JP4756637B2 - Sulfuric acid copper electrolyte and electrolytic copper foil obtained using the sulfuric acid copper electrolyte - Google Patents

Description

  The present invention relates to a copper electrolytic solution used in the production of an electrolytic copper foil, an electrolytic copper foil obtained using the copper electrolytic solution, a surface-treated copper foil obtained from the electrolytic copper foil, and the surface-treated copper foil. The present invention relates to a copper clad laminate obtained by bonding. In particular, the present invention relates to a copper electrolyte that enables stable production of an electrolytic copper foil characterized by having a low profile on the deposition surface side, and a method for producing an electrolytic copper foil using the copper electrolyte.

  Conventionally, electrolytic copper foil has been widely used as a basic material for printed wiring boards. In addition, electronic and electrical devices in which printed wiring boards are frequently used are required to be so-called light and thin, such as miniaturization and weight reduction. Conventionally, in order to realize such a light, thin and small electronic and electrical equipment, in order to make the signal circuit as fine pitch as possible, a thinner copper foil is used and overetching when forming a circuit by etching. Therefore, it has been demanded to shorten the set time and improve the etching factor of the circuit to be formed.

  On the other hand, electronic and electrical devices that are reduced in size and weight are also requested to be highly functional. Accordingly, in order to secure the component mounting area as much as possible within the limited substrate area, it has been required to improve the etching factor of the circuit. In particular, tape-automated bonding (TAB) substrates, chip-on-flexible (COF) substrates, and the like that directly mount IC chips and the like have been required to have low profile electrolytic copper foils that are more than ordinary printed wiring boards. In addition, the phrase “low profile” used here indicates a state in which the unevenness (profile) at the bonding interface between the metal layer as a conductor and the base resin is low, and has been conventionally adopted in the standard. A numerical value obtained by measuring the surface roughness (Rzjis) with a stylus roughness meter is used as an index.

  In order to solve such problems, as disclosed in Patent Document 1 to Patent Document 5, in the method for producing an electrolytic copper foil by electrolysis of a sulfuric acid copper plating solution, acidic copper sulfate containing various additives A method for producing an electrolytic copper foil characterized by using a plating solution has been proposed. When an electrolytic copper foil is manufactured using these manufacturing methods, a low profile precipitation surface is surely formed, and shows extremely excellent properties as a low profile electrolytic copper foil for conventional use.

JP 2004-35918 A JP 2004-162144 A JP 2004-107786 A JP 2004-137588 A JP 9-143785 A

  However, the clock frequency of a personal computer, which is representative of electronic or electrical equipment, has also increased rapidly in response to the widespread use of image processing, and the calculation speed has increased dramatically. That is, the function of using the computer itself in the same manner as an AV device has been added, not just data processing, which is the original role of a conventional computer. The target functions are not limited to the music playback function, but are a DVD recording / playback function, a TV image recording function, a videophone function, and the like, which are added one after another.

  Along with this, functions required for monitors of personal computers are no longer just data monitors, and image quality that can withstand long-time viewing is required even when images of movies and the like are taken. Therefore, it is required to supply such a high quality monitor at a low price and in large quantities. In addition, a liquid crystal panel has been frequently used in place of the CRT in the present monitor, and this liquid crystal panel is already becoming a mainstream product in the field of flat panel displays for home televisions. As the driver of these liquid crystal panels, the tape automated bonding (TAB) substrate or the chip on flexible (COF) substrate is generally used. In order to achieve a high-definition display, it is required to form finer circuits on the driver board in order to cope with an increase in the number of scanning lines.

  Moreover, when using as a collector for lithium ion batteries, it is preferable to use copper foil with a smooth surface. That is, when applying an active material on a copper foil, a copper foil with a smooth surface should be used as a current collector in order to apply the active material-containing slurry onto the copper foil with a uniform coating thickness. Is advantageous. Further, when a capacitor dielectric layer is formed on a copper foil by a sol-gel method, it is similarly advantageous to use a copper foil having a smooth surface.

  From the above, there has been a demand for a lower profile electrolytic copper foil as compared to the low profile electrolytic copper foil that has been supplied to the market.

Sulfate-based copper electrolyte : The present invention is a sulfate-based copper electrolyte containing 3 -mercapto-1-propanesulfonic acid, a quaternary ammonium salt polymer having a cyclic structure, and chlorine, and contains Janus Green. Provided is a sulfate-based copper electrolyte.

  And it is preferable that the Janus green density | concentration in the said sulfuric acid type copper electrolyte solution is 2 ppm-30 ppm.

Method of manufacturing an electrolytic copper foil: present invention, an electrolytic copper foil, characterized in that using the sulfuric acid base copper electrolytic solution, a solution temperature of 20 ° C. to 60 ° C., to electrolysis at a current density of ^30A / dm ^{2 ~90A} / dm 2 A manufacturing method is provided.

