JP2002155140A - Polyimide film, method for producing the same, and metal wiring board using the same as a base material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polyimide film having an excellent high elastic modulus, low thermal expansion coefficient, alkali etching properties, and film-forming properties when the polyimide film is applied to a metallic wiring plate base for a flexible printing circuit applying a metallic wiring to its surface, CSP, BGA, or a TAB tape, and to provide a manufacturing method of the polyimide film, and a metallic wiring circuit plate using the film as a base. SOLUTION: The polyimide film is obtained by copolymerizing pyromellitic dianhydride, phenylenediamine, methylene-dianiline, and 3,4'-oxy-dianiline at a specified mole ratio thereof.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a metal wiring board substrate for a flexible printed circuit or a tape automated bonding tape (hereinafter referred to as a TAB tape) having a metal wiring on the surface thereof. When used as, high elastic modulus, low coefficient of thermal expansion, alkali etching properties,
Furthermore, the present invention relates to a polyimide film having excellent film-forming properties, a method for producing the same, and a metal wiring board for a flexible printed circuit or TAB tape using the polyimide film as a base material.

[0002]

2. Description of the Related Art A TAB tape is provided with a very thin metal wiring on the surface of a heat-resistant film as a base material, and has a "window" for mounting an integrated circuit chip (IC) on the base material. Further, sprockets for precisely feeding the TAB tape are provided near both ends of the TAB tape.

In the above TAB tape, an IC is inserted into a "window" opened in the TAB tape, joined to metal wiring provided on the surface of the TAB tape, and then mounted on the TAB tape.
By joining the tape to the printed circuit for wiring electronic devices, the process of mounting the IC on the electronic circuit is automated, the process is simplified, the productivity is improved, and the electrical characteristics of the electronic device on which the IC is mounted are improved. Has been used to improve.

[0004] The TAB tape has a three-layer structure in which a conductive metal foil is laminated on the surface of a heat-resistant base film via an adhesive such as a polyester base, an acrylic base, an epoxy base or a polyimide base. When,
One having a two-layer structure in which a conductive metal layer is directly laminated on the surface of a heat-resistant base film without using an adhesive is used.

[0005] Therefore, the base film of the TAB tape is required to have heat resistance. In particular, the bonding between the IC and the metal wiring on the TAB tape and the connection between the TAB tape mounting the IC and the printed circuit for electronic equipment wiring are required. Conventionally, a polyimide film has been used so as to withstand high temperatures such as solder welding applied to a base film at the time of joining.

However, when a polyimide film and a metal foil or a metal layer are laminated and a metal wiring is formed by chemical etching of the metal foil or the metal layer, the difference in dimensional change between the polyimide film and the metal due to the heat received. If the deformation of the TAB tape is large, the workability is significantly impaired or sometimes impossible when mounting the IC or joining the TAB tape mounting the IC to the printed circuit for wiring the electronic device. Because it will be
It is required that the thermal expansion coefficient of the polyimide film be approximated to that of metal to reduce the deformation of the TAB tape.

Further, it is possible to reduce a dimensional change due to a tensile force or a compressive force applied to a TAB tape mounted on an IC and bonded to a printed circuit for wiring an electronic device, to make the metal wiring finer and to distort the metal wiring. Load reduction and mounted IC
This is important for reducing the strain load on the substrate, and a higher elastic modulus is required for the polyimide film as the base material.

Definition of polymer alloy or polymer blend ("New perspectives and practical application of polymer alloy: high value-added series of polymer", supervision; Saburo Akiyama, Shinichi Izawa, publishing; CMC Corporation, publication year; 1997 According to the report, April 2014), regarding the high modulus of polymers, block copolymerization, blending, and blending (IPN, Interpenetrating-p
olymer-network), graft polymerization, etc., are considered to be in the category.

In particular, with respect to increasing the elastic modulus of polyimide, Mita et al. (J. Polym. Sci., Part C: Polym. Lett., 26
(5), 215-223) proposes that a blend of polyimides is more likely to have a higher modulus of elasticity than a copolymerized polyimide when compared using the same raw material due to the molecular composite effect. However, since polyimide molecules have a large molecular cohesion, a mere blend tends to have a phase-separated structure. Therefore, some physical bonding is required to suppress phase separation.

[0010] The polymer proposed for that purpose is
Yui et al. ("Design and Future Prospects of Functional Supramolecules: New Materials and New Materials Series", supervised by Naoya Ogata, Minoru Terano, Nobuhiko Yui,
(Publishing: CMC Co., Ltd., Publication year: June 1998)
Interpenetrating-network-polymer (hereinafter referred to as mixed polymer).

