Classifications

• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
  • C08J7/00—Chemical treatment or coating of shaped articles made of macromolecular substances
  • C08J7/04—Coating
  • C08J7/044—Forming conductive coatings; Forming coatings having anti-static properties
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
  • C08J5/00—Manufacture of articles or shaped materials containing macromolecular substances
  • C08J5/18—Manufacture of films or sheets
• • C—CHEMISTRY; METALLURGY
  • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
  • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
  • C23C28/00—Coating for obtaining at least two superposed coatings either by methods not provided for in a single one of groups C23C2/00 - C23C26/00 or by combinations of methods provided for in subclasses C23C and C25C or C25D
• • C—CHEMISTRY; METALLURGY
  • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
  • C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
  • C25D3/00—Electroplating: Baths therefor
  • C25D3/02—Electroplating: Baths therefor from solutions
  • C25D3/30—Electroplating: Baths therefor from solutions of tin
• • C—CHEMISTRY; METALLURGY
  • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
  • C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
  • C25D3/00—Electroplating: Baths therefor
  • C25D3/02—Electroplating: Baths therefor from solutions
  • C25D3/38—Electroplating: Baths therefor from solutions of copper
• • C—CHEMISTRY; METALLURGY
  • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
  • C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
  • C25D5/00—Electroplating characterised by the process; Pretreatment or after-treatment of workpieces
  • C25D5/54—Electroplating of non-metallic surfaces
  • C25D5/56—Electroplating of non-metallic surfaces of plastics
• • C—CHEMISTRY; METALLURGY
  • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
  • C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
  • C25D7/00—Electroplating characterised by the article coated
  • C25D7/06—Wires; Strips; Foils
  • C25D7/0614—Strips or foils
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
  • H01B5/00—Non-insulated conductors or conductive bodies characterised by their form
  • H01B5/14—Non-insulated conductors or conductive bodies characterised by their form comprising conductive layers or films on insulating-supports
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
  • C08J2379/00—Characterised by the use of macromolecular compounds obtained by reactions forming in the main chain of the macromolecule a linkage containing nitrogen with or without oxygen, or carbon only, not provided for in groups C08J2361/00 - C08J2377/00
  • C08J2379/04—Polycondensates having nitrogen-containing heterocyclic rings in the main chain; Polyhydrazides; Polyamide acids or similar polyimide precursors
  • C08J2379/08—Polyimides; Polyester-imides; Polyamide-imides; Polyamide acids or similar polyimide precursors

