JP2007247007A - Copper electrolyte, method for manufacturing additive used for copper electrolyte, and electrodeposition copper film obtained by using the copper electrolyte - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sulfuric acid-based copper electrolyte capable of stably yielding a uniform electrodeposition copper film as the electrolyte has an equivalent gloss as compared to the conventional sulfuric acid-based copper electrolyte. <P>SOLUTION: The sulfuric acid-based copper electrolyte includes a bis(3-sulfopropyl)disulfide component. The conventional sulfuric acid-based copper electrolyte added with the As the supply source of bis(3-sulfopropyl)disulfide component, a bis(3-sulfopropyl)disulfide copper hydrate is used. The bis(3-sulfopropyl)disulfide copper hydrate is manufactured by a process of causing crystallization using an organic solvent from a solution mixture prepared by adding a cupric chloride to an aqueous 3-mercapto-1-propane sodium sulfate. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a sulfuric acid-based copper electrolyte containing a bis (3-sulfopropyl) disulfide component, an additive used in the copper electrolyte, a method for producing the same, and an electrodeposited copper film obtained using the copper electrolyte About.

  Metallic copper is widely used for decorative purposes because of its ease of workability, and because it is a good electrical conductor and is relatively inexpensive and easy to handle, electrolytic copper foil is widely used as a basic material for printed wiring boards. Has been. In order to cope with the fine pitch of the printed wiring board accompanying the reduction in the thickness of electrical and electronic equipment, it has been required to lower the profile of the deposited surface of the electrolytic copper foil. Of the electronic component applications, printed wiring board terminal plating minimizes connection reliability and gold usage and reduces costs, and copper plating in the pattern plating process also requires smooth and glossy electrodeposition. It was. However, in some applications, it may be possible to allow appearance irregularities such as streak patterns, such as only a guarantee of thickness, and it is difficult to say that gloss and appearance are always compatible. there were. The technology for obtaining an electrodeposited copper film at such a level is already in widespread use as a globally feasible technology, and there is a demand for technological development to acquire superiority through further differentiation. And the subject of differentiation mentioned above includes stability of external appearance and characteristics and low cost in common with the use of electronic parts including the use of decoration and the production of electrolytic copper foil.

  Against this background, research has been made especially in the field of electrolytic copper foil for printed wiring boards having a high level of required quality. In Patent Document 1, an untreated copper foil suitable for forming a fine pattern is produced by electrolysis. In addition, a compound having a mercapto group, a chloride ion, and a low molecular weight glue having a molecular weight of 10,000 or less and a high molecular weight polysaccharide are added to a sulfuric acid copper plating solution, and the compound having a mercapto group is 3-mercapto 1-propanesulfonic acid. A method is disclosed in which the molecular weight of the salt and the low molecular weight glue is 3000 or less and the high molecular polysaccharide is hydroxyethyl cellulose. According to the examples, it is assumed that sodium 3-mercapto-1-propanesulfonate is used as the 3-mercapto-1-propanesulfonate.

  Further, Patent Document 2 discloses that a rough surface is roughened by allowing an oxyethylene surfactant, polyethyleneimine or a derivative thereof, a sulfonate salt of an active organic sulfur compound, and a chloride ion to be present in an electrolytic solution used for producing an electrolytic copper foil. Low rough surface electrolytic copper having a roughness Rz of 2.0 μm or less, a rough surface with no unevenness on the rough surface, and a uniform low roughness, and an elongation at 180 ° C. of 10.0% or more Obtaining a foil is disclosed. As typical compounds of sulfonates of suitable active organic sulfur compounds, Chemical Formula 4 shows sodium 3-mercapto 1-propanesulfonate and Chemical Formula 5 shows sodium bis (3-sulfopropyl) disulfide. Yes.

JP 09-143785 A JP 2004-263289 A

  However, when 3-mercapto-1-sulfonic acid is used as an additive to obtain gloss, the chemicals available for use in actual operations are mainly sodium salts as described above, and production activities are continued. As a result, alkali metals or alkaline earth metals such as sodium contained in these additives accumulate in the copper electrolyte. Then, it becomes difficult to obtain a stable electrodeposited copper film from the solution, and additional operations such as liquid renewal and phlebotomy are necessary to recover to a normal state. The decrease in the operating rate due to this will also increase the cost. That is, in the conventional technology, a smooth electrodeposited copper film can be obtained in the short term, but the actual situation is that the long-term continuous production stability has not been achieved.

