JP2010222651A - Copper-clad laminate and method of forming copper plating film - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a copper-clad laminate capable of forming a fine-pitch microcircuit by improving etching factor of a copper plating film, and to provide a method of forming the copper plating film for the film-formation to the copper-clad laminate. <P>SOLUTION: The method of forming the copper plating film comprises: a process of adding additives for precipitating carbon and oxygen into plated copper such as PEG, SPS, JGB and citric acid to a copper plating liquid in one copper plating tank 28 or a plurality of copper plating tanks 12, 13, 14; and a process of immersing a resin film 1 into the copper plating liquid to form one layer of copper plating layer 8 or a plurality of layers of copper plating layers 4, 5, 6, whereby the precipitation amounts of carbon and oxygen increase stepwise or gradually toward the plating layer on the downstream side from the copper plating layer on the upstream side at least on the surface of the resin film. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a copper-clad laminate used for manufacturing a printed wiring board incorporated in a mobile phone, a display, or the like, and a method for forming a copper plating film to be formed on the copper-clad laminate.

  The copper-clad laminate is obtained by sequentially depositing a nickel chromium alloy sputtered film and a copper sputtered film on a resin film that is a material to be plated, and forming a copper plated film on the copper sputtered film.

  The copper-clad laminate is an intermediate processed product for obtaining the printed wiring board on which a conductor circuit is formed by performing a patterning process.

  As the patterning process, there is a method of cutting a surplus copper plating film with a cutter or a laser to form a conductor circuit. However, since there are problems such as the time required for forming the conductor circuit and the difficulty in processing, the subtractive method is generally performed.

  In this subtractive method, first, a photoresist is applied to a position to be a conductor circuit on a copper plating film, and a pattern mask made of this photoresist is formed by a photolithography method. Then, by spraying an etching solution such as a ferric chloride aqueous solution on the pattern mask, the copper plating film exposed at the opening of the pattern mask is removed, and then the pattern mask is removed with the etching solution. A circuit is formed. As the copper etching solution, a ferric chloride aqueous solution is mainly used.

  However, when the copper plating film exposed to the opening of the pattern mask is removed by the etching solution, the surface side of the copper plating film is side-etched, and thus the conductor circuit is formed as shown in FIG. The top width T becomes narrow and the cross-sectional shape becomes trapezoidal.

  Therefore, in the subtractive method, if the etching is performed until electrical insulation between the conductor circuits is ensured, the wiring pitch width becomes too wide. However, there is a problem that a fine pitch fine circuit cannot be formed.

In order to solve this problem, in Patent Document 1 described below, when a copper plating layer is formed on a material to be plated by an electrolytic plating method, the fine current pitch is controlled by a subtractive method by controlling the plating current density supplied to the electrode. A device capable of forming a fine circuit has been proposed.
This is because the crystal density of the copper is changed from large to small by continuously controlling the current density from a low current density to a high current density, and the surface of the copper plating layer from the plated material side. The structure is continuously changed from a copper plating layer having an easy etching structure to a copper plating layer having a difficult etching structure in the direction. Accordingly, during the etching process, the etching rate of the copper plating layer on the surface side is slow, and the etching rate of the copper plating layer on the material to be plated side is fast. It is possible to improve the ratio of the amount of progress, that is, the etching factor of the copper plating film.

JP 2004-190073 A

  However, in the invention of Patent Document 1, even if the crystal structure of copper is changed by controlling the current density, the crystalline state of copper is unstable immediately after the production of the copper-clad laminate, and the heat treatment in the production process (Drying device etc.) makes the fine copper crystals of the copper plating film on the surface side coarse and uniform. For this reason, it is very difficult to maintain the copper fine crystal state of the copper plating film on the surface side, and as a result, there is a problem that the etching factor cannot be improved reliably.

  The present invention has been made to solve the problems of the prior art, and by improving the etching factor of the copper plating film, it is possible to form a fine pitch fine circuit even if the subtractive method is performed. A copper-clad laminate and a method for forming a copper-plated film on the copper-clad laminate are provided.

  In order to solve the above-described problem, the method for forming a copper plating film according to claim 1 includes immersing the material to be plated in a copper plating solution in a plurality of copper plating tanks in order, so that at least the material to be plated is obtained. In the method for forming a copper plating film in which a plurality of copper plating layers are formed stepwise on the surface, carbon and oxygen are co-deposited on the copper to be plated, and additives having different eutectoid amounts of the carbon and oxygen are added. And using the additive in the plating solution so that the amount of eutectoid increases stepwise from the upstream plating tank to the downstream plating tank. is there.

  Further, in the method for forming a copper plating film according to claim 2, a plurality of the plating materials are stepwise formed on at least the surface of the plating material by sequentially immersing the plating material in a copper plating solution in a plurality of copper plating tanks. In the method of forming a copper plating film for forming a copper plating layer, an additive for co-depositing carbon and oxygen into the copper to be plated is used, and the plating tank on the upstream side is directed toward the plating tank on the downstream side. The amount of the additive added to the plating solution is adjusted so that the concentration of the additive increases stepwise.