As a specific example of the conventional mixing, JP-A-63-175025 discloses that a polyamic acid (A) with pyromellitic acid and 4,4'-diaminodiphenyl ether and a polyamic acid (A) with pyromellitic acid and phenylenediamine are disclosed. Polyamic acid composition (C) with polyamic acid (B)
Has been proposed. Further, JP-A-63-175025
Japanese Patent Application Laid-Open Publication No. H11-216, proposes a polyimide produced from the polyamic acid composition (C).

However, in these conventional mixing methods, since the polyamic acid is polymerized in advance and then mixed, sufficient physical entanglement (mixing) cannot be performed, so that phase separation may occur at the stage of imidizing the polyamic acid. In some cases, there is a problem that only a slightly cloudy polyimide film can be obtained.

JP-A-1-131241, JP-A-1-131242, US Pat. No. 5,081,229 and JP-A-3-46292 disclose pyromellitic dianhydride, paraphenylenediamine and 4,4'-diamino. A block copolymerized polyimide film produced from a block copolymerized polyamic acid composed of diphenyl ether has been proposed, and furthermore, a diamine and an acid dianhydride are reacted in non-equivalent amounts in an intermediate step, whereby a block having a substantially equimolar composition is obtained. A method for producing a component copolymerized polyamic acid film has been proposed.

However, in these conventional methods, although the polyamic acid blend solution hardly causes a phase separation, the molecular composite effect is insufficient and the high rigidity is sometimes unsatisfactory. In addition, in order to produce a polymer having a block component having a controlled molecular chain as a copolymer component, the reaction step becomes complicated, the reaction time becomes long, and the step in which the reactive terminal is excessively present is required. Therefore, the polyamic acid in the middle of the process is unstable and the viscosity easily changes, and there is a problem in production such as gelation.
In addition, this method may not be sufficient to increase the Young's modulus.

In addition, in order to improve the adhesive strength of the adhesive, the surface of the polyimide film as a substrate may be roughened by etching with an alkali solution. In some cases, holes (through holes) for wiring are formed by alkali etching. For this reason, a demand for a polyimide film having excellent alkali etching properties is increasing.

Further, a film having good flatness is desired in order to improve the handleability in the processing step. By increasing the draw ratio during film formation, the flatness of the film is improved. For this reason, a film composition that can be drawn at a high draw ratio is preferred.

As a conventional method for obtaining a polyimide film satisfying these required characteristics, JP-A-1-131241, JP-A-1-131242 and JP-A-3-46292 disclose a conventional method. A polyimide film produced from a polyamic acid consisting of melitic dianhydride, paraphenylenediamine and 44'-diaminodiphenyl ether has been proposed, and furthermore, a diamine and an acid dianhydride are reacted in non-equivalent amounts in a further step. A method for producing a block component polyamic acid film has been proposed.

However, in the above-mentioned conventional method, when used as a metal wiring board base material, a polyimide film satisfying a high degree of elasticity, a low coefficient of thermal expansion, an alkali etching property and a film forming property is obtained. Not be able to
Further improvements were required.

[0019]

SUMMARY OF THE INVENTION The present invention has been achieved as a result of studying the above-mentioned problems in the prior art as a problem. A flexible printed circuit having metal wiring on the surface thereof has been achieved. Film having high elastic modulus, low coefficient of thermal expansion, alkali etching property, and film forming property when applied to metal wiring board base material for CSP, BGA or TAB tape, method for producing the same, and base material using the same It is an object of the present invention to provide a metal wiring circuit board as follows.

[0020]

In order to achieve the above object, the polyimide film of the present invention is composed of pyromellitic dianhydride, phenylenediamine, methylene dianiline, and 3,4'-oxydianiline. Characterized by satisfying the formulas (1-a) to (1-c).

10 mol% ≦ X ≦ 60 mol% Formula (1-a) 20 mol% ≦ Y ≦ 80 mol% Formula (1-b) 10 mol% ≦ Z ≦ 70 mol% Formula (1-c) where X is mol% of phenylenediamine based on total diamine amount Y is mol% of methylene dianiline based on total diamine amount Z is 3,4 based on total diamine amount The molar ratio of all anhydrides to all diamines is about 0.9 to 1.1.

Further, the polyimide film of the present invention is characterized by being manufactured from a polyamic acid having a block component or a mixed polymer component.

In the polyimide film of the present invention, it is preferable that the phenylenediamine is p-phenylenediamine. By applying these conditions, it is expected that a more excellent effect can be obtained. it can.

The polyimide film of the present invention can be obtained by combining a general method for producing polyimide. Preferred production methods for easily obtaining the present invention include the following steps (A) to (E). ) Are sequentially performed.

