JP2010043292A - Method of forming partially plated film on hoop material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of forming a plated film precisely at a desired position of a hoop material worked into a fine and complicated shape. <P>SOLUTION: The method of forming the partially plated film on the hoop material includes: a self-organized film forming step of forming a self-organized film on the surface of a continuously delivered hoop like conductive substrate; a film removing step of removing a required part of the self-organized film on the continuously delivered hoop like conductive substrate; and an electroplating step of forming a conductive film by electroplating on the part of the continuously delivered hoop like conductive substrate where the self-organized film is removed in the film removing step. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a method for forming a partial plating film for forming a partial plating film on the surface of a conductive substrate of a hoop member.

Conventionally, plating film is used to provide soldering work, corrosion resistance, wear resistance, etc. to the surface of semiconductor leadframes such as IC and LSI leadframes, connector terminals, relay terminals, etc., formed on hoop members. A method of forming is known. As a metal source used for forming such a plating film, noble metals such as gold, silver, rhodium, palladium, cobalt, and platinum are widely used. Since such noble metal plating is expensive, it is preferable to minimize the plating area, and a partial plating method in which a plating range is limited to only a necessary portion and a partial plating method is widely used (for example, The following patent documents 1-3).
JP-A-53-97936 JP-A-57-9894 JP 2000-345385 A

  When forming a partial plating film on the hoop member, it is difficult to accurately form the plating film at a desired position because the hoop member itself is processed into a fine and complicated shape.

  In the present invention, after a self-assembled film is formed on a hoop-like conductive substrate that is continuously fed in one direction, only the part of the self-assembled film on which an electroplating film is to be formed is removed, and the removal is performed. An object of the present invention is to provide a method of forming a plating film with high accuracy only at a desired position of a hoop member processed into a fine and complicated shape by electroplating only a portion.

  The method of forming a partially plated film on the hoop member of the present invention includes a self-assembled film forming step of forming a self-assembled film on the surface of a hoop-like conductive substrate that is continuously sent out, and a continuous feed out. A film removing step for removing a desired portion of the self-assembled film on the surface of the hoop-like conductive substrate, and a portion where the self-assembled film on the surface of the hoop-shaped conductive substrate that is continuously fed is removed. And an electroplating step of forming a conductive film by electroplating. According to such a process, it is uniform autonomously only by bringing a hoop member processed into a fine and complicated shape into contact with a liquid or gas phase field where organic molecules capable of forming a self-assembled film exist. An insulating film having a thickness can be formed. And, since only the part of the self-assembled film where the electroplating film is to be formed can be easily removed by laser processing or the like, only the removed part is electroplated to form a fine and complicated shape. The conductive film can be accurately formed at a desired position of the processed hoop member.

  Further, the self-assembled film forming step is a step of pulling up the conductive substrate after immersing the conductive substrate in a chemical adsorption solution in which an organic molecule capable of forming the self-assembled film is dissolved in a solvent. The self-assembled film is preferable because it can be formed with simple equipment.

  Moreover, it is preferable that the self-assembled film forming step includes a step of repeating a unit operation of immersing the conductive substrate in the chemical adsorption solution and then pulling up the chemical adsorption solution a plurality of times. According to such a process, for example, a thick self-assembled film in which 10 to 50 molecular layers are accumulated can be formed. According to such a thick self-assembled film, it is possible to suppress insulation failure due to pinholes, insulation failure due to the tunnel effect, insulation breakdown against high voltage, etc., thereby maintaining sufficient insulation. The partial plating film can be formed accurately. In the unit operation, after pulling up the conductive substrate, the surface is irradiated with an energy beam such as an electron beam or X-ray, immersed in an aqueous potassium permanganate solution, or plasma-treated. More preferably, the surface activation treatment is performed. Such a surface activation treatment can facilitate the chemical bonding of the accumulated molecular layers. Further, it is more preferable to immerse in a chemical adsorption solution in which organic molecules capable of forming different types of self-assembled films are dissolved each time the unit operation is repeated. By forming a self-assembled film using different kinds of organic molecules in this way, the surface characteristics of the self-assembled film, specifically, for example, hydrophilicity, water repellency, lipophilicity, oil repellency, lubricity Insulating properties can be controlled with high accuracy. In particular, when a hydrophobic group is present on the surface of the formed self-assembled film, a hoop member having excellent antifouling properties can be formed.

