KR100809827B1 - Manufacturing method of copper clad laminated sheet - Google Patents

Abstract

The manufacturing method of the copper clad laminated board which improved the adhesive force of copper foil and polyimide resin is provided. A method for producing a copper clad laminate obtained by forming a resin layer on a surface-treated copper foil, the method of soft etching the copper foil with an acid solution, and at least one of an amino group and a thiol group having a function of improving the adhesion between the copper foil and the resin layer. A surface treatment step of surface treatment with a treatment solution in which an organic surface treatment agent having more than one functional group is dissolved, a washing step of partially dissolving and removing the surface layer of the organic surface treatment agent using an organic solvent that can dissolve the organic surface treatment agent, and a surface treatment. The manufacturing method of the copper clad laminated board which has the adhesion lamination process which adhere | attaches the film of a polyimide precursor on the obtained copper foil, and the imidation process which imides a polyimide precursor.

Copper foil, polyamide, surface treatment, copper clad laminate, adhesion

Description

MANUFACTURING METHOD OF COPPER CLAD LAMINATED SHEET}

This invention relates to the manufacturing method of the copper clad laminated board characterized by using the surface-treated copper foil and making a resin film closely.

The printed circuit board which circuit-processed the laminated board which consists of an insulating material and a conductive material is used for the electronic circuit of an electronic device. A printed wiring board is formed by fixing a conductive pattern based on an electrical design on the surface (and inside) of an insulating board with a conductive material, and is a plate-shaped rigid printed wiring board according to the type of resin used as a substrate. boards) and flexible, flexible printed wiring boards. The flexible printed wiring board is characterized by having flexibility, and has become an essential part for connection in a movable part such as repeating constant bending. Moreover, since it can be accommodated in the state bent in an electronic device, it is used also as a space-space wiring material. Although the polyimide ester and polyimide are used for the resin used as a base material for the flexible board which becomes a material of a flexible printed wiring board, polyimide is predominantly large as a usage-amount. On the other hand, copper is generally used as the conductive material in terms of conductivity. A flexible substrate using copper as the conductive material is also called a copper clad laminate.

The flexible substrate has a three-layer flexible substrate and a two-layer flexible substrate in its structure. A three-layer flexible board | substrate is a laminated board which consists of three layers of a base film, an adhesive agent, and copper foil, using adhesives, such as an epoxy resin and an acrylic resin, in order to integrate base film, such as a polyimide, and copper foil together, and to integrate. On the other hand, the two-layer flexible board | substrate employ | adopts a special method and is a laminated board comprised from two layers of a base film and copper foil, without using an adhesive agent. Since the two-layer flexible substrate uses only polyamide resin excellent in heat resistance as the organic material, it is more reliable than the three-layer flexible substrate using an adhesive such as epoxy resin or acrylic resin, which is inferior in heat resistance, and the entire circuit is thinned. Is possible and its usage is increasing.

In recent years, the demand for high performance and high functionality in electronic devices has increased, and along with this, there has been a demand for higher density of printed wiring boards, which are circuit board materials used in electronic devices. In order to increase the density of the printed wiring board, it is necessary to reduce the width and the spacing of the circuit wiring, that is, to fine pitch. As described above, the printed wiring board is a material in which a conductive material and a resin film are bonded to each other. As a conventional conductive material, in order to increase the adhesive strength with the resin, a high roughness or roughened copper foil is used. there was. However, when a laminated sheet made of copper foil having high roughness is used for a purpose where fine pitch is required, root remaining of copper foil in the resin is generated or etching linearity is lowered when the circuit is formed by etching. The problem arises such that the circuit width tends to be uneven. For this reason, in order to make a printed wiring board high density and fine pitch, it is necessary to use copper foil with a small surface roughness.

However, the copper foil having a small surface roughness has a small anchoring effect, that is, the intercalation of the surface of the copper foil into the concave-convexities of the resin is small, so that mechanical adhesive strength cannot be obtained, and therefore, the adhesive strength to the resin is low. Therefore, raising the adhesive force of copper foil with small surface roughness and resin becomes a subject.

