JP6350351B2 - Metal substrate surface treatment method - Google Patents

Description

  The present invention relates to a method for surface treatment of a metal substrate with a silane coupling agent.

  A joined body of a metal substrate and a resin is used in a wide range of industrial fields mainly in the electric and automobile fields. Examples of such a joined body of a metal substrate and a resin include a lead frame of a semiconductor package used for an electronic component and a power card used for an automobile.

  As a metal base material used for a joined body with a resin, those subjected to metal plating are widely used. In metal plating, two or more kinds of metals having different properties may be used in combination, for example, a metal such as gold that does not have a functional group on the surface and a nickel or metal having a functional group such as a hydroxyl group on the surface. A metal such as aluminum is used in combination.

  When a metal substrate having a metal plating having a functional group such as a hydroxyl group on the surface is bonded to the resin, a method in which the metal substrate is surface-treated with a silane coupling agent and bonded to the resin is widely used. In this method, the hydroxyl group of the silane coupling agent is bonded to a functional group such as a hydroxyl group on the surface of the metal substrate, so that the functional group of the silane coupling agent is imparted to the surface of the metal substrate. The metal base material and the resin are bonded to each other. For example, Patent Document 1 discloses a method of manufacturing a resin composite molded product in which a metal part is inserted, and the metal part surface is previously treated with a silane coupling agent and then molded using a phenol resin molding material. A method for producing a metal insert resin composite molded product characterized by the above is described.

  On the other hand, in the case of a metal such as gold that does not have a functional group on the surface, it is difficult to use the above-described surface treatment method using a silane coupling agent for joining a metal material and a resin. This is because a metal such as gold does not have a functional group on the surface, and therefore cannot be bonded to the silanol group of the silane coupling agent, and the bonding strength of the obtained bonded body is lowered.

  In order to join a metal substrate having a metal plating such as gold having no functional group on the surface with a sufficient strength, it is necessary to introduce a functional group such as an amino group on the surface of the metal plating. As a method for introducing a functional group onto the surface of gold plating, a method using an alkanethiol derivative having a mercapto group that easily binds to gold is known (Patent Document 2).

  In electronic parts and automobile parts, etc., in which a joined body of a metal substrate and a resin is used, a metal plating part such as gold having no functional group on the surface and a metal plating having a functional group such as a hydroxyl group on the surface When a surface treatment is performed to join a metal base material having both portions to a resin, it is difficult to treat each metal plating portion separately due to its shape and manufacturing process. For example, a power card for automobile parts has a structure in which a gold-plated copper plate and a nickel-plated copper plate are wrapped in a mold resin such as an epoxy resin, and it is difficult to separately process the gold-plated portion and the nickel-plated portion. For this reason, in such parts, the surface of the gold-plated portion is treated in a separate surface treatment step using an alkanethiol derivative and the surface of a metal-plated portion having a functional group such as a hydroxyl group using a silane coupling agent. It is difficult to process.

JP 2009-126126 A JP 2001-152363 A

  As described above, in the conventional metal substrate surface treatment method, a metal substrate having a gold-plated portion and a metal-plated portion other than gold having a functional group on the surface is used in the same surface treatment step. It was difficult to impart a functional group to the surface of the metal substrate by surface treatment. Therefore, the present invention provides a surface treatment method capable of imparting a functional group to a metal substrate having a gold plating portion and a metal plating portion other than gold on the surface and having a functional group on the surface by the same kind of surface treatment process. The purpose is to provide.

  As a result of various studies on means for solving the above problems, the present inventors treated a metal substrate with a silane coupling agent having a thiol group, and then treated with a silane coupling agent having a specific functional group. By treating the metal substrate, the functional group can be imparted to the metal substrate having a gold-plated portion and a metal-plated portion other than gold on the surface by the same surface treatment process. The headline and the present invention were completed.

