAC-ST30 (manufactured by Nissan Chemical Industries, Ltd.) in which colloidal silica was dispersed in dimethylacetamide. When 40.5 parts by mass (including 8.1 parts by mass of silica) and 217 parts by mass of pyromellitic dianhydride are added and stirred at 25 ° C. for 5 hours, a brown viscous polyamic acid solution B is obtained. Obtained. The reduced viscosity (ηsp / C) of this polyamic acid was 3.7 dl / g.

[Reference Example 3]
(Preparation of polyamic acid solution)
The wetted part of the vessel equipped with a nitrogen introduction tube, a thermometer, and a stirring rod, and the infusion piping were substituted with nitrogen in the reaction vessel made of austenitic stainless steel SUS316L, and then 108 parts by mass of phenylenediamine was added. Next, Snowtex (registered trademark) DMAC-ST30 (manufactured by Nissan Chemical Industries, Ltd.) obtained by dispersing 4010 parts by mass of N-methyl-2-pyrrolidone and completely dissolving the colloidal silica in dimethylacetamide. When 40.5 parts by mass (including 8.1 parts by mass of silica) and 292.5 parts by mass of diphenyltetracarboxylic dianhydride are added and stirred at 25 ° C. for 12 hours, a brown viscous polyamic acid solution C was obtained. (Ηsp / C) of this reduced viscosity polyamic acid was 4.5 dl / g.

[Reference Example 4]
After replacing the inside of the reaction vessel equipped with a nitrogen introduction tube, a thermometer, and a stirring rod with nitrogen, 930 parts by mass of 1,3-bis (4-aminophenoxy) benzene was introduced, and 15000 parts by mass of dimethylacetamide were introduced uniformly. After stirring well, 40.5 parts by mass of Snowtex (trade name) DMAC-Zl (manufactured by Nissan Chemical Industries, Ltd.) obtained by dispersing colloidal silica in dimethylacetamide (including 8.1 parts by mass of silica) Was added, 990 parts by weight of 4,4′-oxydiphthalic anhydride was added, and the mixture was stirred for 17 hours. A pale yellow and viscous polyamic acid solution (D) was obtained. Ηsp / C of this polyamic acid was 3.1 dl / g.

(Creation of easy-adhesive narrow film)
Using the polyamic acid solutions A and C obtained in the reference example, each was separately coated on a non-slip material surface of a polyethylene terephthalate film A-4100 (manufactured by Toyobo Co., Ltd.) using a comma coater ( The coating width was 1240 mm) and dried at 90 ° C. for 60 minutes. The polyamic acid film that became self-supporting after drying was peeled from the support and cut at both ends to obtain a green film having a thickness of 15 μm and a width of 1200 mm. The obtained green film was subjected to heat treatment with the apparatus shown in FIGS. 1 and 2 by gripping both ends with a pin tenter under the conditions of a pin sheet, a brush roll, a pressing roll, and a supporting jig as shown in parentheses below. The pins are arranged so that the pin interval is constant when the pin sheets are arranged, the pin height from the pin base is 8 mm, the pin sheet interval is 1140 mm, and the length of the pin sheet in the longitudinal direction is The length in the width direction is 95 mm, the length in the longitudinal direction of the table set outside the pin sheet in the width direction is 95 mm, the length in the width direction is 15 mm, and the periphery of the table is chamfered. did. In addition, the brush roll has a two-layer structure using two kinds of materials in the width direction, made of Conex with a strand diameter of 0.3 mm, and on the outside a metal element with a strand diameter of 0.5 mm. A line was placed.
(The pin sheet has a flat plate shape, the distance between the press roll and the film grip start portion is 150 mm, the support jig uses a Teflon (registered trademark) bar, and the distance between the support jig and the film grip start portion is 170 mm).
The heat treatment settings for the tenter are as follows. The first stage was heated at 180 ° C. for 5 minutes and the temperature was raised at a rate of 4 ° C./second, and the second stage was heated at 460 ° C. for 5 minutes under two conditions, ignoring productivity and speed. And the imidization reaction was allowed to proceed. Then, it cooled to room temperature in 5 minutes, wound up in roll shape, and obtained the 9-micrometer-thick polyimide film A and the polyimide film C which exhibit the brown color from each polyamic-acid solution.
A polyamic acid solution (D) diluted 10 times with DMAC (dimethylacetamide) was prepared, and coated on one side of the obtained polyimide film A and polyimide film C using a bar coater. Subsequently, it dried at 90 degreeC for 10 minute (s), and the easily-adhesive polyimide film A and the easily-adhesive polyimide film C were obtained. The ratio of the easy-adhesion layer in these to the thickness 1 of the polyimide film A and the polyimide film C is 0.1 / 1.
The resulting easy-adhesive polyimide film A and easy-adhesive polyimide film C were each slit to prepare a narrow long slit film A having a width of 35 mm and a narrow long slit film C.