  Therefore, as a result of earnest research, the present inventors have a composition that excludes alkali metals or alkaline earth metals such as sodium, which is an inhibitor of the additive effect contained in 3-mercapto-1-sulfonate. By using an additive, the inventors have come up with a substance that continues to be effective as an additive, a method for producing the substance, and a sulfuric acid-based copper electrolyte containing the additive.

  The present invention relates to a sulfate-based copper electrolyte containing a bis (3-sulfopropyl) disulfide component (hereinafter referred to as “SPS component” in the present application), and the SPS component is bis (3-sulfopropyl) as a supply source. ) A sulfuric acid-based copper electrolyte characterized by using a disulfide copper (hereinafter referred to as “SPS-Cu” in this application) hydrate is provided.

  The sulfuric acid-based copper electrolyte preferably contains a quaternary ammonium salt polymer having a cyclic structure and chloride ions.

  The sulfuric acid copper electrolyte preferably contains glue and chloride ions.

This invention is a manufacturing method of the SPS-Cu hydrate used for the said sulfuric acid system copper electrolysis, Comprising: It has the following processes, The manufacturing method of the SPS-Cu hydrate characterized by the above-mentioned is provided.
a) A step of obtaining a mixed solution by adding cupric chloride to an aqueous solution of sodium 3-mercapto-1-propanesulfonate (hereinafter referred to as “MPS-Na” in the present application).
b) A step of crystallizing SPS-Cu hydrate by adding an organic solvent to the mixed solution.
c) A step of washing the crystallized SPS-Cu hydrate crystals with an organic solvent.
d) A step of drying the SPS-Cu hydrate crystals.

  The mixed solution in step a) has an MPS-Na concentration of 0.5 mol / l to 2.0 mol / l, and the molar ratio of cupric chloride to MPS-Na in the mixed solution ([chlorinated first [Copper] / [MPS-Na]) is preferably 1.5 or more.

  The amount of the organic solvent added in the step b) is preferably 1 to 5 times the volume of the mixed solution obtained in the step a).

  It is also preferred that the organic solvent used in step b) is a ketone.

  The ketones are preferably acetone.

  The organic solvent used in the step c) is preferably an organic solvent that dissolves cupric chloride and makes SPS-Cu hydrate hardly soluble.

  The organic solvent used in the step c) is more preferably any one selected from ketones, alcohols, and nitriles, or a mixture thereof.

  And it is also preferable to wash | clean until the chlorine concentration in the organic solvent which is a washing | cleaning liquid becomes below 20 mg / l in the said process c).

Present invention using the above-mentioned sulfuric acid base copper electrolytic solution, the liquid temperature 20 ° C. to 60 ° C., provide a method of forming a conductive析銅coating, characterized in that the electrolysis at a current density of ^15A / dm ^{2 ~90A} / dm 2 To do.

  This invention provides the manufacturing method of the electrolytic copper foil characterized by peeling off the copper film electrodeposited on the cathode using the formation method of the said electrodeposited copper film.

  This invention provides the electrolytic copper foil obtained by the said manufacturing method.

  The present invention provides a surface-treated copper foil in which one or more of roughening treatment, rust prevention treatment, and silane coupling agent treatment are performed on the surface of the electrolytic copper foil.

  It is preferable that the surface roughness (Rzjis) of the bonding surface of the surface-treated copper foil with the insulating layer constituting material is 5 μm or less.

  This invention provides the copper clad laminated board characterized by bonding the said surface-treated copper foil with an insulating-layer constituent material.

  When the sulfuric acid-based copper electrolyte according to the present invention is used to form an electrodeposited copper film, a smooth electrodeposited copper film is more stable even in long-term continuous operation than when a copper electrolyte according to the prior art is used. Therefore, it can be applied as a method for forming an electrodeposited copper film in various applications such as stable production of low profile electrolytic copper foil. In particular, the sulfuric acid-based copper electrolytic solution according to the present invention is effective in a production form that takes a system configuration that optimizes the properties of the electrolytic solution while the electrolytic solution circulates between the electrolytic step and the step of adding the additive.