  Further, the self-organized film forming step is a step of bringing the conductive base material into contact with vapor formed by vaporizing organic molecules capable of forming the self-assembled film. From the point that can be formed.

  According to the present invention, a plating film can be accurately formed at a desired position of a hoop member processed into a fine and complicated shape.

  An embodiment according to the present invention will be described with reference to the drawings.

  FIG. 1 is a process diagram for explaining a method for forming a partially plated film according to the present embodiment, FIG. 2 is a schematic diagram for explaining a self-assembled film forming step according to the present embodiment, and FIG. FIG. 4 is a schematic explanatory diagram for explaining an electroplating process in the present embodiment, and FIG. 4 is a schematic explanatory diagram for explaining a laser removal processing process in the embodiment.

  In the present embodiment, a hoop member A (hereinafter also simply referred to as a base material) on which a partially plated film is formed has comb-shaped portions a,... A formed by high-definition processing as shown in FIG. Is provided. Further, the hoop member A has conductivity. And in this embodiment, a partial plating film is formed in the part shown to A1 of the comb-tooth shaped part.

  In the present embodiment, as shown in FIG. 1, first, pretreatment for removing and purifying oil on the surface of the hoop member A is performed (S1 to S3). Specifically, first, the hoop member A wound around the delivery reel 1 is continuously delivered and immersed in the ethanol ultrasonic treatment tank 2 to perform the ethanol ultrasonic cleaning process (S1). After performing the pure water ultrasonic cleaning process (S2) by immersing in the water ultrasonic processing tank 3, it is sent to the drying furnace 4 and dried (S3).

  Next, as shown in FIG. 1, following the drying step (S3), a self-assembled film M is formed on the entire surface of the hoop member A (S4).

  The self-assembled film in the present embodiment is formed by regularly adsorbing organic molecules that are chemisorbed on the substrate surface when specific organic molecules having molecular assembly properties are brought into contact with the substrate surface. Such an organic molecular thin film. Specifically, a monomolecular film that is a thin film formed by adsorbing one end of an organic molecule on the surface of the base material and arranged in a line, or a thin film formed by accumulating a plurality of organic molecules (hereinafter, (Also referred to as a cumulative film).

  The organic molecule generally has an adsorptive functional group that is easily chemisorbed on the substrate surface at one end, and the adsorbable functional group has a linear or cyclic saturated or unsaturated carbon chain or its An organic molecule to which a characteristic functional group consisting of a substituent is bonded is used.

  The adsorptive functional group is not particularly limited as long as it is a functional group that easily chemisorbs to the substrate surface as described above, and preferably has a functional group having a polarity opposite to the zeta potential of the substrate surface. Organic molecules are preferably selected. According to the organic molecule having such a functional group, the adsorption rate of the organic molecule is increased by attracting the positive and negative, whereby the film formation rate is increased and a dense self-assembled film can be formed. Specific examples of such adsorptive functional groups include various silyl groups such as a silyl group, a halogenated silyl group, an alkoxysilyl group, and an isocyanate silyl group.

  Specific examples of the halogenated silyl group include a monochlorosilyl group, a dichlorosilyl group, and a trichlorosilyl group. Of these, a chlorosilyl group is preferred. Specific examples of the alkoxysilyl group include a monoalkoxysilyl group, a dialkoxysilyl group, and a trialkoxysilyl group, preferably a methoxysilyl group, an ethoxysilyl group, and a butoxysilyl group.

  In particular, organic molecules having various silyl groups at their terminals can form covalent bonds with active hydrogen present on the surface of the substrate. Since the self-assembled film can be firmly bonded by such a covalent bond, a self-assembled film having excellent durability is formed.