Definitions

• the present invention relates to a conductive film. More specifically, the present invention relates to a conductive film having excellent solder wettability and little deterioration in solder wettability over time.
• the surface of copper and / or copper alloy material is tin-plated and is used for various electronic components such as terminals and connectors for realizing electrical connection.
• the purpose of tin plating is to reduce the contact resistance value. Further, it is for improving the corrosion resistance of the surface of the copper and / or the copper alloy material, and also for imparting good solder wettability.
• Patent Document 1 a diffusion barrier layer made of nickel plating is formed between the copper base material and tin plating (Patent Document 1), or an intermediate layer made of an intermetallic compound of nickel and tin is provided (Patent Document 1).
• Patent Document 2 has been proposed. This utilizes the fact that the diffusion coefficient of nickel into the tin-plated layer is much lower than that of copper.
• a surface plating layer composed of a nickel layer and a copper-tin alloy layer is formed in this order on the surface of a base material made of copper and / or a copper alloy, and a conductive material for connecting parts having a tin layer on the surface plating layer.
• Patent Document 3 has been proposed.
• Patent Documents 1 to 3 The method of providing a metal layer such as nickel between a copper and / or copper alloy material and a tin-plated layer as proposed in Patent Documents 1 to 3 described above suppresses deterioration of solder wettability during long-term storage. In that respect, a certain effect can be obtained. However, since it is necessary to sequentially form a large number of metal layers, the process becomes complicated and the cost increases.
• the present inventors are for suppressing the diffusion of copper atoms from the copper layer and / or the copper alloy layer formed on the film substrate to the tin-plated layer laminated on the surface thereof.
• a barrier layer in which copper and a specific organic compound are bonded is formed on the surface of the copper layer and / or the copper alloy layer, and the tin-plated layer is laminated on the barrier layer, whereby the copper atom is tin-plated.
• diffusion into the layer can be suppressed, and have completed the present invention.
• the present invention has a barrier layer made of an organic compound bonded to copper on the surface of a copper layer and / or a copper alloy layer formed on a film substrate, and a tin-plated layer is laminated on the barrier layer. It is a conductive film made of copper. According to this, since the diffusion of copper atoms from the copper layer and / or the copper alloy layer to the tin-plated layer can be effectively suppressed, a conductive film having a small change in solder wettability with time can be obtained.
• the organic compound is one or a mixture of one or more selected from the group consisting of heterocyclic compounds, thiourea compounds, and thiol compounds.
• the heterocyclic compound is preferably selected from the group consisting of triazole compounds, pyrazole compounds, pyrazole compounds, thiazole compounds, and imidazole compounds.
• the arithmetic mean roughness Ra of the surface of the tin-plated layer is preferably 0.02 to 0.3 ⁇ m, more preferably 0.08 to 0.2 ⁇ m. According to this, it becomes possible to further suppress the deterioration of the solder wettability with time.
• the conductive film of the present invention is composed of a flexible film and a copper layer and / or a copper alloy layer formed on the film.
• a film made of a synthetic resin is preferably used as the flexible film.
• the synthetic resin is not particularly limited, and examples thereof include polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polyethylene, polypropylene, and polyimide. Of these, a polyimide film is preferable.
• the thickness of the film is preferably 4 to 100 ⁇ m, more preferably 10 to 50 ⁇ m.
• a method for forming a copper layer and / or a copper alloy layer on the film a known method can be adopted without limitation. Examples thereof include a method of attaching a copper foil and / or a copper alloy foil using an adhesive, a dry film forming method such as a vacuum vapor deposition method and a sputtering method, and a wet film forming method such as an electroless plating method and an electroplating method. Further, a copper layer and / or a copper alloy layer may be formed by combining these methods. A preferred method is a dry film forming method. Other metals that can be used in copper alloys include nickel, zinc, tin and the like.
• the thickness of the copper layer and / or the copper alloy layer is not particularly limited, but is preferably 0.5 to 5 ⁇ m. When the thickness of the copper layer and / or the copper alloy layer is within this range, a conductive film having excellent conductivity and flexibility can be obtained. A more preferred thickness is in the range of 1 to 3 ⁇ m.
• the copper layer and / or the copper alloy layer may be only one layer or two or more layers having different properties may be laminated.
• a barrier layer made of an organic compound bonded to copper is formed on the surface of the copper layer and / or the copper alloy layer.
• the organic compound is preferably an organic compound selected from the group consisting of heterocyclic compounds, thiourea compounds, and thiol compounds.
• the nitrogen atom or sulfur atom contained in the molecular structure can be chemically bonded to the copper atom to form a thin molecular-level film on the surface of the copper layer and / or the copper alloy layer. ..
• heterocyclic compound examples include compounds selected from the group consisting of triazole compounds, pyrrol compounds, pyrazole compounds, thiazole compounds, imidazole compounds, thiadiazol compounds, oxazole compounds, and thiazol compounds. ..
• benzotriazole tolyltriazole, mercaptobenzothiazole, mercaptothiadiazole, benzimidazole, benzimidazole thiol, benzoxazole thiol, methylbenzothiazole, mercaptothiazolin and the like are particularly preferable.