Electrolytic Copper Foil: The electrolytic copper foil according to the present invention is a sulfuric acid copper electrolytic solution containing the above-mentioned “3-mercapto-1-propanesulfonic acid, a quaternary ammonium salt polymer having a cyclic structure, and chlorine, and is Janus Green. It is the electrolytic copper foil obtained by electrolyzing using the sulfuric acid type copper electrolyte solution characterized by including.

Surface-treated copper foil: The surface-treated copper foil according to the present invention is a sulfuric acid-based copper electrolyte containing the above-mentioned “3-mercapto-1-propanesulfonic acid, a quaternary ammonium salt polymer having a cyclic structure, and chlorine. Any one of roughening treatment, rust prevention treatment, silane coupling agent treatment on the precipitation surface of the "electrolytic copper foil obtained by electrolysis using a sulfuric acid copper electrolyte characterized by containing Janus Green" or Two or more types have been performed.

  And the surface roughness (Rzjis) of the bonding surface with the insulating resin base material of the said surface treatment copper foil is provided with the low profile of 5 micrometers or less.

  Copper-clad laminate: The copper-clad laminate according to the present invention is characterized in that the surface-treated copper foil is laminated with an insulating resin base material.

The sulfate-based copper electrolyte according to the present invention is a sulfate-based copper electrolyte characterized by containing 3-mercapto-1-propanesulfonic acid, a quaternary ammonium salt polymer having a cyclic structure, chlorine, and Janus Green. . This sulfate-based copper electrolytic solution enables stable production of an electrolytic copper foil having a lower profile as compared with the copper electrolytic solution used for producing a low profile electrolytic copper foil that has been supplied to the market. Is. In addition, the composition of the sulfuric acid-based copper electrolyte is different from that used in the manufacture of conventional low profile electrolytic copper foils, and it has excellent solution stability, enables stable long-term electrolysis, and enables waste liquid treatment. Even if it considers, it does not cause an increase in cost.

  And the surface treatment copper foil which surface-treated to the deposition surface of the low profile electrolytic copper foil obtained using this sulfuric acid system copper electrolytic solution is a tape automated bonding (TAB) board | substrate with outstanding low profile request | requirement And suitable for forming fine pitch circuits on chip-on-flexible (COF) substrates. And it is suitable also for the use which forms the dielectric material layer for capacitors on a copper foil by the sol-gel method, and the use as a current collection material which comprises the negative electrode of a lithium ion secondary battery.

  Furthermore, the sulfuric acid-based copper electrolyte according to the present invention is not only used for the production of smooth electrolytic copper foil but also for an electro copper plating process in the production process of a printed wiring board, for example, through-holes, due to its excellent throwing power and smooth plating properties. It can be applied to plating and via filling, and can also be expected to have the effect of enabling operation at a high current density even in the electroforming field in which smooth copper plating with a uniform thickness is applied to the surface of a deformed material.

<Sulfate-based copper electrolyte for producing electrolytic copper foil according to the present invention>
The sulfuric acid-based copper electrolyte according to the present invention is a quaternary ammonium salt polymer having a cyclic structure such as 3-mercapto-1-propanesulfonic acid (hereinafter referred to as MPS), diallyldimethylammonium chloride (hereinafter referred to as DDAC), And it is a sulfuric acid type copper electrolyte containing chlorine, and is a sulfuric acid type copper electrolyte characterized by including Janus green. MPS as sulfuric acid base copper electrolytic solution, even with one containing DDAC polymer, and chlorine, as compared with low-profile electrodeposited copper foil which has been supplied to the conventional market, the production of electrolytic copper foil having a lower profile It becomes possible . However , by using a sulfuric acid-based copper electrolyte containing Janus Green , the effect can be obtained even when there is a difference in the polymer structure of the additive DDAC . Therefore, the choices of raw materials are widened, and the influence of the uneven shape of the cathode surface on the electrolytic copper foil deposition surface roughness can be mitigated , and stable production of a low profile electrolytic copper foil becomes possible.

The structural formula of this Janus Green (Janus Green: C ₃₀ H ₃₁ ClN ₆ ) is shown below as chemical formula 1.

And the preferable range of the additive concentration basically contained in the sulfuric acid-based copper electrolyte according to the present invention is 0.5 to 50 ppm for MPS, 1 to 50 ppm for DDAC polymer, and 5 to 60 ppm for chlorine. Yes, it is more preferable to contain Janus Green 2 ppm to 30 ppm. A more preferable Janus Green concentration range is 5 ppm to 15 ppm. Note that MPS may dimerize in the electrolyte solution, but the MPS referred to here is described with the concept including the dimer and the case where it is added as a dimer from the beginning.

If the Janus Green concentration is less than 2 ppm, the effect of leveling the difference in the DDAC polymer structure cannot be obtained, and the effect of reducing the profile and the influence of the unevenness of the cathode surface on the precipitation surface roughness cannot be sufficiently obtained. It is. And even if added over 30 ppm, both the effect of leveling the difference in the DDAC polymer structure, the effect of lowering the profile of the precipitation surface, and the effect of reducing the unevenness of the cathode surface on the precipitation surface roughness are saturated. It has been reached and cannot be said to be useful.