[Patent Document 1] Japanese Patent Publication No. 2003-27162

[Patent Document 2] Japanese Patent Publication No. 2002-321310

For example, Japanese Laid-Open Patent Publication No. 2003-27162 discloses a laminate for a two-layer printed wiring board made of a resin substrate using a varnish containing polyamic acid as a raw material. A method of providing a copper alloy foil for a laminated sheet having a small surface roughness that can be directly bonded to a polyimide is disclosed. In the above method, however, nickel, copper silicon master alloy, silver, aluminum, copper beryllium master alloy, cobalt, copper master alloy, magnesium, manganese, copper phosphorus master alloy, iron, tin, Addition of titanium and zinc is necessary, and the organic rust-preventing treatment with copper foil is only performed to improve the wettability with varnish containing polyamic acid, and insufficient effect of improving adhesion.

Japanese Laid-Open Patent Publication No. 2002-321310 discloses a method of forming a thick film of an azole compound on a copper surface by contacting the copper surface with an aqueous solution containing an azole compound and an organic acid, thereby improving adhesion to the resin. However, only by adopting this method, the effect of improving the adhesiveness was insufficient.

As mentioned above, the method of improving the adhesive force of copper foil and resin, and the manufacturing method of a copper clad laminated board are examined variously, but the method which satisfy | fills this is not discovered yet. As a result of this inventor's examination, copper foil and a resin layer, The present invention finds that the above-mentioned problems can be solved by bringing the surface-treated copper foil subjected to the organic surface treatment, which has a function of improving the adhesive strength, to the polyimide precursor film prepared by heating and drying the varnish containing polyamic acid. Completed.
Therefore, an object of this invention is to provide the manufacturing method of the copper clad laminated board with favorable adhesiveness.

In order to achieve the above object, that is, this invention provides the manufacturing method of the copper clad laminated board obtained by forming a resin layer on the surface-treated copper foil. In more detail, the surface treatment process of surface-treating copper foil with the processing liquid which melt | dissolved the organic surface treatment agent which has at least 1 or more types of functional group, and has the function which improves the adhesive force between copper foil and a resin layer, and melt | dissolves the said organic surface treatment agent A method for producing a copper clad laminate comprising a washing step of partially dissolving and removing the surface layer of the organic surface treatment agent using a possible organic solvent, and an adhesion lamination step of bringing the film of the polyimide precursor into close contact with the copper foil subjected to the surface treatment. to provide.

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First, a surface treatment step (referred to as surface treatment step A) in which the copper foil is surface treated with a treatment solution in which at least one functional group has an organic surface treatment agent having a function of improving adhesion between the copper foil and the resin layer. Explain.

Although the copper foil used by this invention is not specifically limited, The preferable thickness of the copper foil at the time of using for a flexible substrate use is the range of 5-50 micrometers, More preferably, it is the range of 8-30 micrometers, but fine pitch is required Thin copper foil is suitably used for the copper clad laminated board used for the use, In this case, the range of 8-20 micrometers is suitable. Moreover, since this invention obtains the outstanding adhesiveness with respect to a resin layer even if it uses the copper foil with small surface roughness, it is suitable especially when using the copper foil with small surface roughness. The surface roughness of preferable copper foil is suitable for the range of 0.1-3 micrometers in 10-point average roughness. Particularly, for copper foil used for the application of fine pitch, the surface roughness is suitably 0.1 to 1 µm at a 10-point average roughness. In addition, copper foil contains the copper alloy foil whose main component is copper foil.

In order to perform surface treatment process A satisfactorily, it is preferable to provide the process of wash | cleaning with an acid aqueous solution beforehand in order to remove the surface oxide of the copper foil surface. This process is called a soft etching process. Any aqueous solution may be used as long as the acid aqueous solution used is acidic, and aqueous hydrochloric acid and sulfuric acid are particularly preferred. The concentration is preferably in the range of 0.5 to 50 wt%, but is preferably in the range of 1 to 5 wt%. It is preferable that pH is two or less.

The organic surface treatment agent used in the surface treatment step A is a compound having at least one or more functional groups, and the treatment liquid is obtained by dissolving the organic surface treatment agent in a solvent that can dissolve. The organic surface treatment agent is selected from increasing the adhesive force between the copper foil and the numerical layer. For that purpose, the organic surface treatment agent has a functional group which raises the adhesive force of both. As such a functional group, an amino group or a thiol group is illustrated as a preferable thing. Advantageously, it is a compound which has an amino group and a thiol group as a functional group, More preferably, it is a heterocyclic compound which has an amino group and a thiol group as a substituent.