That is, the gist of the present invention is as follows.
(1) A method of surface-treating a metal substrate having gold and a metal other than gold having a hydroxyl group on the surface with a silane coupling agent, wherein the metal substrate is made of a silane coupling agent having a mercapto group And a silane cup having at least one functional group selected from vinyl group, epoxy group, styryl group, methacryl group, acrylic group, amino group, ureido group, mercapto group, sulfide group and isocyanate group And a second step of treating the metal substrate with an aqueous solution containing a ring agent.
(2) The surface treatment method according to (1), wherein the metal other than gold is at least one selected from nickel, aluminum, iron, copper, zinc, tin, magnesium, stainless steel, and alloys thereof.
(3) The surface treatment method according to (1) or (2), wherein the functional group of the silane coupling agent used in the second step is at least one selected from an epoxy group, a methacryl group, an acrylic group, and an amino group.
(4) The surface treatment method according to any one of (1) to (3), wherein the metal substrate is treated with an aqueous solution of a silane coupling agent in the first step.
(5) The surface treatment method according to any one of (1) to (3), wherein in the first step, the metal substrate is treated with a stock solution or a non-aqueous solution of a silane coupling agent.

  According to the present invention, there is provided a surface treatment method capable of imparting a functional group to a gold-plated portion and a metal substrate having a functional group on the surface and having a metal plated portion other than gold on the surface by the same surface treatment step. It becomes possible.

FIG. 1A is a diagram illustrating the bonding strength of a bonded body of an Au-plated lead frame material and an epoxy resin in Examples 1 and 2 and Comparative Example 1-3. FIG. 1B is a diagram showing the bonding strength of the joined body of the Ni-plated lead frame material of Examples 1 and 2 and Comparative Example 1-3 and an epoxy resin.

  Hereinafter, preferred embodiments of the present invention will be described in detail.

  The present invention relates to a method of surface-treating a metal substrate having gold and a metal other than gold on the surface with a silane coupling agent. The surface treatment method of the present invention includes a first step of treating a metal substrate with a silane coupling agent having a mercapto group, and a second step of treating the metal substrate with an aqueous solution containing a silane coupling agent having a predetermined functional group. Process. In the surface treatment method of the present invention, functional groups can be imparted to the surfaces of both gold and a metal other than gold by the same kind of two-step surface treatment process.

  The metal substrate has gold and a metal other than gold on the surface. The metal base material should just have a gold part and metal parts other than gold | metal | money on the surface at least. The metal substrate may be composed only of gold and a metal other than gold. The metal substrate preferably has a gold-plated portion and a metal-plated portion other than gold on a metal layer selected from nickel, iron, copper, zinc, cobalt, tin, chromium, and alloys thereof. It is.

  Metals other than gold have hydroxyl groups on the surface. In the surface treatment method of the present invention, a hydroxyl group on a metal surface other than gold is bonded to a hydroxyl group of a silane coupling agent, whereby a functional group can be imparted to the metal surface. Examples of metals other than gold having a hydroxyl group on the surface include nickel, aluminum, iron, copper, zinc, tin, magnesium, stainless steel, and alloys thereof without being particularly limited.

I. First Step In the first step, the metal substrate is treated with a silane coupling agent having a mercapto group.
The silane coupling agent used in the first step is, for example, a compound having a mercapto group and a group that generates a silanol group by hydrolysis, such as a dialkylalkoxysilyl group, an alkyldialkoxysilyl group, or a trialkoxysilyl group. is there.

  The silane coupling agent used in the first step is not particularly limited. For example, 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, 3-mercaptopropyldiethoxymethoxysilane, 3-mercaptopropyltrisilane. Propoxysilane, 3-mercaptopropyl dipropoxymethoxysilane, 3-mercaptopropyltributoxysilane, 3-mercaptopropyldibutoxymethoxysilane, 3-mercaptopropylmethyldimethoxysilane, 3-mercaptopropyldimethylmethoxysilane, 3-mercaptopropylmethyl Diethoxysilane, 3-mercaptopropyldimethylethoxysilane, 3-mercaptopropylmethyldipropoxysilane, 3-mercaptopropylpropoxydimethylsilane 3-mercaptopropylmethyldiisopropoxysilane, 3-mercaptopropylisopropoxydimethylsilane, 3-mercaptopropylmethyldibutoxysilane, 3-mercaptopropyldimethylbutoxysilane, 2-mercaptoethyltrimethoxysilane, 2-mercaptoethyltriethoxy Examples include silane, mercaptomethyltrimethoxysilane, mercaptomethyltriethoxysilane, and the like. 3-mercaptopropylmethyldimethoxysilane and 3-mercaptopropyltrimethoxysilane are preferable, and 3-mercaptopropyltrimethoxysilane is more preferable. A silane coupling agent may be used individually by 1 type, or may use 2 or more types together.