<Sulfate-based copper electrolyte according to the present invention>
The present invention is a sulfate-based copper electrolyte containing an SPS component, wherein the SPS component contained in the sulfate-based copper electrolyte is added using SPS-Cu hydrate. Even if MPS-Na is added to the sulfuric acid-based copper electrolytic solution, it dimerizes in the copper electrolytic solution to take an SPS structure, and becomes a sulfuric acid-based copper electrolytic solution containing an SPS component. May cause a phenomenon of inhibiting the surface of electrodeposited copper film from being homogenized due to accumulation of Na, and an SPS component is added as SPS-Cu because Na blood phlebotomy process is necessary to continue stable production. It is preferable.

  Here, the structural formula of MPS is shown in Chemical Formula 1, and the structural formula of SPS-Cu is shown in Chemical Formula 2. As is apparent from this structural formula, since SPS is a dimer of MPS and SPS-Cu is a Cu salt thereof, the effect as an additive can be obtained equally. Furthermore, as described above, since MPS is dimerized in a copper electrolyte solution to obtain an SPS structure, the dimerization reaction is in progress in the solution immediately after the addition, and the additive used when the electrolyte solution is used. However, it is presumed that the use of SPS-Cu is a dimer from the beginning, so that a stable effect can be obtained from the beginning of the addition.

  And the preferable range of the additive concentration basically contained in the sulfuric acid-based copper electrolyte solution according to the present invention is that the SPS concentration is 0.5 to 50 ppm, and a quaternary ammonium salt polymer having a cyclic structure is used. The concentration of the quaternary ammonium salt polymer having a cyclic structure of 1 ppm to 50 ppm, the glue concentration when glue is used is 1 ppm to 50 ppm, and the chlorine concentration is 5 ppm to 100 ppm. Here, the quaternary ammonium salt polymer having a cyclic structure is preferably a diallyldimethylammonium chloride polymer (hereinafter referred to as “DDAC” in the present application). The term “glue” used in the present application includes those commercially available under the names of gelatin, collagen, etc., depending on their molecular weight and purification level, and is used as a generic term for them.

<Method for producing SPS-Cu hydrate according to the present invention>
This invention provides the manufacturing method of SPS-Cu hydrate characterized by having the following processes. By applying the steps shown in the following steps a) to d), a desired SPS-Cu hydrate can be stably obtained with high purity.

a) A step of adding CuCl ₂ to an MPS-Na aqueous solution to obtain a mixed solution.
b) A step of crystallizing SPS-Cu hydrate by adding an organic solvent to the mixed solution.
c) A step of washing the crystallized SPS-Cu hydrate with an organic solvent.
d) A step of drying the SPS-Cu hydrate crystals.

In the above step a), the starting material for the production of SPS-Cu is MPS-Na. Since MPS changes to SPS which is a dimer by reaction with Cu ²⁺ , the copper salt obtained by the above steps a) to d) also has an SPS structure which is a dimer. Any raw material may be used as long as it is an MPS salt. However, since the production object is a Cu salt of MPS dimer, MPS-Na is the most readily available at present. . Therefore, if MPS is easily available in the form of other alkali metals such as K, Ca, Li, and alkaline earth metal salts, these can also be used.

At this time, the molar ratio ([CuCl ₂ ] / [MPS-Na]) is 1.5 or more with respect to the amount of MPS-Na in the aqueous solution having an MPS-Na concentration of 0.5 mol / l to 2.0 mol / l. It is preferable to add CuCl ₂ so that Here, the molar ratio was set to 1.5 or more because an excessive amount of addition is preferable in order to bring the equilibrium state of the chemical reaction in the direction of formation of the SPS-Cu hydrate. Since the effect is not improved even when added, the upper limit of the molar ratio is preferably 4.

The amount of the organic solvent added to the mixed solution in step b) is preferably 1 to 5 times the volume ratio of the mixed solution obtained in step a). Here, the addition of the organic solvent is useful because the solubility of the SPS-Cu hydrate formed in the mixed solution is lowered to cause crystallization and the formation reaction proceeds while shifting the equilibrium state. In order to accelerate the crystallization, it is of course possible to stir and cool, but it is also effective to introduce a seed crystal. At this time, if the addition amount of the organic solvent is less than 1 time, the effect of promoting crystallization is small, and if adding more than 5 times, CuCl ₂ , NaCl and MPS-Na are also crystallized, The optimum range is 1 to 5 times the capacity ratio. In addition, it can be effective to determine the optimum amount by adding the organic solvent in small portions while observing the crystallization state of SPS-Cu. The organic solvent used here is preferably a ketone, and more preferably acetone. It is more preferable to remove the supernatant liquid when the crystallization of the SPS-Cu hydrate reaches the end point, and to move to the next step of washing the crystallized crystals.