(A) Block component of pyromellitic dianhydride, phenylenediamine, methylene dianiline and 3,4'-oxydianiline in an inert solvent with phenylenediamine and pyromellitic dianhydride Or a step of reacting using at least pyromellitic dianhydride or a diamine in an amount of 1 to 99% by weight of the total amount to form a polyamic acid having a mixed polymer component,
(B) a step in which the remaining raw materials are additionally used in the polyamic acid polymer from the step (A), and finally a reaction is carried out by using all of the used amount; (C) a polyamic acid solution from the step (B) Mixing a conversion agent capable of converting polyamic acid to polyimide, and (D) casting or extruding the mixture from step (C) on a smooth surface to form a polyamic acid-polyimide gel film. And (E) heating the gel film from the step (D) at a temperature of 200 to 500 ° C. to convert the polyamic acid to polyimide.

In the method for producing a polyimide film of the present invention, the formula (1) of the polyamic acid is represented by the following formula: 20 mol% ≦ X ≦ 50 mol% (2-a) formula 30 mol% ≦ Y ≦ 70 mol% Formula (2-b) 10 mol% ≦ Z ≦ 50 mol% Formula (2-c) The molar ratio of all acid anhydrides to all diamines is about 0.98 to 1. 02. Further, the phenylenediamine is p
-Phenylenediamine is a preferable condition, and by applying these conditions, it is possible to expect a further excellent effect.

Further, a metal wiring board for a flexible printed circuit or a tape automated bonding tape according to the present invention is characterized in that the above-mentioned polyimide film is used as a base material and metal wiring is provided on the surface thereof.

[0028]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The configuration and effects of the present invention will be described below in detail.

The polyimide constituting the film of the present invention may be either a block polymer, a random polymer, or a mixed polymer.

The preferred block component or mixed polymer component is a polyamic acid composed of phenylenediamine and pyromellitic dianhydride, or a polyamic acid composed of 3,4'-oxydianiline and pyromellitic dianhydride. After forming a polyamic acid containing a block component or a mixed polymer component, the polyimide is converted to imide to obtain a polyimide containing a block component or a mixed polymer component.

The reaction for forming the polyamic acid is carried out at least in two parts, and a polyamic acid containing a block component or a mixed polymer component is formed and incorporated into a polyimide molecular chain by imide conversion.

When the polyimide film of the present invention is applied to a flexible printed circuit, a metal wiring board base material for CSP, BGA or TAB tape, it has a high elastic modulus, a low coefficient of thermal expansion, and alkali etching property. A polyimide film that satisfies film-forming properties at the same time can be realized.

By further incorporating a block component or a mixed polymer component into the polyimide polymer,
Each of the above characteristics can be set in a more preferable range. Particularly preferred block components or mixed polymer components in this case are those obtained by reaction with phenylenediamine and pyromellitic dianhydride.

The diamine used in the present invention includes:
A linear diamine, such as phenylenediamine, and 3,
There are pseudo-linear diamines such as 4'-oxydianiline and flexible diamines such as methylene dianiline. In the present invention, phenylenediamine acts to increase the modulus of the film. Other diamines can be used in combination within the range of the addition amount which does not inhibit the object of the present invention.

As the phenylenediamine used in the present invention, in addition to p-phenylenediamine, m-phenylenediamine, o-phenylenediamine and the like, a phenylenediamine partially having a substituent can be used, and particularly preferred. Is p-phenylenediamine. If the amount of phenylenediamine is less than 10 mol%, the rigidity is insufficient, and 6
If it exceeds 0 mol%, the film elongation is low. Methylene dianiline is an aromatic diamine that is easily available and inexpensive because it is produced in relatively large quantities, and has the effect of imparting flexibility. When the amount of methylene dianiline is less than 20 mol%, the cost of the film increases, and when it exceeds 80 mol%, the elongation of the film becomes insufficient. According to the present invention, 3,4'-oxydianiline acts to increase the elongation of the film and improve the film forming property. When 3,4′-oxydianiline is less than 10 mol%, the film elongation becomes insufficient. On the other hand, if it exceeds 90 mol%, the glass transition temperature becomes low, the heat resistance becomes poor, and the heat shrinkage becomes particularly large.

The tetracarboxylic dianhydride used in the present invention is pyromellitic dianhydride, but tetracarboxylic dianhydride and the like can be used in combination within a range of an addition amount which does not inhibit the object of the present invention. For example, less than 50 mol% of biphenyltetracarboxylic dianhydride or benzophenonetetracarboxylic dianhydride can be added. It is produced by imid conversion of the obtained polyamic acid.

The modulus of elasticity of the polyimide film can be adjusted by the use ratio of phenylenediamine and 3,4'-oxydianiline component in the diamine component used in producing polyamic acid. When a large amount of phenylenediamine component is used, high elastic modulus and dimensional stability are improved, but there is a disadvantage that water absorption is increased. If a large amount of methylene dianiline component is used, the elongation of the film becomes small, and the film-forming property may be deteriorated. Therefore, it is necessary to carefully adjust the molar ratio of each component in order to balance each characteristic value.

