JPH0438767B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for manufacturing a flexible printed circuit, characterized in that it uses a flexible substrate consisting of a polyamide-polyimide block copolymer or a copper foil coated with a polyamide-polyimide copolymer. Flexible printed circuits are known to have many industrial advantages over rigid printed circuits. Such printed circuits can be practically fitted into systems in any form as electrical building blocks and therefore require less space in electronic equipment;
Moreover, it is easy to handle because it is resistant to vibration. High demands are naturally placed on flexible substrates laminated with insulating materials and used in the production of printed circuits.
The coating layer must have very good adhesion to the metal foil and the processing steps during printed circuit production must be harmless. That is, the coating layer must have good solder bath stability and be stable to the solvents used in printed circuit board technology. The flexible substrate must also be capable of being bent, rolled, twisted, and folded without tearing the coating layer. It is known to coat metal foil with polyimide film by coating the polyimide film onto copper foil treated with a binder. Laminates with a binder layer produced in this way do not meet the above requirements in all respects. In particular, improvement of electrical characteristics is desired. It is also known from US Pat. No. 3,682,960 to coat metals with polyamic acids and mixtures of polyamic acids modified with amide. The layer of polyimide and polyamideimide obtained on the metal after heating, however, is not sufficiently flexible and easily peels off from the edges of the metal foil when bent. To avoid this drawback, U.S. Patent No.
No. 4148969 proposed the use of a laminate consisting of metal foil laminated with polyparabanic acid,
The polyparabanic acid used therein is produced by hydrolysis of the reaction product of diphenylmethane diisocyanate and hydrogen cyanide. Apart from the complexity of producing the polyparabanic acid used, it is necessary to handle hydrogen cyanide in the first step, which requires special handling. Furthermore, JP-A No. 49-51559 provides a printed wiring board substrate made by directly adhering a specific aromatic polyamide-imide and a metal plate. The peel strength was shown to be 6.5 kg/cm. Here, the copper foil is coated with an organic solvent solution consisting of a polyamide-polyamic acid block copolymer or a polyamide-polyamic acid copolymer, and the metal coating is heated to evaporate the organic solvent to form a polyamide-polyimide block copolymer or a polyamide-polyimide copolymer. In contrast, it has been found that a flexible substrate having a polymer film firmly adhered to a copper foil without an intermediate layer can be used for the production of flexible printed circuits. That is, the present invention provides a method for manufacturing a flexible printed circuit made of copper foil laminated with a polymer without providing an intermediate layer, in which the polymer layer has the formula [-(A)-(E)] _o -- () (In the formula, n represents an integer from 1 to 500, and A is a formula or represents a polyamide block having a structural unit represented by This represents a polyimide block having a structural unit represented by: ) A polyamide-polyimide block copolymer having a repeating structural unit represented by
or formula a or a The polyamic acid represented by formula XI A polyamide obtained by reacting a _dicarboxylic acid dichloride _represented by _the formula XII with a diamine represented by the formula - Polyimide copolymer [in the above formula, a and b are independent of each other and represent an integer of 2 to 100, R ₂ and
R ₄ are independent of each other and are optionally a monocyclic aromatic group optionally substituted with a halogen atom, an alkyl or alkoxy group each having 1 to 4 carbon atoms; Depending on the case, the aromatic nucleus may be substituted by a halogen atom, an alkyl or alkoxy group having 1 to 4 carbon atoms, respectively, via -O-, -CH ₂ - or -SO ₂ -. Represents a non-fused bicyclic aromatic group, a heterocyclic group, an alkylene group having 2 to 12 carbon atoms or a dicyclohexylmethane group bonded to each other, and R ₁ is an aromatic group or a heterocyclic group or a C -Number of atoms is 2 to 8
represents an alkylene group in which the carbonyl groups are bonded to different carbon atoms and R ₃ is 5- or 6-
C of different rings in which a cycloalkyl group, a benzene ring or an aromatic nucleus of a member ring is bonded via a bridging group of -O-, -CO- or -CONH-, and carbonyl groups are adjacent in pairs. - Represents a non-fused bicyclic aromatic group bonded to an atom. ] This is a method for manufacturing a flexible printed circuit, characterized by using a flexible base material comprising: The layer consisting of a polyamide-polyimide block copolymer adhered to the copper foil has the following formula: n represents an integer from 1 to 500, A represents a polyamide block of the formula or, E represents a polyimide block of the formula or, a and b are mutually independent, represent an integer from 2 to 100, and R ₂
and R ₄ are independent of each other, and in some cases, the number of halogen atoms and C atoms is 1 to 4, respectively.