  On the other hand, the characteristic functional group bonded to the adsorptive functional group includes a linear or cyclic saturated or unsaturated hydrocarbon group, or a part or all of hydrogen in the hydrocarbon group is a halogen atom, a hydroxyl group, or an alkynyl group. And a hydrocarbon group substituted by a group, a carboxyl group, an ester residue, an aromatic group, or a derivative group thereof.

Specific examples of the organic molecule include the following general formula:
_{H (CH 2) m SiR n} X 3-n ··· (1)
_{CH 2 = CH (CH 2)} m SiR n X 3-n ··· (2)
_{OH (CH 2) m SiR n} X 3-n ··· (3)
_{COOH (CH 2) m SiR n} X 3-n ··· (4)
_{A (CH 2) q SiR n} X 3-n ··· (5)
(In the general formulas (1) to (5), R is an alkyl group having 1 to 100 carbon atoms, X is a halogen group, isocyanic group (CN) or hydroxyl group, A is an aromatic group, an aliphatic ether residue, an aliphatic group. An organic molecule represented by a carboxylic acid ester residue or a siloxylated alkyl residue, m is an integer of 1 to 15, n is an integer of 0 to 3, and q is an integer of 0 to 15) or a derivative thereof (halogen) And the like.

  Specific examples of the organic molecules represented by the general formulas (1) to (5) include, for example, n-octadecyltrimethoxysilane represented by the general formula (1) and the general formula (2). Examples thereof include vinyltriethoxysilane and p-aminophenyltrimethoxysilane represented by the general formula (5).

  In the present embodiment, the cleaned hoop member A is brought into contact with a chemisorbed liquid obtained by dissolving organic molecules capable of forming a self-assembled film as described above in a predetermined solvent, so that the surface of the hoop member A is self-adapted. Form an organized membrane. Specifically, for example, as shown in FIG. 2, after the hoop member A wound around the delivery reel 1 is continuously sent out and cleaned, the fed hoop member A is continuously fed with the chemical adsorption solution. The self-assembled film M can be formed by immersing in the accommodated chemical adsorption liquid tank 5 and attaching the chemical adsorption liquid to the surface and then pulling it up.

  The solvent used for the preparation of the chemical adsorption solution is appropriately selected according to the type of organic molecule, and specific examples thereof include hexadecane, chloroform, carbon tetrachloride, silicone oil, hexane, toluene and the like. . These solvents may be used alone or in combination of two or more.

  Although the density | concentration of the organic molecule melt | dissolved in a chemical adsorption liquid is not restrict | limited in particular, As a specific example, it is preferable that it is about 1-20 volume%, for example.

  In addition to the method shown in FIG. 2, the hoop member A wound around the delivery reel 1 is continuously sent out and sent out as a contact method for bringing the hoop-like conductive substrate into contact with the chemical adsorption liquid. In addition, a method of applying a chemical adsorption liquid to the surface of the hoop member A by using a spray method or a roll coating method may be used.

  The contact time between the hoop member A and the chemical adsorption liquid is preferably 1 to 600 minutes, and more preferably 10 to 30 minutes, for example. Moreover, as temperature of a chemical adsorption liquid, it is preferable that it is the range of 10-80 degreeC, for example, and 20-30 degreeC, for example.

  In addition, when forming the accumulated film formed by accumulating a plurality of organic molecules as the self-assembled film M, the unit operation of immersing the hoop member A in the chemical adsorption solution and then pulling it up may be repeated a plurality of times. preferable. Thus, by repeating the dipping process a plurality of times, organic molecules are gradually accumulated, and for example, a self-assembled film having a film thickness such that 10 to 50 molecular layers are accumulated can be formed. As shown in FIG. 6, the method of immersing the hoop member A in such a chemical adsorption solution a plurality of times uses a chemical adsorption solution tank 5a having a long shape with respect to the traveling direction of the hoop member A, and a roller 5b. , 5b,..., 5b... Can be performed by a method of repeating the unit operation of lifting the hoop member A after immersing it in the chemical adsorption solution.