The polyamic acid of the present invention is 175 ° C. or less,
Preferably, at a temperature of 90 ° C. or lower, the above-mentioned tetracarboxylic dianhydride component and diamine component are mixed at a molar ratio of about 0.90 to 1.10, preferably 0.95 to 1.05, more preferably 0.98 to 0.98. From 1.02 to 1.02, and reacted with each component in a non-reactive organic solvent.

Each of the above components may be independently and sequentially supplied to an organic solvent, or may be simultaneously supplied. Alternatively, an organic solvent may be supplied to a mixed component. In order to achieve this, it is preferable to sequentially add each component to the organic solvent.

When the respective components are sequentially supplied, it is preferable to supply the diamine component and the tetracarboxylic dianhydride component, which are block components or mixed polymer components, in preference to the supply components. That is, in order to produce a polyamic acid containing a block component or a mixed polymer component, the reaction is carried out at least twice, and first, a polyamic acid containing a block component or a mixed polymer component is obtained. Is converted into imide, thereby incorporating a block component or a mixed polymer component into the obtained polyimide.

The time required to form the polyamic acid block component or mixed polymer component may be determined by the reaction temperature and the ratio of the block component or mixed polymer component in the polyamic acid. About 20 minutes to about 20 hours is appropriate.

At this time, as described later, in order to form a polymer containing a block component, the diamine component and the tetracarboxylic dianhydride component are substantially non-equimolar in the reaction step (A). Further, in order to form a mixed polymer component, the diamine component and the tetracarboxylic dianhydride component are substantially equimolar in the reaction step, or the dicarboxylic acid anhydride is used when the diamine excess reaction step is performed. Block ends. The fact that the diamine component and the tetracarboxylic dianhydride component are substantially equimolar, or that the terminal is blocked with a dicarboxylic anhydride in the reaction step in which the diamine is excess, is due to the first formed in these reaction steps. This means that the second polymer component is chemically inert and the polyimide polymer formed in the subsequent reaction is not incorporated at the first polymer end. However, since the reaction of the first component of the mixed polymer and the subsequent reaction of forming the polyimide are performed in the same reaction vessel, a molecular composite (composite of different molecules) is easily formed, and the first mixing is performed. The characteristics of the polymer component can be further exhibited.

Specifically, pyromellitic dianhydride (PMDA) is used as a tetracarboxylic dianhydride component, p-phenylenediamine (PDA), methylene dianiline (MDA) is used as a diamine component, and 3,4'-oxygen. A production example of a polyimide polymer using dianiline (34'ODA) and containing a block component or a mixed polymer component composed of PMDA and PDA will be described below.

First, PDA is dissolved in dimethylacetamide (DMAc) as an organic solvent, and PMDA is added to complete the reaction of the block component or the mixed polymer component. Next, after adding and dissolving MDA and 34'ODA to the solution, PMDA is added to the solution and reacted to obtain a four-component polyamic acid solution containing a block component or a mixed polymer component of PDA and PMDA.

In this case, a small amount of 34 ′ ODA is added to the PDA supplied first, or the PDA to be reacted first is added.
It is also possible to control the size of the block component or mixed polymer component by making the molar ratio between PMDA and PMDA unequal, and adding an amount of an endcapping agent that sufficiently reacts with the excess diamine component. However, in order to make the effect of the block component or the mixed polymer component effective, it is preferable to use a mixed polymer in which the molar ratio between PDA and PMDA is substantially equal.

The terminal capping agent to be used can be preferably added by adding a terminal capping agent such as dicarboxylic anhydride or silylating agent in the range of 0.001 to 2% based on the solid content (polymer concentration). . Acetic anhydride or phthalic anhydride is used as the dicarboxylic anhydride, and non-halogen hexamethyldisilazane, N, O- (bistrimethylsilyl) acetamide, and N, N-bis (trimethylsilyl) urea are particularly preferably used as the silylating agent. .

The end point of the production of polyamic acid is determined by the polyamic acid concentration of the solution and the viscosity of the solution.
In order to accurately determine the viscosity of the solution at the end point, it is effective to add a part of the finally supplied component as a solution of an organic solvent used in the reaction, but it does not significantly reduce the polyamic acid concentration. Such adjustment is necessary.

The polyamic acid concentration in the solution is 5 to 4
0% by weight, preferably 10 to 30% by weight.

The organic solvent is non-reactive with the respective components and the polyamic acid as a polymerization product,
It is preferred to select from those which can dissolve all of the components and dissolve the polyamic acid.

Preferred organic solvents include N, N-dimethylacetamide, N, N-diethylacetamide,
N, N-dimethylformamide, N, N-diethylformamide, N-methyl-2-pyrrolidone, and the like,
These can be used alone or as a mixture, and in some cases, can be used in combination with a poor solvent such as benzene.

In producing the polyimide film of the present invention, the polyamic acid solution thus obtained is pressurized by an extruder or a gear pump and sent to a polyamic acid film production step.

