JPH08197695A - Adhesive insulating film and production thereof - Google Patents

Abstract

PURPOSE: To enhance heat resistance and low temp. adhesiveness by laminating a membrane composed of a polyimide copolymer, a polyamide acid copolymer or a polyisoimide copolymer having two specific repeating units within a specific mol ratio range to the surface of a polyimide film having no adhesiveness. CONSTITUTION: A membrane composed of a polyimide copolymer, a polyamide acid copolymer or a polyisoimide copolymer having repeating units (1), (2) represented by formulae I, II (wherein Ar is a divalent org. group, Ar2 is a tetravalent aromatic group, Ar3 is a divalent aromatic group and X is a trivalent bonding group represented by formula III) in a mole ratio range (1)/(2) of 50/50-99/1 is laminated to the single surface or both surfaces of a polyimide film having no adhesiveness. As a result, an adhesive insulating film excellent in heat resistance, low water absorbability and dielectric characteristics and not deteriorated in electric characteristics upon the absorption of moisture during keeping is obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an adhesive insulating film and a method for manufacturing the same, and more particularly, to a cover lay film or a base for a flexible printed circuit board (hereinafter referred to as FPC) or a tape for fixing lead-on-chip / lead frame. The present invention relates to an adhesive insulating film which is preferably used as a film and which has excellent processability and adhesiveness, particularly low hygroscopicity and dielectric properties, and a method for producing the same.

[0002]

2. Description of the Related Art In recent years, electronic devices have become more sophisticated, more sophisticated, and smaller in size, and electric parts used therewith are required to be smaller and lighter. Has been. As for a wiring board on which electronic parts are mounted according to such market demand, flexible FPC has attracted attention as compared with a normal hard printed wiring board, and demand for FPC is rapidly increasing.

By the way, the FPC has a basic structure in which a circuit pattern is formed on a flexible and thin base film and the circuit surface is protected by a coverlay film. The films are glued together.

In this FPC, an insulating film made of the same material is used for the base film and the coverlay film, and the insulating film has mechanical properties, electrical properties, and chemical resistance from the viewpoint of manufacturing and using the FPC. It has required properties such as chemical resistance, heat resistance, and environment resistance. Examples of such an insulating film include a polyester film, a polyimide film, a fluororesin film, a polyamide film, and a polyethylene film. Among them, a polyimide film, particularly an aromatic polyimide film has excellent heat resistance and mechanical properties. It is currently most widely used due to its strength and electrical characteristics.

Then, the base film and the copper foil are bonded together via an adhesive to produce a copper-clad laminated tape, and the copper foil of the copper-clad laminated tape is etched to form a circuit pattern. After that, a coverlay film coated with an adhesive for the purpose of protecting the circuit surface is placed on the formed circuit pattern and thermocompression-bonded by a press or the like to adhere the FP.
C is created. At this time, it is necessary to process the cover lay film such as making holes or windows in the terminal part of the circuit or the connection part with the component, and the cover lay film having the holes or the like is formed on the circuit formed above. The pattern is bonded to a predetermined position of the pattern.

Conventionally, epoxy-based adhesives and the like have been the mainstream as the adhesives used for this purpose, but such adhesives have problems such as low heat resistance and poor flexibility as compared with polyimide films. However, the excellent characteristics of the polyimide film used as the base film or the coverlay film could not be fully utilized.

Further, it is difficult to make a hole or the like in the thin coverlay film coated with such an adhesive, and the coverlay film having the holes or the like is further aligned to a predetermined position on the circuit. The pasting work was almost like manual work, the workability was poor, and the cost was high. Furthermore, when the thickness of the adhesive layer applied to the coverlay film is thin, voids may occur between the circuit surface and the coverlay film, while when the thickness of the adhesive layer is large, However, there is a problem in that the adhesive may squeeze out into the perforated portion or the like to cause poor conduction.

Therefore, in order to fully utilize the excellent characteristics of the polyimide film, various polyimide adhesives have been developed from the viewpoint that it is preferable to use a polyimide heat-resistant adhesive. 12592
JP-A-4-50279 discloses various thermoplastic polyimides that can be used as heat-resistant adhesives. By using such a polyimide-based adhesive, it becomes possible to make holes etc. by alkali etching after attaching the coverlay film to the circuit surface, and when attaching the coverlay film as described above. It is no longer necessary to align. As a result, the workability of FPC production is considerably improved, the cost can be reduced, and there is no fear of the adhesive squeezing out from the perforated portion of the film.

[0009]

However, these thermoplastic polyimides have a problem that they cannot be bonded unless the bonding temperature, that is, the processing temperature is high and the temperature is 300 ° C. or higher.

Further, these thermoplastic polyimides do not dissolve in a general-purpose organic solvent in the state of polyimide,
There is a problem of poor solubility, in order to use the thermoplastic polyimide as an adhesive, a solution of a polyamic acid which is a precursor thereof at the time of use is applied on an insulating film as a base film or a coverlay film, A step of forming an adhesive layer by drying and then heating to imidize was required. Then, the copper foil or the like was bonded by heating the adhesive layer thus formed to 300 ° C. or higher. Such a process is a troublesome work in manufacturing the FPC, and it has been difficult to further simplify the manufacturing process of the FPC. Further, these thermoplastic polyimides have a problem in physical properties that they have a high water absorption rate and have poor electric properties after moisture absorption, and thus they have been limited in use in various applications.