As the heterocycle constituting the heterocyclic compound, there may be a monocyclic ring having 1 to 4 N or a condensed ring having 2 to 3 rings as the hetero element, or 1 or 2 O or S as other hetero elements. And preferably, they are a 5-6 membered aromatic heterocycle or its condensed ring.

More preferably a compound shown by the Examples of the organic surface treatment agent is _{(NH 2) m-Ar- (} SH) n. Ar is m + n-valent aromatic heterocycle or its condensed ring, and m and n are the integers of 1-2 independently. Ar may be a monocyclic ring having 1 to 4 N or a condensed ring having 2 to 3 rings as a ring constituent atom, and may have a substituent such as an alkyl group.

Specific examples of preferred organic surface treatment agents include the following compounds, but are not limited thereto.

5-amino-1H-tetrazole, 2-amino-1,3,5-triazine-4,6-dithiol, 3-amino1,2,4-triazine, 3-amino-1,2,4 -Triazole, 4-amino-1,2,4-triazole, 3-amino-1,2,4-triazole-5-carboxylic acid, 3-amino-1,2,4-triazole-5- Thiol, 2-amino-5-trifluoromethyl-1,3,4-thiadiazole, 5-aminoindazole, 4-aminoindole, 5-aminoindole, 3-amino-1H-isoindole, 1- Aminoisoquinoline, 5-aminoisoquinoline, 3-aminoisoxazole, 5-amino-2-mercaptobenzimidazole, 6-amino-2-mercaptobenzothiazole, 4-amino-6-mercaptopyrazolo [3,4-d] pyrimidine, 2-amino-4-methoxybenzothiazole, 3-amino-5-phenylpyrazole, 3-amino-1-phenyl-2-pyrazolin-5-one, 2 -Amino-4-phenyl-5-tetradecylthiazole, 2-amino-5-phenyl-1,3,4-thiadiazole, 2-amino-4-phenylthiazole, 4-amino-5-phenyl- 4H-1,2,4-triazole-3-thiol, 3-aminophthalhydrazine, 2-amino-6- (methylsulfonyl) benzo Azole, 2-amino-4-methylthiazole, 2-amino-5- (methylthio) -1,3,4-thiadiazole, 3-amino-5-methylthio-1H-1,2,4- Thiazole, 6-amino-1-methyluracil, 3-amino-5-nitrobenzisothiazole, 9-amino-1,2,3,4-tetrahydroacridine, 9-aminoacridine, 2 -Amino-1,3,4-thiadiazole, 5-amino-1,3,4-thiadiazole-2-thiol, 2-aminothiazole, 2-amino-4-thiazoleacetic acid, 2- Amino-2-thiazoline, 2-amino-6-thiasianatebenzothiazole, DL-α-amino-2-thiophenacetic acid, 3-amino-5-hydroxypyrazole, 2-amino-3 -Hydroxypyridine, 5-amino-8-hydroxyquinoline, 2-amino-4-hydroxy-6-trifluoromethylpyrimidine, 2-aminoimidazole, 5-aminoimidazole-4-carboxyamide, 4-amino-5-imidazolecarboxyamide, 2-amino-4,5-amidazoledicarbonitrile, 4-amino-6-hydroxy-2-mercaptopyrimidine, 2-amino-4-hydroxy -6- Methylpyrimidine, 2-amino-6-purinethiol, aminopyrazine, 3-aminopyrazine-2-carboxylic acid, 3-aminopyrazole, 3-amino-4-pyrazolecarbonitrile, 3-amino-4-pyra Solcarboxyamide, 3-amino-4-pyrazolecarboxylic acid, 4-aminopyrazole [3,4-d] pyrimidine, 1-aminopyrene, 2-aminopyridine, 3-aminopyridine, 4-aminopyridine, 4-amino-5- (4-pyridyl) -4H-1,2,4- triazol-3-thiol, 2-amino-pyrimidin-4-amino pyrimidines, N ⁴ - (2-amino-4 Pyrimidinyl) sulfanylamide, 3-aminopyrrolidine, 4-aminoquinaldine, 3-aminoquinoline, 3-aminorodanine, 1- (3-aminopropyl) imidazole, 2-aminopurine, adenine, 4- (aminomethyl) piperidine, 3- (aminomethyl) piperidine, 2- (aminomethyl) piperidine, 3-amino-5-methylpyrazole, 2- (aminomethyl) pyridine, 3- (Aminomethyl) pyridine, 4- (aminomethyl) pyridine, 2-amino-4-methylpyrimidine, 3-amino-2-methyl-4- (3H) quinazoli , 5-amino-2-methylindole, 5-amino-3-methylisothiazole, 3-amino-5-methylisoxazole, 3-amino-2-methoxydibenzofuran, 2-amino-α- ( Methoxyimino) -4-thiazoleacetic acid, 2-amino-4-methoxy-6-methylpyrimidine, 2-amino-4-methoxy-6-methyl-1,3,5-triazine, 3 -Amino-5- (4-methoxyphenyl) pyrazole, 5-amino-2-methoxypyridine, 4-amino-6-methoxypyrimidine, 8-amino-6-methoxyquinoline, 2- (amino Methyl) benzamidazole, 2-amino-1-methylbenzimidazole, azaadenine, thiaguanine and the like can be used alone or in combination.