  Furthermore, the film-forming method of the copper plating film of Claim 3 forms a copper plating layer in the at least surface of a to-be-plated material by immersing a to-be-plated material in the copper plating tank which accommodated the copper plating liquid. In the method of forming a copper plating film, an additive for co-depositing carbon and oxygen into the copper to be plated is added to the copper plating solution, and the concentration of the additive is gradually increased during copper plating. The additive is added to the copper plating solution over time.

  And the film-forming method of the copper plating film of Claim 4 WHEREIN: The said additive contains at least 1 sort (s) of polyethyleneglycol, bis (3-sulfopropyl) disulfide, Janus green B, and citrate containing carbon. It is characterized by being.

  A copper-clad laminate according to claim 5 is formed by forming a copper plating film on the material to be plated by the copper plating film forming method according to any one of claims 1 to 4. It is characterized by.

According to the film-forming method of the copper plating film of Claim 1, a to-be-plated material is immersed in the copper-plating liquid in a some copper plating tank sequentially, and several stepwise on the surface of a to-be-plated material. When forming a copper plating layer, carbon and oxygen are co-deposited on the copper to be plated, and additives having different amounts of eutectoid of the carbon and oxygen are used, and the upstream side plating tank and the downstream side In order to increase the amount of eutectoid in a stepwise manner toward the plating tank, because the additive is added to the plating solution, on the surface of the material to be plated, in the thickness direction, It becomes possible to form a copper plating layer in which the amount of eutectoid of carbon and oxygen increases stepwise. Then, the carbon and oxygen are co-deposited to refine the crystal grain size of the copper plating layer, and in order to prevent the eutectoid from dissolving the copper plating layer, the copper plating is gradually performed in the thickness direction. As a result, the etching rate of the copper plating film is improved.
Therefore, it is possible to manufacture a copper-clad laminate capable of forming a fine pitch fine circuit even when a subtractive method is performed when manufacturing a printed wiring board.

Moreover, according to the film-forming method of the copper plating film of Claim 2, by immersing a to-be-plated material in the copper plating solution in a some copper plating tank in order, it is stepwise on the surface of a to-be-plated material. When forming a plurality of copper plating layers, an additive for co-depositing carbon and oxygen on the copper to be plated is used, and the above steps are gradually performed from the upstream plating bath toward the downstream plating bath. Since the addition amount of the additive added to the plating solution is adjusted so that the concentration of the additive is high, the coating is performed in the same manner as in the method for forming a copper plating film according to claim 1. A copper plating layer in which the amount of eutectoid of carbon and oxygen increases stepwise can be formed on the surface of the plating material in the thickness direction. Then, the carbon and oxygen are co-deposited to refine the crystal grain size of the copper plating layer, and in order to prevent the eutectoid from dissolving the copper plating layer, the copper plating is gradually performed in the thickness direction. As a result, the etching rate of the copper plating film is improved.
Accordingly, similar to the method for forming a copper plating film according to claim 1, a copper-clad laminate capable of forming a fine-pitch fine circuit even when a subtractive method is performed when a printed wiring board is manufactured. Can be manufactured.

Furthermore, according to the film-forming method of the copper plating film of Claim 3, a copper plating layer is formed in the surface of a to-be-plated material by immersing a to-be-plated material in the copper plating tank which accommodated the copper plating liquid. When the copper plating solution is added, an additive for co-depositing carbon and oxygen into the copper to be plated is added to the copper plating solution, and the concentration of the additive gradually increases during copper plating. Since the additive is added over time, it is possible to form a copper plating layer on the surface of the material to be plated, in which the amount of eutectoid of carbon and oxygen gradually increases in the thickness direction. Become. Then, the carbon and oxygen are co-deposited to refine the crystal grain size of the copper plating layer, and in order for this eutectoid to suppress the dissolution of the copper plating layer, the copper plating layer gradually increases in the thickness direction. As a result, the etching rate of the copper plating film is improved.
Therefore, similarly to the method of forming a copper plating film according to claims 1 and 2, it is possible to form a fine-pitch fine circuit even if a subtractive method is performed when a printed wiring board is manufactured. A copper-clad laminate can be manufactured.

By the way, copper is oxidized by Fe ³⁺ ions and dissolved as copper ions in an aqueous ferric chloride solution as an etching solution, as shown in the following half reaction formula.
Cu + Fe ³⁺ → Cu ⁺ + Fe ²⁺

It is said that the dissolution rate of copper in the etching solution is strongly influenced by the rate at which Fe ³⁺ ions are reduced to Fe ²⁺ ions.