Therefore, the present inventors have solved the above-mentioned conventional problems, have excellent heat resistance, exhibit excellent adhesiveness at low temperatures, have low water absorption, and have excellent dielectric properties, and are FPC base films. As a result of earnestly researched for the purpose of providing an adhesive insulating film which can be suitably used as a cover lay film and can eliminate the step of applying an adhesive at the time of use, and a manufacturing method thereof, the present invention Was reached.

[0012]

The gist of the adhesive insulating film according to the present invention is that a polyimide film having the general formula (1)

Embedded image And the general formula (2) 9

[Chemical 9] (In the formulas (1) and (2), Ar ₁ represents a divalent organic group, Ar ₂ represents a tetravalent aromatic group, Ar ₃ represents a divalent aromatic group, and X represents a trivalent compound.

[Chemical 10] Represents a bonding group represented by. ), And the mole fraction ([1] / [2]) of the repeating units (1) and (2) is in the range of 50/50 to 99/1. , A polyamic acid copolymer or a polyisoimide copolymer are laminated.

Further, in such an adhesive insulating film, Ar ₁ in the general formulas (1) and (2) is
1

[Chemical 11] Ar ₂ is one of the divalent organic groups represented by
Two

[Chemical 12] In a tetravalent aromatic group represented, Ar ₃ is of 13

[Chemical 13] It is a divalent aromatic group represented by.

In the adhesive insulating film, the polyimide film having no adhesive property is
Four

Embedded image It consists of a polyimide copolymer having a repeating unit represented by.

Further, another feature of the adhesive insulating film according to the present invention is a copolymer having a repeating unit represented by any one of the general formulas (1) and (2) described above. It consists of

Next, the gist of the method for producing an adhesive insulating film according to the present invention is that a compound having a repeating unit represented by any one of the general formulas (1) and (2) described above is used. A film made of a polymer is disposed on both sides or one side of a polyimide film having no adhesive property and thermally laminated.

Another feature of the method for producing an adhesive insulating film according to the present invention is that it has a repeating unit represented by any one of the general formulas (1) and (2) described above. A varnish of a copolymer is cast and applied on both sides or one side of a polyimide film having no adhesiveness and dried.

[0018]

The adhesive insulating film of the present invention has a repeating unit represented by the general formula (1) and the general formula (2) on one or both sides of a polyimide film having no adhesiveness. (1) Molar fraction of (2) ([1] /
[2]) a polyimide copolymer having a range of 50/50 to 99/1, a polyisoimide copolymer which is a structural isomer thereof, or a thin film made of a polyamic acid copolymer which is a precursor thereof is laminated. The copolymer plays the role of an adhesive layer in the adhesive insulating film. Then, the adhesive insulating film is superposed on a copper foil or the like and laminated at a temperature close to the glass transition temperature of the copolymer, whereby the copper foil or the like can be firmly adhered.

More specifically, in such an adhesive insulating film, the polyimide copolymer weight in which the repeating unit (1) or (2) has a molar fraction ([1] / [2]) in the range of 50/50 to 99/1. The coalescence has a low glass transition temperature and exhibits excellent adhesiveness when laminated at a low temperature.

An adhesive insulating film obtained by laminating a polyamic acid copolymer which is a precursor thereof and a polyisoimide copolymer which is a structural isomer was obtained at the time of laminating the copolymer or obtained. Easily converted to polyimide by heating when adhering the adhesive insulating film to copper foil etc.,
It exhibits the same characteristics as an adhesive insulating film formed by laminating a polyimide copolymer.

Further, these copolymers have low water absorption and excellent dielectric properties, and thus, as an adhesive insulating film of the present invention, which is obtained by laminating one side or both sides of a polyimide film having no adhesiveness. Can be supplied and can be suitably used as a base film or a coverlay film without adverse effects due to water absorption during storage.

In the adhesive insulating film of the present invention, a general polyimide film can be used as the polyimide film having no adhesiveness to be laminated with the above-mentioned copolymer.

[Chemical 15] A polyimide film having a repeating unit represented by the following formula has good adhesion when laminated with the above-mentioned copolymer and can be preferably used.

Further, the above general formulas (1) and (2)
A film made of a copolymer having a repeating unit represented by the formula (1) has mechanical strength such that it can be used as a coverlay film, a base film, etc., and the film itself is used as an adhesive insulating film. It can also be used as a base film.

By using such an adhesive insulating film as a coverlay film or a base film for an FPC, it is not necessary to apply an adhesive on the insulating film at the time of manufacturing the FPC, and the manufacturing process of the FPC can be simplified. it can. Since all are polyimide-based, it is possible to fabricate an FPC having excellent heat resistance and the like, in which the excellent properties of polyimide are fully utilized. Further, particularly when it is used as a coverlay film, it is not necessary to make a hole in the coverlay film in advance, align the position with the coverlay film, and bond the coverlay film on the circuit, and the workability of FPC manufacturing is improved.

