Conductive film-forming bath

Abstract

An object of the present invention is to provide a novel conductive film-forming bath comprising an alkaline aqueous solution that can be used to form a film by electroplating on a non-conductive plastic material, the conductive film-forming bath being capable of forming a film by electroplating that has an excellent appearance and that does not suffer from reduced adhesiveness with respect to a non-conductive plastic material. The present invention relates to a conductive film-forming bath comprising an aqueous solution containing a copper compound, a complexing agent, an alkali metal hydroxide, and a water-soluble polymer having a polyoxyalkylene structure.

Claims

1. A conductive film-forming bath comprising an aqueous solution containing a copper compound, a complexing agent, an alkali metal hydroxide, a water-soluble polymer having a polyoxyalkylene structure, formic acid as a reducing agent, and C.sub.2-5 aliphatic polyalcohol compound.

2. The conductive film-forming bath according to claim 1, wherein the water-soluble polymer having a polyoxyalkylene structure is with a backbone having a repeating structure of a structural unit: an oxyalkylene group represented by Formula (1): (O-Ak)-, wherein Ak represents alkylene, and wherein the polymer has one or more hydrophilic groups.

3. The conductive film-forming bath according to claim 1, wherein the water-soluble polymer having a polyoxyalkylene structure has a number average molecular weight of 300 or more.

4. A method for forming a conductive film on a non-conductive plastic material, the method comprising bringing a non-conductive plastic material to which a catalyst substance is applied into contact with the conductive film-forming bath of claim 1.

5. A method for electroplating a non-conductive plastic material, the method comprising a step of performing electroplating after a conductive film is formed using the conductive film-forming bath by the method of claim 4.

6. A conductive film-forming bath comprising an aqueous solution containing a copper compound, a complexing agent, an alkali metal hydroxide, a water-soluble polymer having a polyoxyalkylene structure, and a C2-5 aliphatic polyalcohol compound, wherein a temperature of the conductive film-forming bath is in a range of 55 to 80? C.

7. The conductive film-forming bath according to claim 6, further comprising a reducing agent.

8. The conductive film-forming bath according to claim 7, wherein the reducing agent is at least one component selected from the group consisting of carboxyl-containing reducing compounds and reducing saccharides having 6 or more carbon atoms.

9. The conductive film-forming bath according to claim 6, wherein the water-soluble polymer having a polyoxyalkylene structure is with a backbone having a repeating structure of a structural unit: an oxyalkylene group represented by Formula (1): (O-Ak)-, wherein Ak represents alkylene, and wherein the polymer has one or more hydrophilic groups.

10. The conductive film-forming bath according to claim 6, wherein the water-soluble polymer having a polyoxyalkylene structure has a number average molecular weight of 300 or more.

11. A method for forming a conductive film on a non-conductive plastic material, the method comprising bringing a non-conductive plastic material to which a catalyst substance is applied into contact with the conductive film-forming bath of claim 6.

12. A method for electroplating a non-conductive plastic material, the method comprising a step of performing electroplating after a conductive film is formed using the conductive film-forming bath by the method of claim 11.

Description

EXAMPLES

Example 1

(1) A flat plate made of a PC/ABS polymer alloy (Iupilon PL-2010, produced by Mitsubishi Engineering-Plastics Corporation) measuring 100 mm?40 mm?3 mm and having a surface area of about 1 dm.sup.2 was used as a substrate to be treated.

(2) A jig for use in plating operations had two contact portions for contact with the substrate to be treated, the two contact portions being spaced 11 cm apart. The contact portions were constructed from stainless steel rods with a diameter of 2 mm. The portion other than the contact portions was coated with a vinyl chloride sol by baking. The following steps (1) to (9) were sequentially performed to form a film by electroplating.

(1) Degreasing Treatment

(3) First, the substrate to be treated was set in the jig, which was immersed at 50? C. for 5 minutes in a solution of an alkaline degreasing agent (Ace Clean A-220, 50 g/L aqueous solution, produced by Okuno Chemical Industries Co., Ltd.), and washed with water.