a monocyclic aromatic group which may be substituted with an alkyl or alkoxy group, optionally substituted with a halogen atom, an alkyl or alkoxy group each having 1 to 4 carbon atoms; Good too,
A non-fused bicyclic aromatic group in which aromatic nuclei are bonded to each other via -O-, _-CH2- or _-SO2- ,
or a heterocyclic group, R ₁ represents an aromatic group or a heterocyclic group, in which case the carbonyl group is bonded to a different carbon atom, and R ₃ is a benzene ring or an aromatic nucleus is -O-, -CO- or Represents a non-fused bicyclic aromatic group that is bonded to each other via a -CONH- bridging group, in which the carbonyl group is bonded to carbon atoms of different adjacent rings in pairs. , a block copolymer is preferred. In particular, these layers are such that A represents a polyamide block of the formula, E represents a polyimide block of the formula, a is an integer from 2 to 50, and b is an integer from 2 to 50, especially from 10 to
It is composed of a polyamide-polyimide block copolymer having a formula representing an integer of 50. In a preferred embodiment, these layers are A
represents a polyamide block of the formula, E represents a polyimide block of the formula, a is an integer of 2 to 50, b is an integer of 10 to 50, and R ₁ is 1,3
-phenylene group, R ₂ represents 4,4'-diphenyl ether-, diphenylmethane- or 1,3-phenylene group, R ₃ represents a benzene ring or benzophenone ring system, and R ₄ represents 4,4'-diphenyl ether-, diphenylmethane- or 1,3-phenylene group; enyl ether-, 4,4'-diphenylmethane-, 1,3-
or a polyamide-polyimide block copolymer of the formula representing a 1,4-phenylene group. In a further preferred embodiment, the layer adhered onto the copper foil comprises a polyamic acid of formula a or a.
dicarboxylic acid dichloride of formula 11 and diamine of formula 12 [wherein b represents an integer of 2 to 50, R ₁ is (-CH ₂ ) ₄ -- or 1,3-phenylene group, preferably 1,3-phenylene] represents a group, R ₂ is 1,
3-phenylene or 4,4'-diphenyl ether group, R ₃ represents a benzene ring or benzophenone ring system, R ₄ represents 1,3- or 1,4-phenylene, 4,4'-diphenyl ether or 4,
4′-diphenylmethane group],
A polyamide obtained by subsequently cyclizing the obtained polyamide-polyamic acid copolymer.
Made of polyimide copolymer. The flexible base material used in the present invention is a copper foil having the formula [(--A ₁ ) (--E ₁ )] _o -- () (wherein A ₁ has an average molecular weight of 350 to 20,000 and has the formula or represents a polyamide block having a structural unit represented by the formula _or This represents a polyimide block having a structural unit represented by: ), or an organic solvent solution of a polyamide-polyamic acid block copolymer having a repeating structural unit represented by formula a or a The polyamic acid represented by formula XI _An organic solvent solution of _a polyamide- _polyamic acid copolymer obtained by reacting a dicarboxylic acid dichloride represented by Represents an atom or an alkyl group having 1 to 4 C atoms, n, a, b, R ₁ ,
R ₂ , R ₃ and R ₄ have the same meanings as in the formulas. ] and then heating the coated copper foil at a temperature of 50 to 300°C until at least a non-tacky layer is obtained. The cyclization of a polyamide-polyamic acid block copolymer to a polyamide-polyimide block copolymer or a polyamide-polyamic acid copolymer to a polyamide-polyimide copolymer can each be more or less satisfactorily depending on the lamination method, temperature and heating time employed. It will be done. To obtain optimum properties, the layer material may be heated for several additional hours, if desired.