<The manufacturing method of the electrolytic copper foil which concerns on this invention>
The method for producing an electrolytic copper foil according to the present invention includes a copper concentration of 50 g / l to 120 g / l, a free sulfuric acid concentration of about 60 g / l to 250 g / l, and a liquid temperature of 20 ° C. to 60 ° C. it is to electrolysis at a current density of ^{30A / dm 2 ~90A / dm 2} . The liquid temperature is 20 ° C to 60 ° C, more preferably 40 ° C to 55 ° C. When the liquid temperature is less than 20 ° C., the deposition rate decreases, and the variation in mechanical properties such as elongation and tensile strength increases. On the other hand, when the liquid temperature exceeds 60 ° C., the amount of evaporated water increases and the liquid concentration fluctuates quickly, and the deposited surface of the obtained electrolytic copper foil cannot maintain good smoothness. The current density is preferably ^{30A / dm 2 ~90A / dm 2} , more preferably from ^{40A / dm 2 ~70A / dm 2} . When the current density is less than 30 A / dm ² , the copper deposition rate is small and the industrial productivity is poor. On the other hand, when the current density exceeds 90 A / dm ² , the roughness of the deposited surface of the obtained electrolytic copper foil increases, and the low profile cannot be maintained.

<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, this is simply referred to as “electrolytic copper foil”. This electrolytic copper foil generally adopts a continuous production method, and between a drum-shaped rotating cathode and a lead-based anode or an insoluble anode (DSA) arranged to face each other along the shape of the rotating cathode, It is produced by flowing a sulfuric acid-based copper electrolyte, depositing copper on the drum surface of the rotating cathode using an electrolytic reaction, and continuously peeling the deposited copper from the rotating cathode and winding it in a foil state. . At this stage, no surface treatment such as rust prevention treatment has been performed, and copper immediately after electrodeposition is in an activated state and is very easily oxidized by oxygen in the air.

  The surface of the electrolytic copper foil that has been peeled off from the rotating cathode is in contact with the rotating cathode. The surface of the rotating cathode surface that is mirror-finished is a transfer surface, and is glossy and smooth. . On the other hand, the surface shape on the side that was the precipitation side shows a mountain-shaped uneven shape because the crystal growth rate of the deposited copper differs for each crystal surface, and this is called a rough surface or a precipitation surface. This deposited surface serves as a bonding surface with the insulating layer when the copper clad laminate is manufactured. And the smaller the surface roughness of the deposited surface, the better the low profile electrolytic copper foil. And, in the electrolytic copper foil according to the present invention, the surface roughness of this deposited surface is smoother than the glossy surface of the copper foil produced using a general rotating cathode, so the term rough surface is not used, In the present specification, this is referred to as “deposition surface”.

  In order to make a comparison with the low profile electrolytic copper foil that has been supplied to the market in the past, the manufacturing method disclosed in Patent Document 1 to Patent Document 5 described above is traced, and an electrolytic copper foil having a thickness of 12 μm is manufactured. As shown in Comparative Example 1, the value of the surface roughness (Rzjis) on the deposition surface side when the roughness of the cathode surface is optimized is a level exceeding 0.8 μm even in the low profile. On the other hand, as shown in Example 1, the electrolytic copper foil according to the present invention obtains a low profile with a surface roughness Rzjis = 0.6 μm or less on the deposition surface side by optimizing the roughness of the cathode surface. It becomes possible. Here, the lower limit value is not particularly limited, but the lower limit value of the surface roughness measurement by the stylus roughness meter is empirically about 0.1 μm in Rzjis.

  Moreover, the difference with the conventional low profile electrolytic copper foil can be caught clearly by using glossiness as a parameter | index which shows the smoothness of the precipitation surface of the electrolytic copper foil which concerns on this invention. The glossiness used in the present invention was measured by irradiating the surface of the copper foil with measurement light at an incident angle of 60 ° and bounced off at a reflection angle of 60 ° along the flow direction (MD direction) of the electrolytic copper foil. The measurement was performed based on JIS Z 8741-1983, which is a method for measuring glossiness, using a digital variable angle gloss meter VG-1D manufactured by Nippon Denshoku Engineering Co., Ltd. And when the glossiness [Gs (60 °)] of the precipitation surface of the electrolytic copper foil having a thickness of 12 μm manufactured by tracing the manufacturing method disclosed in Patent Document 1 to Patent Document 5 is measured, it is about 250 to 380. Some glossiness is within the range. On the other hand, the electrolytic copper foil according to the present invention can achieve a glossiness [Gs (60 °)] of 500 or more by optimizing conditions such as optimizing the roughness of the cathode surface. Here, the upper limit value of glossiness is not defined, but it seems that the upper limit is about 780 empirically.

  Furthermore, since the surface roughness of the deposited surface of the electrolytic copper foil obtained here is almost equal to or less than the surface roughness of the cathode, it is measured with a stylus-type roughness meter that has been conventionally adopted as a standard. The surface shape is evaluated by a surface analysis device manufactured by Zygo, and is published as reference data.