(2) Etching Treatment

(4) Next, the resulting substrate was immersed at 67? C. for 10 minutes in an etching solution comprising an aqueous solution containing 400 g/L of chromic anhydride and 400 g/L of sulfuric acid to give a rough surface to the resin substrate.

(3) Neutralizing Process

(5) Thereafter, the resulting substrate was washed with water and immersed at room temperature for 60 seconds in an aqueous solution of 15 mL/L of CRP conditioner 551M (a resin surface control agent), whose pH had been adjusted to 7 with sodium hydroxide.

(4) Pre-Dipping Treatment

(6) Then, pre-dipping was performed at room temperature for 1 minute by dipping the substrate into an aqueous solution containing 250 mL/L of 35% hydrochloric acid.

(5) Catalyzing Treatment

(7) The substrate was then immersed at 35? C. for 6 minutes in a colloidal solution (pH: 1 or less) containing 83.3 mg/L of palladium chloride (50 mg/L as Pd), 8.6 g/L of stannous chloride (4.5 g/L as Sn), and 250 mL/L of 35% hydrochloric acid to cause a catalyst to uniformly adhere to the substrate.

(6) Conductive Film Formation Treatment

(8) Thereafter, the substrate was sufficiently washed with water to form a conductive film. For conductive film-forming baths, aqueous solutions (present invention baths 1 to 28) were used that were obtained by adding the water-soluble polymer having a polyoxyalkylene structure shown in Tables 1 to 4 below to an aqueous solution (basic bath) that contained 4 g/L of copper sulfate pentahydrate, 20 g/L of Rochelle salt, and 60 g/L of sodium hydroxide (hereinafter referred to as basic bath A). The substrate was immersed in each of the conductive film-forming baths for 30 minutes at 60? C. to form a conductive film.

(9) For a comparative test, basic bath A to which a water-soluble polymer was not added (comparative bath 1) and basic baths A to which the water-soluble compound shown in Table 3 below was added (comparative baths 2 to 5) were used as conductive film-forming baths, and conductive films were formed in the same manner as described above.

(7) Copper Sulfate Plating Treatment

(10) Then, the substrate was sufficiently washed with water and subjected to a subsequent copper electroplating step while held in the same jig. A copper electroplating bath was prepared by adding as a brightener 5 mL/L of Top Lucina 2000MU and 0.5 mL/L of Top Lucina 2000A (both produced by Okuno Chemical Industries Co., Ltd.) to an aqueous solution containing 50 g/L of copper sulfate-5H.sub.2O, 50 g/L of sulfuric acid, and 50 mg/L of chlorine ions. Using this bath, a copper electroplating operation was performed at a liquid temperature of 25? C. and a current density of 3 A/dm.sup.2 for 5 minutes using a phosphorus-containing copper sheet as an anode and the substrate as a cathode while applying mild air agitation.

(8) Nickel Plating Treatment

(11) Thereafter, the substrate was washed with water, immersed at 25? C. for 1 minute in 50 g/L of TOP SUN (produced by Okuno Chemical Industries Co., Ltd.) as an activating agent, and sufficiently washed with water. Subsequently, a plating solution was prepared by adding as a brightener 20 mL/L of KAI ACNA B-1 and 1 mL/L of KAI ACNA B-2 (both produced by Okuno Chemical Industries Co., Ltd.) to an aqueous solution containing 280 g/L of nickel sulfate, 50 g/L of nickel chloride, and 40 g/L of boric acid. Using this solution as a nickel electroplating solution, a nickel electroplating operation was performed at a liquid temperature of 55? C. and a current density of 3 A/dm.sup.2 for 20 minutes.

(9) Chromium Plating Treatment

(12) Thereafter, the substrate was washed with water. Then, an aqueous solution containing 250 g/L of chromic anhydride and 1 g/L of sulfuric acid was used as a chromium plating solution to perform a chromium plating operation at a liquid temperature of 40? C. and a current density of 12 A/dm.sup.2 for 3 minutes using a lead sheet as an anode and the substrate as a cathode.

Evaluation of Adhesiveness

(13) Each sample in which a plating film was formed by the method described above was evaluated for the adhesiveness of each of the formed plating films by using the following method. Tables 1 to 4 also show the results.

