JPH08134232A - Polyimide film, laminate, and flexible circuit board - Google Patents

Abstract

PURPOSE: To obtain a polymide film which is excellent in mechanical properties, heat resistance, and chemical resistance and has high dimensional accuracy, satisfactory suitability for alignment, and good handleability by incorporating a specific element and forming a specific surface state. CONSTITUTION: The film is produced from a polymer obtained from an aromatic tetracarboxylic acid ingredient consisting mainly of biphenyltetracarboxylic acid and an aromatic diamine ingredient and contains a minute amount of P. It has a finely roughened surface which has a maximum roughness of 5-50nm, an average projection diameter of 5-200nm, and a number of projections per mm<2> of 5×10<4> to 1×10<8> , and in which projections each consisting of an aggregate of particles account for up to 10% of all projections. The content of P is preferably 5-500ppm. This film is obtained, for example, by incorporating a phosphorus compound and inactive inorganic particles such as colloidal silica into a solution of an aromatic polyamic acid, forming the solution into a film, imidizing the polymer, and then removing the solvent.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improved polyimide film. More specifically, it has excellent mechanical properties, heat resistance, and chemical resistance, changes little during various manufacturing processes, and has high dimensional accuracy in the parts manufacturing process.
The present invention relates to a polyimide film that is well aligned when mounting other components and that is easily handled.

[0002]

2. Description of the Related Art Conventionally, a polyimide film composed of an aromatic tetracarboxylic acid component and an aromatic diamine component has excellent electrical insulation properties, mechanical properties, heat resistance, dimensional stability, etc., and is flexible. It is suitable as a support for use in the production of printed wiring copper clad boards (FPC boards) and carrier tapes for TAB.

However, demands for high quality, high precision, high productivity, and low cost in the electronic industry field have become stronger and stronger in recent years, and the polyimide film has a dimensional accuracy in the component manufacturing process and other components are mounted. It is necessary to improve the handling such as the alignment when doing and the slipperiness in the manufacturing process / transportation process. For this reason,
As described in JP-A-88852, there is a method of improving the running property (sliding property) of a polyimide film by solution-forming a dope containing surface-treated inorganic particles having a particle size of 0.7 to 10 μm. was suggested.

[0004] However, although this known technique improves the slipperiness in the manufacturing process / transporting process, on the other hand, impurities such as metals are easily mixed in, defects occur due to foaming of the film, and film mechanical However, there is a problem in that the physical properties of the polyimide film deteriorate, and the reliability of the excellent properties inherent in the polyimide film is impaired.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to provide a polyimide film having chemical resistance while maintaining excellent physical properties, mechanical properties and heat resistance at a high level. It can be adhered even if it is stuck to the material,
A polyimide film having high dimensional accuracy and good handling, a laminate thereof, and a flexible circuit substrate.

[0006]

That is, the present invention provides:
The polymer is composed of an aromatic tetracarboxylic acid component having a biphenyltetracarboxylic acid component as a main component and an aromatic diamine component, and contains a trace amount of P element in the film, and the surface of the film has a maximum roughness. Is in the range of 5 to 50 nm, and the average projection diameter is in the range of 5 to 200 nm, 1 mm ²
Micro projections are formed in the range of 5 × 10 ⁴ to 1 × 10 ⁸ projections per hit, and the number of projections composed of agglomerated particles is 10% or less of the total number of projections. The present invention relates to an aromatic polyimide film.

According to the present invention, the polymer is composed of an aromatic tetracarboxylic acid component having a biphenyltetracarboxylic acid component as a main component and an aromatic diamine component, and the film contains a trace amount of P element. On the surface of the film,
The maximum roughness is in the range of 5 to 50 nm, and the average projection diameter is 5 to 2
The number of protrusions per 1 mm ² is 5 × 10 in the range of 00 nm.
Micro projections are formed in the range of ⁴ to 1 x 10 ⁸
Further, the same kind or different kinds of base materials are laminated directly or through an adhesive on an aromatic polyimide film in which the number of projections composed of a plurality of agglomerated particles is 10% or less of the total number of projections. The present invention relates to a laminated body.

