JPWO2019188837A1 - Manufacturing method of surface-treated copper foil, copper-clad laminate, and printed wiring board - Google Patents

Abstract

It has excellent adhesion to resin, chemical resistance and heat resistance, and etching residue is unlikely to remain. Therefore, adhesion reliability of both copper foil-base material and base material-base material in the production of printed wiring boards A surface-treated copper foil that can be improved is provided. This surface-treated copper foil is provided on at least one surface of the copper foil and the copper foil, and has a Zn adhesion amount of 3 mg / m2 or more and 100 mg / m2 or less, a Ni adhesion amount of 5 mg / m2 or more and 60 mg / m2 or less, and Mo adhesion. The amount is 2.0 mg / m2 or more and 40 mg / m2 or less, and Ni / (Zn + Ni + Mo), which is the ratio of the Ni adhesion amount to the total amount of Zn adhesion amount, Ni adhesion amount and Mo adhesion amount, is 0.40 or more and 0. It is provided with a Zn—Ni—Mo layer of .80 or less.

Description

The present invention relates to a method for manufacturing a surface-treated copper foil, a copper-clad laminate, and a printed wiring board.

In the process of manufacturing a printed wiring board, copper foil is widely used in the form of a copper-clad laminate bonded to an insulating resin base material. In this respect, it is desired that the copper foil and the insulating resin base material have high adhesion in order to prevent the wiring from peeling off during the production of the printed wiring board. Therefore, in ordinary copper foils for manufacturing printed wiring boards, the bonded surfaces of the copper foils are roughened to form irregularities composed of fine copper particles, and the irregularities are pressed into the inside of the insulating resin base material. By exerting the anchor effect, the adhesion is improved.

By the way, for the purpose of preventing deterioration of the copper foil due to an oxide film (rust) that may occur on the surface of the copper foil during storage or the like, the surface of the copper foil is usually subjected to a rust preventive treatment, and the rust preventive treatment layer. Various alloy layers are known as. For example, Patent Document 1 (Japanese Unexamined Patent Publication No. 2008-285751) discloses a surface-treated copper foil in which the total amount of Zn and Ni on the adhesive surface to be bonded to the insulating resin base material is 40 mg / m ² or more. According to this copper foil, the surface of the copper foil can be sufficiently coated with the Zn—Ni alloy, so that the adhesion to the insulating resin base material and the chemical resistance can be improved. Further, Patent Document 2 (Japanese Unexamined Patent Publication No. 62-142389) discloses a copper foil for a printing circuit having a Ni-Mo layer, and according to this copper foil, chemical resistance and heat resistance after circuit formation are disclosed. It is said to have excellent sex.

Japanese Unexamined Patent Publication No. 2008-285751 Japanese Unexamined Patent Publication No. 62-142389

By the way, with the recent increase in functionality of portable electronic devices and the like, the frequency of signals is increasing regardless of whether they are digital or analog in order to process a large amount of information at high speed, and printed wiring boards suitable for high frequency applications are becoming available. It has been demanded. In such a printed wiring board for high frequency, reduction of transmission loss is desired in order to enable transmission of high frequency signals without deteriorating the quality. The printed wiring board is provided with a copper foil processed into a wiring pattern and an insulating base material, and the transmission loss is mainly composed of a conductor loss caused by the copper foil and a dielectric loss caused by the insulating base material. .. Therefore, in order to reduce the conductor loss caused by the copper foil and the dielectric loss caused by the insulating base material, it is convenient if a copper foil having small irregularities and an insulating base material having a low dielectric loss tangent can be used. However, when a copper foil having small irregularities is used, the above-mentioned anchoring effect is weakened, so that the physical adhesion between the copper foil and the base material is reduced, and the peel strength (peeling) is particularly high after chemical immersion or soldering process. The decrease in strength) becomes a problem. In addition, an insulating base material having a low dielectric loss tangent generally has a low functional group activity and a low chemical adhesion to a copper foil. Moreover, when the unevenness of the copper foil is small, the surface of the insulating base material that is in contact with the copper foil when the copper foil is etched and removed becomes flat, so that not only the copper foil and the base material but also the insulation is insulated. The adhesion between the base material and the base material with other insulating base materials laminated on the surface of the base material is also reduced. In this regard, when the Ni-Mo layer as disclosed in Patent Document 2 is used as the rust preventive treatment layer for the copper foil, the residue derived from the Ni-Mo layer remains on the surface of the insulating base material after etching the copper foil. There is a problem that the adhesive force is further lowered by hindering the resin adhesion with other insulating substrates laminated on the surface of the insulating substrate.