(14) First, each sample was allowed to stand at ?30? C. for 60 minutes, at room temperature for 30 minutes, at 70? C. for 60 minutes, and at room temperature for 30 minutes. This process was defined as one cycle, and three cycles were repeated. Thereafter, blistering of the plating film was visually observed, and the adhesiveness of the plating film was evaluated according to the following criteria. A: No blistering occurred in the plating film. B: Blistering occurred in 0 to 10% of the plating area. C: Blistering occurred in 10 to 80% of the plating area. D: Blistering occurred in 80 to 100% of the plating area.

(15) TABLE-US-00001 TABLE 1 Water-soluble polymer Number average Conductive film- molecular Polymer Amount forming bath Type weight number added Adhesiveness Present Polyethylene glycol 2000 Polymer 1 0.1 g/L A invention bath 1 (PEG #2000/NOF Corporation) Present Polypropylene glycol 700 Polymer 2 0.1 g/L A invention bath 2 (Polypropylene glycol, diol type, 700/Wako Pure Chemical Industries, Ltd.) Present Polyoxyethylene 1420 Polymer 3 0.1 g/L A invention bath 3 polyoxypropylene glycol (Newpol PE-75/Sanyo Chemical Industries, Ltd.) Present Polyoxyethylene lauryl 1200 Polymer 4 0.1 g/L A invention bath 4 ether (Polyoxyethylene (23) lauryl ether/Wako Pure Chemical Industries, Ltd.) Present Polyoxypropylene butyl 1200 Polymer 5 0.1 g/L A invention bath 5 ether (Newpol LB-285/Sanyo Chemical Industries, Ltd.) Present Polyoxyethylene 970 Polymer 6 0.1 g/L A invention bath 6 polyoxypropylene butyl ether (Newpol 50HB-280/Sanyo Chemical Industries, Ltd.) Present Polyoxyethylene 1000 Polymer 7 0.1 g/L A invention bath 7 polyoxypropylene monoamine (JEFFAMINE M- 1000/HUNTSMAN) Comparative bath 1 Not added D

(16) TABLE-US-00002 TABLE 2 Water-soluble polymer Conductive film- Polymer Amount forming bath Type number added Adhesiveness Present Ammonium polyoxyethylene oleyl Polymer 8 0.1 g/L A invention bath 8 cetyl ether sulfate (Hitenol 18E/Dai-Ichi Kogyo Seiyaku Co., Ltd.) Present Ammonium polyoxyethylene lauryl Polymer 9 0.1 g/L A invention bath 9 ether sulfate (Hitenol LA-16/Dai-Ichi Kogyo Seiyaku Co., Ltd.) Present Ammonium polyoxyethylene Polymer 10 0.1 g/L A invention bath styrenated phenyl ether sulfate 10 (Hitenol NF-17/Dai-Ichi Kogyo Seiyaku Co., Ltd.) Present Disodium lauryl polyoxyethylene Polymer 11 0.1 g/L A invention bath sulfosuccinate 11 (Neo-Hitenol L-30/Dai-Ichi Kogyo Seiyaku Co., Ltd.) Present Sodium polyoxyethylene lauryl Polymer 12 0.1 g/L A invention bath ether acetate 12 (Neo-Hitenol ECL-45/Dai-Ichi Kogyo Seiyaku Co., Ltd.) Present Polyoxyethylene alkyl(C8)ether Polymer 13 0.1 g/L A invention bath phosphoric acid ester 13 (Plysurf A208F/Dai-Ichi Kogyo Seiyaku Co., Ltd.) Present Polyoxyethylene styrenated Polymer 14 0.1 g/L A invention bath phenyl ether 14 (Noigen EA-157/Dai-Ichi Kogyo Seiyaku Co., Ltd.)