Since the polyimide copolymer, the polyamic acid copolymer, or the polyisoimide copolymer can form a film having excellent self-supporting property, the film is not adhered to both surfaces of the polyimide film. Alternatively, the adhesive insulating film of the present invention can be easily manufactured by arranging the adhesive insulating film on one surface and thermally adhering the film to adhere it.

Further, since such a copolymer can be dissolved in an organic solvent, a desired catalyst or the like is added to the varnish of the above-mentioned copolymer, if necessary, and the varnish is treated as a polyimide film having no adhesive property. It is also possible to obtain the adhesive insulating film of the present invention by coating on both sides or one side and drying.

[0027]

EXAMPLES The adhesive insulating film according to the present invention and the method for producing the same will be described below.

The adhesive insulating film according to the present invention has the general formula (1) on one or both sides of a polyimide film having no adhesive property.

Embedded image And the general formula (2) 17

[Chemical 17] (In the formula, Ar ₁ is a divalent organic group, Ar ₂ is a tetravalent aromatic group,
Ar ₃ represents a divalent aromatic group. In addition, X is trivalent 18

Embedded image Represents a bonding group represented by. ), And the mole fraction ([1] / [2]) of the repeating units (1) and (2) is in the range of 50/50 to 99/1. , A polyamic acid copolymer and a polyisoimide copolymer are laminated.

In such an adhesive insulating film, the molar fraction of the repeating units (1) and (2) ([1] /
The copolymer having [2]) in the range of 50/50 to 99/1 forms an adhesive layer, and can be specifically obtained by the following method.

That is, in an inert gas atmosphere such as argon or nitrogen, the general formula (3) NH ₂ —Ar ₃ —H ₂ N (3) (in the formula, Ar ₃ represents a divalent aromatic group) The aromatic diamine represented by is dissolved or diffused in an organic solvent. In this solution, the compound of general formula (4)

[Chemical 19] (Wherein Ar ₁ represents a divalent organic group) and an aromatic diester dianhydride represented by the general formula (5)

Embedded image (In the formula, Ar ₂ represents a tetravalent aromatic group), an aromatic tetracarboxylic acid dianhydride is added in the form of a solution or a slurry with a solid or an organic solvent, and -10 to 5
A solution of the polyamic acid copolymer used in the present invention can be obtained by reacting at 0 ° C, more preferably at -5 to 20 ° C for 30 minutes to 6 hours.

In such a reaction, the ratio of the acid dianhydride component can be arbitrarily selected, but the aromatic diester acid dianhydride represented by the general formula (4) and the general formula (5) It is preferable to use it so that the molar ratio of the aromatic tetracarboxylic acid dianhydride represented by (4) is in the range of 50:50 to 99: 1. This is because if the proportion of the aromatic diester dianhydride is less than 50%, the processing temperature, that is, the glass transition temperature becomes high, and if it is more than 99%, the polymer becomes poor in self-supporting property. The aromatic diamine represented by the general formula (3) is preferably used in an equimolar amount to the total amount of the acid dianhydride component.

In the reaction, contrary to the above, first, the acid dianhydride component represented by the general formula (4) and the general formula (5) is dissolved or diffused in an organic solvent,
A solution or slurry of a solid or organic solvent of the aromatic diamine represented by the general formula (3) may be added to the solution.

More specifically, as the aromatic diester dianhydride represented by the general formula (4) used in the present invention, aromatic diester dianhydrides having any structure can be used, but particularly Is Ar ₁ in the general formula (4) is

[Chemical 21] 2,2-bis (4-hydroxyphenyl) propanebenzoate-3,3 ', 4,4'-tetracarboxylic dianhydride (ESDA) or 3,3', 4,4 '-Ethylene glycol dibenzoate tetracarboxylic dianhydride (EG
It is preferred to use either DA) or 3,3 ', 4,4'-propylene glycol benzoate tetracarboxylic dianhydride (TMPG).

As the aromatic tetracarboxylic dianhydride represented by the general formula (5), aromatic tetracarboxylic dianhydrides having any structure can be used, but particularly, the general formula (5) Ar _{2 in}

[Chemical formula 22] It is preferable to use 3,3 ′, 4,4′-benzophenone tetracarboxylic acid dianhydride (BTDA) represented by

As the aromatic diamine represented by the general formula (3), aromatic diamines having any structure can be used. In particular, Ar ₃ in the general formula (3) is

[Chemical formula 23] It is preferable to use 2,2-bis [4- (4-aminophenoxy) phenyl] propane (BAPP) represented by

Examples of the organic solvent used in the reaction for producing the novel aromatic polyamic acid copolymer solution include sulfoxide solvents such as dimethyl sulfoxide and diethyl sulfoxide, N, N-dimethylformamide, N, N. -Formamide solvents such as diethylformamide, acetamide solvents such as N, N-dimethylacetamide and N, N-diethylacetamide, and the like can be mentioned. These may be used alone or as a mixed solvent of two or three or more. Furthermore, together with these polar solvents, acetone, methanol, ethanol,
It can also be used as a mixed solvent with a non-solvent of a polyamic acid copolymer such as isopropanol or benzenemethylcellosolve.

By such a reaction, the above repeating units (1) and (2) are contained, and the molar fraction ([1] / [2]) of the repeating units (1) and (2) is 50/50 to 99. / 1
Thus, a solution of the polyamic acid copolymer having the above range can be obtained.