Further, according to the present invention, the polymer is composed of an aromatic tetracarboxylic acid component having a biphenyltetracarboxylic acid component as a main component and an aromatic diamine component, and the film contains a trace amount of P element. On the surface of the film, the maximum roughness is in the range of 5 to 50 nm, and the average projection diameter is 5
The number of protrusions per 1 mm ² is 5 × in the range of up to 200 nm
Minute protrusions are formed in the range of 10 ⁴ to 1 × 10 ^{8 and the} number of protrusions composed of agglomerated particles is 1 of the total number of protrusions.
The present invention relates to a flexible circuit board, wherein a metal foil is laminated on at least one surface of a polyimide film of 0% or less, either directly or via an adhesive.

[0009] As the aromatic tetracarboxylic acid component in the present invention, for example 2,3,3 ^{', 4'} - biphenyl tetracarboxylic acid component, 3,3 ^{', 4,4'} - biphenyl and biphenyl tetracarboxylic acid component An aromatic tetracarboxylic acid component containing a tetracarboxylic acid component in an amount of 50 mol% or more, particularly 60 mol% or more based on all tetracarboxylic acid components is preferable. Also, if not biphenyltetracarboxylic acid component alone, 3,3 aromatic tetracarboxylic acid component balance ^{', 4,4'} - benzophenone tetracarboxylic acid component include pyromellitic acid component, bis (3,4-dicarboxy Phenyl) methane component, 2, 2
-A bis (3,4-dicarboxyphenyl) propane component, bis (3,4-dicarboxyphenyl) sulfone and the like may be combined with the biphenyltetracarboxylic acid component. The greater the proportion of the biphenyltetracarboxylic acid component in the wholly aromatic tetracarboxylic acid component, the more
The polyimide film is optimal because it is excellent in terms of elastic modulus and chemical resistance. On the other hand, when the proportion of the biphenyltetracarboxylic acid component in the wholly aromatic tetracarboxylic acid component decreases, the polyimide film tends to have reduced elastic modulus and chemical resistance.

As the aromatic diamine component in the present invention
Are, for example, p- or m-phenylenediamine components,
3,5-diaminotoluene component, 2,5-diaminotoluene
Phenylenediamine components such as ene components are fully aromatic
50 mol% or more, especially 60 mol% or more in the diamine component,
Among them, especially aromatic diamido containing 70 mol% or more
A preferable example is a phosphorus component. Especially with aromatic diamine components
Then, p-phenylenediamine component of 60 mol% or more,
Aromatic diamine component containing 70 mol% or more is particularly preferable.
Are listed in. 4,4 as an aromatic diamine component^'-J
Aminodiphenyl ether component, 3,4^'-Diaminodi
Phenyl ether component, 3,3^'-Diaminodiphenyl
Synthesis of diaminodiphenyl ethers such as ether components
Minutes, 4, 4 ^'-Diaminodiphenylmethane component, 4,4
^'-Diaminodiphenylpropane component, 4,4^'− Zia
Minodiphenyl sulfone component, 4,4^'-Diaminodiph
Phenylenediamine components such as phenyl sulfide components
May be combined with. Among these combinations, 4,
4^'-Diamino such as diaminodiphenyl ether component
Diphenyl ethers and phenylenediamines
Is preferred. In particular, a set of two aromatic diamine components
In combination, p-phenylenediamine component and 4,4^'-J
A combination with aminodiphenyl ether is preferred. all
Ratio of phenylenediamine components in aromatic diamine components
Heat resistance of polyimide film
It is preferable because it has excellent physical properties. On the contrary, this ratio is small
When it disappears, the heat resistance and mechanical properties of the polyimide film
Tends to decrease.

The polyimide film of this invention contains a small amount of
It is necessary to contain the P (phosphorus) element in an amount of preferably 5 to 500 ppm (weight ratio), particularly preferably 10 to 400 ppm, and particularly preferably 15 to 300 ppm.

If P is not contained in the polyimide film, it becomes difficult to produce with high productivity a polyimide film which gives a laminate having good appearance and excellent quality. Especially, the elongation tends to decrease.