<Surface-treated copper foil according to the present invention>
The electrolytic copper foil produced using the sulfuric acid-based copper electrolyte solution according to the present invention is any one of roughening treatment, rust prevention treatment, and silane coupling agent treatment on the precipitation surface according to the use in the surface treatment step or As the surface-treated copper foil subjected to two or more kinds, it is generally used for bonding to the insulating layer constituting material of the printed wiring board, and this is referred to as “surface-treated copper foil”.

  In the surface treatment step, roughening treatment is performed on the smooth precipitation surface obtained as described above, and even if rust prevention treatment is performed, the conventional low profile surface treatment copper foil is further. Naturally, a surface-treated copper foil having a low profile roughened surface can be obtained.

  Here, the roughening treatment generally employs either a method in which fine metal particles are adhered to the deposited surface of the electrolytic copper foil or a roughened surface is formed by an etching method. Here, the former method for depositing and forming fine metal particles will be exemplified. This roughening treatment process includes a burn plating process for depositing and adhering fine copper grains on the deposition surface of the electrolytic copper foil, and a covering plating process for preventing the fine copper grains from falling off.

In the step of depositing and adhering fine copper particles on the deposition surface of the electrolytic copper foil, the condition of burnt plating is adopted as the electrolysis condition. Therefore, generally, the copper concentration in the solution used in the step of depositing and adhering fine copper particles is set to a low concentration so that the burn plating conditions can be easily created. The burn plating conditions are not particularly limited, and are determined in consideration of the characteristics of the production line. For example, if a copper sulfate-based solution is used, a copper concentration of 5 to 20 g / l, a free sulfuric acid concentration of 50 to 200 g / l, and other additives (α-naphthoquinoline, dextrin, glue, thiourea, etc.) as necessary In addition, electrolytic plating is performed under the conditions of a liquid temperature of 15 to 40 ° C. and a current density of 10 to 50 A / dm ² .

In addition, the covering plating process for preventing the fine copper grains from falling off is to uniformly coat the copper so as to cover the fine copper grains under smooth plating conditions in order to prevent the fine copper grains deposited and deposited by the burn plating. It is a process for making it precipitate. Therefore, here, the same solution as that used in the above-described electrolytic copper foil manufacturing process can be used as a copper ion supply source. The smooth plating conditions are not particularly limited and are determined in consideration of the characteristics of the production line. For example, if a copper sulfate solution is used, the copper concentration is 50-80 g / l, the free sulfuric acid concentration is 50-150 g / l, the liquid temperature is 40-50 ° C., and the current density is 10-50 A / dm ^2. Electrolytic plating.

Next, a method for forming a rust prevention treatment layer will be described. The rust-proofing layer is for preventing the surface of the surface-treated copper foil from being oxidatively 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 may be any of organic rust prevention using benzotriazole, imidazole or the like, or inorganic rust prevention using zinc, chromate, zinc alloy or the like. What is necessary is just to select the rust prevention according to the intended purpose of the surface-treated copper foil. In the case of organic rust prevention, it is possible to employ techniques such as dip coating, shower ring coating, and electrodeposition method with an organic rust preventive. In the case of inorganic rust prevention, it is possible to use a method of depositing a rust-preventive element on the surface of the electrolytic copper foil layer by electrolysis or other so-called substitution deposition method. For example, a zinc pyrophosphate plating bath, a zinc cyanide plating bath, a zinc sulfate plating bath, or the like can be used for the zinc rust prevention treatment. For example, in the case of a zinc pyrophosphate plating bath, the zinc concentration is 5 to 30 g / l, the potassium pyrophosphate concentration is 50 to 500 g / l, the liquid temperature is 20 to 50 ° C., the pH is 9 to 12, and the current density is 0.3 to 10 A / dm ^2. The electrolytic plating is performed under the above conditions.

  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 for the silane coupling agent treatment is not particularly limited, considering the properties of the insulating layer constituting material used, the plating solution used in the printed wiring board manufacturing process, and the like. , An epoxy silane coupling agent, an amino silane coupling agent, a mercapto silane coupling agent and the like can be arbitrarily selected and used.

  More specifically, vinyl trimethoxy silane, vinyl phenyl trimethoxy lane, γ-methacryloxypropyl trimethoxy silane, γ-glycol are mainly used for the same coupling agent as used for prepreg glass cloth for printed wiring boards. Sidoxypropyltrimethoxysilane, 4-glycidylbutyltrimethoxysilane, γ-aminopropyltriethoxysilane, N-β (aminoethyl) γ-aminopropyltrimethoxysilane, N-3- (4- (3-aminopropoxy) ) Putoxy) propyl-3-aminopropyltrimethoxysilane, imidazole silane, triazine silane, γ-mercaptopropyltrimethoxysilane and the like can be used.