(17) TABLE-US-00003 TABLE 3 Water-soluble polymer Number average Conductive film- molecular Polymer Amount forming bath Type weight number added Adhesiveness Present Polyethylene glycol 300 Polymer 0.1 g/L B invention bath (PEG #300/NOF 15 15 Corporation) Present Polyethylene glycol 600 Polymer 0.1 g/L A invention bath (PEG #600/NOF 16 16 Corporation) Present Polyethylene glycol 1000 Polymer 0.1 g/L A invention bath (PEG #1000/NOF 17 17 Corporation) Present Polyethylene glycol 2000 Polymer 0.1 g/L A invention bath (PEG #2000/NOF 18 Corporation) Present Polypropylene glycol 8000 Polymer 0.1 g/L A invention bath (Polypropylene glycol 19 19 8000/Wako Pure Chemical Industries, Ltd.) Present Polyethylene glycol 20000 Polymer 0.1 g/L A invention bath (PEG #2000/NOF 20 20 Corporation) Comparative bath 2 Ethylene glycol 62 0.1 g/L D Comparative bath 3 Diethylene glycol 106 0.1 g/L D Comparative bath 4 Triethylene glycol 150 0.1 g/L D Comparative bath 5 Triethylene glycol 150 20 g/L D

(18) TABLE-US-00004 TABLE 4 Conductive film- Water-soluble polymer formind bath Type Amount added Adhesiveness Present invention Polymer 18 0.3 ppm B bath 21 Present invention Polymer 18 0.5 ppm B bath 22 Present invention Polymer 18 1 ppm A bath 23 Present invention Polymer 18 5 ppm A bath 24 Present invention Polymer 18 10 ppm A bath 25 Present invention Polymer 18 0.1 g/L A bath 26 Present invention Polymer 18 1 g/L A bath 27 Present invention Polymer 18 10 g/L A bath 28

(19) As is clear from the results shown in Tables 1 to 4, plating films with excellent adhesiveness were formed with the use of the conductive film-forming baths (present invention baths (1 to 28) in which a water-soluble polymer having a polyoxyalkylene structure was added to basic bath A, which contained copper sulfate, Rochelle salt, and sodium hydroxide.

(20) In contrast, plating films exhibited unsatisfactory adhesiveness when formed with the use of basic bath A (comparative bath 1) to which water-soluble polymer is not added or baths (comparative baths 2 to 5) in which a water-soluble polyol compound, which is not a polymer, was added to basic bath A.

Example 2 (Reducing Agent Added)

(21) The same substrate to be treated and jig as used in Example 1 were used and the same procedures as in Example 1 were performed up to the catalyst, application step.

(22) After the catalyst application step above, the substrate was sufficiently washed with water, and conductive films were formed under the same conditions as in Example 1, using conductive film-forming baths (present invention baths 29 to 56). For present invention baths 29 to 56, aqueous solutions were used that were obtained by adding the water-soluble polymer having a polyoxyalkylene structure shown in Tables 5 to 7 to an aqueous solution that contains 4.8 g/L of copper sulfate pentahydrate, 30 g/L of disodium ethylenediaminetetraacetate, 30 g/L of sodium hydroxide, and 2 g/L of formaldehyde (hereinafter referred to as basic bath B). Thereafter, the resulting product was washed with water, and copper electroplating, nickel plating, and chromium plating were performed under the same conditions as in Example 1. The types of polymers in the tables are the same as those shown in Tables 1 to 3.

(23) For a comparative test, basic bath B to which a water-soluble polymer was not added (comparative bath 6) and basic baths B to which the water-soluble compound shown in Table 6 below was added (comparative baths 7 to 10) were used as conductive film-forming baths to form a conductive film under the same conditions as in Example 1. Thereafter, the resulting product was washed with water, and copper electroplating, nickel plating, and chromium plating were performed under the same conditions as in Example 1.

(24) After plating films were formed by the above method, the adhesiveness of the formed plating films were evaluated as in Example 1. Tables 5 to 7 also show the results.