On the surface of the polyimide film of the present invention, the maximum roughness is in the range of 5 to 50 nm (nanometer), the average projection diameter is in the range of 5 to 200 nm, and the number of projections per mm ² is 5 × 10 ^4. Microprojections are formed in the range of up to 1 × 10 ^{8 and the} number of projections composed of a plurality of agglomerated particles is 10% or less, preferably 5% or less, and particularly preferably 3% or less of the total number of projections. is there.

It is necessary that the maximum roughness of the surface of the polyimide film, the average projection diameter, the number of projections, and the number of projections composed of agglomerated particles be within the above range, and if it is out of the above range, preferable slipperiness is obtained. Failure to do so may cause problems such as a short circuit between the circuits of a laminated body manufactured using this film, for example, a flexible printed circuit board.

The maximum roughness of the polyimide film according to the present invention is obtained by using a stylus type roughness meter (for example, Taristep, manufactured by Rank Tape Hobson Co.) and having a cutoff of 0.
33Hz, vertical magnification 200,000 times, horizontal magnification 2,000 times, measurement length 5
0 μm means a value measured by a method according to JIS-B-0601.

The projections on the film surface were photographed in 5 fields of view with a scanning electron microscope at an observation magnification of 1 to 30,000 times (particularly around 20,000 times), the diameter of each projection was measured, and the number distribution was measured. Was calculated, and the average projection diameter was calculated from this distribution curve. Furthermore, the ratio of the number of projections to the total number of projections was determined by defining the projections having a projection diameter of 1.5 times or more the average projection diameter as projections composed of particles in which a plurality of particles are aggregated. It is preferable to appropriately change the observation magnification based on the size of the diameter of the protrusion.

The polyimide film having fine protrusions according to the present invention can be preferably formed, for example, with an inert inorganic material particle having an average particle diameter of 10 to 150 nm as a core inside the film. Colloidal silica can be used as a starting material for the particles of the inert inorganic substance.

The polyimide film of the present invention preferably has a phosphorus-containing compound and particles of an inert inorganic substance such as colloidal silica present in a solution of an aromatic polyamic acid, and the composition is used to form a film. It can be obtained by imidization and solvent removal. That is, first, a dispersion liquid of fine particulate inert inorganic material particles such as colloidal silica was added to an organic polar amide solvent such as N-methylpyrrolidone, dimethylacetamide, or dimethylformamide, which is a polymerization solvent for producing an aromatic polyamic acid. After that, it is mixed and dispersed by a homogenizer, an ultrasonic homogenizer, etc., and preferably dehydrated by a method such as distillation to an extent that it does not hinder the polymerization, and preferably further redispersion and filtration, classification by centrifugation, etc. A solvent dispersion mixture for an aromatic polyamic acid containing colloidal silica is obtained.

An aromatic polyamic acid may be obtained by directly adding an aromatic tetracarboxylic acid component and an aromatic diamine component to the dispersion mixture and polymerizing. In this case, the phosphorus-containing compound can be appropriately added to the mixed system. Further, a phosphorus-containing compound and a dispersion mixture of an amide solvent of colloidal silica or alcohol may be added to the prepolymerized aromatic polyamic acid solution. In any case, the mixture is sufficiently stirred and mixed to prepare a film-forming mixture in which fine particles of the inert inorganic material particles are highly dispersed.

Examples of the phosphorus-containing compound include:
Monocaproyl phosphate, monooctyl phosphate, monolauryl phosphate, monomyristyl phosphate, monocetyl phosphate, monostearyl phosphate, monoethylene ester of triethylene glycol monotridecyl ether, tetra Ethylene glycol monolauryl ether monophosphate, diethylene glycol monostearyl ether monophosphate, dicaproyl phosphate, dioctyl phosphate, dicapryl phosphate, dilauryl phosphate, dimyristyl phosphate, dicetyl phosphorus Acid ester, distearyl phosphate ester, tetraethylene glycol mononeopentyl ester
Phosphoric acid esters such as ter diphosphoric acid ester, triethylene glycol monotridecyl ether diphosphoric acid ester, tetraethylene glycol monolauryl ether diphosphoric acid ester, diethylene glycol monostearyl ether diphosphoric acid ester And amine salts of these phosphoric acid esters. As the amine, ammonia, monomethylamine, monoethylamine, monopropylamine, monobutylamine, dimethylamine, diethylamine, dipropylamine, dibutylamine, trimethylamine, triethylamine, tripropylamine, tributylamine, monoethanolamine, diethylanol, There are triethanolamine and the like.