The organic solvent used in step c) is preferably an organic solvent that is soluble in CuCl ₂ and hardly soluble in SPS-Cu hydrate. For example, ketones, alcohols, and nitriles can be used, and these can be used alone or in combination. Specifically, it can be selected from acetone for ketones, ethanol and methanol for alcohols, and acetonitrile for nitriles. Since these solvents are soluble in CuCl ₂ , it is possible to wash away the salts adhering to the crystallized SPS-Cu hydrate, and the high purity because it does not dissolve the SPS-Cu hydrate itself. SPS-Cu hydrate is obtained. It is preferable to use the same organic solvent for crystallization used in the previous step b) because of its high convenience. For example, when acetone is selected as a common organic solvent, the vapor pressure at room temperature is relatively low. Since it is easy to handle and has a low boiling point, it also has the advantage of facilitating the drying operation in the subsequent step d).

And in the said process c), it is preferable to wash | clean until the chlorine concentration in the organic solvent which is a washing | cleaning liquid will be 20 mg / l or less. By keeping the amount of CuCl ₂ adhering to the crystal at a low level by thorough washing, the amount of chlorine brought into the sulfuric acid-based copper electrolyte is minimized, and fluctuations in the chlorine concentration in the electrolyte are minimized. To do. Moreover, the lower limit concentration of 20 mg / l almost coincides with a level at which the color of copper ions (which looks yellow when acetone is used as a solvent) becomes invisible, and the end point is determined using the color of the cleaning solution as a secondary index. But there is no real harm. Even if chlorine is contained at this level, there is no inconvenience in using the used organic solvent in the step b).

  In step d), the crystals obtained in step c) are dried. As described above, the use of a solvent having a low boiling point in step c) enables drying at a low temperature or reduced pressure, which is preferable from the viewpoint of manufacturing cost reduction.

<Method for Forming Electrodeposited Copper Film According to the Invention>
In the method for forming an electrodeposited copper film according to the present invention, a cathode for forming an electrodeposited copper film in an electrolytic cell holding or circulating a sulfuric acid-based copper electrolyte having a liquid temperature of 20 ° C. to 60 ° C. is defined as an anode. are opposed disposed, it is to electrolysis at a current density of ^{15A / dm 2 ~90A / dm 2} . The copper concentration of the sulfuric acid-based copper electrolyte at this time is preferably 20 g / l to 120 g / l, and the free sulfuric acid concentration is preferably 60 g / l to 220 g / l. At this time, when the current density is less than 15 A / dm ² , the industrial productivity becomes extremely poor, and when the current density exceeds 90 A / dm ² , the surface roughness of the deposited surface of the obtained electrodeposited copper film is small. It gets bigger. When the copper concentration is less than 20 g / l, although it depends on the current density and the state of stirring of the electrolytic solution, it becomes difficult to obtain a smooth electrodeposited copper film, and when it exceeds 120 g / l, crystallization of copper sulfate hydrate is observed. This is not preferable. When the free sulfuric acid concentration is less than 60 g / l, the electrolysis voltage increases, leading to an increase in power costs. When the free sulfuric acid concentration exceeds 220 g / l, the crystallization of copper sulfate hydrate occurs as in the case where the copper concentration exceeds the upper limit. It is not preferable because it will be seen. However, when metallic copper is used as a soluble anode for the anode or when plating is applied to through-holes with a large aspect ratio, the current density is further reduced, and the generation of anode slime can be achieved by reviewing the liquid temperature and other conditions. It is also possible to optimize the conditions according to the purpose such as preventing or improving the throwing power.