The polyamic acid solution is filtered to remove foreign substances, solids, high-viscosity impurities and the like mixed in the raw materials or generated in the polymerization step, and formed into a film through a die for forming a film or a coating head. Molded, extruded onto a rotating or moving support, heated from the support to produce a polyamic acid-polyimide gel film in which the polyamic acid is partially imidized, and the gel film becomes self-supporting, The polyimide film is peeled off from the support when it can be peeled off from the support, introduced into a drier, heated by the drier to dry the solvent, and the imide conversion is completed to produce a polyimide film.

At this time, the use of a 20 μm-cut sintered metal fiber filter is effective for removing the gel formed on the way. More preferred is a 10 μm cut metal fiber sintered filter, and most preferred is a 1 μm cut metal fiber sintered filter.

Polyimides can be converted into imides by a thermal conversion method using only heating, a chemical conversion method in which a polyamic acid mixed with an imide conversion agent is heated, or a polyamic acid is immersed in a bath of an imide conversion agent. Although any of them can be adopted, in the present invention, the chemical conversion method is applied to a flexible printed circuit, a CSP, a metal wiring board base material for a BGA or TAB tape as compared with the thermal conversion method. In addition, it is suitable for simultaneously realizing a high elastic modulus, a low coefficient of thermal expansion, an alkali etching property and a film forming property.

Further, the method of mixing a polyamic acid with an imidizing agent by a chemical conversion method, forming the film into a film, and performing a heat treatment is advantageous in that the time required for the imidization is short and the imidization can be performed uniformly. It is easy to peel off from the support, and furthermore, it has advantages such as strong odor and the ability to handle the imide conversion agent requiring isolation in a closed system. It is preferably employed as compared with the method of immersing in a bath.

In the present invention, a tertiary amine which promotes imidization and a dehydrating agent which absorbs water generated by imidization are used in combination as imidizing agents. The tertiary amines are added and mixed in an approximately equimolar or slightly excessive amount with the polyamic acid, and the dehydrating agent is added in an amount about 2 times the molar amount or slightly in excess of the polyamic acid. Adjusted appropriately for

The imide conversion agent may be added at any time after the completion of the polymerization of the polyamic acid and the polyamic acid solution reaches the film forming die or the coating head. From the viewpoint of prevention, it is preferable to add the mixture shortly before reaching the film forming die or the coating head and mix the mixture with a mixer.

As the tertiary amine, pyridine or β-
Although picoline is preferred, α-picoline, 4-methylpyridine, isoquinoline, triethylamine and the like can also be used. The amount used is adjusted according to the respective activity.

As the dehydrating agent, acetic anhydride is most generally used, but propionic anhydride, butyric anhydride, benzoic acid, formic anhydride and the like can also be used.

The polyamic acid film containing the imidization agent is converted into an imidized polyamic acid-polyimide gel film by heat received from the support and the space on the opposite side of the support. Peeled off.

In this case, the larger the amount of heat applied from the support and the space on the opposite surface, the more the imide conversion is promoted and the faster the exfoliation occurs. Since the film is deformed and becomes a defect of the film, it is desirable to determine the amount of heat in consideration of the position of the peeling point and the defect of the film.

The gel film peeled from the support is introduced into a drier, and the solvent is dried and the imidization is completed.

This gel film contains a large amount of an organic solvent, and its volume is greatly reduced during the drying process. Therefore, in order to concentrate the dimensional shrinkage due to the volume reduction in the thickness direction, both ends of the gel film are gripped with a tenter clip, and the gel film is introduced into a dryer (tenter) by the movement of the tenter clip. It is common practice to heat and consistently perform solvent drying and imidization.

The drying and imidization are carried out at 200 to 50
It is performed at a temperature of 0 ° C. The drying temperature and the imide conversion temperature may be the same temperature or different temperatures, but in the stage of drying a large amount of the solvent, prevent the bumping of the solvent as a lower temperature, and when there is no possibility of bumping of the solvent, raise the temperature to a higher temperature. Preferably, the temperature is increased stepwise so as to promote imide conversion.

In the tenter, the distance between the tenter clips at both ends of the film can be expanded or reduced to stretch or relax. The stretching ratio is 1.0 to 1.3 times in the machine axis direction. The stretching ratio in the width direction is 0.9 to 1.3 times.

A cut sheet-like polyimide film preferably containing a block component or a mixed polymer component and obtained by imide conversion by a chemical conversion method can be produced by cutting from the continuous film produced as described above. However, to produce a small amount of film, as shown in Examples below, in a resin or glass flask, preferably to produce a polyamic acid containing a block component or mixed polymer component, A mixed solution obtained by mixing a chemical conversion agent with a polyamic acid solution,
Cast onto a support such as a glass plate, heat it, peel off from the support as a partially imidized self-supporting polyamic acid-polyimide gel film, fix it on a metal fixing frame, etc. and change the dimensions Can be produced by a method in which the solvent is dried and imide conversion is carried out by heating while preventing the occurrence of the solvent.