[Production Example 1]
The polyamic acid solution A obtained in Reference Example 1 was coated on the non-slip surface of a polyethylene terephthalate film A-4100 (manufactured by Toyobo Co., Ltd.) using a comma coater (coating width 1240 mm, backup roll It was dried at 90 ° C. for 60 minutes using a roundness of 2 (μm). The polyamic acid film that became self-supporting after drying was peeled from the support and cut at both ends to obtain a green film having a thickness of 10 μm and a width of 1200 mm.
In the apparatus shown in FIG. 1 and FIG. 2, the following brackets are used to superpose the 35 mm wide narrow slit film A (adhesive narrow slit film A) on both side ends of the obtained green film. As shown in the figure, both ends were gripped by a pin tenter under the conditions of a pin sheet, a brush roll, a pressing roll, and a support jig, and heat treatment was performed. The pins are arranged so that the pin interval is constant when the pin sheets are arranged, the pin height from the pin base is 8 mm, the pin sheet interval is 1140 mm, and the length of the pin sheet in the longitudinal direction is The length in the width direction is 95 mm, the length in the longitudinal direction of the table set outside the pin sheet in the width direction is 95 mm, the length in the width direction is 15 mm, and the periphery of the table is chamfered. did. In addition, the brush roll has a two-layer structure using two kinds of materials in the width direction, made of Conex with a strand diameter of 0.3 mm, and on the outside a metal element with a strand diameter of 0.5 mm. A line was placed.
(The pin sheet has a flat plate shape, the distance between the press roll and the film grip start portion is 150 mm, the support jig uses a Teflon (registered trademark) bar, and the distance between the support jig and the film grip start portion is 170 mm).

The heat treatment settings for the tenter are as follows. The first stage was heated at 200 ° C. for 5 minutes and the heating rate was 4 ° C./second, and the second stage was heated at 450 ° C. for 5 minutes under two conditions to advance the imidization reaction. The maximum wind speed in the tenter was 0.5 m / sec.
Up to the middle point of the first stage of the tenter, the width of the pins at both ends was reduced by 2% to 98% of the initial width. In the second half of the first stage, the pin width is slightly widened to 99% of the initial width, expanded to 102% in the temperature rise interval, and further expanded to the middle point of the second stage to 103%, and thereafter constant Processed in width. Then, it cooled to room temperature in 5 minutes, cut off the part where the flatness of the both ends of a film was bad with a slitter, wound up in roll shape, and obtained polyimide film A1 which exhibits brown. As for the tensile strength at break of this film, the tensile elongation at break was 510 MPa and 37%, respectively. The water absorption rate was 0.92%. The thickness spot was 8%.
Similarly, polyimide films A2, A3, and A4 having various thicknesses were obtained. The physical properties of the obtained film are shown in Table 1.

[Production Example 2]
Using the polyamic acid solution B obtained in Reference Example 2, the same procedure was followed to obtain a polyimide film B. The tensile strength at break of this film was 320 MPa and 62%, respectively. Moreover, the water absorption rate was 0.44%. The thickness spot was 15%. The physical properties of the obtained film are shown in Table 2.