<The manufacturing method of the electrolytic copper foil which concerns on this invention>
This invention provides the manufacturing method of the electrolytic copper foil which peels off the copper film electrodeposited on the rotating cathode using the formation method of the said electrodeposited copper film. Specifically, it is usual to use an electrolytic cell composed of a drum-shaped rotating cathode and a lead alloy-based anode or a dimensionally stable anode (DSA) arranged to face each other along the shape of the rotating cathode. . Then, a sulfuric acid-based copper electrolyte is passed between the rotating cathode and the anode, and copper is deposited on the drum surface of the rotating cathode using an electrolytic reaction, and the deposited copper is continuously peeled off from the rotating cathode to form a foil. It is produced by winding in the state. At this time, when the current density is less than 15 A / dm ² , the industrial productivity becomes extremely poor. When the current density exceeds 90 A / dm ² , the roughness of the deposited surface of the obtained electrolytic copper foil is large. Therefore, production of low profile electrolytic copper foil tends to be difficult. A more preferable current density is 50 A / dm ^{2 to} 70 A / dm ² .

<Electrolytic copper foil according to the present invention>
The “electrolytic copper foil” referred to in the present invention is a state in which no surface treatment is performed, and is sometimes referred to as “untreated copper foil”, “deposited foil” or the like. In the present specification, these are simply referred to as “electrolytic copper foil”. At this stage, there is no surface treatment such as rust prevention treatment, and the copper immediately after electrodeposition is in an activated state and is in a state where it is very easily oxidized by oxygen in the air. In general, surface treatment is performed as described above.

  The surface of the electrolytic copper foil that has been peeled off from the rotating cathode by the above-described manufacturing method is a mirror-finished surface of the rotating cathode that has been transferred and is glossy and smooth. This is called “glossy surface”. On the other hand, the surface shape on the side that was the precipitation side usually shows a mountain-shaped uneven shape because the crystal growth rate of the deposited copper differs for each crystal face, and this side is called the "deposition face" The smaller the surface roughness of the deposited surface, the better the low profile electrolytic copper foil. In general, the deposited surface subjected to the surface treatment serves as a bonding surface with the insulating layer when the copper-clad laminate is manufactured.

<Surface-treated copper foil according to the present invention>
The electrolytic copper foil produced using the sulfuric acid-based copper electrolyte according to the present invention is one or two of roughening treatment, rust prevention treatment, and silane coupling agent treatment on the surface according to the application in the surface treatment step. Generally, it is used for an application in which a seed or more is applied and bonded to the insulating layer constituting material of the printed wiring board, and this is referred to as “surface-treated copper foil”. The roughening treatment is generally performed on the precipitation surface.

  The roughening treatment here is a treatment for physically improving the adhesion with the insulating layer constituting material, and fine metal particles are adhered to the surface of the electrolytic copper foil, or roughened by etching. Either method is used. In many cases, the former roughening treatment process applied by forming fine metal particles is generally adopted, and the burn plating process for depositing fine copper particles on the deposition surface of the electrolytic copper foil and this fine process are performed. It is comprised with the covering plating process for preventing drop-off | omission of a copper grain.

  Next, the rust prevention treatment will be described. This rust prevention treatment is to provide a coating layer for preventing the surface of the copper foil from being oxidized and corroded so as not to hinder the manufacturing process of the copper clad laminate and the printed wiring board. . The method used for the rust prevention treatment can be either organic rust prevention using benzotriazole or imidazole, or inorganic rust prevention using zinc, chromate, zinc alloy, etc. What is necessary is just to select the rust prevention method to be used. In the case of organic rust prevention, it is possible to employ techniques such as dip coating, showering coating, and electrodeposition using an organic rust inhibitor solution. In the case of inorganic rust prevention, it is possible to deposit an antirust element on the surface of the electrolytic copper foil layer using an electrolysis method, an electroless plating method, a sputtering method, a displacement precipitation method, or the like.

  And a silane coupling agent process is a process for improving the adhesiveness with an insulating layer constituent material chemically after a roughening process, a rust prevention process, etc. are complete | finished. As used herein, the silane coupling agent used in the silane coupling agent treatment is not particularly limited, considering the properties of the insulating layer constituent material used, the plating solution used in the printed wiring board manufacturing process, and the like. , An epoxy-based silane coupling agent, an amino-based silane coupling agent, a mercapto-based silane coupling agent, and the like. The silane coupling agent adsorption layer can be formed by techniques such as dip coating, showering coating, and electrodeposition using a silane coupling agent solution.