For example, heat at 300℃. Polyamide-polyamic acid block copolymers used for laminating copper foils are known, for example, according to the method described in DE 2342464, and can be prepared by formula The polyamide represented by the formula a or a polyamic acid dianhydride represented by formula a The polyamide represented by the formula a It is produced by reacting with a polyamic acid represented by (where a, b, R ₁ , R ₂ , R ₃ and
R ₄ represents the same meaning as in formula ~, and the terminal anhydride group of formula a is the _C--
bonded to an atom). The preparation of polyamides and polyamic acids of the formulas a to a is also described in DE-A-2342464. It further includes a polyamic acid block of formula a or a. Polyamide-polyamic acid copolymers used for coating copper foils are known from DE 23 42 454 A1. Furthermore, the above-mentioned German publications disclose that polyamide-polyamic acid block copolymers or polyamide-polyamic acid copolymers are suitable for coating and fixing various materials such as metals, polymers or cellulosic materials. , the copper foil coated with polyamide-polyimide block polymer or polyamide-polyimide copolymer is extremely flexible, i.e. can be repeatedly bent and folded without forming tears in the polymer film, and has good solder bath stability. There is no suggestion that it exhibits good stability towards the solvents used in chemical and printed circuit board technology. The polyamide-polyamic acid block copolymers and polyamide-polyamic acid copolymers used according to the invention generally have an intrinsic viscosity of from 0.5 to 25 to 0.1 to 2.5, in particular from 0.8 to 1.5. The intrinsic viscosity ηinh, where measurements are made on the molecular weight of the polymer, is calculated by the following formula: ηinh=lnη/ηo/C where Little n=natural logarithm η=solution (appropriate solvent, e.g. N,N-dimethylacetamide, N,N-dimethylformamide, N-methylpyrrolidone,
0.5% by weight of the polymer in concentrated sulfuric acid), ηo = viscosity of the solvent, C = concentration of the polymer solution (g polymer/100 ml of solvent). Viscosity measurements are carried out at 25°C. Polyamide-polyamic acid block copolymers or polyamide-polyamic acid copolymers which are preferably produced in anhydrous organic solvents and with exclusion of moisture are advantageously processed in organic solvent solution. Suitable organic solvents include N,N-dimethylacetamide, N,N-diethylacetamide,
N,N-dimethylformamide, N,N-dimethylmethoxyacetamide, N-methyl-2-pyrrolidone, N-acetyl-2-pyrrolidone, N-methyl-ε-caprolactam, hexamethylphosphate triamide (hexametapol), N, N, N′,
N'-tetramethylurea, tetrahydrothiophene dioxide (sulfolane) and dimethyl sulfoxide. It is also possible to use mixtures of solvents. On the other hand, these preferred solvent systems include aromatic, cycloaliphatic or aliphatic hydrocarbons or chlorinated hydrocarbons,
Dilutions can also be made, for example, with benzene, toluene, xylene, cyclohexane, pentane, hexane, petroleum ether, methylene chloride, tetrahydrofuran, cyclohexanone and dioxane. In order to increase the storage stability of a solution of a polyamide-polyamic acid block copolymer or polyamide-polyamic acid copolymer in an organic solvent, a water-absorbing substance such as a molecular sieve may be added to the solution. Preferably, the molecular sieve is added in an amount of about 10% by weight based on the amount of organic solvent solution. Molecular sieves are commercially available, such as those manufactured by Merck. Furthermore, organic coating solutions that are surprisingly handled at higher temperatures or mechanically are treated with flow modifiers (Fliessmittel), such as "Modaflow" (product of Monsanto) "FC430" prior to processing.
It has been found advantageous to add FC170 (product of 3M Company) or "Lodyne S107" (product of Ciba Geigy Company). Flow modifiers (also called Verlaufmittel) are known substances that reduce the surface tension of solutions. Coating the copper foil with an organic polymer solution can be carried out both manually and with a coating device. Vertical coating equipment can also be used. Since the laminated material is rolled up as desired, it is important for mechanical coating to obtain a non-tacky coating layer on the copper foil. To obtain optimal properties, these laminated materials are heated at even higher temperatures, for example 180° C. for 4 hours and 210° C. for 2 hours. This results in virtually complete cyclization of the polyamide-polyamic acid block copolymer or polyamide-polyamic acid block copolymer to the corresponding polyamide-polyimide block copolymer or polyamide-polyimide copolymer. Copper foil coated in this manner can be directly used as a printed circuit by exposing a film coated with a photographic lacquer to the metal surface through a photographic mask and developing the exposed copper foil in a well-known manner. Can be used for manufacturing. This results in a flexible printed circuit. Example 1 A. Preparation of a polyamide block with terminal amino groups. nylene diamine
Completely dissolve 7.786 g (0.072 mol) in 100 g of anhydrous N,N-dimethylacetamide with stirring and cool to -15°C. Add isophthalic acid dichloride in solid form little by little over 30 minutes at -15°C to -10°C. The reaction mixture is then allowed to react for 1 hour at 0°C. Next, add 12.952 g of trimethylamine to 30
Add dropwise at 0°-5°C for 1 hour and stir the solution for an additional hour at 5-10°C. The precipitated triethylamine hydrochloride was suction filtered through a glass filter, and the filter cake was mixed with 40 g of anhydrous N,N-dimethylacetamide.