Therefore, as in the method for forming a copper plating film according to claim 4, at least one of polyethylene glycol, bis (3-sulfopropyl) disulfide, Janus Green B, and citrate containing carbon as the additive. By using one kind, it is possible to co-deposit carbon and oxygen on copper to be reliably plated. When a small amount of the carbon and oxygen eutectoid is co-deposited on the plated copper in order to suppress the reduction reaction activity of copper, the reduction reaction of Fe ³⁺ ions is suppressed. As a result, the dissolution rate of the copper plating layer, that is, the etching rate can be reduced.

  Moreover, according to the copper clad laminated board of Claim 5, a copper plating film is formed into the said to-be-plated material by the film-forming method of the copper plating film in any one of Claim 1 thru | or 3. Therefore, when a conductor circuit of a printed wiring board is formed by etching, a fine pitch fine circuit can be formed even if a subtractive method is performed.

1 is a longitudinal sectional view showing a first embodiment of a copper-clad laminate according to the present invention. It is a longitudinal cross-sectional view which shows 2nd Embodiment of the copper clad laminated board which concerns on this invention. BRIEF DESCRIPTION OF THE DRAWINGS The printed wiring board formed by patterning the copper clad laminated board which concerns on this invention is shown, (a) is a longitudinal cross-sectional view of the printed wiring board formed from FIG. 1, (b) is FIG. It is a longitudinal cross-sectional view of the printed wiring board formed from. It is a schematic block diagram of the plating apparatus which manufactures the copper clad laminated board of FIG. It is a schematic block diagram of the plating apparatus which manufactures the copper clad laminated board of FIG. It is a longitudinal cross-sectional view of the printed wiring board formed by patterning the conventional copper clad laminated board. The copper-clad laminate which concerns on an Example is shown, (a) is a longitudinal cross-sectional view of a 1st copper-clad laminate, (b) is a longitudinal cross-sectional view of a 2nd copper-clad laminate. It is a graph which shows the ratio which occupies the area of the copper clad laminated board for every particle size of the copper in the copper plating layer of the surface side of the 1st copper clad laminated board of FIG. It is a graph which shows the ratio which occupies the area of the copper clad laminated board for every particle size of the copper in the copper plating layer by the side of the resin film of the 1st copper clad laminated board of FIG. It is a microscope picture which shows the state after circuit formation of the 1st copper clad laminated board of FIG. It is a microscope picture which shows the state after circuit formation of the 2nd copper clad laminated board of FIG.

1st Embodiment of the copper clad laminated board concerning this invention is described using FIG.
First, a nickel chromium alloy sputtered film 2 and a copper sputtered film 3 having a total thickness of 5 to 200 nm are sequentially formed on a belt-shaped resin film 1 having a thickness of 20 to 50 μm.

  And the 1st copper plating layer 4, the 2nd copper plating layer 5, and the 3rd copper plating layer 6 are laminated | stacked on the copper sputtered film 3 so that it may become 5-15 micrometers in total thickness in order.

  The copper plating layers 4, 5, 6 are obtained by eutectizing carbon and oxygen on plated copper, and the third copper plating layer 6 on the surface side is the first copper plating layer on the resin film 1 side. Compared to 4, the amount of eutectoid of carbon and oxygen is increased.

  Accordingly, in the copper-clad laminate 7, the amount of carbon and oxygen eutectoid is greater in the copper plating layer 5 than in the copper plating layer 4 on the resin film 1 side, and in the copper plating layer 6 more than the copper plating layer 5. A copper plating film composed of copper plating layers 4, 5 and 6 in which the amount of eutectoid of carbon and oxygen increases stepwise from the resin film 1 in the thickness direction of the surface. Has been.

Next, two embodiments of the method for forming a copper plating film formed on the copper-clad laminate 7 will be described.
First, in the first embodiment, the surface of the belt-shaped resin film 1 is cleaned with a plasma treatment in an argon atmosphere, and the hydrophilicity is improved on the same surface. A film 2 and a copper sputtered film 3 are successively formed on the nickel chromium alloy sputtered film 2 successively.

  Next, after winding the resin film 1 on which the nickel chromium alloy sputtered film 2 and the copper sputtered film 3 are formed into a roll shape, the winding roll 10 is attached to the unwinding member attached to the plating apparatus 11 as a shaft. Install in the vertical direction.

  As shown in FIG. 4, the plating apparatus 11 includes a plurality of (three tanks in this embodiment) electrolytic copper plating tanks 12 installed on the downstream side of the resin film 1 unwound from the winding roll 10 by the unwinding member. , 13 and 14. And these electrolytic copper plating tanks 12, 13, and 14 are arrange | positioned in a line along the conveyance direction of the resin film 1, and a copper sulfate plating solution is contained in each electrolytic copper plating tank 12,13,14. Reserved.

  Here, an additive formed by mixing SPS and PEG is added to the copper sulfate plating solution in the first electrolytic copper plating tank 12.

  Further, an additive made of PEG is added to the copper sulfate plating solution in the second electrolytic copper plating tank 13.