  And it is preferable that the said surface treatment copper foil is provided with the low profile whose surface roughness (Rzjis) of the bonding surface with the insulating layer constituent material is 5 micrometers or less. Although the surface roughness (Rzjis) of the electrolytic copper foil itself according to the present invention is about 1 μm, the average particle of the copper particles formed on the surface when the aforementioned roughening treatment is performed in the surface treatment step. The diameter is often about 1 to 3 microns, resulting in a maximum value of about 5 μm. By providing such a low profile roughened surface, it is possible to ensure practically sufficient adhesion when laminated to the insulating layer constituent material, sufficient heat resistance characteristics when used as a printed wiring board, It is possible to obtain chemical resistance, peel strength and the like.

<Copper-clad laminate according to the present invention>
And the copper clad laminated board which concerns on this invention is what laminated | stacked the said surface-treated copper foil with the insulating-layer constituent material, It is characterized by the above-mentioned. Here, although it is a step of bonding with the insulating layer constituting material, it is not necessary to set conditions specific to the surface-treated copper foil according to the present invention, and known methods such as hot pressing, film laminating, and casting Is applicable. And, by using the copper clad laminate according to the present invention in which the low-profile surface-treated copper foil as described above is laminated, it becomes possible to produce a fine pitch printed wiring board that has been conventionally difficult to produce. .

<Formation of electrodeposited copper film>
The electrodeposited copper film was evaluated by producing an electrolytic copper foil whose appearance and surface roughness were easy to evaluate. In the production of the electrolytic copper foil, a batch type apparatus that can circulate the electrolytic solution was used in both the examples and the comparative examples, DSA was used as the anode, and a flat plate made of titanium and having a surface roughness of Rzjis = 0.86 μm was used as the cathode. . Since it has been empirically found that the influence of the surface condition of the titanium cathode is strong until the second sheet immediately after the start of the test, all the third and subsequent sheets are evaluated in the examples. Each test No. In Example 2, the third and fourth sheets of the four samples prepared in Example 2 without any liquid adjustment were evaluated. One surface of the electrolytic copper foil obtained here is a glossy surface to which the surface shape of the titanium cathode is transferred, and the other surface side is a deposition surface to be evaluated.

[Example 1]
In Example 1, using ion-exchanged water, the copper concentration is 80 g / l, the free sulfuric acid concentration is 140 g / l, the DDAC polymer concentration is 4 ppm, the chlorine concentration is 20 ppm, and SPS-Cu hydrate is added and listed in Table 1. A sulfuric acid-based copper electrolyte having a concentration of 1 was prepared. Then, this sulfuric acid-based copper electrolyte was electrolyzed at a current density of 60 A / dm ² at a liquid temperature of 50 ° C., and three electrolytic copper foils having a thickness of 12 μm were obtained. Table 1 shows the evaluation data of the glossiness [Gs (60 °)] and the surface roughness [Rzjis] of the deposited surface of the electrolytic copper foil obtained on the third sheet, together with the production conditions. The MD described in the table is Machine Direction (the vertical direction during the electrolytic test, which corresponds to the traveling direction of the web-like copper foil in the continuous production state using the rotating drum), and TD is the Transverse Direction. It is used as an abbreviation (direction orthogonal to MD), and indicates the direction of incidence and reflection of light when measuring glossiness [Gs (60 °)]. The surface roughness (Rzjis) is measured in the TD direction according to JIS B 0601-2001. Moreover, the glossiness is measured according to JIS Z 8741-1997, using a VG-2000 type manufactured by Nippon Denshoku Industries Co., Ltd.

  The above results show that the electrolytic copper foil obtained from the SPS-Cu-free electrolyte has glossiness [Gs (60 °)] of 7.3 and 7.4, and surface roughness Rzjis of 1.82 μm. It is difficult to say glossy foil. On the other hand, the electrolytic copper foil obtained by using a sulfuric acid-based copper electrolyte prepared using SPS-Cu hydrate has a gloss [Gs (60 °)] of 477 to 571, The surface roughness Rzjis is 0.63 μm to 0.83 μm, and it is confirmed that an electrodeposited copper film having smooth and high gloss can be obtained by using a copper electrolyte containing SPS-Cu hydrate. It was done.