  In repeating the unit operation, it is preferable to perform a surface activation treatment for activating the surface of the formed self-assembled film after the hoop member A is pulled up. By performing such surface activation treatment, free end groups on the side where the organic molecules constituting the self-assembled film M are not adsorbed can be activated. Examples of such surface activation treatment include a method of irradiating energy rays such as an electron beam and an X-ray, a treatment of immersing in an aqueous potassium permanganate solution, a method of plasma treatment, and the like. By such surface activation treatment, a hydroxyl group, a carboxyl group or the like can be introduced into the free end. Then, by repeating the step of further immersing the hoop member A having the activated film in this manner in the chemical adsorption solution, the accumulation of the desired accumulated number of layers such that the accumulated organic molecules are chemically bonded. A conductive substrate having a film can be formed. As shown in FIG. 6, such a surface activation treatment method is performed by a method of irradiating the hoop member pulled up by the rollers 5 b, 5 b... With an energy beam using a predetermined light irradiation device 5 c. be able to.

  In the repetition of the unit operation, the surface characteristics of the self-assembled film formed by using a chemical adsorption solution in which organic molecules capable of forming different types of self-assembled films are used during the repetition. Specifically, for example, hydrophilicity, water repellency, lipophilicity, oil repellency, lubricity, insulation, and the like can be controlled with high accuracy. In particular, when a hydrophobic group such as a fluorine atom-containing group is present on the surface of the formed self-assembled film, a hoop member having excellent antifouling properties can be formed. As shown in FIG. 6, the method of immersing in a chemical adsorption solution in which organic molecules capable of forming different types of self-assembled films are dissolved uses a chemical adsorption solution tank 5a that is long in the advancing direction of the hoop member. In the unit operation of immersing by the rollers 5b, 5b... And then pulling up, it can be performed by accommodating different types of organic molecules in each chamber partitioned by the partition wall 5d.

  Further, as a contact method for bringing organic molecules into contact with the hoop-like conductive base material, in addition to the method using the chemical adsorption liquid as described above, the hoop member A wound around the delivery reel 1 is continuously provided. It is also possible to use a method in which a vapor formed by vaporizing organic molecules capable of forming a self-assembled film is brought into contact with the surface of the hoop member A fed out.

  As shown in FIGS. 1 and 2, the self-assembled film thus formed can be further heated and annealed in the drying furnace 6 to further advance self-assembly (S5). . Such annealing is preferably performed in a drying furnace at a temperature of 50 to 120 ° C., more preferably 60 to 100 ° C., for about 30 to 90 minutes.

  The film thickness of the self-assembled film is usually 0.5 to 2 nm, more preferably about 1 to 2 nm, and the film thickness of the cumulative film is 4 to 100 nm, more preferably 10 to 30 nm. It is preferable that it is a grade. Moreover, it is preferable that the accumulation layer number of an accumulation film is 10-50 layers, Furthermore, 40-50 layers.

  In this way, the hoop member A on which the self-assembled film M is formed is once wound up by the take-up reel 7.

  Next, a removal step (S4) for removing a desired portion of the self-assembled film M formed on the surface of the hoop member A will be described with reference to FIG.

  As a method for removing a desired portion of the self-assembled film M formed on the surface of the hoop member A, for example, as shown in FIG. 3, the self-assembled film M formed on the hoop member A that is continuously fed out. Such a method is preferably used that a desired part of the material is removed by laser processing.

  As a laser processing means, a YAG laser such as a SHG-YAG laser is preferably used. Since the self-assembled film M formed in this embodiment is a very thin film, the self-assembled film can be easily removed partially with relatively low power.

  In the laser processing, as shown in FIG. 3, the hoop member A on which the self-assembled film is formed is continuously sent out in one direction and guided onto the processing table T of the laser processing apparatus R. By irradiating the laser beam to the position, it is possible to remove only the part of the self-assembled film where electroplating is desired.