  As the silane coupling agent used in the first step, commercially available ones may be used, for example, KBM-803 (3-mercaptopropyltrimethoxysilane) and KBM-802 (3-mercaptopropyl) manufactured by Shin-Etsu Silicone. Methyldimethoxysilane) and the like can be used.

  In the first step, the treatment of the metal substrate with the silane coupling agent is not particularly limited, and can be performed by bringing the metal substrate into contact with the silane coupling agent. The contact of the metal substrate with the silane coupling agent can be performed, for example, by immersing the metal substrate in a solution or stock solution of the silane coupling agent. When the metal substrate is immersed in a solution or stock solution of the silane coupling agent, the immersion temperature is usually 0 to 50 ° C., and the immersion time is selected according to the concentration of the silane coupling agent solution or stock solution used. Usually, it is 10 seconds to 24 hours. The contact of the metal substrate with the silane coupling agent can also be performed by spraying or roll coating.

  The metal base material treated with the silane coupling agent may be used for the second step as it is, but may be used for the second step after the drying step or the post-treatment step. When drying the treated metal substrate, for example, it can be dried at a temperature of room temperature (25 ° C.) to 50 ° C., but may be dried by blowing air onto the metal substrate. As the post-treatment, for example, the metal base is usually heat-treated at a temperature of 100 to 200 ° C., usually for 30 minutes to 2 hours.

  In the method of the present invention, the silane coupling agent treatment may be performed a plurality of times in the first step.

II. Second Step In the second step, the metal substrate is treated with an aqueous solution containing a silane coupling agent having a predetermined functional group.

  The functional group of the silane coupling agent used in the second step is at least one selected from vinyl group, epoxy group, styryl group, methacryl group, acrylic group, amino group, ureido group, mercapto group, sulfide group and isocyanate group. It is.

  The silane coupling agent used in the second step is, for example, a group that hydrolyzes a silanol group such as a dialkylalkoxysilyl group, an alkyldialkoxysilyl group, or a trialkoxysilyl group, a vinyl group, an epoxy group, or a styryl. A compound having at least one group selected from a group, a methacryl group, an acrylic group, an amino group, a ureido group, a mercapto group, a sulfide group and an isocyanate group.

  Examples of the silane coupling agent having a vinyl group include vinyltrimethoxysilane and vinyltriethoxysilane.

  Examples of the silane coupling agent having an epoxy group include 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3- Examples thereof include glycidoxypropylmethyldiethoxysilane and 3-glycidoxypropyltriethoxysilane.

  Examples of the silane coupling agent having a styryl group include p-styryltrimethoxysilane.

  Examples of the silane coupling agent having a methacryl group include 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, and 3-methacryloxypropyltriethoxysilane. Is mentioned.

  Examples of the silane coupling agent having an acrylic group include 3-acryloxypropyltrimethoxysilane.

  Examples of the silane coupling agent having an amino group include N-2- (aminoethyl) -3-aminopropylmethyldimethoxysilane, N-2- (aminoethyl) -3-aminopropyltrimethoxysilane, and 3-amino. Propyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-triethoxysilyl-N- (1,3-dimethyl-butylidene) propylamine, N-phenyl-3-aminopropyltrimethoxysilane, N- (vinylbenzyl) ) -2-aminoethyl-3-aminopropyltrimethoxysilane hydrochloride and the like.

  Examples of the silane coupling agent having a ureido group include 3-ureidopropyltrialkoxysilane.

  Examples of the silane coupling agent having a mercapto group include those used in the first step.

  Examples of the silane coupling agent having a sulfide group include bis (triethoxysilylpropyl) tetrasulfide.

  Examples of the silane coupling agent having an isocyanate group include 3-isocyanatopropyltriethoxysilane.

  A commercially available silane coupling agent may be used. For example, the above silane coupling agent is commercially available from Shin-Etsu Silicone.