[Example 2]
In Example 2, the DDAC polymer used in Example 1 was replaced with glue, ion exchange water was used to give a copper concentration of 80 g / l, free sulfuric acid concentration of 140 g / l, glue concentration of 3 ppm, chlorine concentration of 10 ppm, and SPS- A sulfuric acid-based copper electrolyte was prepared by adding Cu hydrate to a SPS-Cu concentration of 1.5 ppm. Then, this sulfuric acid-based copper electrolytic solution was electrolyzed at a current temperature of 60 A / dm ² at a liquid temperature of 50 ° C., and four sheets with a thickness of 12 μm were prepared without adding an additive. Degree [Gs (60 °)] and surface roughness (Rzjis) were evaluated. The results are shown in Table 2.

  When the gloss [Gs (60 °)] of the electrolytic copper foil deposited surface obtained above is observed, it is 300 to 421 when glue is used, and the gloss [Gs (60) when a DDAC polymer is used. °)]. However, the appearance was uniform and no streaky pattern was generated, and the surface roughness (Rzjis) was 0.78 μm and 0.83 μm, which was almost the same level as when DDAC polymer was used. . Therefore, even when glue is used as an additive, it is possible to form a high-gloss and smooth electrodeposited copper film having a glossiness [Gs (60 °)] of 300 or more.

[Comparative Example 1]
In the comparative example 1, it was set as the copper electrolyte which assumed the case where use was continued as MPS-Na as an additive. Therefore, basically, as in the examples, using ion-exchanged water, the copper concentration was 80 g / l, the free sulfuric acid concentration was 140 g / l, the DDAC polymer concentration was 4 ppm, the chlorine concentration was 20 ppm, and MPS-Na was added to reduce the MPS-Na concentration. A sulfuric acid-based copper electrolyte with 6 ppm was prepared. And adjusted to Na concentration described in Table 3 was added over Na ₂ SO ₄ in order to reproduce the accumulation of Na ion. Here, it is considered that about 10 ppm of Na was present as an impurity even in the electrolyte solution without addition of Na ₂ SO ₄ . Then, this sulfuric acid-based copper electrolytic solution was set at a liquid temperature of 50 ° C., and electrolysis was carried out at a current density of 60 A / dm ² without adding an additive to produce five 12 μm-thick electrolytic copper foils. The glossiness [Gs (60 °)] and visual appearance were evaluated, and the inhibitory effect of the additive effect by Na was investigated. The results are shown in Table 3.

  From the above, smooth electrolytic copper foil obtained by using a copper electrolyte of Na concentration: 0.5 g / l to 3.0 g / l assuming that the concentration of Na is increased by continuing the addition of MPS-Na Then, it is possible to obtain a copper foil having a gloss level [Gs (60 °)] of 400 to 650, but a streak pattern is generated as a result of visual inspection of the appearance. Therefore, a stable and uniform electrodeposited copper film having a high glossiness cannot be obtained from a sulfuric acid-based copper electrolyte containing a high concentration of Na ions. From this, it can be seen that the technical significance of using SPS-Cu hydrate is very large in terms of preventing accumulation of Na in the electrolytic solution.

  As described above, when SPS-Cu is used, which is a sulfuric acid-based copper electrolyte containing SPS according to the present invention, there is no need to worry about accumulation of Na in the copper electrolyte, and gloss with a uniform low profile Thus, the formation of the electrodeposited copper film having the above can be carried out stably for a long period of time using the same electrolytic solution. Therefore, it can be convinced that the above-described copper electroforming and printed wiring board processing processes also exhibit excellent effects with respect to similar quality requirements. In the above, good results have been obtained as a solution structure for the purpose of producing an electrolytic copper foil. However, in the actual operation, the optimum range may be changed depending on the intended use. And the sulfuric acid-based copper electrolyte according to the present invention does not deny the presence of other additives, and can further enhance the effects of the above additives or contribute to stabilizing the quality during continuous production. If it is confirmed, etc., it may be added arbitrarily. However, the use of Na salts as other additives is not preferable for the purpose of the present invention.