  Furthermore, the copper sulfate plating solution in the third electrolytic copper plating tank 14 is an addition of SPS (bis (3-sulfopropyl) disulfide), PEG (polyethylene glycol), and JGB (Janus Green B). An agent has been added.

  The plating apparatus 11 is provided with feeding water washing tanks 15, 16, 17, and 18 between the electrolytic copper plating tanks 12, 13, and 14 and upstream and downstream of the electrolytic copper plating tanks 12, 13, and 14, respectively. It has been.

  On the other hand, each power supply washing tank 15, 16, 17, 18 rotates in contact with the surface of the resin film 1 to supply electricity to the copper sputtered film 3 together with a rotating roller 19 that stably conveys the resin film 1. A flexible power supply roller 20 is incorporated.

  Further, sulfuric acid that decomposes and removes inorganic contaminants adhering to the surface of the copper sputtered film 3 between the feeding water washing tank 15 installed on the upstream side of the first electrolytic copper plating tank 12 and the unwinding member. Is installed in the pickling tank 21.

  On the other hand, a rust prevention tank 22, a washing tank 23, a drying device 24, and a take-up roller 25 are arranged in this order downstream from the feeding water washing tank 18 installed on the downstream side of the third electrolytic copper plating tank 14. Has been.

  The resin film 1 unwound from the winding roll 10 by the plating apparatus having the above-described configuration is disposed in the electrolytic copper plating tanks 12, 13, and 14 after the surface of the copper sputtered film 3 is cleaned in the pickling tank 21. The copper plating layers 4, 5, 6 are formed on the surface of the copper sputtered film 3 by immersing in a copper sulfate plating solution to which different additives are sequentially added.

  At that time, first, the resin film 1 is energized to the copper sputtered film 3 in the feeding water rinsing tanks 15 and 16, whereby the surface of the copper sputtered film 3 is plated on the copper plated film 12 in the first electrolytic copper plating tank 12. The 1st copper plating layer 4 which codeposited 10-30 ppm oxygen and 20-30 ppm carbon is formed.

  Next, the first copper plating layer 4 is energized in the feeding water rinsing tanks 16, 17, so that in the second electrolytic copper plating tank 13, the surface of the first copper plating layer 4 is plated with 500 to 850 ppm of plated copper. A second copper plating layer 5 in which oxygen and 100 to 200 ppm of carbon are co-deposited is formed.

  Next, when the second copper plating layer 5 is energized in the feeding water washing tanks 17 and 18, 500 to 850 ppm of copper plated on the surface of the second copper plating layer 5 in the third electrolytic copper plating tank 14. 3rd copper plating layer 6 which co-deposited the oxygen and 400-1500 ppm of carbon is formed.

  In addition, when carbon is eutectoid in the copper plating layer, if the carbon content (eutectoid) amount exceeds 2000 ppm, the specific resistance value of the copper plating film exceeds 3 μΩcm. In this case, the electrical conductivity is remarkably lowered, so that the carbon content is preferably 2000 ppm or less.

  Thereafter, the resin film 1 on which the copper plating layers 4, 5, 6 are formed is immersed in the rust prevention liquid in the rust prevention tank 22, then washed in the water washing tank 23, and dried in the drying device 24. After being wound, it is wound around the winding roller 25. Thereby, the copper-clad laminate 7 is obtained.

Next, a second embodiment of a method for forming a copper plating film to be formed on the copper-clad laminate will be described.
The film forming method of this embodiment is different from that of the first embodiment in that three different types of additives are added to the three electrolytic copper plating tanks 12, 13, and 14, respectively. The difference from the first embodiment is that one kind of additive is added to the electrolytic copper plating tanks 12, 13, and 14 of the tank so as to have different concentrations. For this reason, about the process same as 1st Embodiment, such as the formation process of the sputtered films 2 and 3, description is abbreviate | omitted by using the same code | symbol.

  In the second embodiment, the same plating apparatus 11 as in the first embodiment is used, and in the copper sulfate plating solution in the first electrolytic plating tank 12, SPS (bis (3-sulfopropyl) disulfide) and An additive formed by mixing PEG (polyethylene glycol) and JGB (Janus Green B) is added in a predetermined addition amount to co-deposit carbon and oxygen on copper as a plating.

  Then, an additive formed by mixing SPS (bis (3-sulfopropyl) disulfide), PEG (polyethylene glycol), and JGB (Janus Green B) into the copper sulfate plating solution in the second electrolytic copper plating tank 13. However, it is added in a larger amount than the first electrolytic copper plating tank 12.

  Furthermore, an additive formed by mixing SPS (bis (3-sulfopropyl) disulfide), PEG (polyethylene glycol), and JGB (Janus Green B) in the third electrolytic copper plating tank 14 is added to the second electrolytic copper plating tank 14. It is added in a larger amount than the copper plating tank 13.