A polyimide copolymer can be obtained by thermally and / or chemically dehydrating and ring-closing (imidizing) this polyamic acid copolymer solution, but for convenience of use and production, it is formed into a film. It is preferably obtained in the state of the formed polyimide film.

Explaining by way of example, in the method of thermal dehydration ring closure, first, a solution of the above aromatic polyamic acid copolymer is placed on a support plate, an organic film such as PET, or a support such as a drum or an endless belt. It is cast or coated on to form a film, and dried to obtain a film having self-supporting property. This drying is preferably carried out at a temperature of 150 ° C. or lower for about 5 to 90 minutes.

Next, this is further heated and dried to be imidized to obtain a film made of a polyimide copolymer having the repeating units (1) and (2). The temperature during heating is preferably in the range of 150 to 350 ° C.
There is no limit to the heating rate at the time of heating, but gradually heating,
It is preferable that the maximum temperature be the above temperature. The heating time varies depending on the film thickness and the maximum temperature, but in general, it is preferably in the range of 10 seconds to 5 minutes after the maximum temperature is reached. When the film having the self-supporting property is heated, it is preferable to peel it off from the support, fix the ends in this state and heat it, because a polymer having a small linear thermal expansion coefficient can be obtained.

In the method of chemically dehydrating and ring-closing, the same method as in the case of thermally dehydrating by adding a stoichiometric or more stoichiometric dehydrating agent and a catalytic amount of a tertiary amine to the solution of the polyamic acid copolymer is used. When treated by the method, the desired polyimide film can be obtained in a shorter time than when thermally dehydrated.

Comparing the thermal imidization method and the chemical imidization method, the chemical method has the advantage that the obtained polyimide film has a large mechanical strength and a small linear thermal expansion coefficient. There is. In addition, it is also possible to use the method of thermally imidizing and the method of chemically imidizing together.

By thus forming the polyamic acid copolymer in the form of a film and imidizing it by a thermal and / or chemical method, a polyamic acid copolymer in the form of a film can be obtained.

A polyisoimide copolymer can be obtained by isoimidizing the above polyamic acid copolymer solution by a known reaction that can be easily analogized by those skilled in the art. Specifically, after dicyclocarbodiimide (DCC), trifluoroacetic acid, or the like is mixed with the polyamic acid copolymer solution, the polyimide film is formed into a film, dried, and heated as in the case of obtaining a polyimide film. By doing so, it can be made into an imidized product, and a film-like polyisoimide copolymer is obtained.

The molecular weights of the polyamic acid copolymer, the polyimide copolymer and the polyisoimide copolymer are not particularly limited, but in order to maintain the strength of the obtained film, the number average molecular weight is 50,000 or more, more preferably 80,000 or more, particularly 100,000 or more, more preferably 12
10,000 or more is preferable.

However, in many cases, it is difficult to directly measure the molecular weight of the polyimide copolymer, and in such a case, it is estimated by an indirect method. For example, when the polyimide copolymer is synthesized from the polyamic acid copolymer, the value corresponding to the molecular weight of the polyamic acid copolymer is the molecular weight of the polyimide copolymer.

The polyimide copolymer obtained as described above has a molar fraction ([1] / [2]) of the repeating units represented by the above general formulas (1) and (2) of 50. / 5
It is in the range of 0 to 99/1 and has excellent thermoplasticity, heat resistance, low-temperature adhesiveness, low water absorption and low dielectric constant characteristics. Further, polyisoimide copolymer which is a polyamic acid copolymer or a structural isomer which is a precursor of these,
It is easily converted to polyimide by heating and exhibits the same characteristics as the polyimide copolymer.

That is, each of the above copolymers has excellent heat resistance, which is a characteristic of polyimide, and has a clear glass transition temperature between 100 ° C. and 250 ° C. depending on its composition, which is close to the glass transition temperature. Excellent adhesion is obtained by laminating at temperature. Further, these copolymers show a low water absorption rate of 1% or less when immersed in pure water at 20 ° C. for 24 hours, and have a dielectric constant of 1 MHz.
It shows a low dielectric constant of 3 or less (normal state).

The film-like polyimide copolymer, polyamic acid copolymer, or polyisoimide copolymer obtained as described above is provided on both sides or one side of a polyimide film having no adhesive property. The adhesive insulating film according to the present invention can be manufactured by thermocompression bonding. As the polyimide film having no adhesiveness, a general polyimide film can be used, but in particular, due to its adhesiveness with the above-mentioned copolymer,

[Chemical formula 24] It is preferable to use a polyimide film having a repeating unit represented by

As another method for producing the adhesive insulating film of the present invention, a solution of the polyamic acid copolymer, the polyimide copolymer, or the polyisoimide copolymer is used to prepare a polyimide film having no adhesive property. It may be applied on both sides or one side and dried.

A catalyst for imidization or isoimidation may be added to the polyamic acid copolymer solution,
After coating and drying, it may be further heated to imidize or isoimidize. For example, 100 g of a polyamic acid copolymer solution is mixed with dicyclocarbodiimide (D
CC) (13 g) and well stirred, and the solution is applied on a polyimide film having no adhesiveness and the solution is heated at 150 ° C. for 3 days.
Isoimidation can be carried out by drying for 0 minutes and then heating at 200 ° C. for 5 minutes. However, it is considered that the isoimidated copolymer layer is easily imidized and converted into polyimide.