Moreover, as a solvent which melt | dissolves an organic surface treating agent, C1-C8 hydrocarbon alcohols, for example, methanol, ethanol, a propanol, isopropanol, butanol, tert- butanol, pentanol, hexanol, heptanol, an octanol, etc. C3-C6 hydrocarbon ketones, for example, acetone, propanone, methyl ethyl ketone, pentanone, hexanone, methyl isobutyl ketone, cyclohexanone and the like, hydrocarbon ethers having 4 to 12 carbon atoms, for example Hydrocarbon esters having 3 to 7 carbon atoms, such as diethyl ether, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol dibutyl ether, tetrahydrofuran, for example, acetic acid Amides having 3 to 6 carbon atoms, such as methyl, ethyl acetate, propyl acetate, butyl acetate, γ-butyrolactone, and diethyl malonate, for example, dimethylformamide, dimethylacetamide, tetramethylurethane, and hex Methyl phosphate triamide, a C 2 sulfoxide compound such as dimethyl sulfoxide, and the like, a C 1-6 halogen-containing compound such as chloromethane, bromomethane, dichloromethane, chloroform, carbon tetrachloride, dichloroethane, Hydrocarbon compounds having 4 to 8 carbon atoms, such as 1,2-dichloroethane, 1,4-dichlorobutane, trichlorethane, chlorbenzene, and o-dichlorbenzene, for example, butane, hexane, heptane, octane, benzene and toluene Although xylene etc. can be used, it is not limited to this.

The organic surface treatment agent concentration of the treatment liquid is preferably used at 0.0001 to 1 mol / l, and it is considered advantageous in view of the low adhesion of the extra organic surface treatment agent to the copper foil surface at the lower concentration side. Since the effect of improving the adhesion of the adhesive disappears, more preferably 0.0005 to 0.002 mol / l.

When the copper foil surface is treated with the treatment liquid, the treatment liquid and the copper foil surface may be in contact with the entire surface of the treatment, and the method is not limited, but it is preferable to make the contact uniformly. Copper foil may be immersed in process liquid, or may be sprayed on copper foil with a spray, etc., or you may apply it to copper foil with a suitable tool. Moreover, the temperature of the processing liquid at this time becomes like this. Preferably it is 10-100 degreeC, More preferably, it is the range of 10-50 degreeC.

After the completion of the surface treatment step A, it is necessary to perform a washing step (called a washing step B) in which an organic surface treatment agent that is excessively adhered to the copper foil surface is dissolved and removed with an organic solvent. As the organic solvent used in this washing step B, a solvent capable of dissolving the organic surface treatment agent can be used. As an example, the above-mentioned organic solvent can be used, but inexpensive methanol is used suitably from an economic point of view.