  Also, instead of laser processing, only the desired part is removed using means such as charged particle beam processing (electron beam, ion beam), machining, or exposure through a photomask with a desired pattern formed. May be.

  Next, an electroplating process for forming a conductive film by electroplating on the portion from which the self-assembled film has been removed will be described with reference to FIGS.

  As described above, the hoop member A from which the self-assembled film where electroplating is to be formed has been removed is continuously fed from the feed reel 1 and immersed in the plating pretreatment tank 8 as shown in FIG. Thus, a pre-plating process (S7) is performed. Next, after performing an electroplating process (S8) by continuously immersing in the electroplating tank 9, a pure water ultrasonic cleaning process (S9) is further performed, and then sent to a drying furnace to be dried.

  The plating pretreatment tank 8 is divided into, for example, a degreasing tank 8a, a soft etching tank 8b, and a pickling tank 8c, and by immersing the hoop member A in which the self-assembled film M is formed in each tank in order. Pre-plating treatment is performed.

  The hoop member A on which the preprocessed self-assembled film is formed is then immersed in the electroplating tank 9.

  FIG. 7 shows a schematic enlarged view of the electroplating tank 9. As shown in FIG. 7, the electroplating tank 9 is provided with an insoluble electrode 9a to which a positive potential is applied. For example, an electroplating solution 9b such as a gold bromide solution for gold plating is stored. Has been. The hoop member A is connected to the cathode side of the power supply device 9c, and the insoluble electrode 9a is connected to the anode side of the power supply device 9c.

  The hoop member A travels through the electroplating tank 9 at a predetermined speed, for example, in the direction of the white arrow while applying a negative potential.

  The insoluble electrode 9a is, for example, in a plate shape and is disposed in parallel to the hoop member A at a certain distance from the hoop member A. Then, the plating film is attached only to the portion where the self-assembled film is removed by the current flowing between the insoluble electrode 9a to which the positive potential is applied and the hoop member A to which the negative potential is applied. Since the self-assembled film M functions as an insulating layer, no current flows through the portion where the self-assembled film is formed, so that the plating film does not adhere.

  As a metal used for plating, various metals that can be used for electroplating, such as silver, rhodium, palladium, cobalt, platinum, nickel, silver, copper, and tin, can be used in addition to the above-described gold.

  By such a process, a plating film, which is a conductive film, is formed only in a portion where the self-assembled film on the surface of the hoop member A is removed. Then, the surface of the hoop member A is cleaned in the pure water tank 10 after the plating film is formed (S9).

  As described above, according to the method of this embodiment, the self-assembled film that can easily form a thin and uniform insulating layer is used as the insulating layer, so that it has a fine and complicated shape. A conductive film can be easily and accurately formed only on a desired portion of the hoop member A.

  Hereinafter, the contents of the present invention will be described more specifically with reference to examples. The present invention is not limited to the examples.

Example 1
A copper hoop member A having a width of 20 mm is continuously fed from the feed reel 1 by using a self-organized film forming process having a configuration as shown in FIG. 2, and the ethanol ultrasonic treatment tank 2 and the pure water ultrasonic treatment tank 3 are sent. After washing by immersing in each for 60 seconds, it was dried by passing through a drying furnace 4 set at 150 ° C. Subsequently, the dried hoop member A was immersed in a 5% by mass solution of n-octadecyltrimethoxysilane (ODS) at room temperature contained in the chemical adsorption bath 5 for 20 seconds × 10 times, and then set to 120 ° C. Annealing treatment was performed in the drying furnace 6 for 300 seconds. Then, after the annealing treatment, the treated hoop member A was taken up by the take-up reel 7.

  Next, the self-organization formed on the surface of the hoop member A by the SHG-YAG laser device 12 while continuously feeding the hoop member A from the feed reel 1 using the laser processing process having the configuration shown in FIG. After removing the chemical film by a width of 1 mm, the treated hoop member A was taken up by the take-up reel 7.