  As a functional group of the silane coupling agent used in the second step, a vinyl group, an epoxy group, a styryl group, a methacryl group, an acrylic group, an amino group, and an isocyanate group are preferable from the viewpoint of adhesiveness with a resin. From the viewpoint, an epoxy group, a methacryl group, an acrylic group, and an amino group are more preferable.

  As an example, as the silane coupling agent having an amino group, N-2- (aminoethyl) -3-aminopropyltrimethoxysilane is preferable, which is commercially available as KBM-603 from Shin-Etsu Silicone.

  In the second step, the silane coupling agent is used as an aqueous solution. In the aqueous solution, the silane coupling agent has a hydroxyl group (hydroxyl group in the silanol group) generated by hydrolysis. The solvent for the aqueous silane coupling agent solution is preferably water, but an organic solvent may be used in combination with water in order to increase the solubility of the silane coupling agent. The organic solvent is not particularly limited, and examples thereof include alcohols such as methanol, ethanol, butanol, and hexanol, and ketones such as acetone and butanone. When the organic solvent is used in combination with water, the proportion of the organic solvent in the solvent is, for example, 1 to 70% by weight and preferably 5 to 30% by weight as long as the silane coupling agent is hydrolyzed.

  The density | concentration of the silane coupling agent aqueous solution of a 2nd process is 0.01 to 30 weight% normally, Preferably, it is 0.1 to 20 weight%. The concentration of the aqueous silane coupling agent solution in the second step is preferably higher than the concentration of the aqueous silane coupling agent solution in the first step when the aqueous silane coupling agent solution is used in the first step. By making the concentration of the aqueous solution of the silane coupling agent in the second step higher than that in the first step, in the first step, the silane coupling agent in the first step bonded to the metal surface other than gold can be efficiently added. It can be replaced with a two-step silane coupling agent.

  In the second step, the treatment of the metal substrate with the silane coupling agent is not particularly limited, and can be performed by bringing the metal substrate into contact with the silane coupling agent aqueous solution. The contact of the metal substrate with the silane coupling agent aqueous solution can be performed, for example, by immersing the metal substrate in the silane coupling agent aqueous solution. When the metal substrate is immersed in the silane coupling agent aqueous solution, the immersion temperature is usually 0 to 50 ° C., and the immersion time can be selected according to the concentration of the silane coupling agent solution or stock solution used, Usually, it is 10 seconds to 24 hours. The contact of the metal substrate with the aqueous silane coupling agent solution can also be performed by spraying or roll coating.

  In this invention, you may perform a drying process and a post-processing process after a 2nd process. When drying the treated metal substrate, for example, it can be dried at a temperature of room temperature (25 ° C.) to 50 ° C., but may be dried by blowing air onto the metal substrate. As the post-treatment, for example, the metal base is usually heat-treated at a temperature of 100 to 200 ° C., usually for 30 minutes to 2 hours.

  In the surface treatment method of the present invention, in the first step, the metal substrate is preferably treated with an aqueous solution of a silane coupling agent, or treated with a stock solution or a non-aqueous solution of a silane coupling agent. The form of the silane coupling agent of the 1st process used for a process of a metal base material can be selected according to the kind of metal base material and silane coupling agent to be used. In the first step, when a stock solution or non-aqueous solution of a silane coupling agent is used, the silane coupling agent in the first step can be selectively bonded to the gold plating surface, and the silane coupling agent used in the first step Since the amount can be reduced and the reaction time of the second step can be shortened, it is preferable from the viewpoint of production efficiency. In the first step of the surface treatment method of the present invention, the reaction in the case of using an aqueous solution of a silane coupling agent and the case of using a stock solution or non-aqueous solution of a silane coupling agent will be described in detail below.

(1) When using an aqueous solution of a silane coupling agent in the first step In the first step of the surface treatment method of the present invention, when treating a metal substrate with an aqueous solution of a silane coupling agent, a solvent for the aqueous solution of the silane coupling agent As water, water is preferable, but an organic solvent may be used in combination with water in order to increase the solubility of the silane coupling agent. The organic solvent is not particularly limited, and examples thereof include alcohols such as methanol, ethanol, butanol, and hexanol, and ketones such as acetone and butanone. When using an organic solvent with water, the ratio of the organic solvent in a solvent is 1 to 70 weight%, for example, Preferably, it is 5 to 30 weight%. The aqueous silane coupling agent solution may contain a hydroxide such as sulfuric acid, hydrochloric acid, nitric acid, acetic acid and potassium hydroxide, ammonia, etc. as a pH adjuster. The concentration of the silane coupling agent aqueous solution is, for example, 0.01 to 20% by weight, preferably 0.1 to 10% by weight, and more preferably 0.5 to 5% by weight. In an aqueous solution, the silane coupling agent has a hydroxyl group generated by hydrolysis.