By the way, since the film made of the copolymer having the above repeating unit has sufficient mechanical strength so that it can be used as a base film or the like, both surfaces of the polyimide film having no adhesive property as described above or Not only can it be laminated on one side to be used as an adhesive layer, but the film itself made of the above copolymer can be used as the adhesive insulating film of the present invention.

The adhesive insulating film of the present invention obtained as described above exhibits excellent adhesiveness at low temperature, and can be easily bonded by superposing the adhesive insulating film and a copper foil or the like and thermocompression bonding. A copper clad laminated tape can be produced. In addition, the adhesive insulating film of the present invention exhibits excellent heat resistance, further has low water absorption and excellent dielectric properties, and the adhesive insulating film does not absorb moisture during storage to deteriorate electrical properties and the like. Furthermore, since all such adhesive insulating films are made of polyimide resin, the excellent characteristics of polyimide can be fully utilized.

Therefore, according to the present invention, it can be supplied as an adhesive insulating film, and the adhesive insulating film is
It can be suitably used as a base film or a coverlay film for FPC. That is, when used as a base film or a coverlay film, it is not necessary to apply an adhesive to form an adhesive layer at the time of bonding as in the past, and the manufacturing process of the FPC can be simplified. Further, it can be bonded at a laminating temperature lower than that when a conventional thermoplastic polyimide is used as an adhesive, and the adhesive strength is excellent.

In particular, when used as a cover lay film, it is not necessary to preliminarily make holes to align and bond the film, and the adhesive insulating film of the present invention is bonded to the circuit surface as a cover lay film. Later, a hole or a window to be a terminal portion of a circuit or a connection portion with a component can be formed in the coverlay film by alkali etching, which greatly improves workability.

As described above, by using the adhesive insulating film of the present invention, it is not necessary to apply an adhesive in the production of FPC, workability is improved, and the characteristics of polyimide can be fully utilized and heat resistance is improved. An FPC having excellent properties and flexibility can be manufactured. Other,
The adhesive insulating film of the present invention is suitable for double-sided FPC and multilayer FP.
It is also preferably used in the production of C, and can be used as a lead-on-chip / lead-frame fixing tape or the like, and other uses are not particularly limited.

Although the adhesive insulating film and the method for producing the same according to the present invention have been described above, the present invention is not limited to these examples, and the present invention is applicable within the scope of the present invention. The present invention can be implemented with various improvements, changes and modifications based on the knowledge of those skilled in the art.

Hereinafter, the present invention will be described more specifically with reference to Examples, but the present invention is not limited to these Examples. In the examples, DMF is N, N-dimethylformamide. Also, BAPP is 2,2-bis [4-
(4-aminophenoxy) phenyl] propane and T
MPG is 3,3 ', 4,4'-propylene glycol benzoate tetracarboxylic dianhydride, BTDA is 3,3', 4,4'-benzophenone tetracarboxylic dianhydride, EGDA is 3,
3 ', 4,4'-ethylene glycol dibenzoate tetracarboxylic dianhydride, ESDA is 2,2-bis (4-hydroxyphenyl) propanedibenzoate-3,3', 4,4'-tetracarboxylic dianhydride Anhydrous.

Example 1 In a 500 ml three-neck separable flask (1) equipped with a stirrer, 16.4 g (40 mmol) of BAPP and 140.
0 g was added and stirred under a nitrogen atmosphere to sufficiently dissolve it. Next, 2.6 g (8 m) of BTDA was placed in a 50 ml eggplant flask (2).
mol) and 13.1 g (31 mmol) of TMPG were collected and added as a solid to the BAPP solution in the separable flask (1). The wall surface of the eggplant flask (2) is 5 g of DMF.
It was washed with and poured into a separable flask (1).
After leaving for 1 hour with stirring, 0.4g (1mmo
The solution prepared by dissolving TMPG of 1) in 5.0 g of DMF is placed in a separable flask (1),
The varnish inside was gradually added while paying attention to the viscosity. After reaching the maximum viscosity, the addition of the TMPG solution was terminated to obtain a polyamic acid solution.

On the other hand, in a 100 ml volumetric flask (3), 10.0 g of isoquinoline, 10.0 g of acetic anhydride and 10.
0 g was stirred well. Then, the solution in the volumetric flask (3) was added to 100 g of the polyamic acid solution prepared above, and well stirred for 2 minutes to degas. This solution is PE
Apply on T film, heat at 80 ℃ for 25 minutes, PE
After peeling off the T film, the end was fixed and the temperature was continuously raised from 100 ° C. to 250 ° C., and after the temperature was raised, it was heated for 5 minutes to imidize to obtain a 25 μm thick thermoplastic polyimide film.

The glass transition temperature (° C.), water absorption rate (%), and dielectric constant of the obtained thermoplastic polyimide film were examined. The glass transition temperature was measured by TMA, and the water absorption rate was measured according to ASTM D-570.
The rate of weight change after immersion in pure water at 0 ° C. was measured. Regarding the dielectric constant, the Q meter method (normal state, 1 MHz)
Was measured by

The 25 μm thick thermoplastic polyimide film obtained above was treated with aminosilane (A110).
0, a 2 wt% solution of methanol)
NPI (registered trademark; 25 μm thick polyimide film,
(Made by Kanegafuchi Chemical Industry Co., Ltd.), 300 ° C,
The adhesive insulating film of the present invention was obtained by laminating and adhering under the conditions of 2.2 cm / min and 10 kg / cm ² .