The aromatic polyamic acid in the film-forming mixture is, for example, a biphenyl tetracarboxylic acid having an imidation ratio of 20% or less obtained by polymerization at low temperature from the above-mentioned aromatic tetracarboxylic acid component and aromatic diamine component. It is a carboxylic acid type polyimide precursor and has an inherent viscosity (measurement temperature: 30
C, concentration: 0.5 g / 100 ml solution, solvent: N-methyl-2-pyrrolidone) is 0.1 to 7, especially 0.2 to 5, and the solvent has a concentration of about 2 to 50% by weight, particularly 5-4
It is preferable that the polymer is uniformly dissolved to 0% by weight. The logarithmic viscosity is a value calculated by the following equation. Logarithmic viscosity = natural logarithm (solution viscosity / solvent viscosity) / solution concentration

The above film-forming mixture is preferably 100 parts by weight of the aromatic polyamic acid and 5 to 150 parts by weight of an organic polar amide solvent, preferably 10 to 120 parts by weight, particularly preferably 20 to 100 parts by weight. And, preferably, 0.01 to 1 part by weight, particularly 0.02 to 0.8 part by weight, of amine salt of amine phosphate and / or phosphate ester, and preferably 0.1 to 100 parts by weight of polyamic acid. Molding into a self-supporting film made of an aromatic polyamic acid composition containing 02 to 6 parts by weight, particularly preferably 0.1 to 4 parts by weight of an inert inorganic material particle, particularly a long solidified film. Is preferred.

The above-mentioned self-supporting film of polyamic acid is, for example, approximately equimolar to the above-mentioned aromatic tetracarboxylic acid component and aromatic diamine component (the addition order of each component is not particularly limited, You may add equimolar,
You may add in several steps. ) In the solvent,
At low temperatures below about 100 ° C., particularly preferably 0-80
The high molecular weight aromatic polyamic acid (aromatic polyimide precursor) obtained by polymerization at a temperature of ℃ for 0.1 to 10 hours is uniformly dissolved in the solvent at a concentration of about 2 to 50% by weight. To the aromatic polyamic acid solution, the composition obtained by adding the solvent-dispersed mixture of the phosphorus-containing compound and the particles of the inert inorganic substance described above and uniformly mixing and dispersing is used as a dope solution for film formation. Preferably, a liquid thin film is formed on the surface of the support at a casting temperature of about 150 ° C. or less, and particularly preferably at a casting temperature of about 0 to 140 ° C., and the thin film of about 150 ° C. or less is preferably formed on the support. The drying temperature is particularly preferably about 20 to 140 ° C., and preferably about 0.1.
A self-supporting film having a thickness of preferably 10 to 160 μm formed by a film forming method such as a solution casting method of drying for 1 to 1 hour can be preferably used.

Further, the above-mentioned self-supporting film of polyamic acid is, for example, approximately equimolar to the above-mentioned aromatic tetracarboxylic acid component and aromatic diamine component (the addition order of each component is not particularly limited, To about 100 ° C. or lower, particularly preferably at a temperature of 0 to 80 ° C. in the solvent. Aromatic polyamic acid in which a high molecular weight aromatic polyamic acid (aromatic polyimide precursor) obtained by polymerization for 0.1 to 10 hours is uniformly dissolved in an organic solvent at a concentration of about 2 to 50% by weight. To the acid solution, a chemical conversion agent such as pyridine, a tertiary amine compound such as β-picoline or an acid anhydride such as acetic anhydride, and a solvent dispersion mixture of the above-mentioned phosphorus-containing compound and inert inorganic substance particles are added to homogenize Mixed in The composition thus obtained is used as a dope solution for film formation, preferably at a casting temperature of about 0 to 150 ° C., particularly preferably at a casting temperature of about 2 to 140 ° C., on a metal drum or metal endless. It is cast on a support surface such as a belt to form a liquid thin film, and the thin film is dried on the support at a drying temperature of preferably about 150 ° C. or less, particularly preferably 2.
At a drying temperature of about 0 to 140 ° C., preferably about 0.1
A self-supporting film formed by a film-forming method such as a casting method of drying for 1 hour can be preferably used. The polyimide film of the present invention can be obtained by drying and imidizing by peeling the self-supporting film and subjecting it to heat treatment. A polyimide film having a thickness of 10 to 125 μm is preferably used. If necessary, the obtained polyimide film may be further treated by plasma treatment, corona treatment or the like.