By adopting a Zn—Ni—Mo layer having a predetermined composition as a rust preventive treatment layer, the present inventors have excellent adhesion to a resin, chemical resistance and heat resistance, and etching residues are less likely to remain. Therefore, it is possible to provide a surface-treated copper foil capable of improving the adhesion reliability of both the copper foil-base material and the base material-base material when used in the production of a printed wiring board. I got the knowledge.

Therefore, an object of the present invention is that the adhesiveness to the resin, the chemical resistance, and the heat resistance are excellent, and the etching residue is hard to remain. Therefore, when used in the production of a printed wiring board, the copper foil-base material is used. And to provide a surface-treated copper foil capable of improving the adhesion reliability of both the substrate and the substrate.

According to one aspect of the present invention, the copper foil and
Provided on at least one surface of the copper foil, the Zn adhesion amount is 3 mg / m ² or more and 100 mg / m ² or less, the Ni adhesion amount is 5 mg / m ² or more and 60 mg / m ² or less, and the Mo adhesion amount is 2.0 mg / m. Ni / (Zn + Ni + Mo), which is m ² or more and 40 mg / m ² or less and is the ratio of the Ni adhesion amount to the total amount of the Zn adhesion amount, the Ni adhesion amount, and the Mo adhesion amount, is 0.40 or more and 0. With a Zn-Ni-Mo layer of .80 or less,
A surface-treated copper foil is provided.

According to another aspect of the present invention, the surface-treated copper foil and
An insulating base material provided on at least one surface of the surface-treated copper foil, and
A copper-clad laminate is provided.

According to another aspect of the present invention, there is provided a method for manufacturing a printed wiring board, which comprises manufacturing a printed wiring board using the surface-treated copper foil or the copper-clad laminate.

It is a process flow chart which shows the manufacturing process (steps (a)-(d)) of the evaluation sample in the adhesion evaluation between the base materials of Examples 1-9.

Definitions Definitions of terms or parameters used to identify the present invention are shown below.

As used herein, the "maximum height Sz" is a parameter representing the distance from the highest point to the lowest point on the surface, which is measured according to ISO25178. The maximum height Sz can be calculated by measuring the surface profile of a predetermined measurement area (for example, a region of 22500 μm ² ) on the copper foil surface with a commercially available laser microscope.

In the present specification, "M adhesion amount (M is Zn, Ni or Mo)" means the weight (mg) of M per unit area existing in the rust preventive treatment layer (typically Zn-Ni-Mo layer). / M ² ). The amount of M adhered is calculated by dissolving a predetermined area on the surface of the copper foil on the side having the rust preventive treatment layer with an acid and analyzing the M concentration in the obtained solution based on the ICP emission spectrometry method. Can be done.

In the present specification, the "electrode surface" of the electrolytic copper foil refers to the surface on the side in contact with the cathode when the electrolytic copper foil is produced.

In the present specification, the "precipitation surface" of the electrolytic copper foil refers to the surface on which electrolytic copper is deposited during the production of the electrolytic copper foil, that is, the surface on the side not in contact with the cathode.

Surface-treated Copper Foil The surface-treated copper foil of the present invention includes a copper foil and a Zn—Ni—Mo layer provided on at least one surface of the copper foil. If desired, the Zn—Ni—Mo layer may be provided on both sides of the copper foil. The Zn-Ni-Mo layer has a Zn adhesion amount of 3 mg / m ² or more and 100 mg / m ² or less, a Ni adhesion amount of 5 mg / m ² or more and 60 mg / m ² or less, and a Mo adhesion amount of 2.0 mg / m ² or more and 40 mg. It is less than / m ² . Then, Ni / (Zn + Ni + Mo), which is the ratio of the Ni adhesion amount to the total amount of the Zn adhesion amount, the Ni adhesion amount, and the Mo adhesion amount, is 0.40 or more and 0.80 or less. By adopting the Zn-Ni-Mo layer having a predetermined composition as the rust preventive treatment layer in this way, the adhesion to the resin, the chemical resistance and the heat resistance are excellent, and the etching residue is hard to remain, and therefore the printed wiring is printed. In the production of a plate, it is possible to improve the adhesion reliability of both the copper foil and the base material and between the base material and the base material.