[Production Example 3]
Using the polyamic acid solution C obtained in Reference Example 3, the same procedure was followed to obtain a polyimide film C. The tensile strength at break of this film was 530 MPa and 46%, respectively. The water absorption rate was 0.34%. The thickness spot was 12%. The physical properties of the obtained film are shown in Table 2.

[Examples 1-3]
About polyimide film A1-3 of each manufacture example, the thing with a release sheet of the polyester film (thickness 43 micrometers) which has an acrylic adhesive layer as a backing film for reinforcement (water absorption 0.35%, linear expansion coefficient is 14 ppm / The adhesive layer surface of the polyester film and one surface of the polyimide film were bonded together while peeling the release sheet in a clean room. At the time of this bonding, no problem occurred in each example.
Each obtained backing film polyimide film for reinforcement was put into a roll-to-roll sputtering machine, and after the plasma treatment was performed on the polyimide film surface without the backing film for reinforcement, sputtering was performed. The plasma treatment and sputtering conditions are as follows.
That is, when the film has a width of 250 mm, the surface of the polyimide film is first treated by glow discharge of oxygen, and the conditions during the treatment are O ₂ gas pressure 2 × 10 ⁻³ Torr, flow rate 50 SCCM,
Discharge frequency 13.56MHz, output 250W, processing time, film feed speed 0.1m / m
Since the effective plasma irradiation width is about 10 cm in in, one plasma irradiation time is 1 minute. Thereafter, the NiCr base thin film layer having a thickness of 15 nm was formed on one surface of the film by a DC magnetron sputtering method using an argon gas with a NiCr alloy as a target. The degree of vacuum at the time of forming the thin film layer is 3 × 10 ⁻³ Torr. Then, a copper thin film layer having a thickness of 250 nm was immediately formed by DC magnetron sputtering using argon gas with copper as a target. The composition of the target NiCr alloy was Ni 80% by mass and Cr 20% by mass 3N purity. The target Cu had a purity of 4N. Each target has a rectangular shape with a width of 12 cm in the film feeding direction and a width of 27 cm in the film feeding direction. Four rectangular targets are installed in the film feeding direction. The targets are approaching by two but were used for NiCr. Since the distance between the target and the target used for Cu is separated, the NiCr sputtered atoms and Cu atoms do not reach the film after being mixed in vacuum, and the underlying NiCr thin film Each Cu thin film is formed without being mixed with each other to form a two-layer thin film. The thickness of the thin film was 20 nm for the NiCr layer and 200 nm for the Cu layer.
Note that the sputtering apparatus is a roll-to-roll system, and the film is moved from the roll to the unwinding chamber, the sputtering chamber, the spare chamber, and the winding chamber, and the surface treatment, NiCr layer creation, and Cu layer are sequentially performed. Creation is performed and then wound on a roll. Each chamber is roughly partitioned by a slit. In the sputtering chamber, the film is in contact with the chill roll, and is cooled by the temperature of the chill roll (−5 ° C.). A thin film is formed by metal particles from two Cu targets without using any target.
Next, the surface of the polyimide film on which the sputtering was applied was further plated. That is, a thick copper plating layer (thickening layer) having a thickness of 5 μm is formed on the surface of the sputtering polyimide film using a copper sulfate plating bath in a state where the reinforcing backing film is still attached, and subsequently 80 It dried at 1 degreeC for 1 minute, and the polyimide film with which the target metal thin film layer (functional thin film layer) was laminated | stacked was obtained.
Next, the same reinforcing film as the reinforcing backing film is pasted to the metal thin film layer surface of the polyimide film using a roll laminator machine, and the first reinforcing backing film is peeled off to reinforce the upper surface of the functional thin film layer of the present invention. A laminated polyimide film obtained by laminating a film for use was obtained. The functional thin film layer is composed of a NiCr thin film 20 nm as an underlayer by sputtering, a copper thin film 200 nm thereon, and a thick copper plating layer having a thickness of 5 μm.
Each of the obtained reinforcing films and the polyimide film on which the functional thin film layer was laminated were evaluated. The evaluation results are shown in Table 3.