Thus, the polyimide film of the present invention obtained by the imide conversion by the chemical conversion method is more flexible than the polyimide film obtained by the thermal conversion method. When applied to a metal wiring board substrate for TAB tape, it is suitable for simultaneously realizing a high elastic modulus, a low coefficient of thermal expansion, a low coefficient of hygroscopic expansion, and a low water absorption, and has excellent alkali etching properties. It is.

Therefore, a flexible printed circuit, a metal wiring board for CSP, BGA or TAB tape formed by applying a metal wiring on the surface of the polyimide film of the present invention as a base material, has a high elastic modulus and low thermal expansion. It expresses a high-performance characteristic that simultaneously satisfies a coefficient, an alkali etching property, and a film forming property.

In the polyimide film of the present invention, the elastic modulus is preferably 4 GPa or more, the thermal expansion coefficient is preferably 10 to 20 ppm / ° C., and the water absorption is 2% or less, particularly preferably 1% or less. . With respect to the alkali etching property, it is a preferable condition that the film is dissolved. Although the evaluation method is described below, the evaluation can be performed under alkaline conditions and the erosion rate of the surface can be evaluated. When the alkali etching rate is high, the productivity of through hole processing of CSP or BGA is good.

Since the film is exposed to a high temperature near 300 ° C. during the solder bath process, the smaller the heat shrinkage, the better. If the heat shrinkage exceeds 1%, it may be difficult to use. It is preferably at most 1%, more preferably at most 0.1%.

[0071]

EXAMPLES The present invention will now be described in detail with reference to examples, but the present invention is not limited to these examples. In addition, each film characteristic value is measured by the following method.

In the following examples, the abbreviations DMAc are dimethylacetamide, PMDA is pyromellitic dianhydride, PDA is p-phenylenediamine, and MDA is
Is methylene dianiline, and 34 'ODA is 3,
Abbreviation for 4'-oxydianiline. (1) Modulus of elasticity and elongation at break The modulus of elasticity was measured at room temperature according to JIS K7113 at room temperature.
It was determined from the slope of the initial rising portion of the tension-strain curve obtained at a tensile speed of 300 mm / min using a Tensilon type tensile tester manufactured by NREC.

The elongation at break was taken as the elongation at break of the sample. (2) Coefficient of thermal expansion The coefficient of thermal expansion was measured using a TMA-50 thermomechanical analyzer manufactured by Shimadzu Corporation at a temperature rising rate of 10 ° C./min and a temperature decreasing rate of 5 ° C./min for the second time ( Fall) 50 ° C to 200 ° C at the time of temperature
It was determined from the dimensional change during. (3) Water Absorption The water absorption was measured in a constant temperature and humidity chamber (STPH-101, manufactured by Tabai Espec Corp.) at 25 ° C. and adjusted to 95% RH for 48 hours. The weight difference was determined as a percentage. (4) Alkali etching property The alkali etching property is as follows. One surface of the polyimide film is treated with a 1 / N solution of ethanol / water mixed solution having a volume ratio of 80/20.
The thickness of the film before and after contacting it with a potassium hydroxide solution at 40 ° C. for 120 minutes was measured using a Mitutoyo LITEM.
It was determined by measuring with an ATIC thickness gauge. Evaluation criteria were determined as follows according to the thickness change rate.

○ Thickness change rate 5% or more △ Thickness change rate 1% or more and less than 5% × Thickness change rate less than 1%.

At the level ○, the through-hole processing speed was high in the alkaline etching step of the polyimide film, indicating good productivity. The △ level is a practical level, though the through hole processing speed is not fast. At the × level, the through-hole processing speed is low, which is not a practical level. (5) Evaluation of the amount of warpage of the metal laminate A polyimide-based adhesive was applied to the polyimide film, and a copper foil was bonded thereon at a temperature of 250 ° C. Thereafter, the temperature was raised to a maximum temperature of 300 ° C. to cure the adhesive, and the obtained metal laminate was cut into a sample size of 35 mm × 120 mm, left at 25 ° C. and 60% RH in an atmosphere for 24 hours. Warpage was measured.
For the warpage, the sample was placed on a glass plate, and the heights of the four corners were measured and averaged. The evaluation criteria were determined as follows according to the amount of warpage.

○ The amount of warpage is less than 1 mm △ The amount of warpage is 1 mm or more and less than 3 mm × The amount of warpage is 3 mm or more × When using as a metal wiring circuit board, the level is a level at which handling becomes difficult when transported in a post-process. (6) Film-forming property The prepared film was converted into a polymer film by a biaxial stretching apparatus for research (BIX-703, manufactured by Iwamoto Seisakusho Co., Ltd.).
The film was stretched at 00 ° C. by a biaxial stretching method at a biaxial equivalence to determine a film breaking area. Preheating time 60 seconds, unilateral stretching speed 1
0 cm / min, extremely good The stretch ratio at break exceeds 1.3 times.