In this respect, the conventional surface-treated copper foil that has been subjected to rust prevention treatment is necessarily excellent in adhesion reliability between the copper foil and the base material and between the base material and the base material when used for a printed wiring board. It wasn't. For example, a surface-treated copper foil provided with a Zn—Ni layer as disclosed in Patent Document 1 is inferior in heat resistance, and the peel strength after a soldering step or the like is lowered. Further, as described above, when a printed wiring board is produced using a surface-treated copper foil provided with a Ni—Mo layer as disclosed in Patent Document 2, a residue derived from the Ni—Mo layer after copper foil etching is produced. Remains on the surface of the insulating base material, and the resin adhesion between the base material and the base material is reduced. On the other hand, the surface-treated copper foil of the present invention is provided with a Zn—Ni—Mo layer containing Zn, Ni and Mo at a predetermined adhesion amount and adhesion ratio as a rust preventive treatment layer, thereby providing chemical resistance and heat resistance. Although it is excellent in terms of the above, it dissolves quickly in a copper etching solution (for example, a cupric chloride etching solution) and is unlikely to generate a residue derived from the rust preventive treatment layer. As a result, the surface-treated copper foil of the present invention is excellent not only in the adhesion between the copper foil and the base material in the normal state but also in the adhesion after the soldering process and the acid treatment. It is possible to exhibit stable and high adhesion. In addition, in the manufacturing process of the printed wiring board, the residue is unlikely to remain on the surface of the insulating base material after the copper foil is etched and removed, so that the resin adhesion with other insulating base materials laminated on the surface of the insulating base material is hindered. It is fully exhibited without any problem, and a high adhesion between the base materials can be ensured. As described above, when the surface-treated copper foil of the present invention is used for a printed wiring board, it is possible to improve the reliability of both the copper foil and the base material and between the base material and the base material. It is extremely suitable for applications of printed wiring boards for high frequencies, where the adhesion between the foil and the base material and between the base material and the base material tends to decrease.

Zn is a basic component that provides rust prevention performance, and is a metal that has excellent solubility in a copper etching solution but is inferior in heat resistance. From the above viewpoint, the amount of Zn adhered to the Zn—Ni—Mo layer is 3 mg / m ² or more and 100 mg / m ² or less, preferably 3 mg / m ² or more and 80 mg / m ² or less, and more preferably 4 mg / m ² or more and 50 mg. / M ² or less, more preferably 5 mg / m ² or more and 30 mg / m ² or less. Within such a range, it is possible to improve the solubility of the Zn—Ni—Mo layer in the copper etching solution and effectively prevent the formation of a residue while ensuring the desired heat resistance.

Ni is a metal that has excellent chemical resistance and heat resistance, but is difficult to dissolve in a copper etching solution. From the above viewpoint, the amount of Ni adhered to the Zn-Ni-Mo layer is 5 mg / m ² or more and 60 mg / m ² or less, preferably 10 mg / m ² or more and 50 mg / m ² or less, and more preferably 15 mg / m ² or more and 30 mg. It is less than / m ² . Within such a range, the chemical resistance and heat resistance of the copper foil are improved while ensuring excellent solubility of the Zn—Ni—Mo layer during copper foil etching, and after chemical immersion or soldering. It is possible to effectively prevent a decrease in the adhesive force with the insulating base material after the process.

Although Mo is a metal that contributes to the prevention of diffusion of Cu, if it is present in a large amount, a residue is likely to be generated during copper foil etching. From the above viewpoint, the amount of Mo adhered to the Zn—Ni—Mo layer is 2.0 mg / m ² or more and 40 mg / m ² or less, preferably 2.0 mg / m ² or more and 20 mg / m ² or less, and more preferably 2. It is 2 mg / m ² or more and 10 mg / m ² or less. Within such a range, diffusion of Cu can be effectively prevented while ensuring excellent solubility of the Zn—Ni—Mo layer during copper foil etching. As a result, the heat resistance of the copper foil is improved, and it is possible to effectively prevent a decrease in the adhesive force with the insulating base material after the soldering process or the like.

Ni / (Zn + Ni + Mo), which is the ratio of the Ni adhesion amount to the total amount of Zn adhesion amount, Ni adhesion amount and Mo adhesion amount, is 0.40 or more and 0.80 or less, preferably 0.45 or more and 0.75 or less. More preferably, it is 0.50 or more and 0.65 or less. Within such a range, while ensuring good chemical resistance and heat resistance of the copper foil, good solubility of the Zn—Ni—Mo layer in the copper etching solution is also ensured, and a residue is left during the copper foil etching. Can be effectively prevented from occurring.