Wash with B. Production of a polyamic acid block having an anhydride group at the terminal In the apparatus described in A, 34.9 g (0.16 mol) of pyromellitic dianhydride was mixed with anhydrous N,
Suspend in 100 g of N-dimethylacetamide with stirring. Cool the suspension to −15° C. with stirring. Next, 30.436 g (0.152 mol) of 4,4-diaminodiphenyl ether was completely dissolved in 140 g of N,N-dimethylacetamide while stirring.
When this solution is added dropwise to the suspension at -15°C to -10°C over 1 hour, the pyromellitic dianhydride gradually dissolves. The reaction mixture becomes viscous and clear. The reaction is then continued for an additional hour at 0°C to 5°C. C Production of polyamide-polyimide block copolymer A solution of the polyamide obtained in A and having an amino group at the end is added to the viscous solution of the polyamic acid having an anhydride group at the end obtained in B with vigorous stirring under a nitrogen atmosphere. is added dropwise within 5 minutes at 0°C to 5°C. 100g of anhydrous N,N-dimethylacetamide
Wash the addition funnel with water and add this solution to the reaction mixture. Stir to mix evenly and heat at 10°C to 15°C for 1 hour.
React at ℃. Transparent and viscous, with an intrinsic viscosity of 1.08 dl/g (C=
A pale yellow polyamide-polyamic acid block copolymer of 0.5% N,N-dimethylacetamide solution is obtained. This solution can be used directly for copper foil lamination. D. Coating of copper foil The block copolymer solution is uniformly applied onto the copper foil and the solvent is removed by pre-drying at 70° C. to 150° C./20 mbar for 7 hours. Laminated copper foil then 10
Upon heat treatment for a time of 200 DEG C. to 250 DEG C./0.1 mbar, the polyamic acid block cyclizes into a polyimide block. A flexible, transparent, and smooth laminate with excellent adhesion is obtained on copper foil. This stack exhibits excellent electrical properties. Stability of coated copper foil in chlorinated hydrocarbons at room temperature

【table】

[Table] No corrosion; Film: Flexible.
Laminating Cu− to produce printed circuits
The surface was coated with photosensitive paint, exposed through a photographic mask, developed in a chlorinated solvent, and etched in FeCl ₃ . A flexible printed circuit with conductor paths with excellent adhesion was obtained. Example 2 In the same manner as in Example 1, m-phenylenediamine 15.572 g (0.144 mol), isophthalic acid dichloride 25.988 g (0.128 mol), triethylamine
25.904g (0.256mol) and N-methylpyrrolidone
195 g of triamide block, pyromellitic anhydride 69.800 g (0.32 mol), 4,4'-diaminodiphenyl ether 60.872 g (0.304 mol)
and 615 g of N-methylpyrrolidone to produce a polyamic acid block. The two solutions are mixed and reacted in the same manner as in Example 1. The resulting polyamide-polyimide acid block copolymer solution had an intrinsic viscosity of 0.98 dl/g (0.5 dl/g of N-methylpyrrolidone).
% solution). This copolymer solution was mixed using a Rachel (slit width 500μ).
TW - treated 35μ thick copper foil (Luxembourg)
Yater's product). The painted foil is placed horizontally in a circulating air oven and heated. At this time the temperature is gradually increased to 70-170°C and then kept at this temperature for 2 hours. This process evaporates the solvent and forms an inseparable polyamide-polyimide film on the copper foil. This layer material has a total thickness of 60~
It is 63μ. However, it has excellent thermal stability. That is, it can be immersed in a hot solder bath at 260°C for 5 minutes without any damage. This is important because the flexible printed circuit must not be damaged by the soldering process. Furthermore, the laminate material has a remarkable solvent stability, especially towards the solvents used in printed circuit technology. Table 2 below shows the percentage weight gain of a laminate made of block copolymer and copper when immersed in a solvent for 15 hours at 25°C.

[Table] No damage was observed even when the laminated material was stored for 60 days in the solvents shown in Table 1 of Example 1. Etching test in FeCl ₃ : time 15 minutes; no corrosion; film: flexibility. Example 3 In the same manner as in Example 2, a polyamide block was prepared using 195 g of N,N-dimethylacetamide instead of N-methylpyrrolidone as the solvent, and 69.800 g (0.32 mol) of pyromellitic anhydride, 4.