  The resin film 1 unwound from the winding roll 10 by the plating apparatus 11 having the above configuration is subjected to electrolytic copper plating baths 12, 13, and 14 after the surface of the copper sputtered film 3 is washed in the pickling bath 21. The copper plating layers 4, 5, 6 are formed on the surface of the copper sputtered film 3 by being immersed in copper sulfate plating solutions having different concentrations of additives.

  At that time, first, the resin film 1 is energized to the copper sputtered film 3 in the feeding water rinsing tanks 15 and 16, whereby the surface of the copper sputtered film 3 is carbonized on the surface of the copper sputtered film 3 in the first electrolytic plating tank 12. And the 1st copper plating layer 4 which co-deposited oxygen is formed.

  Next, the first copper plating layer 4 is energized in the feeding water rinsing tanks 16 and 17, whereby the first copper plating is applied to the plated copper on the surface of the first copper plating layer 4 in the second electrolytic copper plating tank 13. A second copper plating layer 5 in which carbon and oxygen are co-deposited with a larger amount of eutectoid than layer 4 is formed.

  Next, when the second copper plating layer 5 is energized in the feeding water washing tanks 17 and 18, the second copper plating is applied to the plated copper on the surface of the second copper plating layer 5 in the third electrolytic copper plating tank 14. A third copper plating layer 6 in which carbon and oxygen are co-deposited with a larger amount of eutectoid than plating layer 5 is formed.

  Thereafter, the resin film 1 on which the copper plating layers 4, 5, 6 are formed is immersed in the rust prevention liquid in the rust prevention tank 22, then washed in the water washing tank 23, and dried in the drying device 24. After that, it is taken up by the take-up roller 25. Thereby, the copper-clad laminate 7 is obtained.

According to the method for forming a copper plating film according to the first embodiment having the above-described configuration, an additive composed of PEG and SPS is added to the copper sulfate plating solution in the three electrolytic copper plating baths 12, 13, and 14 sequentially. , An additive consisting of PEG, and an additive consisting of PEG, SPS and JGB are added in order, and the resin film 1 is immersed in the copper sulfate plating solution stepwise. It becomes possible to form the copper plating layers 4, 5, and 6 in which the amount of eutectoid of carbon and oxygen increases stepwise in the thickness direction. The carbon and oxygen eutectoid has a stepwise decrease in the etching rate of the copper plating layers 4, 5 and 6 in the thickness direction in order to suppress the reduction reaction activity of copper during etching. As a result, the etching factor of the copper plating film is improved.
Therefore, in actuality, it is possible to manufacture a copper-clad laminate capable of forming a fine-pitch fine circuit even when a subtractive method is performed when manufacturing a printed wiring board.

In addition, according to the method for forming a copper plating film according to the second embodiment, the copper sulfate plating solution in the three copper plating tanks is sequentially changed from the first electrolytic copper plating tank 12 to the third electrolytic copper plating tank 14. In view of this, the amount of additive consisting of PEG, SPS, and JGB added to the copper sulfate plating solution is adjusted so that the concentration of the additive increases stepwise. Similarly to the copper plating film forming method described above, copper plating layers 4, 5, and 6 in which the amount of eutectoid of carbon and oxygen gradually increases in the thickness direction on the surface of the resin film are formed. Is possible. The carbon and oxygen eutectoid has a stepwise decrease in the etching rate of the copper plating layers 4, 5 and 6 in the thickness direction in order to suppress the reduction reaction activity of copper during etching. As a result, the etching factor of the copper plating film is improved.
Therefore, in actuality, it is possible to manufacture a copper-clad laminate capable of forming a fine-pitch fine circuit even when a subtractive method is performed when manufacturing a printed wiring board.

  And according to the copper clad laminated board which concerns on 1st Embodiment, the copper which consists of the copper plating layers 3, 4, and 5 in which the eutectoid amount of carbon and oxygen increases stepwise toward the thickness direction of the resin film. Since the plating film is formed, when the printed wiring board is manufactured, the copper sputtered film 3 and the copper plating film are etched with a ferric chloride aqueous solution, and then the nichrome alloy sputtered film 2 is etched to conduct the conductor circuit. 3A, the top width T of the conductor circuit becomes narrower than the design value due to side etching of the copper plating layer 6 as the surface layer, as shown in FIG. This can be effectively prevented and a fine pitch fine circuit can be formed.

Next, 2nd Embodiment of the copper clad laminated board concerning this invention is described using FIG.
First, as in the first embodiment of the copper-clad laminate, a nickel chromium alloy sputtered film 2 and a copper sputtered film 3 having a total thickness of 5 to 200 nm are formed on a belt-shaped resin film 1 having a thickness of 20 to 50 μm. Are sequentially formed.

  And the copper plating layer 8 is laminated | stacked on the copper sputter layer 3 by thickness 5-15 micrometers.

  The copper plating layer 8 is obtained by eutecting carbon and oxygen on plated copper, and gradually increases the eutectoid amount of carbon and oxygen from the resin film 1 toward the surface thickness direction. Yes.