In order to examine the adhesive strength of the obtained adhesive insulating film, a copper foil (35 μm thick) was overlaid on the film and heated and pressed at 250 ° C. and 20 kg / cm ² for 10 minutes to form a copper-clad laminated tape. Then, the peel strength (kg / kg) of the copper-clad laminated tape was obtained according to JIS K6481.
cm) was measured. Table 1 shows the results.

[0064]

[Table 1]

Example 2 In a 500 ml three-neck separable flask (1) equipped with a stirrer, 16.4 g (40 mmol) of BAPP and 134.
0 g was added and stirred under a nitrogen atmosphere to sufficiently dissolve it. Next, 4.5 g of BTDA (14 ml) in a 50 ml eggplant flask (2).
mmol) and 10.6 g (25 mmol) of TMPG were collected and added to the BAPP solution in the separable flask (1) as a solid. The wall of the eggplant flask (2) is 5 g of DM
It was washed with F and poured into a separable flask (1). 0.4g (1m
A solution prepared by dissolving 5.0 mol of TMPG in 5.0 g of DMF was gradually added to the separable flask (1) while paying attention to the viscosity of the varnish in the separable flask (1).
After reaching the maximum viscosity, the addition of the TMPG solution was terminated to obtain a polyamic acid solution. Using this polyamic acid solution, film formation was carried out in the same manner as in Example 1 to form an imidized film of 25 μm.
A thick thermoplastic polyimide film was obtained. The glass transition temperature (° C.), water absorption rate (%) and dielectric constant of the obtained thermoplastic polyimide film were measured in the same manner as in Example 1.

An adhesive insulating film of the present invention was obtained in the same manner as in Example 1 except that this thermoplastic polyimide film was used. The peel strength (kg / cm) of the obtained adhesive insulating film was measured in the same manner as in Example 1. Table 1 shows the results.

Example 3 In a 500 ml three-neck separable flask (1) equipped with a stirrer, 16.4 g (40 mmol) of BAPP and 128.
0 g was added and stirred under a nitrogen atmosphere to sufficiently dissolve it. Next, 6.4 g (20 g) of BTDA was placed in a 50 ml eggplant flask (2).
mmol) and TMPG (8.1 g, 19 mmol) were collected and added as a solid to the BAPP solution in the separable flask (1). The wall surface of the eggplant flask (2) is 5 g of DMF.
It was washed with and poured into a separable flask (1).
After leaving for 1 hour with stirring, 0.4g (1mmo
The solution prepared by dissolving TMPG of 1) in 5.0 g of DMF is placed in a separable flask (1),
The varnish inside was gradually added while paying attention to the viscosity. After reaching the maximum viscosity, the addition of the TMPG solution was terminated to obtain a polyamic acid solution. Using this polyamic acid solution, film formation and imidization were carried out in the same manner as in Example 1 to obtain a thermoplastic polyimide film having a thickness of 25 μm. The glass transition temperature (° C.), water absorption rate (%) and dielectric constant of the obtained thermoplastic polyimide film were measured in the same manner as in Example 1.

An adhesive insulating film of the present invention was obtained in the same manner as in Example 1 except that this thermoplastic polyimide film was used. The peel strength (kg / cm) of the obtained adhesive insulating film was measured in the same manner as in Example 1. Table 1 shows the results.

Comparative Example 1 For comparison, a thermoplastic polyimide polymer composed of BTDA and BAPP was prepared to obtain an adhesive insulating film. Specifically, in a 500 ml three-neck separable flask (1) equipped with a stirrer, 16.4 g (40 mmol) of BAPP and DMF were added.
105.4 g was added, and the mixture was stirred under a nitrogen atmosphere and sufficiently dissolved. Next, in a 50 ml eggplant flask (2), BTDA12.3
g (38 mmol) was sampled and separable flask (1)
Of BAPP solution in solid form. Eggplant flask
The wall surface of (2) was washed with 5 g of DMF and poured into a separable flask (1). After standing for about 1 hour with stirring, 0.6 g (2 mmol) of BTDA was added to DMF8.
The solution dissolved in 0 g was placed in a separable flask (1),
The varnish in the separable flask (1) was gradually added while paying attention to the viscosity of the varnish. After reaching the maximum viscosity, the addition of the BTDA solution was terminated to obtain a polyamic acid solution. Using this polyamic acid solution, film formation and imidization were carried out in the same manner as in Example 1 to obtain a thermoplastic polyimide film having a thickness of 25 μm. Regarding the obtained thermoplastic polyimide film,
Glass transition temperature (° C) and water absorption rate (%) as in Example 1.
And the dielectric constant were measured.

An adhesive insulating film of the present invention was obtained in the same manner as in Example 1 except that this thermoplastic polyimide film was used. The peel strength (kg / cm) of the obtained adhesive insulating film was measured in the same manner as in Example 1. Table 1 shows the results.