The above heat treatment is first about 100-40.
It is preferable to gradually perform imidization of the polymer and evaporation / removal of the solvent at a temperature of 0 ° C. In addition to the heating, it is preferable to heat at a high temperature of 400 to 600 ° C. In the continuous heat treatment at 250 ° C or higher,
It is preferable to use a pin tenter, a clip, a frame, or the like. By this high temperature heat treatment, the content of volatile components
When the thickness of the film is 100 μm or less, it can be 0.3% (% by weight) or less, and when the thickness of the film is 100 μm or more, it can be 0.9% or less, and the adhesiveness of the polyimide film can be improved. it can.

P in the obtained aromatic polyimide film
The content rate of is a method of burning and ashing a polyimide film with zinc oxide, dissolving with dilute sulfuric acid, adding ammonium molybdate, sodium sulfite, and hydroquinone, and measuring the absorbance (wavelength 655 nm) with a spectrophotometer. Went by. The content of volatile components in the film was calculated by the following calculation formula. Volatile component (% by weight) = [(W ₀ −W) / W ₀ ] × 10
0 W ₀ : Weight after drying in air at 150 ° C. for 10 minutes (Sample: 1
00 × 100 mm ² ) W: weight after drying in air at 450 ° C. for 20 minutes (sample: 1
00 x 100 mm ² )

The laminate of the present invention is obtained, for example, by laminating the above-mentioned polyimide film with a base material of the same kind as a polyimide film or a different kind of base material such as copper directly or through an adhesive. Obtainable. The polyimide film obtained by the present invention preferably has an elastic modulus of 400 kg / mm ² or more,
In particular, it is 420 kg / mm ² or more, and the use of a heat-resistant adhesive is hardly limited, and a laminated plate with a heat-resistant metal can be obtained.

Further, the flexible circuit board of the present invention has an electrolytic copper foil, a rolled copper foil, a copper foil, a rolled copper foil, or a polyimide film, which is directly or at least coated on one side thereof with an adhesive and dried.
It is formed by bonding metal foils such as 42 alloy and curing the adhesive. For example, preferably, an aromatic polyimide film is coated with an adhesive, dried, and laminated with a copper foil to form a circuit, for FPC or TAB, or on one side or both sides of this polyimide film, epoxy type, polyester type, imide type. A polyimide film with a heat-resistant adhesive applied, dried, and heated with a heat-resistant adhesive such as a thermoplastic polyimide solution or a precursor polyamic acid solution, for example, LOC (lead-on-chip). ) For bonding sheet, or by directly depositing metal (copper, chromium, nickel, etc.) on this polyimide film by vapor deposition and sputtering, and further depositing metal (copper, etc.) on it by electrolytic or electroless plating. It can be used as a base film for a two-layer substrate.

The laminated body of the present invention is, for example, FPC, T
It can be preferably used for AB, LOC (read-on-chip) and the like.

[0030]

EXAMPLES Examples of the present invention will be shown below. In the following description, “part” means “part by weight”. The mechanical properties of the polyimide film were measured by ASTM-D-882.

Reference Example 1 3 in 2470 parts of N, N-dimethylacetamide
3 ^{', 4,4'} - biphenyl tetracarboxylic acid and anhydrides 294.33 parts p- phenylenediamine 108.14
Parts were added and reacted for about 10 hours to obtain a polyamic acid solution. The logarithmic viscosity of this polyamic acid is 2.66,
The viscosity of the solution at 30 ° C. was 3100 poise.

Reference Example 2 4,4 ^'in 2570 parts of N, N-dimethylacetamide
-After adding 200.24 parts of diaminodiphenyl ether, 218.12 parts of pyromellitic dianhydride was added, and about 6 parts were added.
The reaction was carried out for a time to obtain a polyamic acid solution. The logarithmic viscosity of this polyamic acid solution is 1.60,
The viscosity at ° C was 300 poise.