Next, using the electroplating process configured as shown in FIG. 4, while continuously feeding the hoop member A from which the self-assembled film where the plating film is desired to be formed by the laser processing process is removed from the delivery reel 1. After plating pretreatment by immersing in degreasing tank 8a for 30 seconds, soft etching tank 8b for 60 seconds, pickling tank 8c for 30 seconds and then immersing in electroplating tank 9 for 30 seconds, nickel plating was formed. . Current density in the electroplating bath 9 at this time was 10A / dm ^2. Then, after the plating was formed, ultrasonic cleaning was performed in the pure water tank 60 for 60 seconds, and the treated hoop member A was taken up by the take-up reel 7.

  When the surface of the plated hoop member A was observed with an optical microscope and an electron microscope, a nickel conductive film with a film thickness of about 1 μm was accurately formed only on the part from which the self-assembled film was removed. The nickel conductive film was not formed at all in the portion where the film was formed.

FIG. 1 is a process diagram for explaining a method of forming a partial plating film according to the embodiment. FIG. 2 is a schematic explanatory diagram for explaining the self-assembled film forming step of the embodiment. FIG. 3 is a schematic explanatory diagram for explaining a laser removal processing step of the embodiment. FIG. 4 is a schematic explanatory diagram for explaining the electroplating process of the embodiment. FIG. 5 is a schematic explanatory view of the hoop member A of the embodiment. FIG. 6 is a schematic explanatory diagram for explaining another example of the self-assembled film forming step. FIG. 7 is a schematic explanatory diagram for explaining the electroplating process of the embodiment.

Explanation of symbols

A Hoop member M Self-assembled film R Laser processing device T Processing table a Comb-shaped part 1 Reel 2 Ethanol ultrasonic treatment tank 3 Pure water ultrasonic treatment tank 4 Drying furnace 5, 5a Chemical adsorption liquid tank 5b Roller 5c Light irradiation Apparatus 5d Bulkhead 6 Drying furnace 7 Reel 8 Plating pretreatment tank 8a Degreasing tank 8b Soft etching tank 8c Pickling tank 9 Electroplating tank 9a Insoluble electrode 9b Electroplating solution 9c Power supply apparatus 10 Pure water tank 12 Laser apparatus

Claims (7)

  A self-assembled film forming step for forming a self-assembled film on the surface of a hoop-like conductive substrate that is continuously fed, and the self-assembled film on the surface of a hoop-shaped conductive substrate that is continuously fed out. A film removing step for removing a desired portion, and an electroplating step for forming a conductive film by electroplating on the portion of the hoop-like conductive substrate surface that is continuously sent out from which the self-assembled film has been removed. A method for forming a partial plating film on a hoop member, comprising:   2. The part according to claim 1, wherein the self-assembled film forming step is a step of bringing the conductive substrate into contact with a chemical adsorption solution in which an organic molecule capable of forming the self-assembled film is dissolved in a solvent. Formation method of plating film.   The method of forming a partially plated film according to claim 2, wherein the self-assembled film forming step includes a step of repeating a unit operation of pulling up from the chemical adsorption solution after immersing the conductive substrate in the chemical adsorption solution a plurality of times. .   The method for forming a partially plated film according to claim 3, wherein in the unit operation, after the conductive substrate is pulled up from the chemical adsorption solution, a surface activation treatment is performed.   5. The method for forming a partially plated film according to claim 3, wherein each time the unit operation is repeated, the partially plated film is immersed in a chemical adsorption solution in which substances capable of forming different types of self-assembled films are dissolved.   2. The formation of a partially plated film according to claim 1, wherein the self-assembled film forming step is a step of bringing the conductive base material into contact with vapor formed by vaporizing organic molecules capable of forming the self-assembled film. Method.   The method for forming a partially plated film according to any one of claims 1 to 6, wherein a hydrophobic group is present on the surface of the self-assembled film to be formed.

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