4′-diaminodiphenylmethane 61.600g
(0.31mol) and N,N-dimethylacetamide
Manufacture polyamic acid block from 615g. The two solutions are mixed and reacted as in Example 1. The intrinsic viscosity of the block copolymer, measured in a 0.5% solution, is 0.8 dl/g. 0.2 parts by weight of the flow modifier "Modaflow" (a product of Monsanto) based on the solids content is added to a portion of the block copolymer solution, and this product is not added to the remaining solution. Both solutions are applied uniformly to the rough surface of the copper foil using a lacquer as described in Example 2. The coated foil is placed horizontally in a furnace and heated to 130°C. The solvent evaporates and a non-tacky coating forms. In total, the laminated material was heated to 130°C for 1 hour and 170°C for 2 hours.
heated for an hour. The solution containing “Modaflow” produces a smooth, perfectly uniform polyamide with good adhesion to the copper.
A polyimide layer was obtained. On the contrary,
Solutions without "Modaflow" resulted in non-uniform polyamide-polyimide layers at this manufacturing condition. The total thickness of the flexible substrate with a satisfactory appearance is
It is 62μ. Copper foil and block copolymer film adhere very tightly to each other; repeated bending and squeezing will not cause damage. Solder bath stability (260°C) is 5 minutes or more. Due to its excellent electrical properties even at high temperatures (see Table 3), this laminate material is suitable for the production of flexible printed circuits with high temperature stability.

[Table] The excellent dielectric properties are evident from the extremely low frequency dependence of the dielectric loss factor (see Table 4).

Table: The laminate material has very good solvent stability, especially towards solvents used in printed circuit board technology.
Table 5 shows the weight gain when the laminate material was soaked in solvent for 16 hours at 25°C.

[Table] No damage was observed when immersed for 60 days in the solvents listed in Table 1 described in Example 1. Etching test in FeCl ₃ : time 15 minutes; no corrosion; film: flexibility. Example 4 Similar to Example 1, m-phenylenediamine
187.0g (1.73mol), isophthalic acid dichloride
312.0g (1.5367mol), triethylamine 310.9g
(3.0724mol) in N,N-dimethylacetamide
Used in 2820g to produce polyamide blocks,
Pyromellitic dianhydride 837.6g (3.84mol), 4,
4′-diaminodiphenyl ether 730.5g
(3.648 mol) in N,N-dimethylacetamide to prepare a polyamic acid block. Both solutions are mixed and reacted with each other analogously to Example 1. The resulting polyamide-polyamic acid block copolymer solution has an intrinsic viscosity of 1.1756 dl/g, measured as a 0.5% solution. 0.2% by weight (based on the solids content of the polyamide-polyamic acid block copolymer) of "Modaflow" is added to this solution. The laminate material was produced as follows: a 35μ thick copper foil was pulled off the roll at a constant speed, passed horizontally into the furnace and wound up again after exiting the furnace. Before entering the furnace, a solution of polyamide-polyamic acid block copolymer is coated to the desired thickness (for example, 400 microns) using a coating device. In the oven the solvent evaporates and a non-tacky fixed film is obtained on the copper. After passing through the furnace, the laminate can be rolled up again without problems. The speed of the copper foil tape and the temperature of the oven are selected such that non-stick laminate material emerges from the oven. To obtain optimal properties, the laminated material may be further heated, for example at 180°C for 4 hours and at 210°C for 2 hours.
Heat for an hour. The laminated material thus obtained can be strongly squeezed without damage; this material has excellent electrical properties. Table 5 shows the relationship between dielectric loss factor tgδ and temperature using the commercially available laminated material “Contiflex”.
This is a comparison with ``GT7510'' (this product is manufactured by pasting polyimide film on copper foil).

[Table] From Table 6, the dielectric loss factor of the commercial product “Contiflex”
It is clear that tgδ is too temperature dependent to be preferred. After soaking for 60 days at room temperature in the solvents listed in Table 1 of Example 1, the laminate material of the invention shows no damage. Solder bath stability is at least 5 minutes at 260°C. Example 5 Analogously to Example 1, 17.844 g (0.09 mol) of 4,4'-diaminodiphenylmethane, 16.242 g (0.08 mol) of isophthalic acid dichloride and 16.19 g (0.16 mol) of triethylamine were prepared in 180 g of dimethylacetamide. A polyamide block was prepared and 58.892 g (0.27 mol) of pyromellitic dianhydride was prepared.
and 51.550 g of 4,4'-diaminodiphenylmethane
(0.26 mol) in 600 g of dimethylacetamide. Both solutions are mixed together and reacted as in Example 1. The resulting polyamide-polyamic acid block copolymer solution has an intrinsic viscosity of 1.246 dl/g (0.5% solution in dimethylacetamide; 20 DEG C.).