Reference Example 3 N-methyl-2-pyrrolidone 1980 parts of 3,3 ^' ,
4,4 ^'- biphenylene dianhydride 147.
2 parts, dianhydrides 100.1 parts pyromellitic acid, 75.7 parts of p-phenylenediamine, 4,4 ^'- diaminodiphenyl et - to obtain a polyamic acid solution by reacting about 6 hours added 60.6 parts of ether . Logarithmic viscosity of this polyamic acid solution (30 ° C., 0.5 g / 100 ml N-methyl-2-
Pyrrolidone) was 2.51 and the viscosity of the solution at 30 ° C. was 2900 poise.

Example 1 A homomixer was used in an amount of 4 parts by weight of dimethylacetamide.
While stirring at 000 rpm, 1 part by weight of an aqueous dispersion colloidal silica having an average particle size of 75 nm and a concentration of 20% by weight was gradually added to obtain colloidal silica dispersed in dimethylacetamide. The water content of this dispersion was 15.8% by volume. Next, this dispersion was distilled under reduced pressure at 15 mmHg and 50 ° C., and then subjected to an ultrasonic homogenizer having an output of 600 W for 6 times.
After time-dispersed treatment, the concentration is 6.3% by weight, the water content is 0.78
Volume% dimethylacetamide dispersed colloidal silica was obtained.

In the polyamic acid solution prepared in Reference Example 1, the previously prepared dimethylacetamide-dispersed colloidal silica was added in an amount of 0.6% by weight in terms of silica based on the weight of the polyamic acid, and monostearyl phosphate ester triethanolamine. 0.1% by weight of salt was added, and sufficiently stirred and mixed to obtain a polyamic acid composition for film formation in which colloidal silica was uniformly dispersed. This composition is cast on an endless metal belt rotating from a T-die to form a coating film, and then hot air of 80 to 130 ° C. is supplied to the surface to dry the composition to obtain a self-supporting film. , Which was continuously peeled off.

This self-supporting film is held by a pin tenter and continuously moved in a high-temperature furnace while being on its surface at 200 to 450 ° C. (holding time at a temperature of 400 ° C. or higher:
Hot air was supplied for 200 seconds to dry and imidize to obtain an aromatic polyimide film having a thickness of 75 μm and a volatile component content of 0.17%.

This polyimide film could be wound up on a roll without any problem during winding up. The physical properties of this polyimide film and the P content in the film are shown in Table 1, and the measurement results of the surface state are shown below. Maximum roughness: 22 nm Average protrusion diameter: 80 nm Number of protrusions: 1.4 × 10 ⁶ protrusions / mm ² Number of protrusions composed of aggregated particles: 1.2% of the total number of protrusions

A bonding sheet (imide adhesive UPA-8513 manufactured by Ube Industries, Ltd.) between the polyimide film (belt surface) and the electrolytic copper foil having a thickness of 35 μm is used.
With a thickness of 20 μm, sandwich the laminate (roat at 130 ° C).
And a copper laminate was prepared. This laminated body is 100 ° C
2 hours, 120 ° C. for 1 hour, and 180 ° C. for 6 hours to cure the adhesive. The copper foil was patterned, then etched, washed with water and dried to obtain a patterned flexible printed circuit board. The adhesive strength of the laminate was set between the copper foil layer and the polyimide film layer to 18
A 0-degree peel test (ASTM-D-903) was performed and evaluated. In addition, the solder heat resistance of the laminated body is 260 ° C ×
Although the test was carried out for 1 minute, no blister occurred and the test was acceptable.

Further, the chemical resistance of the polyimide film is 1
It was judged by the presence or absence of change after immersion in 0% NaOH aqueous solution at 60 ° C. for 1 hour. The results showed that the film maintained its shape with almost no change and showed good results. The results are summarized in Table 1.