In the washing | cleaning process B, the method of wash | cleaning the copper foil surface with an organic solvent is not limited. It may be immersed in a solvent, or it may be sprinkled with a spray, etc., or may be made to soak in a suitable base material, and may wash out. This cleaning dissolves and removes the organic surface treatment agent that has been excessively adhered to the copper foil surface, but not all of the organic surface treatment agent. Advantageously, the organic surface treatment agent is washed away so that the film of the organic surface treatment agent becomes about the thickness of a monomolecular film on the copper foil surface. As this method, there is a method of first providing a step of washing with water before the washing step, then performing the washing step B, and then providing a step of washing with water further. The temperature of the solvent in the said washing process at this time becomes like this. Preferably it is 0-100 degreeC, More preferably, it is the range of 5-50 degreeC. The washing time is preferably in the range of 1 to 1000 seconds, more preferably 3 to 600 seconds. The usage-amount of a solvent becomes like this. Preferably it is 1-500L per 1m <^2> of copper foils, More preferably, it is the range of 3-50L.

In this invention, the adhesive force with the polyimide resin at the time of forming a copper clad laminated board can be improved further by adjusting the quantity of the organic surface treating agent which exists in the copper foil surface by the said washing process. When the heterocyclic compound having an amino group and a thiol group as a functional group was used as the organic surface treatment agent, the amount of copper foil present was 10 kV, using an energy dispersive X-ray (EDX) analyzer (manufactured by Horiba). The emission current is 10.0 μA, and the collection time is 600 seconds. It is preferable that the range of sulfur concentration detected when the copper foil surface is measured is 0.05 to 0.5 wt%, more preferably 0.1 to 0.4 wt%. Do. From another viewpoint, the surface layer surface-treated with the organic surface treatment agent using the amount A of the organic surface treatment agent in the case of surface treatment using the organic surface treatment agent by a conventional method (no cleaning treatment), and the organic solvent dissolving the organic surface treatment agent. The amount B of the organic surface treatment agent obtained after the washing step of partially dissolving and washing the solution is preferably set to be in a range of B / A = 0.12 to 0.8, preferably 0.2 to 0.6. Here, the amount of the organic surface treatment agent is calculated by EDX analysis of elements such as S and N in functional groups such as thiol and amine. If the range of the concentration of the organic surface treatment agent (the sulfur concentration in the case of using the surface treatment agent having a thiol group as a functional group) is out of the above range, it becomes difficult to secure the adhesive force between the copper foil and the resin layer.

 Next, the copper foil surface-treated in this way is entrusted to the adhesion lamination process (also called adhesion lamination process C) which makes a polyimide precursor film adhere on a copper foil.

In the adhesion lamination process C, the precursor film of a polyimide resin adheres and laminates on the surface-treated copper foil obtained as mentioned above. As a precursor film of resin here, the polyimide precursor film created by heat-drying the varnish containing polyamic acid is preferable. Then, it is good to set it as the laminated body by which it was entrusted to the imidation process which imidates a polyimide precursor by heat processing, and the polyimide resin layer was formed on copper foil.

Varnishes containing polyamic acid generally use tetracarboxylic acid or its acid anhydride as the acid component, and diamine compounds as the amine component, and both of them are condensation-polymerized at 0 to 100 ° C in an organic polar solvent under anhydrous conditions. It is synthesize | combined by doing. Moreover, the precursor which introduce | transduced the acryloyl group into this polyimide precursor, and the photosensitive polyimide precursor which introduce | transduced o-nitrobenzyl ester group can also be used. The photosensitive polyimide precursor may contain a photoinitiator, a photosensitizer, a crosslinking aid, etc. as needed.

As a diamine compound used as a raw material of a polyimide precursor solution, it is paraphenylenediamine, metaphenylenediamine, 2, 4- diamino toluene, 1, 3-bis- (3-aminophenoxy) benzene, 4, 4'-diamino-2'-methoxybenzanilide, 3,4'-diaminodiphenylether, 4,4'-diamino-2,2'-dimethylbiphenyl, 4,4'-diaminodi Phenylether, 2,2'-bis [4- (4-aminophenoxy) phenyl] propane, 4,4'-bis (3-aminophenoxy) biphenyl, 4,4'-diaminodiphenylpropane, 3,3'- diamino benzophenone, 4,4'- diamino diphenyl sulfide, etc. are mentioned. These diamine compounds can be used individually or in combination of 2 types or more, respectively.