Add 0.22 g of "Modaflow" to 740 g of this solution.
This mixed solution was applied to the rough surface of a 35 μm thick copper foil using a lacquer (slit width 500 μm), and placed horizontally in an air circulation drying oven at 130°C for 1 hour and at 180°C for 2 hours.
Heat at 210°C for 3 hours and at 240°C for 3 hours. A uniform polyamide-polyimide film adhered to the copper is produced. Table 7 shows the dielectric test data.
Shown below. Example 6 56.71 g (0.26 mol) of pyromellitic dianhydride was added to 500 g of N-methylpyrrolidone (NMP) at 0°C.
A solution of 53.53 g (0.27 mol) of 4,4'-diaminodiphenylmethane dissolved in 400 g of NMP is added dropwise to the suspension at 0-5° C. with stirring. After stirring the resulting clear solution at 0-5°C for 1 hour, 4,4'-diaminodiphenylmethane
Add a solution of 15.86g (0.08mol) dissolved in 300g of NMP. Next, 18.27g of isophthalic acid dichloride
(0.09 mol) was added little by little at 0-5℃ and reacted for 30 minutes, then 10.45 g of propylene oxide
(0.18 mol) dropwise and after further reaction for about 60 minutes, 0.3 g of "Modaflow" is added to the clear solution. This solution has an intrinsic viscosity of 1.72 dl/g (0.5%
NMP solution). This solution is used for coating copper foil as described in Example 5. Finally, 240℃ for another 3 hours
Heat it up. Table 7 shows the dielectric test values of the laminated copper foil. The coating was free of surface defects and could not be peeled off. Example 7 56.71 g (0.26 mol) of pyromellitic dianhydride suspended in 500 g of NMP as in Example 6
A solution of polyamic acid block was prepared from 53.53 g (0.27 mol) of 4,4'-diaminodiphenylmethane dissolved in 400 g of NMP, and added to this solution.
A solution of 8.65 g of m-phenylenediamine dissolved in 200 g of NMP, a solution of 18.25 g (0.09 mol) of isophthalic acid dichloride dissolved in 100 g of NMP, 10.45 g (0.18 mol) of propylene oxide was added to the above solution, and finally “Modaflow” Add 0.3g. The intrinsic viscosity of the solution is 1.48 dl/g (0.5% NMP solution). As described in Example 5, this copper foil laminate is used and finally heated to 240° C. for an additional 3 hours.
The dielectric test data is listed in Table 7. The coating is free of surface defects. Example 8 56.71 g (0.26 mol) of pyromellitic dianhydride suspended in 500 g of NMP as in Example 6
A solution of polyamic acid block was prepared from 53.53 g (0.27 mol) of 4,4'-diaminodiphenylmethane dissolved in 400 g of NMP, and 200 g of NMP was added to this solution.
4.325 g of m-phenylenediamine dissolved in
(0.04mol) and 4,4'-diaminodiphenylmethane
7.93 g (0.04 mol), 18.25 g (0.09 mol) of isophthalic acid dichloride dissolved in 100 g of NMP, 10.45 g of propylene oxide and finally 0.3 “Modaflow”
Add g. The intrinsic viscosity of the solution is 1.24 dl/g (0.5
%NMP solution). This solution was used for coating copper foil as described in Example 5, and finally for an additional 3 hours.
Heat at 240℃. The dielectric test data is shown in Table 7; the coating shows no surface defects. Example 9 m-phenylenediamine was prepared in the same manner as in Example 1.
28.08g (0.26mol), isophthalic acid dichloride
50.75g (0.25mol) and triethylamine 25.25
g (0.25 mol) to 350 g of dimethylacetamide
A polyamide block is prepared in 300 g of dimethylacetamide from 34.88 g (0.16 mol) of pyromellitic dianhydride and 29.70 g (0.15 mol) of 4,4'-diaminodiphenylmethane. Mix the two clear solutions and allow to react for 1 hour. The intrinsic viscosity of the solution is 0.90dl/g
(0.5% dimethylacetamide solution, 20°C). Add 0.2% by weight of “Modaflow” to this solution,
This solution is then used to coat copper foil in the same manner as in Example 5. After evaporation of the solvent, the mixture is heated at 130°C for 1 hour, 180°C for 4 hours, and 210°C for 3 hours to obtain a fixed polyamide-polyimide film. Its dielectric properties are shown in Table 7. The coating is uniform, with no visible craters or patches. Example 10 Same method as Example 7 with intrinsic viscosity of 1.65 dl/g
A solution of polyamide-polyamic acid block copolymer (0.5% NMP solution, 20°C) is prepared. Add 150 g of this solution to commercially available fluidity regulators “FC-170C” and “FC-430” (products of 3M Company), respectively.