Good The stretch ratio at break is 1.1 to 1.2 times.

(2) No problem in practical use.

× Difficult to form a film: The stretch-to-break area ratio was 1 or less. (7) Heat Shrinkage The dimensional change before and after heating at 300 ° C. for 1 hour is measured according to JIS-C2318.

Heat shrinkage C (%) = 100 (A−B) / A, where A: film size before heating B: film size after heating ○ 0.05% or less △ 0.05% ~ 0.1% or less × Exceeds 0.1%. [Example 1] DMA was placed in a 500 cc glass flask.
Add 150 ml of c, feed PDA into DMAc to dissolve, then feed MDA, 34'ODA and PMDA sequentially and stir at room temperature for about 1 hour. Finally, a solution having a polyamic acid concentration of 20% by weight comprising a tetracarboxylic dianhydride component and a diamine component having a stoichiometry of about 100 mol% and a composition shown in Table 1 was prepared.

30 g of this polyamic acid solution was added to 12.7
ml of DMAc, 3.6 ml of acetic anhydride and 3.6 ml
A mixed solution prepared by mixing with β-picoline was prepared, and the mixed solution was cast on a glass plate, and then heated on a hot plate heated to 150 ° C. for about 4 minutes to form a self-supporting polyamic acid-polyimide gel. A film was formed and peeled from the glass plate.

This gel film was fixed to a metal fixing frame provided with a large number of pins, and was heated for 30 minutes while raising the temperature from 250 ° C. to 330 ° C., and then heated at 400 ° C. for about 5 minutes.
A polyimide film having a thickness of about 25 μm was obtained.

Table 1 shows the evaluation results of the characteristic values of the obtained polyimide film. [Examples 2 to 4] In a 500 cc glass flask, D was added.
150 ml of MAc was charged, and PDA was supplied and dissolved in DMAc, followed by supply of PMDA, followed by stirring at room temperature for about 1 hour. MDA and 34 'were added to this polyamic acid solution.
After supplying ODA and completely dissolving, the mixture was stirred at room temperature for about 1 hour. Subsequently, 1 mol% of phthalic anhydride with respect to the diamine component is added, and the mixture is further stirred for about 1 hour. Polyamic acid concentration 2
A 0% by weight solution was prepared.

The solution having a polyamic acid concentration of 20% by weight was treated in the same manner as in Example 1 to obtain a polyimide film having a thickness of about 25 μm.

The results of evaluating the characteristic values of the obtained polyimide film are also shown in Table 1.

[0086]

[Table 1] [Examples 5 to 7] In a 500 cc glass flask, D was added.
Add 150 ml of MAc, feed and dissolve PDA in DMAc, then feed PMDA, at room temperature about 1
Stirred for hours. Subsequently, 1 mol% based on the diamine component
Acetic anhydride was added and stirred for about 1 hour (polymerization of the first polymer was completed).
After 4 ′ ODA was supplied and completely dissolved, PMDA was supplied, and the mixture was stirred at room temperature for about 1 hour (polymerization of the second polymer was completed), and the tetracarboxylic dianhydride component and the diamine component were about 100 mol%. A stoichiometric solution having a polyamic acid concentration of 23% by weight was prepared from components having the compositions shown in Table 2.

This polyamic acid solution was treated in the same manner as in Example 1 to obtain a polyimide film having a thickness of about 50 μm.

Table 2 shows the evaluation results of the characteristic values of the obtained polyimide film.

[0089]

[Table 2] [Comparative Example 1] DMA was placed in a 500 cc glass flask.
c 150 ml, add MDA and 34 'ODA to DM
Ac and dissolve it in Ac, dissolve PMDA, and stir at room temperature for about 1 hour. The tetracarboxylic dianhydride component and the diamine component have a composition of about 100 mol% stoichiometry shown in Table 3 A solution having a polyamic acid concentration of 20% by weight was prepared.

This polyamic acid solution was treated in the same manner as in Example 1 to obtain a polyimide film having a thickness of about 25 μm.

Table 3 shows the characteristic value evaluation results of the obtained polyimide film. [Comparative Examples 2 to 6] In accordance with Comparative Example 1, 150 ml of DMAc was placed in a 500 cc glass flask, and the raw materials and compositions shown in Table 3 were sequentially supplied and dissolved in DMAc, and the resulting mixture was allowed to stand at room temperature for about 1 hour. Stirring was performed to prepare a solution having a polyamic acid concentration or a polyamic acid concentration of 20% by weight in which the tetracarboxylic dianhydride component and the diamine component had a stoichiometric composition of about 100 mol% and a composition shown in Table 3.

This polyamic acid solution or polyamic acid solution was treated in the same manner as in Example 1 to a thickness of about 25 μm.
m was obtained.