  Accordingly, the copper-clad laminate 9 is configured by laminating a copper plating film composed of a copper plating layer 8 that gradually increases the eutectoid amount of carbon and oxygen from the resin film 1 to the surface in the thickness direction. .

Next, a method for forming a copper plating film to be formed on the copper-clad laminate 9 will be described.
In addition, the film-forming method of this embodiment makes an electrolytic copper plating tank into one tank, adds one kind of additive to the electrolytic copper plating tank, and also continues to an electrolytic copper plating tank during electrolytic plating. The point which adds an additive differs from 1st Embodiment and 2nd Embodiment of the film-forming method of the copper plating film in 1st Embodiment of a copper clad laminated board. For this reason, the same code | symbol is used about the process same as 1st Embodiment and 2nd Embodiment of the film-forming method of the copper plating film in 1st Embodiment of copper clad laminated boards, such as the formation process of sputtered films 2 and 3. The explanation is omitted by using.

  As shown in FIG. 5, the plating apparatus 27 used in the present embodiment is schematically represented by an electrolytic copper plating tank 28 composed of one tank installed on the downstream side of the resin film 1 unwound from the winding roll 31 by the unwinding member. It is configured. The electrolytic copper plating tank 28 stores a copper sulfate plating solution.

  Here, an additive formed by mixing SPS (bis (3-sulfopropyl) disulfide), PEG (polyethylene glycol), and JGB (Janus Green B) in the copper sulfate plating solution in the electrolytic copper plating tank 28. Is added in a predetermined amount to co-deposit carbon and oxygen on copper to be plated.

  On the other hand, an additive formed by mixing SPS (bis (3-sulfopropyl) disulfide), PEG (polyethylene glycol), and JGB (Janus Green B) from the outside of the plating apparatus 27 is added to the electrolytic copper plating tank 28. An additive introduction pipe 38 to be introduced is provided.

  In addition, feeding water washing tanks 29 and 30 are provided on the upstream side and the downstream side of the electrolytic copper plating tank 28, respectively.

  Further, in each of the feeding water washing tanks 29 and 30, a rotatable feeding roller that contacts the surface of the resin film 1 and supplies electricity to the copper sputtered film 3 together with a rotating roller 32 that stably conveys the resin film 1. 33 is built-in.

  Also, sulfuric acid for decomposing and removing inorganic contaminants adhering to the surface of the copper sputtered film 3 is accommodated between the feeding water washing tank 29 installed on the upstream side of the electrolytic copper plating tank 28 and the unwinding member. An acid pickling tank 34 is installed.

  On the other hand, a rust prevention tank 35, a water washing tank 36, a drying device 37 and a take-up roller 26 are arranged in this order downstream from the feeding water washing tank 30 installed on the downstream side of the electrolytic copper plating tank 28. .

  The resin film 1 unwound from the winding roll 31 by the plating apparatus 27 having the above configuration is cleaned in the electrolytic copper plating tank 28 after the surface of the copper sputtered film 3 is cleaned by the pickling tank 34. The copper plating layer 8 is formed by being immersed in a plating solution and supplying a current.

  At this time, the copper sulfate plating solution in the electrolytic copper plating tank 28 is SPS (bis (3-sulfopropyl) disulfide), PEG (polyethylene glycol), JGB ( By introducing the additive formed by mixing Janus Green B), the concentration of the additive in the copper sulfate plating solution is gradually increased. Thereby, the copper plating layer 8 in which the amount of eutectoid of carbon and oxygen gradually increases from the resin film 1 toward the surface thickness direction on the surface of the copper sputtered film 3 is formed.

  Next, the resin film 1 on which the copper plating layer 8 is formed is immersed in a rust prevention liquid in the rust prevention tank 35, then washed with water in the water washing tank 36, and dried in the drying device 37. It is wound around the winding roller 26. Thereby, the copper-clad laminate 9 is obtained.

According to the method for forming a copper plating film having the above structure, an additive consisting of PEG, SPS, and JGB is added to a copper sulfate plating solution, and a resin film is immersed in the copper sulfate plating solution. In some cases, the additive is added to the copper sulfate plating solution so that the concentration of the additive gradually increases, so that the surface of the resin film 1 is gradually increased in the thickness direction. It becomes possible to form the copper plating layer 8 in which the amount of eutectoid of carbon and oxygen increases. The carbon and oxygen eutectoid gradually reduces the etching rate of the copper plating layer 8 in the thickness direction in order to suppress the reduction reaction activity of copper during etching. The etching factor of the film is improved.
Therefore, in actuality, it is possible to manufacture a copper-clad laminate capable of forming a fine-pitch fine circuit even when a subtractive method is performed when manufacturing a printed wiring board.