Or add 0.1% by weight of “Lodyne S 107” (product of Ciba Geigy). Each of these solutions is used for coating copper foil. After evaporating the solvent at about 120°C, the laminated film is heated to 240°C and kept at this temperature for 2 hours. The copper foil is thereby coated with a uniform polyamide-polyimide layer. If these flow modifiers are not added, there is a risk that the coating will be non-uniform (craters and orange flakes form).

【table】

Table 7 shows that the dielectric properties of the flexible laminate according to the invention are favorable compared to the commercial products listed in Table 6, as they are independent of the measured temperature. Example 11 Production of coating film on copper foil: (Part 1) Pyromellitic dianhydride in 4000 g of NMP
850.65g (3.90mol) under nitrogen atmosphere at 0-5℃
It was suspended with A solution of 802.95 g (4.05 mol) of 4,4'-diaminodiphenylmethane in 3000 g of NMP was added dropwise to the suspension at 0-5° C. with stirring. After stirring the resulting clear solution for 1 hour at 0-5°C, 129.75 g of m-phenylenediamine
(1.20mol) dissolved in 1500g of NMP
Added within minutes. A solution of 274.5 g (1.35 mol) of isophthalic acid dichloride in 1500 g of NMP is then added in portions at 0-5 °C, and the reaction is continued for 60 min at 0-15 °C under stirring, followed by addition of propylene oxide. After dropping 156.75g (2.69mol) and reacting for about 60 minutes, 4.0g of “Modaflow” was added.
Add 200 g of NMP dissolved in the clear solution. This solution also has a doctor blade (gap width)
500 μm) onto a 35 μm thick copper foil, and dried at 240 μm in an air circulation drying room with the copper foil in a horizontal position.
It was dried at ℃ for 1.5 hours. The coating stability of copper foil against solvents was investigated and the results are shown in the table below. Preparation of comparative coatings: (Part 2) (Preparation of coatings on copper foil according to the method described in Example 1 of U.S. Pat. No. 3,682,960) Polyamide-polyimide (monomeric Body composition was obtained by dissolving 15% by weight of trimellisthoic anhydride and methylene dianiline in dimethylacetamide. The viscosity of this solution was 50 cp at 23°C. Solution B A polyamic acid solution was prepared in dimethylacetamide from an equimolar mixture of pyromellitic dianhydride and 4,4'-diaminophenyl ether. Polymerization was continued until the polymer had a concentration of 0.5 g in 100 ml and an intrinsic viscosity of 1.64 at 25° C. in dimethylacetamide. To improve malleability, 0.25% of a flow control agent consisting of silicone liquid (sold under the trade name Union Carbide L-520) was added to this solution. The final solids concentration of this solution was 15%. Solution A and Solution B to produce a coating on copper foil
Two different mixtures of 70 parts of solution A and solution B
30 parts or by mixing 20 parts of solution A and 80 parts of solution B, respectively. Each of the mixtures was applied onto copper foil in the same manner as above, and the coating films were evaluated, and the results are shown in Table 8. The results in Table 8 show that the painted copper foil was placed in the following solvent.
Weight gain in % after storage for 16.5 hours.

Table 8 It is clear from the results in Table 8 that the coated copper foils produced by the method of the invention have superior solvent stability compared to those in the comparative tests. Example 12 The polymer solution obtained in Example 11 was coated onto a 35 μm thick copper foil using a doctor blade (gap width 500 μm) and the adhesive strength was examined as follows. First, a coating film was specially prepared on copper foil so that the edges of the copper foil were released, and the peel strength of the coating film was examined. It was torn. Therefore, it can be said that the adhesive strength of the coating film to the copper foil in this case is greater than the tensile strength of the coating film. When the tensile strength of the coating film was examined, the tensile strength of the test piece was 605 to 749 kg/cm ² and the tensile force at this time was 260 to 306 kg/cm. Therefore, the peel strength of 6.5 Kg/cm at a peel angle of 180° disclosed in the invention of JP-A-49-51559 mentioned above is,
Although it is difficult to directly compare the results because the results were based on different measurement methods, it was determined that the adhesive strength was at least 40 times as strong.