  When an aqueous silane coupling agent solution is used in the first step, in the first step, the mercapto group of the silane coupling agent is coordinated with gold on the gold surface, and on the metal surface other than gold, the hydroxyl group on the metal surface It is considered that the hydroxyl group or mercapto group of the silane coupling agent is hydrogen bonded. In the next second step, the hydroxyl group of the silane coupling agent coordinated with gold in the first step and the hydroxyl group of the silane coupling agent in the second step are hydrogen bonded, so that the silane coupling in the second step is performed. It is considered that the substituent of the agent is imparted to the gold surface. On the other hand, on the metal surface other than gold, in the first step, the silane coupling agent in the first step hydrogen bonded to the metal surface is replaced with the silane coupling agent in the second step, so that the silane coupling in the second step. It is considered that the functional group of the agent is imparted to the metal surface.

(2) When using a stock solution or non-aqueous solution of a silane coupling agent in the first step In the first step, the metal substrate can be treated with a stock solution or non-aqueous solution of a silane coupling agent. Therefore, it is preferable to treat with a non-aqueous solution of a silane coupling agent. The solvent of the non-aqueous solution of the silane coupling agent is not particularly limited, and examples thereof include organic solvents such as alcohols such as methanol, ethanol, butanol and hexanol, and ketones such as acetone and butanone. The concentration of the silane coupling agent aqueous solution is, for example, 0.01 to 20% by weight, preferably 0.1 to 10% by weight, and more preferably 0.5 to 5% by weight. In the silane coupling agent stock solution or non-aqueous solution, the silane coupling agent is not hydrolyzed and does not have a hydroxyl group.

  When the stock solution or non-aqueous solution of the silane coupling agent is used in the first step, in the first step, the mercapto group of the silane coupling agent is coordinated with gold on the gold surface, and the metal surface other than gold is metal on the metal surface. It is considered that the silane coupling agent does not bind. In the next second step, the hydroxyl group of the silane coupling agent coordinated with gold in the first step and the hydroxyl group of the silane coupling agent in the second step are hydrogen bonded, so that the silane coupling in the second step is performed. It is considered that the substituent of the agent is imparted to the gold surface. On the other hand, on a metal surface other than gold, a hydroxyl group on the metal surface and a hydroxyl group on the silane coupling agent in the second step are hydrogen-bonded, so that a substituent of the silane coupling agent on the second step is imparted to the gold surface. It is thought.

  The present invention also includes a metal substrate treated by the surface treatment method described above. In the metal substrate treated by the surface treatment method of the present invention, the functional group of the silane coupling agent in the second step is imparted to the surface.

  The present invention also includes a joined body obtained by joining a metal base material surface-treated by the above surface treatment method and a resin.

  The resin used for the joined body is not particularly limited, and any of a thermoplastic resin and a thermosetting resin can be used. Examples of the thermoplastic resin include polyethylene resin, polypropylene resin, polystyrene resin, acrylic resin, polyvinyl chloride resin, polycarbonate resin, nylon resin, urethane resin, polyethylene terephthalate (PET) resin, polybutylene terephthalate (PBT) resin, and acrylonitrile. -Butadiene-styrene copolymer (ABS) resin etc. are mentioned. Examples of the thermosetting resin include melamine resin, phenol resin, epoxy resin, urethane resin, polyimide resin, diallyl phthalate resin, unsaturated polyester resin, furan resin and the like.