  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 resin base material is 5 micrometers or less. By providing such a low-profile roughened surface, it is possible to ensure adhesiveness that does not impede practical use when bonded to the insulating layer constituent material, and as a substrate there is no practical impediment to heat resistance and resistance. It is possible to obtain chemical properties and peel strength.

  And the copper clad laminated board which concerns on this invention is what bonded the said surface-treated copper foil with the insulating resin base material, It is characterized by the above-mentioned. Here, although it is a process of pasting with an insulating resin base material, the surface treatment copper foil according to the present invention does not require special condition setting, etc., and is known in the art such as hot pressing, film laminating, and casting. The method 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. .

  In this example, as a sulfuric acid-based copper electrolyte, a copper sulfate solution having a copper concentration of 80 g / l, a free sulfuric acid concentration of 140 g / l, and an MPS concentration described in Table 1, DDAC polymer (manufactured by Senca Co., Ltd.) Unisense FPA100L: hereinafter referred to as DDAC-A, and Nittobo Co., Ltd. PAS-H-1L: hereinafter referred to as DDAC-B)) concentration, chlorine concentration, Janus Green-B concentration Using.

Here, the difference between the two types of DDAC used will be described. Both DDAC-A and DDAC-B have a polymer structure in which DDACs are bonded to each other, but DDAC-A and DDAC-B have different bonding states. In particular,
DDAC-A: [-DDAC-] _n
DDAC-B: [-DDAC-SO _2- ] _n
It is.

Then, using the above-described sulfuric acid-based copper electrolyte having a liquid temperature of 50 ° C., two types of titanium (A (surface roughness Rzjis = 0.86 μm) and B (surface roughness Rzjis = 2.50 μm)) are used for the titanium cathode. Was used for electrolysis at a current density of 60 A / dm ² to obtain four types of electrolytic copper foils with a thickness of 12 μm.

  One surface of the electrolytic copper foil is a glossy surface to which the surface shape of the titanium cathode is transferred, and the surface roughness and glossiness of the deposited surface on the other surface side, and surface shape evaluation data by a surface analysis device manufactured by Zygo ( Reference values) are shown in Table 2 and FIG.

  And as a surface treatment of the above-mentioned various electrolytic copper foils, fine copper particles were deposited on the precipitation surface to form a roughened surface. Prior to the formation of the roughened surface, the surface of the electrolytic copper foil was pickled and cleaned. The pickling treatment conditions were a dilute sulfuric acid solution having a concentration of 100 g / l and a liquid temperature of 30 ° C., and an immersion time of 30 seconds.

Then, after the pickling process is finished, the next step is to form fine copper particles on the precipitation surface of the electrolytic copper foil, the step of depositing fine copper particles on the precipitation surface, and preventing the fine copper particles from falling off. The covering plating process for performing was performed. In the former process of depositing fine copper particles, the solution is a copper sulfate-based solution, which has a copper concentration of 7 g / l, a free sulfuric acid concentration of 100 g / l, a liquid temperature of 25 ° C., and a current density of 10 A / dm ² for 10 seconds. Electrolyzed.

Then, when fine copper particles were adhered and formed on the precipitation surface, copper was uniformly deposited so as to cover the fine copper particles under smooth plating conditions as a covering plating process for preventing the fine copper particles from falling off. Here, as the smooth plating conditions, a copper sulfate solution was used, and the conditions were a copper concentration of 60 g / l, a free sulfuric acid concentration of 150 g / l, a liquid temperature of 45 ° C., and a current density of 15 A / dm ² .

When the above-described roughening treatment was completed, next, the rust prevention treatment was performed on both surfaces of the copper foil. Here, the inorganic rust prevention under the conditions described below was employed. Using a zinc sulfate bath, electrolytic plating was performed at a free sulfuric acid concentration of 70 g / l, a zinc concentration of 20 g / l, a liquid temperature of 40 ° C., and a current density of 15 A / dm ² to form a zinc rust prevention layer.

Further, in the case of this example, a chromate layer was formed by electrolysis on the zinc rust preventive layer. At this time, a solution having a chromic acid concentration of 5.0 g / l, a pH of 11.5, and a liquid temperature of 35 ° C. was used, and electrolysis conditions were a current density of 8 A / dm ² and an electrolysis time of 5 seconds.

  When the rust prevention treatment was completed as described above, the silane coupling agent was adsorbed on the roughened rust prevention treatment layer immediately after washing with water in the silane coupling agent treatment tank. The solution composition at this time was such that ion-exchanged water was used as a solvent and γ-glycidoxypropyltrimethoxysilane was added to a concentration of 5 g / l. The solution was adsorbed by spraying with a shower ring.

  When the treatment with the silane coupling agent is completed, it is finally passed through a furnace in which the atmospheric temperature is adjusted and heated so that the foil temperature becomes 140 ° C. with an electric heater over 4 seconds, moisture is removed, and the silane coupling agent The condensation reaction was promoted to obtain four types of surface-treated copper foils (each surface-treated copper foil was identified as Example 1-1 to Example 1-4 in the table). Table 2 shows the surface roughness of the roughened surface after the surface treatment.