Claims (1)

[Claims] 1. In a method for manufacturing a flexible printed circuit made of copper foil laminated with a polymer without providing an intermediate layer, the polymer layer has the formula [-(A)-(E)] _o -- ( ) (In the formula, n represents an integer from 1 to 500, and A is a formula or represents a polyamide block having a structural unit represented by This represents a polyimide block having a structural unit represented by: ) A polyamide-polyimide block copolymer having a repeating structural unit represented by
or formula a or a The polyamic acid represented by formula XI A polyamide obtained by reacting a _dicarboxylic acid dichloride _represented by _the formula XII with a diamine represented by the formula - Polyimide copolymer [in the above formula, a and b are independent of each other and represent an integer of 2 to 100, R ₂ and
R ₄ are independent of each other and are optionally a monocyclic aromatic group optionally substituted with a halogen atom, an alkyl or alkoxy group each having 1 to 4 carbon atoms; Depending on the case, the aromatic nucleus may be substituted by a halogen atom, an alkyl or alkoxy group having 1 to 4 carbon atoms, respectively, via -O-, -CH ₂ - or -SO ₂ -. Represents a non-fused bicyclic aromatic group, a heterocyclic group, an alkylene group having 2 to 12 carbon atoms or a dicyclohexylmethane group bonded to each other, and R ₁ is an aromatic group or a heterocyclic group or a C -Number of atoms is 2 to 8
represents an alkylene group in which the carbonyl groups are bonded to different carbon atoms and R ₃ is 5- or 6-
Cycloalkyl groups, benzene rings or aromatic nuclei of member rings are bonded to each other via a bridging group of -O-, -CO- or -CONH-, and carbonyl groups of different rings are adjacent in pairs. Represents a non-fused bicyclic aromatic group bonded to a C-atom. ] A method for manufacturing a flexible printed circuit, characterized by using a flexible base material comprising: 2 n represents an integer from 1 to 500, A represents a polyamide block of the formula or , E represents a polyimide block of the formula or , R ₂ and R ₄ are independent of each other,
In some cases, a monocyclic aromatic group in which a halogen atom or a C-atom may be substituted by an alkyl or alkoxy group each having 1 to 4 atoms; A non-fused bicyclic ring in which aromatic nuclei are bonded to each other via -O-, _-CH2- or _-SO2- , each optionally substituted by 1 to 4 alkyl or alkoxy groups R ₁ represents an aromatic group or a heterocyclic group, in which the carbonyl groups are bonded to different carbon atoms, and R ₃ is a benzene ring,
or the aromatic nucleus is -O-, -CO- or -CONH-
represents a non-fused bicyclic aromatic group bonded to each other by a bridging group, in which carbonyl groups are bonded in pairs to carbon atoms of different adjacent rings, a polyamide-polyimide block of the formula Claim 1 in which the polymer layer is made of a copolymer
A method for manufacturing a flexible printed circuit as described in Section 1. 3 A represents a polyamide block of the formula, E
represents a polyimide block of the formula, and a is 2 to
2. A method for producing a flexible printed circuit according to claim 1, wherein the polymer layer consists of a polyamide-polyimide block copolymer of the formula in which b is an integer from 2 to 50, in particular from 10 to 50. 4 A represents a polyamide block of the formula, E
represents a polyimide block of the formula, and a is 2 to
an integer of 50, b represents an integer of 10 to 50, R ₁ represents a 1,3-phenylene group, and R ₂ represents 4,4'-diphenylethyl-, diphenylmethane- or 1,
represents a 3-phenylene group, R ₃ represents a benzene ring or benzophenone ring system, and R ₄ represents 4,
Claim 1, wherein the polymer layer consists of a polyamide-polyimide block copolymer of the formula representing 4'-diphenylethyl, 4,4'-diphenylmethane, 1,3- or 1,4-phenylene groups.
A method for manufacturing a flexible printed circuit as described in Section 1. 5. The polymer layer is formed by reacting a polyamic acid of formula a or a with a dicarboxylic acid dichloride of formula and a diamine of formula 12, where b represents an integer from 2 to 50, and R ₁ is (—CH ₂ ) ₄ — - or 1,3-phenylene group, R ₂ is 1,3-phenylene or 4,
represents a 4′-diphenyl ether group, R ₃ represents a benzene ring or benzophenone ring system, and
R ₄ is a 1,3- or 1,4-phenylene group,
4,4'-diphenyl ether or 4,4'-diphenylmethane group), the polyamide-polyimide copolymer obtained by subsequently cyclizing the obtained polyamide-polyamic acid copolymer. A method for manufacturing a flexible printed circuit as described in Section 1.