  And according to the copper clad laminated board which concerns on 2nd Embodiment, the copper plating film which consists of the copper plating layer 8 in which the eutectoid amount of carbon and oxygen increases gradually toward the thickness direction of a resin film is formed. Therefore, when manufacturing a printed wiring board, the copper sputtered film 3 and the copper plating film are etched with a ferric chloride aqueous solution, and then the nichrome alloy sputtered film 2 is etched to form a conductor circuit. 3B, it is possible to effectively prevent the top width T of the conductor circuit from becoming narrower than the design value by side etching of the copper plating layer 8 on the surface side, as shown in FIG. Thus, a fine pitch fine circuit can be formed.

In addition, according to the method for forming a copper plating film according to the copper-clad laminate of the first embodiment and the second embodiment, carbon-containing polyethylene glycol, bis (3-sulfopropyl) disulfide, Janus Green B In addition, since an additive composed of at least one of citrate and citrate is used, carbon and oxygen can be co-deposited on copper to be reliably plated. When a small amount of the carbon and oxygen eutectoid is co-deposited on the plated copper in order to suppress the reduction reaction activity of copper, the reduction reaction of Fe ³⁺ ions is suppressed. As a result, the dissolution rate of the copper plating layer, that is, the etching rate can be reduced.

  In addition, in the copper-clad laminates 7 and 9 of the present embodiment, the copper-clad laminate is formed in a shape that suppresses the cross-sectional shape of the conductor circuit from becoming trapezoidal by the etching process. Therefore, the top width and the width on the resin film side are equivalent, and the width of the central portion may be narrowed by side etching. In this case, when forming the copper plating layer on the resin film side and the surface side of the copper plating film, an additive having a small amount of eutectoid of carbon and oxygen is added to form the copper plating layer on the center side. It is possible to cope with this by adding an additive that increases the amount of eutectoid of carbon and oxygen.

  First, as a preliminary preparation for manufacturing the first copper-clad laminate according to the present embodiment, the third electrolytic copper plating tank 14 and the feeding water washing tank 18 of the plating apparatus 11 are removed, and the remaining two electrolytic copper plating tanks 12 are removed. 1 and 2 were stored 2 L of the copper sulfate plating solution shown in Table 1 below maintained at 25 ° C. And the additive of Table 2 below is added to the copper sulfate plating solution of the first electrolytic plating tank 12, and the additive of Table 3 below is added to the copper sulfate plating solution of the electrolytic plating tank 13. Added.

  Next, the surface of the belt-shaped resin film (Toray DuPont Kapton EN) 1 was cleaned by plasma treatment in an argon atmosphere, and the hydrophilicity was improved. A sputtered alloy film 2 and a sputtered copper film 3 were successively and successively formed on the sputtered nickel chromium alloy film 2.

  Next, after winding the resin film 1 on which the sputtered films 2 and 3 were formed in a roll shape, the winding roll 10 was placed on the winding member attached to the plating apparatus 11 in the axial direction.

Next, after the surface of the copper sputtered film 3 is cleaned by the acid bath 21, the copper sputtered film 3 is energized for 9 minutes under the condition of a current density of 2 A / dm ² by the feeding water rinsing tanks 15 and 16. In the first electrolytic plating tank 12, a 4 μm copper plating layer 39 was formed on the surface of the copper sputtered film 3.

Next, by supplying electricity to the copper plating layer 4 for 9 minutes under the condition of a current density of 2 A / dm ² by the feeding water washing tanks 16 and 17, the surface of the copper plating layer 39 is 4 μm in the second electrolytic copper plating tank 13. The copper plating layer 40 was formed.

  Thereafter, the resin film 1 on which the copper plating layers 39 and 40 are formed is immersed in the rust prevention liquid in the rust prevention tank 22, then washed in the water washing tank 23 and dried in the drying device 24. It is wound around the winding roller 25. Thereby, as shown in FIG. 7A, a copper-clad laminate 42 on which a copper plating film composed of copper plating layers 39 and 40 was formed was obtained.

  And the amount of eutectoid of carbon and oxygen of each of the copper plating layers 39 and 40 of the copper-clad laminate 42 of this embodiment was measured by a GD-MS method (glow discharge mass spectrometry).

  In addition, the average crystal grain size was measured by an EBSP method (Electron Bas Scatter Diffraction Pattern).

  Further, a photoresist is applied to a position to be a conductor circuit on the copper plating film 41 of the copper-clad laminate of the present embodiment, and a pattern mask made of this photoresist is formed by a photolithography method. And after removing the copper plating film 41 exposed to the opening of the pattern mask by spraying an etching solution such as ferric chloride aqueous solution on the pattern mask, the pattern mask is removed with the etching solution. A conductor circuit was formed, the etching rates of the copper plating layers 39 and 40 were measured, and the cross-sectional shape after the circuit formation was confirmed.