(25) TABLE-US-00005 TABLE 5 Water-soluble polymer Conductive film- Amount forming bath Basic bath Type added Adhesiveness Present invention B Polymer 1 0.1 g/L A bath 29 Present invention B Polymer 2 0.1 g/L A bath 30 Present invention B Polymer 3 0.1 g/L A bath 31 Present invention B Polymer 4 0.1 g/L A bath 32 Present invention B Polymer 5 0.1 g/L A bath 33 Present invention B Polymer 6 0.1 g/L A bath 34 Present invention B Polymer 7 0.1 g/L A bath 35 Present invention B Polymer 8 0.1 g/L A bath 36 Present invention B Polymer 9 0.1 g/L A bath 37 Present invention B Polymer 10 0.1 g/L A bath 38 Present invention B Polymer 11 0.1 g/L A bath 39 Present invention B Polymer 12 0.1 g/L A bath 40 Present invention B Polymer 13 0.1 g/L A bath 41 Present invention B Polymer 14 0.1 g/L A bath 42 Comparative bath 6 B Not added D

(26) TABLE-US-00006 TABLE 6 Type of Number Conductive water- average film-forming Basic soluble molecular Amount Adhesive- bath bath polymer weight added ness Present B Polymer 15 300 0.1 g/L B invention bath 43 Present B Polymer 16 600 0.1 g/L B invention bath 44 Present B Polymer 17 1000 0.1 g/L A invention bath 45 Present B Polymer 18 2000 0.1 g/L A invention bath 46 Present B Polymer 19 8000 0.1 g/L A invention bath 47 Present B Polymer 20 20000 0.1 g/L A invention bath 48 Comparative B Ethylene 62 0.1 g/L D bath 7 glycol Comparative B Diethylene 106 0.1 g/L D bath 8 glycol Comparative B Triethylene 150 0.1 g/L D bath 9 glycol Comparative B Triethylene 150 20 g/L D bath 10 glycol

(27) TABLE-US-00007 TABLE 7 Conductive film- Basic Water-soluble polymer forming bath bath Type Amount added Adhesiveness Present invention B Polymer 18 0.3 ppm B bath 49 Present invention B Polymer 18 0.5 ppm B bath 50 Present invention B Polymer 18 1 ppm B bath 51 Present invention B Polymer 18 5 ppm A bath 52 Present invention B Polymer 18 10 ppm A bath 53 Present invention B Polymer 18 0.1 g/L A bath 54 Present invention B Polymer 18 1 g/L A bath 55 Present invention B Polymer 18 10 g/L A bath 56

(28) As is clear from the results shown in Tables 5 to 7, plating films with excellent adhesiveness were formed with the use of the conductive film-forming baths (present invention baths 29 to 56) in which a water-soluble polymer having a polyoxyalkylene structure was added to basic bath B, which contained copper sulfate, disodium ethylenediaminetetraacetate, sodium hydroxide, and formaldehyde.

(29) In contrast, plating films exhibited unsatisfactory adhesiveness when formed with the use of basic bath B to which a water-soluble polymer was not added (comparative bath 6) and basic baths B to which a water-soluble polyol compound, which is not a polymer, was added (comparative baths 7 to 10).

Example 3 (Reducing Agent Added)

(30) The same substrate to be treated and jig as used in Example 1 were used and the same procedures as in Example 1 were performed up to the catalyst application step.

(31) After the catalyst application step above, the substrate was sufficiently washed with water, and conductive films were formed under the same conditions as in Example 1, using conductive film-forming baths (present invention baths 57 to 84). For present invention baths 57 to 84, aqueous solutions were used that were obtained by adding the water-soluble polymer having a polyoxyalkylene structure shown in Tables 8 to 10 to an aqueous solution containing 4 g/L of copper sulfate pentahydrate, 20 g/L of 5,5-dimethylhydantoin, 10 g/L of Rochelle salt, 70 g/L of sodium hydroxide, and 10 g/L of mannitol (hereinafter referred to as basic bath C). Thereafter, the resulting product was washed with water, and copper electroplating, nickel plating, and chromium plating were performed under the same conditions as in Example 1. The types of polymers in the tables are the same as those shown in Tables 1 to 3.

(32) For a comparative test, basic bath C to which a water-soluble polymer was not added (comparative bath 11) and basic baths C to which the water-soluble compound shown in Table 9 below was added (comparative baths 12 to 15) were used as conductive film-forming baths to form a conductive film under the same conditions as in Example 1. Thereafter, the resulting product was washed with water, and copper electroplating, nickel plating, and chromium plating were performed under the same conditions as in Example 1.