Comparative Example 2 For comparison, a thermoplastic polyimide copolymer having a reduced proportion of TMPG was produced to obtain an adhesive insulating film.
Specifically, in a 500 ml three-neck separable flask (1) equipped with a stirrer, 16.4 g (40 mmol) of BAPP and DM were added.
F110.0g was put and it fully melted by stirring under nitrogen atmosphere. Next, in a 50 ml eggplant flask (2), BTDA10.
3 g (32 mmol) and TMPG 3.0 g (7 mmo
l) was taken and added as a solid to the BAPP solution in the separable flask (1). Wall surface of eggplant flask (2) is 5g
It was washed with DMF, and poured into a separable flask (1). 0.4g after standing for about 1 hour with stirring
A solution of TMPG (1 mmol) dissolved in 5.0 g of DMF was gradually added to the separable flask (1) while paying attention to the viscosity of the varnish in the separable flask (1). After reaching the maximum viscosity, the addition of the TMPG solution was terminated to obtain a polyamic acid solution. Using this polyamic acid solution, film formation and imidization were performed in the same manner as in Example 1 to obtain a thermoplastic polyimide film. The glass transition temperature (° C.), water absorption rate (%) and dielectric constant of the obtained thermoplastic polyimide film were measured in the same manner as in Example 1.

An adhesive insulating film of the present invention was obtained in the same manner as in Example 1 except that this thermoplastic polyimide film was used. The peel strength (kg / cm) of the obtained adhesive insulating film was measured in the same manner as in Example 1. Table 1 shows the results.

Examples 4 to 6 The polyamic acid solutions prepared in Examples 1 to 3 were flowed onto "Apical 25NPI (registered trademark; same as above)" which had been treated with aminosilane in the same manner as in Example 1 using a doctor blade. The adhesive insulating film of the present invention was obtained by spreading and coating and drying at 150 ° C. for 30 minutes. The adhesive layer of each obtained adhesive insulating film was imidized, and
An adhesive insulating film similar to 3 was obtained.

Examples 7 to 9 Examples 1 to 3 except that ESDA was used instead of TMPG.
A polyamic acid copolymer solution was obtained in the same manner as in 1. to obtain a thermoplastic polyimide film. The specific amount of ESDA used in Examples 7 to 9 was 17.9 g (31 mmo).
l), 0.6 g (1 mmol), 14.4 g (25 mm
ol), 11.0 g (19 mmol). Also, B
The amount of DMF used to dissolve APP is appropriately changed depending on the viscosity of the resulting polyamic acid copolymer solution, and is 119.0 g in Example 10 and 12 in Example 11.
6.0 g, and in Example 12 114.0 g of DMF was used. For each thermoplastic polyimide film obtained,
The glass transition temperature (° C.), water absorption rate (%), and dielectric constant were measured in the same manner as in Example 1.

Then, an adhesive insulating film of the present invention was obtained using the above thermoplastic polyimide film in the same manner as in Example 1, and the peel strength (kg / cm) of each adhesive insulating film was measured. Table 2 shows the results.

[0076]

[Table 2]

Comparative Example 3 For comparison, a polyamic acid copolymer solution was obtained in the same manner as in Comparative Example 2 except that TMPG was replaced with ESDA to obtain a thermoplastic polyimide film having a reduced proportion of ESDA. . The specific amount of ESDA used is 4.
It was 0 g (7 mmol), and 110.0 g of DMF was used to dissolve BAPP. With respect to the obtained thermoplastic polyimide film, the glass transition temperature (° C.), the water absorption rate (%), and the dielectric constant were measured in the same manner as in Example 1.

An adhesive insulating film was obtained using this thermoplastic polyimide film in the same manner as in Example 1, and the peel strength (kg / cm) of the obtained adhesive insulating film was measured. These results are shown in Table 2 together with the results of Comparative Example 1.

Examples 10 to 12 Examples 1 to 3 except that EGDA was used instead of TMPG.
A polyamic acid copolymer solution was obtained in the same manner as in 1. to obtain a thermoplastic polyimide film. In addition, Examples 10 to 12
The specific amount of EGDA used in 12.7g (31mm
ol), 0.4 g (1 mmol), 10.3 g (25 m
mol), 7.8 g (19 mmol). Also, B
The amount of DMF used to dissolve APP is appropriately changed depending on the viscosity of the resulting polyamic acid copolymer solution, and is 119.0 g in Example 19 and 12 in Example 20.
6.0 g, and in Example 21 114.0 g DMF was used. For each thermoplastic polyimide film obtained,
The glass transition temperature (° C.), water absorption rate (%), and dielectric constant were measured in the same manner as in Example 1.

Then, an adhesive insulating film of the present invention was obtained using the above thermoplastic polyimide film in the same manner as in Example 1, and the peel strength (kg / cm) of each adhesive insulating film was measured. Table 3 shows the results.

[0081]

[Table 3]

Comparative Example 4 For comparison, a polyamic acid copolymer solution was obtained in the same manner as in Comparative Example 2 except that TMPG was used in place of EGDA to obtain a thermoplastic polyimide film having a reduced EGDA ratio. . The specific amount of EGDA used is 2.
It was 9 g (7 mmol), and BAPP was dissolved using 110.0 g of DMF. With respect to the obtained thermoplastic polyimide film, the glass transition temperature (° C.), the water absorption rate (%), and the dielectric constant were measured in the same manner as in Example 1.