Comparative example

[Comparative Example 1]
In Comparative Example 1, a low profile copper foil according to the prior art was manufactured. Since the characteristics of the electrolytic copper foil deposition surface obtained here are clearly different from those of Example 1 and Comparative Example 2 even when compared with the conventional method, the surface shape of the surface analysis apparatus manufactured by Zygo Co., Ltd. Evaluation is not conducted.

Comparative Example 1-1: As a trace experiment of Example 1-1 disclosed in Patent Document 1, copper sulfate (reagent) and sulfuric acid (reagent) were dissolved in ion-exchanged water, and copper sulfate (pentahydrate conversion) 280 g / l, free sulfuric acid concentration 90 g / l, a copolymer of diallyldialkylammonium salt and sulfur dioxide (manufactured by Nitto Boseki Co., Ltd., trade name PAS-A-5, weight average molecular weight 4000: 4 ppm) and polyethylene glycol ( Average molecular weight 1000: 10 ppm) and 3-mercapto-1-propanesulfonic acid (1 ppm) were added, and the chlorine concentration was further adjusted to 20 ppm using sodium chloride to prepare a sulfuric acid copper plating solution. Then, A was used for the titanium cathode, and electrolysis was performed at a liquid temperature of 40 ° C. and a current density of 50 A / dm ² to obtain an electrolytic copper foil having a thickness of 12 μm. The surface roughness Rzjis of this electrolytic copper foil was 0.85 μm, and the glossiness Gs (60 °) was 283. Thereafter, a surface-treated copper foil was obtained in the same manner as in Example 1, and the surface roughness Rzjis of the roughened surface was 4.5 μm. Details are shown in Table 2 together with examples.

Comparative Example 1-2: A sulfuric acid-based copper electrolytic solution having a copper concentration of 90 g / l and a free sulfuric acid concentration of 110 g / l was passed through an activated carbon filter for cleaning treatment. Next, sodium 3-mercapto-1-propanesulfonate (1 ppm), hydroxyethyl cellulose (5 ppm) and low molecular weight glue (number average molecular weight 1560: 4 ppm) as the polymer polysaccharide, and a chlorine concentration of 30 ppm are added to the electrolyte. Sodium chloride was added to each to prepare an electrolyte solution. Then, A was used as the titanium cathode, and electrolysis was performed at a liquid temperature of 58 ° C. and a current density of 50 A / dm ² to obtain an electrolytic copper foil having a thickness of 12 μm. The surface roughness Rzjis of this electrolytic copper foil was 0.83 μm, and the glossiness Gs (60 °) was 374. Thereafter, a surface-treated copper foil was obtained in the same manner as in Example 1, and the surface roughness Rzjis of the roughened surface was 4.8 μm. Details are shown in Table 2 together with examples.

Comparative Example 1-3: In this comparative example, as the sulfuric acid-based copper electrolyte, a copper sulfate solution having a copper concentration of 80 g / l, free sulfuric acid 140 g / l, diallyldimethylammonium chloride concentration of 4 ppm (Unisense manufactured by Senca Co., Ltd.) FPA100L was used), and a chlorine concentration of 15 ppm was used, and a titanium cathode was electrolyzed using A at a current density of 60 A / dm ² to obtain an electrolytic copper foil having a thickness of 12 μm. The surface roughness Rzjis of this electrolytic copper foil was 3.60 μm, and the glossiness Gs (60 °) was 0.7. Thereafter, a surface-treated copper foil was obtained in the same manner as in Example 1, and the surface roughness Rzjis of the roughened surface was 8.2 μm. Details are shown in Table 2 together with examples.

Comparative Example 1-4: In this comparative example, as the sulfuric acid-based copper electrolyte, a copper sulfate solution having a copper concentration of 80 g / l, free sulfuric acid 140 g / l, diallyldimethylammonium chloride concentration of 4 ppm (Unisense manufactured by Senca Co., Ltd.) FPA100L is used), low molecular weight glue (number average molecular weight 1560: 6 ppm), chlorine concentration 15 ppm, solution temperature 50 ° C. A titanium cathode is electrolyzed at a current density of 60 A / dm ² using A, 12 μm A thick electrolytic copper foil was obtained. The surface roughness Rzjis of this electrolytic copper foil was 3.59 μm, and the glossiness Gs (60 °) was 1.0. Thereafter, a surface-treated copper foil was obtained in the same manner as in Example 1, and the surface roughness Rzjis of the roughened surface was 8.0 μm. Details are shown in Table 2 together with examples.

[Comparative Example 2]
Production of Electrolytic Copper Foil: In this comparative example, the sulfuric acid-based copper electrolyte was a copper sulfate solution having a copper concentration of 80 g / l, a free sulfuric acid concentration of 140 g / l, and the MPS concentration and DDAC (SENCA) described in Table 1. Unisense FPA100L: DDAC-A manufactured by Nittobo Co., Ltd. and PAS-H-1L: DDAC-B manufactured by Nitto Boseki Co., Ltd.) were used in a concentration and chlorine concentration. That is, Janus Green-B is not included in the bath composition of Example 1.