Moreover, as tetracarboxylic acid or its acid anhydride, a pyromellitic dianhydride, 3,4,3 ', 4'- benzophenone tetracarboxylic dianhydride, 3,4,3', 4'- diphenyl sulfontetra Carboxylic dianhydride, trimellitic anhydride tetracarboxylic dianhydride, 3,3 ', 4,4'-biphenyltetracarboxylic dianhydride, 4,4'- oxydiphthalic dianhydride, and the like. These can be used individually or in combination of 2 types or more, respectively.

Examples of the organic solvent used for the polyimide precursor solution include N-methylpyrrolidone (NMP), dimethylformamide (DMF), dimethylacetamide (DMAc), dimethyl sulfoxide (DMSO), dimethyl sulfate, and sulfolane. , Butyrolactone, cresol, phenol, halogenated phenol, cyclohexane, dioxane, tetrahydrofuran, diglyme, triglyme and the like can be used. These solvents can be used individually or in combination of 2 or more types, respectively. Among these, DMAc, NMP, etc. are especially preferable. The amount of solvent used is sufficient to dissolve each component uniformly.

The film of a polyimide precursor is created by heat-drying the varnish containing a polyamic acid. In this case, since the conditions of heat drying are difficult to form a film at low temperature, the polyamic acid imides at high temperature, and adhesiveness falls remarkably, 1 to 20 minutes are preferable at 100-200 degreeC, More preferably, It is 1 to 10 minutes at 110-160 degreeC. This film may contain a solvent, and content is 5 to 70% by weight percentage, Preferably it is 10 to 60%. The film thickness of a polyimide precursor is 10-200 micrometers, Preferably it is 20-100 micrometers.

In the adhesion lamination step C, the film of the polyimide precursor is adhered to the surface-treated copper foil. In this case, the laminating method is preferable. It is preferable that lamination conditions are pressure 0.1-1.5 MPa, lamination temperature 60-200 degreeC, lamination time 1-1000 second, Especially preferably, pressure is 0.5-1.2 MPa, lamination temperature 80-180 degreeC, lamination time 30-600 second. . In lamination, a birch type may be sufficient and the roll-to-roll system which laminates continuously may be sufficient, The method is not limited.

After the film of a polyimide precursor adhere | attaches on the surface-treated copper foil by the adhesion lamination process C, the amidation process which heats a polyimide precursor layer for imidation is performed. In this case, the curing conditions are preferably 120 to 420 ° C for 1 to 300 minutes, particularly preferably 3 to 30 minutes at 130 to 380 ° C. In drying and hardening of a solvent, the birch type which raises temperature in steps may be sufficient, and the continuous hardening type which raises temperature continuously may be sufficient and the method is not limited.

The laminated board obtained by the manufacturing method of the copper clad laminated board of this invention has copper foil on the single side | surface or both surfaces of a polyimide layer, The preferable thickness range of a polyimide layer is 3-100 micrometers, More preferably, it is the range of 10-50 micrometers. The copper clad laminate having copper foil on both sides is manufactured by manufacturing a single-sided copper clad laminate having copper foil on one side, and then hot pressing by overlapping the polyimide of two single copper clad laminated sheets, or by hot pressing the copper foil on the polyimide layer of the single-side copper clad laminate. It can manufacture.

<Example>

Hereinafter, the Example of this invention is described. In addition, unless otherwise indicated in the following Examples, various measurements and evaluation are based on the following.

[Measurement of Copper Surface Sulfur Concentration]

The analysis was performed using an energy dispersive X-ray (EDX) analyzer (Horiba). The acceleration voltage was measured at 10 kV, the emission current was 10.0 μA, and the collection time was 600 seconds. The sulfur concentration on the surface of copper foil is a value representing the mass of sulfur atoms as a percentage of the mass of all atoms detected.

[Evaluation of Adhesion]

The adhesive force between the metal foil and the polyimide resin layer is formed by forming a polyimide resin layer on the copper foil, then cut into a square of 10 mm width using a press machine, and the copper foil is 180 ° C using STROGRAPH V1 manufactured by Toyo Seiki Co., Ltd. Detachment in the direction was measured.