  The resin used for the joined body can be selected according to the functional group of the silane coupling agent used in the second step. For example, when the functional group of the silane coupling agent used in the second step is a methacryl group. Is preferably a polyethylene resin, a polypropylene resin, a polystyrene resin, an ABS resin and an unsaturated polyester resin. When the functional group of the silane coupling agent used in the second step is an acrylic group, the ABS resin and the unsaturated polyester resin are Preferably, when the functional group of the silane coupling agent used in the second step is an amino group, polystyrene resin, acrylic resin, polyvinyl chloride resin, nylon resin, epoxy resin, urethane resin, and furan resin are preferable. As a combination of the functional group of the silane coupling agent used in the second step and the resin, a combination of an amino group and an epoxy resin is most preferable from the viewpoint of the bonding strength of the obtained bonded body.

  Hereinafter, the present invention will be described more specifically with reference to examples. However, the technical scope of the present invention is not limited to these examples.

Example 1
As a metal base material, a copper lead frame material (hereinafter referred to as “Au plated lead frame material”) subjected to gold (Au) plating and a copper lead frame material (hereinafter referred to as “Ni plated lead”) subjected to nickel (Ni) plating. Called “frame material”). In addition, an aqueous solution (acetic acid water) of 3-mercaptopropyltrimethoxysilane (manufactured by Shin-Etsu Silicone: KBM-803) is used as the silane coupling agent in the first step, and N- An aqueous solution of 2- (aminoethyl) -3-aminopropyltrimethoxysilane (manufactured by Shin-Etsu Silicone Co., Ltd .: KBM-603) was used.

  After immersing the Au-plated lead frame material in an aqueous solution of 3-mercaptopropyltrimethoxysilane (acetic acid water) at room temperature (25 ° C.) for 1 hour, N-2- (aminoethyl) -3-aminopropyltrimethoxy It was immersed in an aqueous solution of silane for 1 hour at room temperature. An epoxy resin was transfer-molded and joined to the treated Au-plated lead frame material under the conditions of 175 ° C. and 7 MPa to obtain a joined body of the Au-plated lead frame material and the epoxy resin.

  Similarly, a Ni-plated lead frame material was immersed in an aqueous solution of 3-mercaptopropyltrimethoxysilane (acetic acid water) at room temperature for 1 hour, and then N-2- (aminoethyl) -3-aminopropyltrimethoxysilane. In the aqueous solution at room temperature for 1 hour. An epoxy resin was transfer-molded and joined to the treated Ni-plated lead frame material under the conditions of 175 ° C. and 7 MPa to obtain a joined body of the Ni-plated lead frame material and the epoxy resin.

(Example 2)
As a silane coupling agent in the first step, instead of an aqueous solution (acetic acid water) of 3-mercaptopropyltrimethoxysilane (manufactured by Shin-Etsu Silicone: KBM-803), 3-mercaptopropyltrimethoxysilane (manufactured by Shin-Etsu Silicone): Except for using an ethanol solution of KBM-803), the Au plated lead frame material and the Ni plated lead frame material were respectively treated in the same manner as in Example 1 to join the Au plated lead frame material and the epoxy resin. And a joined body of the Ni-plated lead frame material and the epoxy resin were obtained.

(Comparative Example 1)
The Au plating lead frame material was immersed in an aqueous solution of N-2- (aminoethyl) -3-aminopropyltrimethoxysilane (manufactured by Shin-Etsu Silicone Co., Ltd .: KBM-603) for 1 hour at room temperature. The treated Au-plated lead frame material was bonded to an epoxy resin in the same manner as in Example 1 to obtain a bonded body of the Au-plated lead frame material and the epoxy resin.

  Similarly, the Ni-plated lead frame material was immersed in an aqueous solution of N-2- (aminoethyl) -3-aminopropyltrimethoxysilane (manufactured by Shin-Etsu Silicone Co., Ltd .: KBM-603) for 1 hour at room temperature. The treated Ni-plated lead frame material was bonded to an epoxy resin in the same manner as in Example 1 to obtain a bonded body of the Ni-plated lead frame material and the epoxy resin.

(Comparative Example 2)
The Au-plated lead frame material was immersed in an aqueous solution (acetic acid water) of 3-mercaptopropyltrimethoxysilane (manufactured by Shin-Etsu Silicone Co., Ltd .: KBM-803) for 1 hour at room temperature. The treated Au-plated lead frame material was bonded to an epoxy resin in the same manner as in Example 1 to obtain a bonded body of the Au-plated lead frame material and the epoxy resin.