(33) After plating films were formed by the above method, the adhesiveness of the formed plating films was evaluated as in Example 1. Tables 8 to 10 also show the results.

(34) TABLE-US-00008 TABLE 8 Conductive film-forming Basic Water-soluble polymer bath bath Type Amount added Adhesiveness Present invention C Polymer 1 0.1 g/L A bath 57 Present invention C Polymer 2 0.1 g/L A bath 58 Present invention C Polymer 3 0.1 g/L A bath 59 Present invention C Polymer 4 0.1 g/L A bath 60 Present invention C Polymer 5 0.1 g/L A bath 61 Present invention C Polymer 6 0.1 g/L A bath 62 Present invention C Polymer 7 0.1 g/L A bath 63 Present invention C Polymer 8 0.1 g/L A bath 64 Present invention C Polymer 9 0.1 g/L A bath 65 Present invention C Polymer 10 0.1 g/L A bath 66 Present invention C Polymer 11 0.1 g/L A bath 67 Present invention C Polymer 12 0.1 g/L A bath 68 Present invention C Polymer 13 0.1 g/L A bath 69 Present invention C Polymer 14 0.1 g/L A bath 70 Comparative bath C None D 11

(35) TABLE-US-00009 TABLE 9 Type of Number Conductive water- average film-forming Basic soluble molecular Amount Adhesive- bath bath polymer weight added ness Present C Polymer 15 300 0.1 g/L B invention bath 71 Present C Polymer 16 600 0.1 g/L B invention bath 72 Present C Polymer 17 1000 0.1 g/L A invention bath 73 Present C Polymer 18 2000 0.1 g/L A invention bath 74 Present C Polymer 19 8000 0.1 g/L A invention bath 75 Present C Polymer 20 20000 0.1 g/L A invention bath 76 Comparative C Ethylene 62 0.1 g/L D bath 12 glycol Comparative C Diethylene 106 0.1 g/L D bath 13 glycol Comparative C Triethylene 150 0.1 g/L D bath 14 glycol Comparative C Triethylene 150 20 g/L D bath 15 glycol

(36) TABLE-US-00010 TABLE 10 Conductive film- Basic Water-soluble polymer forming bath bath Type Amount added Adhesiveness Present invention C Polymer 18 0.3 ppm B bath 77 Present invention C Polymer 18 0.5 ppm B bath 78 Present invention C Polymer 18 1 ppm B bath 79 Present invention C Polymer 18 5 ppm A bath 80 Present invention C Polymer 18 10 ppm A bath 81 Present invention C Polymer 18 0.1 g/L A bath 82 Present invention C Polymer 18 1 g/L A bath 83 Present invention C Polymer 18 10 g/L A bath 84

(37) As is clear from the results shown in Tables 8 to 10, plating films with excellent adhesiveness were formed with the use of the conductive film-forming baths (present invention baths 57 to 84) in which a water-soluble polymer having a polyoxyalkylene structure was added to basic bath C, which contained copper sulfate, 5,5-dimethylhydantoin, Rochelle salt, sodium hydroxide, and mannitol.

(38) In contrast, plating films exhibited unsatisfactory adhesiveness when formed with the use of basic bath C to which a water-soluble polymer was not added (comparative bath 11) and basic bath C to which a water-soluble polyol compound, which is not a polymer, was added (comparative baths 12 to 15).

Example 4 (Reducing Agent and Aliphatic Polyalcohol Added)

(39) The same substrate and jig as used in Example 1 were used and the same procedures as in Example 1 were performed up to the catalyst application step.

(40) After the catalyst application step above, the substrate was sufficiently washed with water, and conductive films were formed under the same conditions as in Example 1, using conductive film-forming baths (present invention baths 85 to 112). For present invention baths 85 to 112, aqueous solutions were used that were obtained by adding the water-soluble polymer having a polyoxyalkylene structure shown in Tables 11 to 13 to an aqueous solution containing 4 g/L of copper sulfate pentahydrate, 20 g/L of Rochelle salt, 65 g/L of sodium hydroxide, 10 g/L of formic acid, and 50 g/L of glycerin (hereinafter referred to as basic bath D). Thereafter, the resulting product was washed with water, and copper electroplating, nickel plating, and chromium plating were performed under the same conditions as in Example 1. The types of polymers in the tables are the same as those shown in Tables 1 to 3.