Then, using the above-described sulfuric acid-based copper electrolytic solution with a liquid temperature of 50 ° C., two types of current density A (Rzjis = 0.86 μm) and B (Rzjis = 2.50 μm) were used for the titanium cathode. Electrolysis was performed at 60 A / dm ² to obtain four types of electrolytic copper foils with a thickness of 12 μm. One surface of the electrolytic copper foil is a glossy surface to which the surface shape of the titanium cathode is transferred, and the surface roughness and glossiness of the deposited surface on the other surface side, and surface shape evaluation data by a surface analysis device manufactured by Zygo ( Reference values) are shown in Table 2 and FIG.

  Thereafter, Comparative Example 2-2 and Comparative Example 2-4, in which fine copper particles were observed, were excluded, and two types of surface-treated copper foils were formed in the same manner as in Example 1. The surface roughness Rzjis of the roughened surface was 2.76 μm and 4.18 μm. Details are shown in Table 2 together with examples.

<Comparison between Comparative Example 2 and Comparative Example 1>
When comparing the precipitation surface roughness Rzjis of the electrolytic foil obtained by commonly using A to the cathode made of titanium, the precipitation surface roughness Rzjis of the electrolytic copper foil described in Comparative Example 2 and the electrolytic copper of Comparative Example 1 There is a large difference in the surface roughness Rzjis of the foil, which is considered to be due to the composition of the additive. As long as the copper foil after the roughening treatment is judged from the profile measured using a stylus type roughness meter, the surface-treated copper foils of Comparative Example 1-3 and Comparative Example 1-4 have Rzjis of 8.0 μm and 8. It is a state that can be said to be a low profile at 2 μm. And although the surface-treated copper foils of Comparative Example 1-1 and Comparative Example 1-2 have comparatively good low profile copper foils of 4.8 μm and 4.5 μm in Rzjis, Comparative Example 2- In the surface-treated copper foil No. 1, Rzjis = 2.76 μm, which is a better profile reduction, the level difference is clear.

  Further, when looking at the glossiness here, even if the precipitation surface glossiness of Comparative Example 1 is high, it is in the range of 283 to 374, whereas the precipitation surface glossiness of Comparative Example 2-1 is a completely different value of 630. Show. From this, it can be said that the electrolytic copper foil of Comparative Example 2 has a flatter and nearly mirror-deposited surface compared to the electrolytic copper foil of Comparative Example 1. In this respect, as described above, the sulfuric acid-based copper electrolytic solution containing MPS, DDAC polymer, and chlorine has a lower profile than the low profile electrolytic copper foil that has been supplied to the market. It is said that it is possible to produce electrolytic copper foil.

<Contrast between Example 1 and Comparative Example 2>
As a result of comparing Example 1 and Comparative Example 2 (excluding Comparative Example 2-2 and Comparative Example 2-4 in which fine copper particles are observed) in addition to the comparison between the comparative examples, precipitation of electrolytic copper foil The surface surface roughness Rzjis is 0.38 μm to 1.58 μm in Example 1 according to the present invention and 0.56 μm to 2.06 μm in Comparative Example 2, both of which have a low profile. When the samples prepared in a state where the glossiness is not easily affected by the surface roughness of the titanium cathode are compared with each other, Example 1-1 shows 570 to 654, and Comparative Example 2-1 shows 630. Both show larger numerical values than the electrolytic copper foil of Comparative Example 1 obtained from the prior art.

  However, when other characteristics such as appearance are taken into consideration, it is clear in Table 2 that the level of characteristics exhibited by the electrolytic copper foils obtained in Example 1 and Comparative Example 2 varies depending on whether or not Janus Green is added. . Specifically, this will be described below.

Influence of the surface roughness of the titanium electrode: When comparing the 12 micron copper foil obtained from the combination of the copper electrolyte added with DDAC-A and the titanium electrode B with a larger surface roughness, the copper without the addition of Janus Green In the case of using the electrolytic solution, the surface roughness Rzjis = 2.50 μm of the titanium electrode surface is insufficient with respect to the roughness of the precipitation surface Rzjis = 2.06 μm, whereas Janus Green was added. In the copper foil obtained from the copper electrolyte, the precipitation surface roughness Rzjis = 1.58 μm, which reduces the surface roughness of the titanium electrode surface. As a result, it has been empirically found that when a thin foil of 12 micron copper foil is measured with a stylus type roughness meter, not only the profile of the measured surface but also the influence of the profile of the back surface can be obtained. In addition, the addition of Janus Green improves the ability to circulate on the titanium electrode surface, burying the unevenness of the electrode surface, and indicates that a smooth electrodeposition surface is obtained.