Example 4
A metallized laminated polyimide film of Example 4 was obtained in the same manner as Example 1 except that the plating step was not passed. The evaluation results are shown in Table 3.
Example 5
A metallized laminated polyimide film was obtained in the same manner as in Example 1 except that a commercial product having a polyester film release sheet with an adhesive layer was used as the reinforcing backing film. The evaluation results are shown in Table 4.
[Examples 6 and 7]
A metallized laminated polyimide film was obtained in the same manner as in Example 5 except that the polyimide films B and C of Production Examples 2 and 3 were used as the polyimide film. The evaluation results are shown in Table 4. Example 8
A metallized laminated polyimide film of Example 8 was obtained in the same manner as Example 5 except that the plating step was not passed. The evaluation results are shown in Table 4.

Next, a substrate processing example will be shown.
[Substrate processing example 1]
As shown in FIG. 3, a resist layer is formed with a 50 μm-thick dry film on a core substrate made of glass fiber reinforced epoxy resin with copper foil on both sides, the pattern is exposed and developed, and cupric chloride is etched. A pattern (L / S = 150/150) was created, a hole with a diameter of 0.1 mm was drilled, immersed in a swelling treatment liquid, washed with hot water, immersed in a desmear solution, immersed in a neutralizing solution, and then washed with water. . Then put it in a cleaner conditioner solution, rinse in hot water, activator, reducer, and accelerator, then immerse in an electroless plating solution (CuSO ₄ 10 g / l, 13.7% HCHO ₄ ml / l, EDTA, NaOH) for 20 minutes. As a result, a copper layer corresponding to 0.6 μm is formed. After that, it was immersed in an electrolytic plating solution (CuSO ₄ 85 g / l, H ₂ SO ₄ 190 g / l, a small amount of brightener), and electricity was applied to fill the copper layer and copper in the via hole with copper. (Figure 3: 2. Via hole and pattern formation in core substrate)
Thereafter, an adhesive film (D3410 manufactured by Sony Chemical Co., Ltd.) was roll-laminated at 100 ° C. on the side opposite to the reinforcing film of the polyimide film with the Cu film on which the reinforcing film prepared in Example 1 was laminated. Thereafter, the separator film of the adhesive film is peeled off, the reinforcing film of the polyimide film with the Cu film laminated with the reinforcing film created in Example 1, and the side without the functional film are placed on the glass epoxy substrate, and further After roll laminating at 100 ° C., the reinforcing film was peeled off, and pressed at 160 ° C. for 1 hour for adhesion. (Figure 3: 3. Laminate)
Via holes are made in the film bonded by a CO ₂ laser. (Figure 3: 4. Second layer via formation)
After drilling, plasma desmear treatment inside the via is performed, and at the same time the copper surface is cleaned. The copper pattern of the core substrate, which has appeared by the drilling for reinforcement, is flash etched with acid. Thereafter, via fill plating is performed by electroless copper plating and subsequent electrolytic copper plating, and the via is filled with copper, and at the same time, a copper plating layer is further formed on the outermost surface. (Figure 3: 5. Via fill plating)
Photoresist: FR-200, manufactured by Shipley Co., Ltd. was applied and dried, then contacted and exposed with a glass photomask, and further developed with a 1.2 mass% KOH aqueous solution. Next, etching is performed with a cupric chloride etching line containing HCl and hydrogen peroxide at 40 ° C. and a spray pressure of ₂ kgf / cm ₂ to form a pattern with a minimum wiring pitch of 30 μm, and then to a thickness of 0.5 μm. Electrolytic tin plating was performed, followed by annealing at 125 ° C. for 1 hour to form a pattern on the outermost copper layer. (Figure 3: 6. Second layer pattern formation)
An insulating resist was applied to portions other than the necessary portions. (Figure 3: 7. Insulation resist formation)
A solder ball was attached on one side of the copper pad to obtain a multilayer substrate. (FIG. 3: 8. Solder ball formation) The state of peeling during substrate processing was determined. The evaluation results are shown in Table 3.