  Similarly, the Ni-plated lead frame material was immersed in an aqueous solution (acetic acid water) of 3-mercaptopropyltrimethoxysilane (manufactured by Shin-Etsu Silicone Co., Ltd .: KBM-803) for 1 hour at room temperature. The treated Ni-plated lead frame material was bonded to an epoxy resin in the same manner as in Example 1 to obtain a bonded body of the Ni-plated lead frame material and the epoxy resin.

(Comparative Example 3)
The Au plating lead frame material was immersed in an ethanol solution of 3-mercaptopropyltrimethoxysilane (manufactured by Shin-Etsu Silicone Co., Ltd .: KBM-803) for 1 hour at room temperature. The treated Au-plated lead frame material was bonded to an epoxy resin in the same manner as in Example 1 to obtain a bonded body of the Au-plated lead frame material and the epoxy resin.

  Similarly, the Ni-plated lead frame material was immersed in an ethanol solution of 3-mercaptopropyltrimethoxysilane (manufactured by Shin-Etsu Silicone Co., Ltd .: KBM-803) for 1 hour at room temperature. The treated Ni-plated lead frame material was bonded to an epoxy resin in the same manner as in Example 1 to obtain a bonded body of the Ni-plated lead frame material and the epoxy resin.

  For the joined body of the Au plated lead frame material and the epoxy resin and the joined body of the Ni plated lead frame material and the epoxy resin obtained in Examples 1 and 2 and Comparative Example 1-3, shear serving as a bond strength index The strength was measured with a compression tester. The shear strength of the joined body was measured three times, the average of the three measurements was obtained, and the joint strength of the joined body was determined in three stages.

  The results are shown in Table 1 and FIG. FIG. 1A shows the bonding strength of a bonded body of an Au plated lead frame material and an epoxy resin. FIG. 1B shows the bonding strength of a bonded body of a Ni-plated lead frame material and an epoxy resin. Table 1 shows each measured value (n = 1, n = 2, n = 3) and average value of the bonding strength of the bonded body measured three times, and the bonding strength in three stages (◯, Δ, ×). It showed in.

  From Table 1, FIG. 1 (A) and FIG. 1 (B), in Comparative Example 1, when the Ni-plated lead frame material was used, the joint strength of the joined body was high, but the Au-plated lead frame as the metal substrate When the material was used, the joint strength of the joined body was low. In Comparative Examples 2 and 3, the bonding strength of the joined body was very low in any case using the Ni-plated lead frame material and the Au-plated lead frame material. Compared with Comparative Example 1-3, in Examples 1 and 2, in any case where the Ni-plated lead frame material and the Au-plated lead frame material were used, the joint strength of the joined body exceeded 20 MPa, which was very high. It was. Here, since it is considered that there is a certain positive correlation between the amount of amino groups on the plating surface and the bonding strength of the bonded body, in Examples 1 and 2, compared to Comparative Example 1-3, the metal substrate It was shown that more amino groups were imparted to the plating surface.

  The surface treatment method of this invention can be used for the surface treatment of the metal base material of the joined body of a metal base material and resin used for an electronic component or a motor vehicle part.

Claims (5)

And gold-plated portion, having a hydroxyl group on the surface, and a metal plating portions other than gold to a method for surface treating a metal substrate with a silane coupling agent having a surface,
A first step of treating a metal substrate with a silane coupling agent having a mercapto group;
Metal group in an aqueous solution containing a silane coupling agent having at least one functional group selected from vinyl group, epoxy group, styryl group, methacryl group, acrylic group, amino group, ureido group, mercapto group, sulfide group and isocyanate group A surface treatment method comprising: a second step of treating the material. The surface treatment method according to claim 1 , wherein the metal other than gold is at least one selected from nickel, aluminum, iron, copper, zinc, tin, magnesium, stainless steel, and alloys thereof. The surface treatment method according to claim 1 or 2 , wherein the functional group of the silane coupling agent used in the second step is at least one selected from an epoxy group, a methacryl group, an acrylic group, and an amino group. In the first step, a surface treatment method according to claim 1, for processing a metal substrate with an aqueous solution of a silane coupling agent. The surface treatment method according to any one of claims 1 to 3, wherein in the first step, the metal substrate is treated with a stock solution or a non-aqueous solution of a silane coupling agent.

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