• thiourea compounds include thiourea, diethylthiourea, dibutylthiourea, 1,3-diethyl-2-thiourea, trimethylthiourea, 1,3-dimethylthiourea, 1-acetylthiourea, N-allylthiourea, and ethylenethiourea. And N-methylthiourea and the like.
• thiol compounds include methanedithiol, 1,2-ethanedithiol, 1,1-propanedithiol, triazinethiol and the like.
• the organic compound is preferably a heterocyclic compound, more preferably a triazole compound, and particularly preferably a benzotriazole or a derivative thereof.
• a tin-plated layer is formed so as to be laminated on the barrier layer.
• the thickness of the tin-plated layer is preferably 0.5 to 3.0 ⁇ m. If the thickness of the tin-plated layer is within this range, excellent solder wettability can be maintained for a long period of time.
• the tin plating layer may be formed by either an electroless plating method or an electroplating method, but it is preferably formed by an electroplating method because the film thickness can be controlled and continuous processing is easy.
• the arithmetic mean roughness Ra on the surface of the tin-plated layer is preferably 0.02 to 0.3 ⁇ m, more preferably 0.08 to 0.2 ⁇ m.
• the arithmetic mean roughness Ra on the surface of the tin-plated layer is small, the solder wettability tends to decrease.
• the arithmetic mean roughness Ra of the surface of the tin-plated layer is within the above range, it is possible to obtain a conductive film in which the decrease in solder wettability with time is further suppressed.
• the arithmetic average roughness Ra of the surface of the tin-plated layer refers to the surface roughness of the outermost layer of the conductive film after laminating, and can be measured by a method according to JIS B 0601: 2001 after laminating.
• the relationship between the arithmetic mean roughness Ra on the surface of the tin-plated layer and the decrease in solder wettability with time is caused by the organic matter contained in the tin-plated layer.
• the brighteners added to the plating solution as described later there are some that significantly reduce the solder wettability due to the oxidation thereof. Therefore, it is preferable to carry out the tin plating treatment without excessive use of such a brightener, and as a result, the arithmetic mean roughness Ra of the tin plating layer surface is in the range of 0.02 to 0.3 ⁇ m. It is preferable to do so.
• the arithmetic mean roughness Ra of the surface of the tin-plated layer varies depending on the type of brightener, current density, plating thickness, and the like. It may also be affected by the surface roughness of the underlying copper layer and / or the copper alloy layer.
• a barrier layer made of the organic compound bonded to copper by contacting a treatment liquid in which an organic compound is dissolved with a copper layer and / or a copper alloy layer formed on a film substrate is formed. It includes a first step of forming and a second step of laminating a tin-plated layer on the barrier layer by an electric tin-plating method.
• the method for forming the copper layer on the film substrate is not particularly limited, and a known method can be adopted. Specific examples thereof include a copper vapor deposition method, an electrolytic copper plating method, and an electroless copper plating method. Of these, the copper vapor deposition method is preferably used. If a thin-film deposition method is used to form the copper layer, a copper layer having high surface smoothness can be formed.
• the copper layer may be formed first by the vapor deposition method, and then the copper layer may be further formed on the copper layer by the electrolytic copper plating method. Then, the thickness of the copper layer can be formed more efficiently.
• the second copper layer by the electrolytic copper plating method is laminated on the surface of the copper layer formed by the vapor deposition method.
• the film substrate on which the copper layer and / or the copper alloy layer is formed is brought into contact with the treatment liquid in which the organic compound is dissolved.
• the solvent that can be used in the treatment liquid include water and alcohols.
• a surfactant or the like for dispersing the organic compound may be added.
• the concentration of the organic compound in the treatment liquid is preferably 0.1 to 10 g / L.
• the temperature of the treatment liquid is preferably 20 to 40 ° C., and the contact time is preferably 5 to 60 seconds.
• the barrier layer can be formed on the surface of the copper layer and / or the copper alloy layer with a thickness within the above-mentioned range.
• the second step is a step of forming a tin plating layer by a general electric tin plating method.
• a plating solution used in the electric tin plating method an aqueous solution such as stannous sulfate can be used as the tin supply source, but a commercially available electric tin plating solution may be used.
• the content of organic substances in the tin-plated layer formed in the second step is affected by the composition of the plating solution. Therefore, in order to control the organic matter content of the tin plating layer within a predetermined range, it is necessary to appropriately control the blending amount of the organic matter in the plating solution.
• Examples of organic substances added to the plating solution include various surfactants, brighteners, antioxidants, and the like. It is important to appropriately design the blending amount of these organic substances in the plating solution and appropriately control the content of the organic substances in the tin plating layer formed in the second step.
• the eutectoid organic substances derived from brighteners represented by aldehyde compounds and amine compounds tend to form an oxide film on the surface of the tin-plated layer and significantly reduce the solder wettability. It is preferable to limit the addition.
• carboxylic acids such as acrylic acid, methyl acrylate and methyl methacrylate, and carboxylic acid esters can be added in the range of 0.01 to 1 g / L for the purpose of adjusting the appearance quality. be.
• Each condition of the electric tin plating method in the second step is not particularly limited and may be set within a range in which a tin plating layer having a desired thickness can be formed.
• the temperature of the plating solution can be 20 to 40 ° C.