  In addition, when comparing a 12 micron copper foil obtained from a combination of a copper electrolyte added with DDAC-A and a titanium electrode A having a small surface roughness, the one using a copper electrolyte without addition of Janus Green is titanium. While the surface roughness Rzjis = 0.86 μm of the electrode surface, the electrolytic copper foil deposition surface roughness Rzjis = 0.56 μm, which is a slightly improved level from the surface roughness of the titanium electrode surface, Janus In the copper foil obtained from the liquid system to which green was added, the electrolytic copper foil deposition surface roughness Rzjis = 0.38 μm, and the influence of the titanium electrode surface roughness on the electrolytic copper foil deposition surface roughness was reduced. There is a clear difference in the smoothing effect.

Difference in structure of DDAC polymer: A 12-micron copper foil obtained from a combination of a liquid system to which DDAC-A was added and a titanium electrode A having a small surface roughness was compared in Example 1-1 and Comparative Example 2-1. Then, in the liquid system to which DDAC-A was added as described above, the Rzjis of the electrolytic copper foil deposition surface obtained from the copper electrolytic solution to which Janus Green was added was 0.38 μm and the glossiness was 654. The deposited surface of the electrolytic copper foil obtained using the copper electrolyte without the addition of Janus Green had a large Rzjis of 0.18 microns and a glossiness of about 20 but could not be said to have a large quality level difference. It has become. However, in the liquid system to which DDAC-B was added, the liquid system to which DDAC-A was added in the electrolytic copper foils of Examples 1-2 and 1-4 obtained from the copper electrolytic solution to which Janus Green was added Although the electrolytic copper foil of almost the same level is obtained, the electrolytic copper foils of Comparative Example 2-2 and Comparative Example 2-4 obtained from the liquid system to which Janus Green is not added have fine copper particles. The existence of is seen.

  That is, even if DDAC-B is used, the smoothing effect equivalent to the case where DDAC-A is used can be obtained by adding Janus Green, and the difference in the effect of reducing the profile due to the difference in the polymer structure of DDAC. It can be seen that leveling is possible by the presence of Janus Green.

Comparison of Zygo images: Although the difference between the electrolytic copper foil of Example 1-1 and the electrolytic copper foil of Comparative Example 2-1 is slight on the data in the general evaluation in Table 2, FIG. 1 and FIG. In comparison, the electrolytic copper foil deposited surface of FIG. 1 manufactured by adding Janus Green has a slightly smaller irregularity depth than the electrolytic copper foil deposited surface of FIG. 2, and the surface shape of FIG. The swell is smaller than 2. It is considered that this is a factor that increases glossiness in combination with small roughness.

  From the above comparison, the electrolytic copper foil of Example 1 obtained using the sulfuric acid-based copper electrolyte characterized by containing Janus Green is less affected by the surface shape of the titanium cathode on the precipitation surface shape. In addition, even when the polymer structure of the DDAC as an additive is different, the difference does not appear as a difference in the shape of the precipitation surface. Therefore, it is clear that the effect of adding Janus Green is a further smoothing effect of the precipitation surface that cannot be obtained by adding only the DDAC polymer, and an effect of reducing restrictions on the additive that can be used.

By using the copper electrolyte solution according to the present invention , a low profile copper deposition surface can be obtained. Therefore, the electrolytic copper foil manufactured using this copper electrolyte has a lower profile than the low profile electrolytic copper foil that has been supplied to the market, and is an additive that is a general process control item. The effect of variations in the characteristics of the cathode and the surface shape of the cathode can be minimized. Therefore, even when the surface treatment is performed on the precipitation surface and the roughening treatment is performed, a low-profile surface-treated copper foil with a level that is not conventionally obtained can be obtained stably and easily. Therefore, the sulfuric acid-based copper electrolyte can be used to produce an electrolytic copper foil suitable for applications that require the formation of fine pitch circuits such as tape automated bonding (TAB) substrates and chip-on-flexible (COF) substrates. It is a suitable copper electrolyte.

It is a Zygo image of the 12 micron electrolytic copper foil precipitation surface obtained in Example 1-1. It is a Zygo image of the 12 micron electrolytic copper foil precipitation surface obtained by the comparative example 2-1.

Claims (7)

A sulfuric acid-based copper electrolytic solution containing 3-mercapto-1-propanesulfonic acid, a quaternary ammonium salt polymer having a cyclic structure, and chlorine, which are used for producing an electrolytic copper foil,
A sulfuric acid-based copper electrolyte containing Janus Green. Sulfuric acid base copper electrolytic solution according to claim 1 Janus Green B concentrations of the sulfuric acid base copper electrolytic solution is 2Ppm～30ppm. Electrolytic copper characterized by electrolyzing at a current density of 30 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. Foil manufacturing method. An electrolytic copper foil obtained by the production method according to claim 3. 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 to the precipitation surface of the electrolytic copper foil which concerns on Claim 4. The surface-treated copper foil according to claim 5, wherein the surface-treated copper foil has a low profile having a surface roughness (Rzjis) of a surface to be bonded to the insulating resin base material of 5 μm or less. A copper clad laminate comprising the surface-treated copper foil according to claim 5 or 6 and an insulating resin substrate.