Then, using this thermoplastic polyimide film, an adhesive insulating film was obtained in the same manner as in Example 1, and the peel strength (kg / cm) of the obtained adhesive insulating film was measured. These results are shown in Table 3 together with the results of Comparative Example 1.

From Tables 1 to 3, BAP was used as the diamine component.
P using TMPG (or ESD as an acid dianhydride component)
A or EGDA) and BTDA are mixed, and the molar ratio of the acid dianhydride component ([TMPG (or ESDA, or EG
DA)]: [BTDA]) is used in a ratio of 50:50 to 99: 1, and a film made of a thermoplastic polyimide copolymer has low water absorption and low dielectric constant characteristics and a low glass transition temperature. I understand.

From the above, it can be said that the adhesive insulating film of the present invention can firmly bond copper foil and the like by laminating at low temperature and can be preferably used as a base film or a coverlay film of FPC. Further, it can be said that such an adhesive insulating film can be stored in a normal state without the electric characteristics and the like being deteriorated by moisture absorption.

Since the precursor polyamic acid copolymer and the structural isomer polyisoimide copolymer are easily imidized by heating, their characteristics can be represented as polyimide. Further, the thermoplastic polyimide films produced in the above examples all had sufficient mechanical strength so that the film itself could be used as a base film or a coverlay film.

[0087]

INDUSTRIAL APPLICABILITY As described above, the adhesive insulating film of the present invention has a mole fraction of the repeating unit represented by the general formula (1) or (2) on both sides or one side of a polyimide film having no adhesiveness. The ratio ([1] / [2]) is characterized by laminating a copolymer having a ratio of 50/50 to 99/1. The copolymer exhibits low water absorption and low dielectric properties. It can be supplied as an adhesive insulating film.

The repeating unit has a molar fraction of 50.
A film made of a polyimide copolymer having a ratio of / 50 to 99/1 has sufficient mechanical strength, and as described above, the film itself is not laminated on the polyimide film which does not have adhesiveness. It is also possible to use an adhesive insulating film.

Such an adhesive insulating film exhibits excellent adhesiveness at low temperature, and copper foil or the like can be firmly adhered by laminating copper foil or the like and laminating at relatively low temperature. Further, since all are made of a polyimide-based material, the characteristics of the polyimide such as excellent heat resistance can be sufficiently exhibited without being affected by the adhesive layer. Incidentally, in the adhesive insulating film of the present invention, what is obtained by laminating a polyamic acid copolymer or a polyisoimide copolymer is easily imidized by laminating the copolymer layer or by heating at the time of adhesion. It becomes a polyimide and can exhibit excellent properties.

Therefore, the adhesive insulating film of the present invention is F
It can be suitably used as a base film or a coverlay film which can be used for a PC or a tape for fixing a lead-on-chip / lead frame. Then, by using such an adhesive insulating film as a base film or a coverlay film, it is not necessary to apply an adhesive at the time of manufacturing an FPC or to align the coverlay film when the FPC is manufactured. Can be greatly simplified. Furthermore, by using the adhesive insulating film of the present invention, it is possible to produce an FPC having excellent adhesiveness, heat resistance, electrical characteristics, etc., as compared with conventional ones.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display location B32B 31/20 7148-4F H01B 3/30 Q G

Claims (6)

[Claims] 1. A compound represented by the general formula (1): embedded image on one or both sides of a polyimide film having no adhesive property. And the general formula (2): (In the formulas (1) and (2), Ar ₁ represents a divalent organic group, Ar ₂ represents a tetravalent aromatic group, Ar ₃ represents a divalent aromatic group, and X represents a trivalent compound. [Chemical 3] Represents a bonding group represented by. ), And the molar ratio ([1] / [2]) of the repeating units (1) and (2) is in the range of 50/50 to 99/1. An adhesive insulating film, which is formed by laminating thin films of a polyamic acid copolymer or a polyisoimide copolymer. 2. In the general formula (1) and the general formula (2),
Ar ₁ is chemical 4 [chemical 4] Ar ₂ is one of the divalent organic groups represented by In a tetravalent aromatic group represented, Ar ₃ is of 6 embedded image The adhesive insulating film according to claim 1, which is a divalent aromatic group represented by: 3. The polyimide film having no adhesiveness is represented by the following chemical formula: It consists of a polyimide copolymer which has the repeating unit represented by these, The adhesive insulating film in any one of Claim 1 or Claim 2 characterized by the above-mentioned. 4. An adhesive property comprising a copolymer having a repeating unit represented by the general formula (1) or the general formula (2) according to claim 1 or 2. Insulation film. 5. A film made of a copolymer having a repeating unit represented by the general formula (1) or the general formula (2) according to claim 1 or 2 is provided with an adhesive property. A method for producing an adhesive insulating film, which comprises arranging the polyimide film on both sides or one side of a polyimide film and thermally laminating the polyimide film. 6. The varnish of a copolymer having a repeating unit represented by the general formula (1) or (2) according to claim 1 or 2 does not have adhesiveness. A method for producing an adhesive insulating film, which comprises casting and coating on both sides or one side of a polyimide film and drying.