The polyimide film was slit to form a tape having a width of 35 mm, and a tape having a width of 26 mm was formed on the tape.
Width polyimide adhesive tape (UPA-3 made by Ube Industries)
22, thickness 20 μm) with polyimide tape (belt surface)
Laminate at 120 ° C. in the center of the to prepare a polyimide tape with an adhesive. A sprocket hole and a device hole are punched on this polyimide tape with adhesive, copper foil (35 μ) is laminated at 130 ° C., and the adhesive is heated at 100 ° C. for 2 hours, 120 ° C. for 1 hour, and 180 ° C. for 6 hours. The adhesive was cured by heating for a period of time. Subsequently, two points A and B were engraved on the polyimide tape of this copper clad plate, the lengths of the intervals A and B were measured, and this was designated as L ₀ . Further, this copper clad plate is patterned according to a conventional method, and then subjected to etching, washing with water and drying steps, and then IL (inner lead).
And a circuit such as an OL (outer lead) were formed to obtain a TAB carrier tape. In this TAB carrier tape, the above distance between A and B was measured and designated as L. The dimensional change rate of the TAB carrier tape was calculated using the following formula. Dimensional change rate = [(L ₀ −L) / L ₀ ] × 100 (%) L ₀ : Length between A and B before etching L: Length between A and B after etching Physical properties of polyimide film, Tables 1 and 2 show the dimensional change rate of the TAB carrier tape and other characteristics.

When the IC was mounted on this TAB carrier tape, the dimensional accuracy of the IC pad and the IL was almost constant, and accurate bonding was possible. Furthermore, after the IC was sealed with potting resin and mounted on a printed circuit board, the circuit between the printed circuit board and the other OL had a small dimensional deviation, and accurate bonding was possible.

Example 2 Example 1 was repeated except that a water-dispersed colloidal silica having an average particle diameter of 45 nm was used and the colloidal silica was added at a ratio of 0.6% by weight in terms of silica based on the weight of the polyamic acid. Similarly, a polyimide film having a thickness of 25 μm and a volatile component content of 0.10% was obtained. The polyimide film could be wound up on the roll without any problems during winding. The results of measuring the surface condition are shown below. Maximum roughness: 15.9 nm Average protrusion diameter: 60 nm Number of protrusions: 3.5 × 10 ⁶ protrusions / mm ² Number of protrusions composed of agglomerated particles: 1.2% of the total number of protrusions It evaluated similarly and obtained the favorable result. The results are summarized in Table 1 and Table 2.
Shown in

Example 3 On the polyimide film produced in Example 1, Cr,
After Cu was sputtered in this order to deposit the respective thin films, Cu was formed by electroplating to have a film thickness of 18 μm. Using this laminate, a circuit was formed by etching in the same manner as in Example 1. The results are summarized in Tables 1 and 2.

Comparative Example 1 A polyimide film was prepared in the same manner as in Example 1 except that the polyamic acid solution prepared in Reference Example 2 was used, colloidal silica was not added, and the thickness of the polyimide film was 25 μm. The slipperiness was so bad that it could not be wound up properly on the winding roll.

Example 4 The procedure of Example 1 was repeated, except that the polyamic acid solution prepared in Reference Example 3 was used to produce a polyimide film having a thickness of 25 μm and a volatile component content of 0.12%. The polyimide film could be wound up on the roll without any problems during winding. The results of measuring the surface condition are shown below. Maximum roughness: 23 nm Average protrusion diameter: 85 nm Number of protrusions: 2.5 × 10 ⁶ protrusions / mm ² Number of protrusions composed of agglomerated particles: 2.3% of total number of protrusions In the same manner as in Example 1 using this polyimide film. And evaluated with good results. The results are summarized in Table 1 and Table 2.
Shown in

Comparative Example 2 A polyimide film having a thickness of 25 μm and a volatile component content of 0.29% was prepared in the same manner as in Example 1 except that the polyamic acid solution prepared in Reference Example 2 was used to change the thickness. Obtained. The polyimide film could be wound up on the roll without any problems during winding. The results of measuring the surface condition are shown below. Maximum roughness: 22 nm Average protrusion diameter: 80 nm Number of protrusions: 1.4 × 10 ⁶ protrusions / mm ² Number of protrusions consisting of agglomerated particles: 1.2% of total number of protrusions Same as Example 1 using this polyimide film Evaluated. The results are summarized in Tables 1 and 2.