[Evaluation of Solvent Content of Polyamic Acid Film]

The weight loss of the polyamic acid film was measured using a differential thermal gravimetric simultaneous measuring apparatus SSC / 5200 (manufactured by Seiko Instruments). Solvent content of a polyamic-acid film is the value which expressed the ratio of the weight loss from 100 degreeC to 400 degreeC in percentage.

Synthesis Example 1

The varnish containing the polyamic acid used in the Example was prepared as follows. 425 g of dimethylacetamide, 31.8 g of 2,2'-dimethyl-4,4'-diaminobiphenyl, and 4.9 g of 1,3-bis (4-aminophenoxy) benzene were added to a three-necked flask, and room temperature Stirred for 30 min. Then, 28.6 g of pyromellitic dianhydride and biphenyl-3,4,3 ', 4'- tetracarboxylic dianhydride were added, and it stirred at room temperature for 3 hours under nitrogen atmosphere. The viscosity was measured and found to be 28000 cps at 30 ° C.

Synthesis Example 2

The varnish containing the polyamic acid prepared in the synthesis example 1 was apply | coated to the PET film to which the mold release agent was apply | coated to thickness of about 400 micrometers, and the polyimide precursor film was created by heat-drying at 120 degreeC for 2 minutes. The thickness of the polyimide precursor film was 56 micrometers, and solvent content was 40%.

Example 1

Untreated electrolytic copper foil (surface roughness: 10-point average roughness = about 0.8 micrometer, thickness: 18 micrometers, 20 cm x 13 cm square) was used for the copper foil. First, in order to remove the surface oxide film of the copper foil surface, it was immersed in 5% hydrochloric acid aqueous solution (pH <1, bath temperature about 20 degreeC) for 60 second. In order to remove the adhered acid, it was sufficiently washed with ion-exchanged water, blown with compressed air and dried. The copper foil thus treated was immersed in a treatment liquid (bath temperature of about 20 ° C.) for 30 seconds in which an organic surface treatment agent in which 160 mg of 2-amino-1,3,5-triazine-4,6-dithiol was dissolved in 1 L of methanol was dissolved. Surface treatment was carried out, and it was once pulled up in air and the excess liquid was taken out. Next, it was immersed in 750 mL of ion-exchanged water (bath temperature of about 20 degreeC) for 60 second, and then compressed air was blown for about 15 second, and it dried (1st washing). Furthermore, in order to wash | clean the excess organic surface treatment agent which adhered to the copper foil surface, this copper foil was immersed for 60 second in 750 mL of methanol (bath temperature about 20 degreeC), and it wash | cleans (second wash), and then 750 mL of ion-exchange water (about 20 bath temperature) Immersed in 60 ° C. for 60 seconds, and then compressed air was blown for about 15 seconds to dry (third wash) to obtain a surface-treated copper foil A.

The ratio of the mass of sulfur atoms to the mass of all atoms in the copper foil surface of this surface-treated copper foil A was 0.22%.

The polyimide precursor film prepared in Synthesis Example 2 was laminated to the surface-treated copper foil A at a pressure of 1 MPa, a temperature of 150 ° C. and a time of 300 seconds, and after the heat treatment at 130 ° C., the resin was heat cured at a final temperature of 360 ° C. for 3 minutes. As a film | membrane of mid | medium, the copper clad laminated board which consists of two layers of polyimide and copper foil was produced. The thickness of the polyimide film was about 25 micrometers here.

The obtained copper clad laminate was cut into a rectangle having a width of 10 mm using a press machine, and the adhesive force was evaluated by measuring a 180 mm and 10 mm peel strength at room temperature using a tensile tester. As a result, the adhesive force was 0.94 kN / m.

Example 2

A surface-treated copper foil B was prepared in the same manner as in Example 1 except that 80 mg of 2-amino-1,3,5-triazine-4,6-dithiol was dissolved in an organic surface treatment agent dissolved in 1 L of methanol. Obtained and carried out similarly to Example 1, and measured adhesive force.

Example 3

An organic surface treatment agent in which 174 mg of 4,5-diamino-2,6-dimercaptopyrimidine was dissolved in 1 L of methanol instead of 2-amino-1,3,5, -triazine-4,6-dithiol Except having used the process liquid which melt | dissolved, it carried out similarly to Example 1, obtained surface-treated copper foil C, carried out similarly to Example 1, and measured the adhesive force.