• the current density can be 0.5 to 5.0 A / dm 2
• the processing time can be 20 to 200 seconds.
• the first step and the second step may be continuously carried out. Further, prior to the first step, a step of forming the copper layer and / or a copper alloy layer on the film substrate may be provided and these may be continuously carried out.
• the film base material having a thin copper film formed in advance by the vacuum vapor deposition method is subjected to an electrolytic copper plating method or electrolytic copper. Examples thereof include a step of forming a copper layer to a desired thickness by a plating method. Further, a washing step and a drying step may be appropriately carried out between each of these steps.
• solder wettability evaluation was performed on the samples before and after the treatment for 5 hours in an atmosphere of 155 ° C (assuming storage at 80 ° C for 1 month), and the ratio of the solder major diameter after treatment to the solder major diameter before treatment R. (%) was calculated and evaluated. 100% means that there is no decrease in solder wettability with time, and the higher the value (%), the less the decrease in solder wettability with time.
• Example 1 A copper-deposited polyimide film manufactured by Toray KP Film Co., Ltd. (polyimide film thickness 25 ⁇ m and copper layer thickness 1.5 ⁇ m) was placed in a 1 g / L aqueous solution of 1,2,3-benzotriazole at room temperature (25 ° C). Was immersed for 60 seconds to form a barrier layer (first step). Then, electric tin plating was carried out using the following electric tin plating solution A to form a tin plating layer on the barrier layer (second step). The electric tin plating solution was treated at a temperature of 40 ° C. and a current density of 1.5 A / dm 2 for 140 seconds. Then, it was washed with water and subjected to discoloration prevention treatment using a known discoloration inhibitor.
• an annealing treatment was performed at 150 ° C. for 1 hour using a constant temperature dryer (manufactured by Advantech Toyo Co., Ltd., trade name "DRA630DA”) to obtain a conductive film.
• the thickness of the tin-plated layer in the obtained conductive film was 1.7 ⁇ m, and the arithmetic mean roughness Ra of the surface thereof was 0.14 ⁇ m.
• the ratio R was as good as 97.3%.
• Example 2> Instead of the copper-deposited polyimide film (thickness of the polyimide film 25 ⁇ m and the thickness of the copper layer 1.5 ⁇ m), the copper-deposited polyimide film (thickness of the polyimide film 25 ⁇ m and the thickness of the copper layer 0.3 ⁇ m) is replaced with the following.
• a conductive film was obtained in the same manner as in Example 1 except that a copper layer having a thickness of 1.2 ⁇ m was further laminated by performing electrolytic copper plating using the electrolytic copper plating solution of the above. The electrolytic copper plating treatment was performed at a temperature of 40 ° C. and a current density of 3.0 A / dm 2 for 109 seconds.
• Electropper plating solution Copper sulfate pentahydrate; 200 g / L Sulfuric acid; 55 mL / L Sodium chloride; 85 mg / L Additive for matte copper plating (trade name "CU-SOFT", manufactured by JCU Co., Ltd.); 20 mL / L
• the thickness of the tin-plated layer in the obtained conductive film was 1.8 ⁇ m, and the arithmetic mean roughness Ra of the surface thereof was 0.16 ⁇ m.
• the ratio R was as good as 98.3%.
• Example 3 A conductive film was obtained in the same manner as in Example 1 except that the following electric tin plating solution B was used in place of the electric tin plating solution A at a liquid temperature of 21 ° C.
• Electrode plating solution B Stannous sulfate; 50 g / L Sulfuric acid; 110 mL / L Methyl acrylate; 0.6 g / L Other additives; Appropriate amount (including antioxidants and surfactants)
• the thickness of the tin-plated layer in the obtained conductive film was 2.0 ⁇ m, and the arithmetic mean roughness Ra of the surface thereof was 0.03 ⁇ m.
• the ratio R was as good as 80.6%.
• Example 1 A conductive film was obtained in the same manner as in Example 1 except that the first step (barrier layer formation) was not carried out.
• the thickness of the tin-plated layer in the obtained conductive film was 1.7 ⁇ m, and the arithmetic mean roughness Ra of the surface thereof was 0.10 ⁇ m.
• the solder wettability before the treatment was 11.6 mm, and the solder wettability after the treatment was reduced to 7.7 mm.
• the ratio R was 66.4%, which was poor.
• Example 2 A conductive film was obtained in the same manner as in Example 2 except that the first step (barrier layer formation) was not carried out.
• the thickness of the tin-plated layer in the obtained conductive film was 1.7 ⁇ m, and the arithmetic mean roughness Ra of the surface thereof was 0.16 ⁇ m.
• the ratio R was 75.0%, which was poor.
• the conductive film of the present invention is a conductive film in which deterioration of solder wettability with time is suppressed, and can be manufactured by a simple process as compared with the prior art. Therefore, it can be used for parts that require electrical connection of wearable devices and various electronic devices. It can also be configured as a gasket material for grounding an electronic device housing by winding it around an elastic material.

Landscapes

• Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Engineering & Computer Science (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Materials Engineering (AREA)
• Metallurgy (AREA)
• Electrochemistry (AREA)
• Health & Medical Sciences (AREA)
• Medicinal Chemistry (AREA)
• Polymers & Plastics (AREA)
• Manufacturing & Machinery (AREA)
• Mechanical Engineering (AREA)
• Electroplating Methods And Accessories (AREA)

Priority Applications (3)

Applications Claiming Priority (2)

Publications (1)

Family

ID=81289878

Family Applications (1)

Country Status (4)

Citations (2)

Family Cites Families (16)

• 2021
  • 2021-09-27 JP JP2022557339A patent/JPWO2022085374A1/ja active Pending
  • 2021-09-27 WO PCT/JP2021/035472 patent/WO2022085374A1/ja not_active Ceased
  • 2021-09-27 KR KR1020237013506A patent/KR20230091104A/ko active Pending
  • 2021-09-27 CN CN202180053398.3A patent/CN116209787A/zh active Pending

Patent Citations (2)

Also Published As

Similar Documents

Legal Events