(41) For a comparative test, basic bath D to which a water-soluble polymer was not added (comparative bath 16) and basic baths C to which the water-soluble compound shown in Table 12 below was added (comparative baths 17 to 20) were used as conductive film-forming baths to form a conductive film under the same conditions as in Example 1. Thereafter, the resulting product was washed with water, and copper electroplating, nickel plating, and chromium plating were performed under the same conditions as in Example 1.

(42) After plating films were formed by the above method, the adhesiveness of the formed plating films were evaluated as in Example 1. Tables 11 to 13 also show the results.

(43) TABLE-US-00011 TABLE 11 Conductive film-forming Basic Water-soluble polymer bath bath Type Amount added Adhesiveness Present invention D Polymer 1 0.1 g/L A bath 85 Present invention D Polymer 2 0.1 g/L A bath 86 Present invention D Polymer 3 0.1 g/L A bath 87 Present invention D Polymer 4 0.1 g/L A bath 88 Present invention D Polymer 5 0.1 g/L A bath 89 Present invention D Polymer 6 0.1 g/L A bath 90 Present invention D Polymer 7 0.1 g/L A bath 91 Present invention D Polymer 8 0.1 g/L A bath 92 Present invention D Polymer 9 0.1 g/L A bath 93 Present invention D Polymer 10 0.1 g/L A bath 94 Present invention D Polymer 11 0.1 g/L A bath 95 Present invention D Polymer 12 0.1 g/L A bath 96 Present invention D Polymer 13 0.1 g/L A bath 97 Present invention D Polymer 14 0.1 g/L A bath 98 Comparative bath D None D 16

(44) TABLE-US-00012 TABLE 12 Type of Number Conductive water- average film-forming Basic soluble molecular Amount Adhesive- bath bath polymer weight added ness Present D Polymer 15 300 0.1 g/L B invention bath 99 Present D Polymer 16 600 0.1 g/L B invention bath 100 Present D Polymer 17 1000 0.1 g/L A invention bath 101 Present D Polymer 18 2000 0.1 g/L A invention bath 102 Present D Polymer 19 8000 0.1 g/L A invention bath 103 Present D Polymer 20 20000 0.1 g/L A invention bath 104 Comparative D Ethylene 62 0.1 g/L D bath 17 glycol Comparative D Diethylene 106 0.1 g/L D bath 18 glycol Comparative D Triethylene 150 0.1 g/L D bath 19 glycol Comparative D Triethylene 150 20 g/L D bath 20 glycol

(45) TABLE-US-00013 TABLE 13 Conductive film- Basic Water-soluble polymer forming bath bath Type Amount added Adhesiveness Present invention D Polymer 18 0.3 ppm B bath 105 Present invention D Polymer 18 0.5 ppm B bath 106 Present invention D Polymer 18 1 ppm B bath 107 Present invention D Polymer 18 5 ppm A bath 108 Present invention D Polymer 18 10 ppm A bath 109 Present invention D Polymer 18 0.1 g/L A bath 110 Present invention D Polymer 18 1 g/L A bath 111 Present invention D Polymer 18 10 g/L A bath 112

(46) As is clear from the results shown in Tables 11 to 13, plating films with excellent adhesiveness were formed with the use of the conductive film-forming baths (present invention baths 85 to 112) in which a water-soluble polymer having a polyoxyalkylene structure was added to basic bath D, which contained copper sulfate, Rochelle salt, sodium hydroxide, formic acid, and glycerin.

(47) In contrast, plating films exhibited unsatisfactory adhesiveness when formed with the use of basic bath D to which a water-soluble polymer was not added (comparative bath 16) and basic bath B to which a water-soluble polyol compound, which is not a polymer, was added (comparative baths 17 to 20).