  At this time, in order to compare with the copper-clad laminate of the above embodiment, the electrolytic copper plating tank of the plating apparatus 11 is only one tank of the first electrolytic copper plating tank 12, and the same conditions as the first electrolytic copper plating tank 12 are used. Of the copper sulfate plating solution, and only the additives shown in Table 2 above are added, and the surface of the copper sputtered film 3 is energized for 18 minutes under the condition of a current density of 2 A / dm 2, thereby 12, as shown in FIG. 7B, a second copper-clad laminate 43 was obtained in which a copper plating film comprising an 8 μm copper plating layer 41 was formed on the surface of the copper sputtered film 3. And the conductor circuit was formed by performing the said circuit formation method, and the cross-sectional shape after circuit formation was confirmed.

  Table 4 below shows the carbon and oxygen eutectoid amounts of the copper plating layers 39 and 40 of the copper-clad laminate of this embodiment, and the etching rate. FIG. 8 shows the ratio of the area of the copper-clad laminate of this embodiment for each copper particle size in the copper plating layer 40, and FIG. 9 shows this embodiment for each copper particle size in the copper plating layer 39. The ratio which occupies the area of the copper clad laminated board of a form is shown.

  According to Table 4 above, it can be confirmed that the amount of eutectoid of carbon and oxygen is larger in the copper plating layer 40 than in the copper plating layer 39.

  Moreover, when the average particle diameter of each of the copper plating layers 39 and 40 is measured, the average particle diameter of copper in the copper plating layer 39 is 1.40 μm, and the average particle diameter of copper in the copper plating layer 40 is 0.40 μm. Can be confirmed.

  This proved that the copper to be plated was refined as the amount of eutectoid of carbon and oxygen was increased.

  And when the etching rate at the time of circuit formation is confirmed, the etching rate of the copper plating layer 40 with a large amount of eutectoid of carbon and oxygen is slower than that of the copper plating layer 39 with a small amount of carbon and oxygen. It can be confirmed that

  As a result, it can be demonstrated that the etching rate at the time of circuit formation can be adjusted by adjusting the amount and concentration of the additive added to the electrolytic copper plating tank during copper plating, and the amount of eutectoid of carbon and oxygen. It has been proved that the etching rate decreases as the amount increases.

  On the other hand, when the copper-clad laminate of this embodiment after the circuit formation of FIG. 10 is confirmed, the copper-clad laminate of this embodiment is formed in a square cross-sectional shape of the conductor circuit without side etching. It can be confirmed.

  In comparison, when the second copper-clad laminate after the circuit formation of FIG. 11 is confirmed, the surface side of the copper plating film is side-etched, the top width of the conductor circuit is narrowed, and the cross-sectional shape of the conductor circuit is It can be confirmed that it is formed into a shape.

  As a result, the cross-sectional shape of the conductor circuit is formed in a square shape by forming a copper plating layer so that the amount of eutectoid of carbon and oxygen increases from the resin film 1 toward the surface thickness direction. Was able to prove.

1 Resin film (material to be plated)
4 1st copper plating layer 5 2nd copper plating layer 6 3rd copper plating layer 7 Copper-clad laminate (first embodiment)
8 Copper plating layer 9 Copper-clad laminate (second embodiment)
12 1st electrolytic copper plating tank 13 2nd electrolytic copper plating tank 14 3rd electrolytic copper plating tank 28 Electrolytic copper plating tank

Claims (5)

In the film-forming method of the copper plating film in which a plurality of copper plating layers are formed stepwise on at least the surface of the material to be plated by immersing the material to be plated in a copper plating solution in a plurality of copper plating tanks sequentially.
While co-depositing carbon and oxygen into the copper to be plated, and using additives having different amounts of carbon and oxygen eutectoid, the upstream plating bath is directed toward the downstream plating bath in stages. A method for forming a copper plating film, wherein the additive is added to the plating solution so as to increase the amount of eutectoid. In the film-forming method of the copper plating film in which a plurality of copper plating layers are formed stepwise on at least the surface of the material to be plated by immersing the material to be plated in a copper plating solution in a plurality of copper plating tanks sequentially.
Using an additive for co-depositing carbon and oxygen in the copper to be plated, the concentration of the additive is increased stepwise from the upstream plating tank toward the downstream plating tank. A method for forming a copper plating film, comprising adjusting the amount of the additive added to the plating solution. In the film-forming method of the copper plating film which forms the copper plating layer on at least the surface of the material to be plated by immersing the material to be plated in a copper plating tank containing a copper plating solution,
An additive for co-depositing carbon and oxygen into the copper to be plated is added to the copper plating solution, and the copper plating solution is gradually added to the copper plating solution so that the concentration of the additive gradually increases during copper plating. Method for forming a copper plating film, characterized by adding an additive   The said additive is at least 1 sort (s) of polyethyleneglycol, bis (3-sulfopropyl) disulfide, Janus green B, and a citrate containing carbon, The any one of Claims 1-3 characterized by the above-mentioned. A method for forming a copper plating film.   5. A copper-clad laminate obtained by forming a copper plating film on the material to be plated by the method for forming a copper plating film according to claim 1.