  The sulfuric acid-based copper electrolytic solution according to the present invention accumulates during continuous operation by accompanying 3-mercapto-1-sulfonic acid added to the electrolytic solution, and has an adverse effect on the precipitation form. Because it does not contain similar metals, it can withstand long-term use. Therefore, the sulfuric acid-based copper electrolyte provides stable low profile electrolytic copper foil that is required for applications that require the formation of fine pitch circuits such as tape automated bonding substrates (TAB) and chip-on-flexible substrates (COF). Of course, it is a sulfuric acid-based copper electrolyte suitable for production, and can be suitably used not only for decorative purposes but also for electroplating and copper plating used for processing printed wiring boards.

Claims (17)

A sulfuric acid-based copper electrolyte containing a bis (3-sulfopropyl) disulfide component,
The bis (3-sulfopropyl) disulfide component uses a bis (3-sulfopropyl) disulfide copper hydrate as its supply source. The sulfuric acid-based copper electrolyte according to claim 1, comprising a quaternary ammonium salt polymer having a cyclic structure and chloride ions. The sulfuric acid-based copper electrolyte according to claim 1, comprising glue and chlorine ions. It is a manufacturing method of the bis (3-sulfopropyl) disulfide copper hydrate used for the sulfuric acid system copper electrolyte solution according to any one of claims 1 to 3,
The manufacturing method of the bis (3-sulfopropyl) disulfide copper hydrate characterized by having the following processes.
a) A step of adding a cupric chloride to a sodium 3-mercapto-1-propanesulfonate aqueous solution to obtain a mixed solution.
b) A step of crystallizing bis (3-sulfopropyl) disulfide copper hydrate by adding an organic solvent to the mixed solution.
c) A step of washing the crystallized bis (3-sulfopropyl) disulfide copper hydrate crystals with an organic solvent.
d) A step of drying the crystals of bis (3-sulfopropyl) disulfide copper hydrate. The mixed solution in step a) has a sodium 3-mercapto-1-propanesulfonate concentration of 0.5 mol / l to 2.0 mol / l, and cupric chloride and 3-mercapto-1-propane in an aqueous solution. The molar ratio of sodium sulfonate amount ([cupric chloride] / [3-mercapto-1-propanesulfonic acid sodium salt]) is 1.5 or more, bis (3- (Sulfopropyl) disulfide copper hydrate production method. 6. The screw according to claim 4, wherein the amount of the organic solvent added in the step b) is 1 to 5 times the volume of the mixed solution obtained in the step a). A method for producing (3-sulfopropyl) disulfide copper hydrate. The method for producing bis (3-sulfopropyl) disulfide copper hydrate according to any one of claims 4 to 6, wherein the organic solvent used in the step b) is a ketone. The method for producing bis (3-sulfopropyl) disulfide copper hydrate according to claim 7, wherein the ketones are acetone. The organic solvent used in the step c) is an organic solvent that dissolves cupric chloride and hardly dissolves bis (3-sulfopropyl) disulfide copper hydrate. 9. A method for producing bis (3-sulfopropyl) disulfide copper hydrate according to any one of 8 above. 10. The bis according to claim 4, wherein the organic solvent used in the step c) is any one selected from ketones, alcohols and nitriles or a mixture thereof. A method for producing (3-sulfopropyl) disulfide copper hydrate. The bis (3-sulfopropyl) according to any one of claims 4 to 10, wherein, in the step c), washing is performed until a chlorine concentration in an organic solvent as a washing liquid is 20 mg / l or less. Method for producing disulfide copper hydrate. Electrodeposition characterized by electrolyzing at a current density of 15 A / dm ^{2 to} 90 A / dm ² at a liquid temperature of 20 ° C. to 60 ° C. using the sulfuric acid-based copper electrolytic solution according to claim 1. A method for forming a copper film. A method for producing an electrolytic copper foil, wherein the method for forming an electrodeposited copper film according to claim 12 is used to strip the copper film electrodeposited on the cathode. The electrolytic copper foil obtained using the manufacturing method of the electrolytic copper foil of Claim 13. The surface-treated copper foil which performed any 1 type, or 2 or more types of the roughening process, the antirust process, and the silane coupling agent process on the surface of the electrolytic copper foil of Claim 14. The surface-treated copper foil according to claim 15, wherein the surface-treated copper foil has a surface roughness (Rzjis) of a bonding surface with the insulating layer constituting material of 5 μm or less. A copper clad laminate comprising the surface-treated copper foil according to claim 15 or 16 and an insulating layer constituting material.