Comparative Example 3 4% by weight of ultrafine titanium dioxide having a primary particle diameter of 30 nm produced by a vapor phase method was added to dimethylacetamide and dispersed using a homomixer at 8000 rpm for 15 minutes.
This dimethylacetamide-dispersed titanium dioxide was used as Reference Example 2.
A polyimide having a thickness of 25 μm and a volatile component content of 0.41% in the same manner as in Comparative Example 2 except that the polyamic acid solution prepared in 1. was added at a ratio of 1% by weight in terms of titanium dioxide with respect to the polyamic acid. I got a film. The results of measuring the surface condition of this film are shown below. Maximum roughness: 65 nm Average protrusion diameter: 22 nm Number of protrusions: 2.2 × 10 ⁶ protrusions / mm ² Number of protrusions composed of agglomerated particles: 20.2% of total number of protrusions In the same manner as in Example 1 using this polyimide film Evaluated. The results are summarized in Tables 1 and 2.

Comparative Example 4 The polyamic acid solution prepared in Reference Example 2 was used, the monostearyl phosphate ester triethanolamine salt and colloidal silica were not added, and the solution was cast on a stainless steel belt to form a coating film. After forming, 80 ~
After supplying 130 ° C hot air and drying, it tried to peel from the stainless belt surface, but it is difficult to peel and the film is cut or peel marks are left on the peeled surface to produce a good film. I couldn't.

[0049]

[Table 1]

[0050]

[Table 2]

[0051]

Since the present invention is configured as described above, it has the following effects.

The polyimide film of the present invention has a large tensile elastic modulus and excellent chemical resistance, does not change even after undergoing various manufacturing processes, has high dimensional accuracy in the manufacturing process, and has a position when mounting other articles. Good alignment.

The laminate using this polyimide film has a large adhesive strength within a practical range and does not change even after various manufacturing steps.

The flexible circuit board of the present invention has good solder heat resistance, a small dimensional change rate, and good alignment when mounting other components.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location C08K 3/00 C08L 79/08 LRB

Claims (6)

[Claims] 1. A polymer comprising an aromatic tetracarboxylic acid component containing a biphenyltetracarboxylic acid component as a main component and an aromatic diamine component, and containing a trace amount of P element in the film, and the surface of the film. Maximum roughness is 5-5
In the range of 0 nm, the average protrusion diameter is in the range of 5 to 200 nm, and the number of protrusions per 1 mm ² is 5 × 10 ⁴ to 1 × 10 ^8.
A polyimide film, wherein minute projections are formed in each range, and the number of projections composed of a plurality of agglomerated particles is 10% or less of the total number of projections. 2. The content of P element in the film is 5 to 50.
The aromatic polyimide film according to claim 1, which has an amount of 0 ppm. 3. The polymer is biphenyl tetracarboxylic acid.
Aromatic tetracarboxylic acid component and aroma
It consists of a group diamine component and a trace amount of P element in the film.
The film has a maximum roughness of 5 to 5 on the surface of the film.
In the range of 50 nm, the average projection diameter is in the range of 5 to 200 nm
To 1 mm²The number of protrusions per hit is 5 × 10 ^Four~ 1 × 10⁸
Fine projections are formed in each area and aggregated particles
Poly with 10% or less of all protrusions
The same kind of resin can be directly applied to the imide film or via an adhesive.
Or a product characterized by laminating different types of base materials
Layered body. 4. The content of P element in the film is 5 to 50.
It is 0 ppm, The laminated body of Claim 3. 5. The polymer is biphenyltetracarboxylic acid.
Aromatic tetracarboxylic acid component and aroma
It consists of a group diamine component and a trace amount of P element in the film.
The film has a maximum roughness of 5 to 5 on the surface of the film.
In the range of 50 nm, the average projection diameter is in the range of 5 to 200 nm
To 1 mm²The number of protrusions per hit is 5 × 10 ^Four~ 1 × 10⁸
Fine projections are formed in each area and aggregated particles
Poly with 10% or less of all protrusions
Direct or adhesive to at least one side of the imide film
Foil characterized by being laminated with metal foil via an agent
Substrate for flexible circuit. 6. The content of P element in the film is 5 to 50.
It is 0 ppm, The board for flexible circuits of Claim 5.