Example 4

Instead of 2-amino-1,3,5-triazine-4,6-dithiol, 150 mg of 5-amino-1,3,4-thiazole-2-thiol dissolved in 1 L of methanol was dissolved. Except having used the processing liquid, it carried out similarly to Example 1, obtained surface-treated copper foil D, and carried out similarly to Example 1, and measured the adhesive force.

Comparative Example 1

The copper foil was immersed for 30 seconds in a treatment solution (bath temperature of about 20 ° C.) in which an organic surface treatment agent in which 320 mg of 2-amino-1,3,5-triazine-4,6-dithiol was dissolved in 1 L of methanol was subjected to surface treatment. Subsequently, only (first cleaning) was performed as a washing | cleaning process, and it carried out similarly to Example 1 except not having performed methanol washing (2nd washing) and 3rd washing. The ratio of the mass of sulfur atoms to the mass of all atoms in the copper foil surface of this surface-treated copper foil was 0.69%. The results are shown in Table 1.

Comparative Example 2

It carried out similarly to Example 1 except not having surface-treated with the processing liquid containing the organic surface treating agent (2-amino-1,3,5-triazine-4,6-dithiol) with respect to copper foil. . The ratio of the mass of sulfur atoms to the mass of all atoms in the copper foil surface of this surface-treated copper foil was 0.00%. The results are shown in Table 1.

Copper clad laminate Sulfur concentration on the surface of copper foil (%) Adhesive force (kN / m) Example 1 0.22 0.94 Example 2 0.18 0.90 Example 3 0.25 0.68 Example 4 0.34 0.80 Comparative Example 1 0.69 0.40 Comparative Example 2 0.00 0.50

ADVANTAGE OF THE INVENTION According to this invention, copper foil and polyimide can be adhere | adhered by the laminating method, without the need of the roughening process and metal processing to copper foil conventionally performed for the improvement of adhesive force, and are excellent in adhesiveness, and are high density suitable for fine pitch formation. It is possible to manufacture copper clad laminates used in printed wiring boards, and their industrial value is high.

Claims (9)

A surface treatment step of surface treating the copper foil with a treatment liquid in which at least one functional group has dissolved an organic surface treatment agent having a function of improving adhesion between the copper foil and the resin layer; A washing step of partially dissolving and removing the surface layer of the organic surface treatment agent using an organic solvent that can dissolve the glass surface treatment agent; And An adhesion lamination step of bringing the film of the precursor of the polyimide resin into close contact with the copper foil subjected to the surface treatment; Method for producing a copper clad laminate, characterized in that consisting of. The method for manufacturing a copper clad laminate according to claim 1, further comprising an imidization step after the adhesion lamination step. The method for manufacturing a copper clad laminate according to claim 1, further comprising a step of soft etching copper foil with an acid solution before performing the surface treatment step. The method of claim 3, wherein the acid aqueous solution used for the soft etching is pH 2 or less. The organic solvent according to claim 1, wherein the organic solvent used in the washing step is a C1-8 alcohol, a C3-6 ketone, a C4-12 ether, a C3-7 ester, or a C3-6 A method for producing a copper clad laminate comprising at least one organic solvent selected from the group consisting of amides, a sulfoxide compound having 2 carbon atoms, a halogen containing compound having 1 to 6 carbon atoms and a hydrocarbon compound having 4 to 8 carbon atoms. The organic solvent used in the washing step is methanol, ethanol, propanol, isopropanol, butanol, tetrahydrofuran, ethyl acetate, butyl acetate, acetone, methyl ethyl ketone, cyclohexanone, diethyl ether, A dimethyl sulfoxide, dimethyl acetamide, dimethylformamide, toluene, hexane and dichloromethane, at least one organic solvent selected from the group consisting of a method for producing a copper clad laminate. The method for manufacturing a copper clad laminate according to claim 1, wherein the washing with the organic solvent in the washing step is performed for 3 to 600 seconds at a solution temperature of 0 to 50 ° C. The method for producing a copper clad laminate according to claim 1, wherein the organic surface treating agent is a compound having an amino group as a functional group. The method for producing a copper clad laminate according to claim 1, wherein the organic surface treating agent is a heterocyclic compound having an amino group and a thiol group as a functional group.