[Substrate processing examples 2 to 8]
Substrate processing was performed in exactly the same manner as in Substrate Processing Example 1 except that the laminated polyimide film used was that of Examples 2-8. The peeling state during substrate processing was determined. The evaluation results are shown in Tables 3 and 4.

[Comparative Examples 1-3]
As a comparative example, the polyimide films A1 to C of the reference example were used, a reinforcing backing film was attached, and the film was placed in a roll-to-roll sputtering machine, and then plated after sputtering. The plating conditions after sputtering here are the same as those in Example 1. Then, when the backing film for reinforcement was peeled off and pasted on a glass fiber reinforced epoxy substrate, a part pasted with the wrinkles of the film remaining was generated. The evaluation results are shown in Table 5.
What used the film of A4 cannot be said to have a big effect on lightness (lightness thinning).
As another comparative example, the polyimide films A1 to C of the reference example were used, and the sputtering film was put into a roll-to-roll sputtering machine without attaching a reinforcing backing film.
In sputtering, a NiCr thin film of 20 nm was formed as an underlayer, and a copper thin film of 200 nm was formed thereon. At this time, none of the films traveled well, wrinkles occurred during film feeding, and film bulging occurred at the wrinkles. In addition, instability of film running along the way occurred.

  The reinforcing polyimide, the functional thin film layer, the polyimide film of the present invention, and the laminated polyimide film obtained by laminating an adhesive or pressure-sensitive adhesive layer in this order as required are very easy to handle even if it is an extremely thin polyimide film. Therefore, it is possible to easily and stably form an ultra-thin polyimide insulating layer on a multilayer wiring board, so that it can be widely applied to substrate materials for multilayer wiring boards that require lightness, lightness, and thinness. Is a big one.

BRIEF DESCRIPTION OF THE DRAWINGS It is the schematic of the pin sheet | seat which provided the stand in the width direction outer side of the pin which contacts the film in the pin tenter type film processing machine used at the time of the polyimide film used by this invention, (a) is a front view, (b) is a side view FIG. It is the schematic of the pin insertion part of the film in the pin tenter type film processing machine used at the time of the polyimide film manufacture used by this invention. It is a figure which shows the board | substrate processing example in this invention. It is a figure which illustrates the lamination polyimide film in the present invention.

Explanation of symbols

1: Brush roll 2: Pin 3: Pin base 4: Stand 5: Support jig 6: Pressing roll 7: Precursor film 11: Single-sided copper-clad film with reinforcing film 11a: Second layer conductor 11b: Second layer insulation Layer 11c: Second layer adhesive 12: Double-sided copper-clad film 12a: Core substrate insulating layer 12b: Core substrate conductor layer 13: Insulating resist 14: Solder ball 21: Reinforcing film 22: Functional thin film layer 23: Polyimide film 24 : Adhesive layer

Claims (5)

  A laminated polyimide film, wherein a functional thin film layer is formed on one surface of a polyimide film having a thickness of 0.5 to 10 μm, and a reinforcing film is laminated on the upper surface of the functional thin film layer.   The laminated polyimide film according to claim 1, wherein the polyimide film is a polyimide film mainly composed of polyimide benzoxazole obtained by condensation of aromatic tetracarboxylic acid anhydrides and diamines having a benzoxazole structure.   The laminated polyimide film according to claim 1 or 2, wherein the functional thin film layer contains copper, nickel or molybdenum as a main component and has a thickness of 100 nm to 10 µm.   The laminated polyimide film according to any one of claims 1 to 3, wherein an adhesive layer or an adhesive layer is laminated on a surface opposite to the surface on which the functional thin film layer of the polyimide film is formed.   A reinforcing backing film having an adhesive layer is laminated on one side of the polyimide film, then a functional thin film layer is formed on the opposite side of the polyimide film reinforcing backing film laminate surface, and then the adhesive layer is formed on the functional thin film layer surface. The method for producing a laminated polyimide film according to any one of claims 1 to 4, wherein a reinforcing film having an adhesive layer is laminated, and then the reinforcing backing film having the adhesive layer is peeled off.