Table 3 also shows the evaluation results of the characteristic values of the obtained polyimide film.

[0094]

[Table 3] As is clear from the results shown in Tables 1, 2 and 3, the random polyimide film and block polyimide film of the present invention obtained by the chemical conversion method comprising PMDA, PPD and 34 'ODA are two-component polyimide. Compared with film, it has high elastic modulus, low coefficient of thermal expansion, alkali etching property, and film forming property at the same time, and is used as a metal substrate for flexible printed circuit, CSP, BGA or TAB tape. It has a suitable performance.

[0095]

As described above, the polyimide film of the present invention is more flexible than a polyimide film obtained by a thermal conversion method, because it is a flexible printed circuit, a metal wiring board for CSP, BGA or TAB tape. When applied to a substrate, high elastic modulus, low coefficient of thermal expansion, alkali etching property,
And has excellent film-forming properties.

Therefore, a flexible printed circuit, a metal wiring board for CSP, BGA or TAB tape formed by applying a metal wiring to the surface of the polyimide film of the present invention as a base material, has a high elastic modulus and a low thermal expansion. A high-performance characteristic that simultaneously satisfies a coefficient, a low coefficient of hygroscopic expansion, a low water absorption and an alkali etching property.

Continuation of the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (reference) // B29K 79:00 B29K 79:00 B29L 7:00 B29L 7:00 C08L 79:08 C08L 79:08 A (72) Inventor Koichi Sawazaki 31-6, Shintakara-cho, Tokai-shi, Aichi Prefecture F-term (reference) 4F071 AA60 AF20 AF62 AG28 AH13 BB02 BB06 BC01 4F205 AA40A AC05 GA07 GB02 GE24 GW06 GW31 4J043 PA05 PA08 PA09 PA09 PB21 PB22 PB23 QB26 QB31 RA35 SB04 TA22 TB01 TB02 UA121 UA122 UA131 UA132 UB011 UB121 UB152 VA012 VA041 VA052 XA16 XA19 XB35 YA06 YA08 ZA04 ZA23 ZA32 ZA33 ZA60 ZB11 ZB50 5F046MM48

Claims (7)

[Claims] 1. A polymer prepared from pyromellitic dianhydride and a polyamic acid comprising phenylenediamine, methylene dianiline and 3,4'-oxydianiline, and represented by the formulas (1-a) to (1-c): A polyimide film characterized by satisfying the following. 10 mol% ≦ X ≦ 60 mol% Formula (1-a) Formula 20 mol% ≦ Y ≦ 80 mol% Formula (1-b) Formula 10 mol% ≦ Z ≦ 70 mol% (1) Where X is the mole% of phenylenediamine based on the total amount of diamine, Y is the mole% of methylene dianiline based on the total amount of diamine, and Z is 3,4′-oxy based on the total amount of diamine. Mole% of dianiline The molar ratio of total anhydride to total diamine is about 0.9 to 1.1. 2. The polyimide film according to claim 1, wherein the polyimide film is produced from a polyamic acid having a block component or a mixed polymer component. 3. The polyimide film according to claim 1, wherein the phenylenediamine is p-phenylenediamine. 4. A method for producing a polyimide film having a block component or a mixed polymer component, which comprises sequentially performing the following steps (A) to (E). (A) pyromellitic dianhydride, phenylenediamine,
Methylene dianiline and 3,4'-oxydianiline are combined in an inert solvent with at least pyrroleic acid to form a polyamic acid having a block component or a mixed polymer component with phenylenediamine and pyromellitic dianhydride. A step of using 1 to 99% by weight of the total amount of melitic dianhydride or diamine to cause a reaction, and (B) adding the remaining raw materials to the polyamic acid polymer from the step (A), (C) mixing the polyamic acid solution from the step (B) with a conversion agent capable of converting a polyamic acid into a polyimide, and (D) the step (D) Casting or extruding the mixture from C) onto a smooth surface to form a polyamic acid-polyimide gel film; and The gel film from a), 200
Converting polyamic acid to polyimide by heating at a temperature of 500 ° C. 5. The polyimide film according to claim 1,
A method for producing a polyimide film, which is produced by the method according to claim 4. 6. The polyamic acids (1-a) to (1-a)
The method for producing a polyimide film according to claim 5, wherein c) the following formulas (2-a) to (2-c). 20 mol% ≦ X ≦ 50 mol% Formula (2-a) 30 mol% ≦ Y ≦ 70 mol% Formula (2-b) Formula 10 mol% ≦ Z ≦ 50 mol% (2 -C) Formula The molar ratio of all anhydrides to all diamines is about 0.98 to 1.02. 7. A flexible printed circuit or tape automated bonding tape, comprising a polyimide film according to claim 1 as a base material and metal wiring applied to the surface thereof. For metal wiring board.