The Zn—Ni—Mo layer may be a layer containing Zn, Ni and Mo (preferably an alloy layer). Further, the amount of Zn adhered to the Zn—Ni—Mo layer may be appropriately adjusted by providing a Zn layer on the surface of the Zn—Ni—Mo layer.

From the viewpoint of improving the adhesion to the insulating base material, it is preferable that the surface-treated copper foil further includes a roughened layer composed of a plurality of roughened particles between the copper foil and the Zn—Ni—Mo layer. The thickness of the roughened layer is preferably 0.01 μm or more and 0.50 μm or less, and more preferably 0.05 μm or more and 0.30 μm or less.

The surface-treated copper foil preferably has a maximum height Sz of 7.0 μm or less, more preferably 1.0 μm or more, on the surface on the Zn—Ni—Mo layer side (that is, the outermost surface on the side away from the copper foil). It is 7.0 μm or less. Within such a range, it becomes more suitable for fine pitch circuit formation and high frequency applications. In particular, such low roughness reduces the skin effect of the copper foil, which is a problem in high-frequency signal transmission, reduces the conductor loss caused by the copper foil, and thereby significantly reduces the transmission loss of the high-frequency signal. can do.

The surface-treated copper foil preferably further includes a chromate layer or a silane coupling agent layer on the surface of the Zn—Ni—Mo layer, and more preferably includes both a chromate layer and a silane coupling agent layer. By further providing a chromate layer and / or a silane coupling agent layer, rust prevention, moisture resistance and chemical resistance are improved, and in addition, adhesion to an insulating base material is achieved by combining with a Zn-Ni-Mo layer. Can also be improved.

The thickness of the surface-treated copper foil is not particularly limited, but is preferably 0.1 μm or more and 105 μm or less, and more preferably 0.5 μm or more and 70 μm or less. The surface-treated copper foil is not limited to a normal copper foil having a Zn-Ni-Mo layer on the surface, but a copper foil with a carrier having a Zn-Ni-Mo layer on the surface of the copper foil. May be good.

Method for Producing Surface-treated Copper Foil An example of a preferred method for producing the surface-treated copper foil according to the present invention will be described. This preferred production method includes preparing a copper foil and surface-treating the copper foil with a solution containing Zn, Ni and Mo. However, the surface-treated copper foil according to the present invention is not limited to the method described below, and may be produced by any method.

(1) Preparation of Copper Foil As the copper foil used for producing the surface-treated copper foil, both electrolytic copper foil and rolled copper foil can be used, and electrolytic copper foil is more preferable. Further, the copper foil may be unroughened copper foil or may be pre-roughened. The thickness of the copper foil is not particularly limited, but is preferably 0.1 μm or more and 105 μm or less, and more preferably 0.5 μm or more and 70 μm or less. When the copper foil is prepared in the form of a copper foil with a carrier, the copper foil is formed by a wet film forming method such as a non-electrolytic copper plating method and an electrolytic copper plating method, a dry film forming method such as sputtering and chemical vapor deposition, or a dry film forming method. It may be formed by a combination thereof.

When the copper foil is roughened, the surface of the copper foil to be roughened preferably has a maximum height Sz of 2.0 μm or less measured in accordance with ISO25178, more preferably. Is 1.5 μm or less, more preferably 1.0 μm or less. When it is within the above range, it becomes easy to realize a surface profile in which Sz is desirable and low on the surface of the surface-treated copper foil. The lower limit of Sz is not particularly limited, but is typically 0.1 μm or more.

(2) Roughing Treatment It is preferable to roughen the surface of the copper foil to which the low Sz is imparted. The surface of the copper foil to be roughened may be either an electrode surface or a precipitation surface, and is not particularly limited. The roughening treatment is performed in a copper sulfate solution containing a copper concentration of 4 g / L or more and 25 g / L or less and a sulfuric acid concentration of 50 g / L or more and 300 g / L or less at a temperature of 20 ° C. or more and 60 ° C. or less at 10 A / dm ² or more and 100 A. It is preferable to carry out electrolytic precipitation at / dm ² or less, and this electrolytic precipitation is preferably carried out for 1 second or more and 20 seconds or less. The roughening treatment is a known plating that goes through at least two types of plating steps, including a burn-plating step of depositing and adhering fine copper particles on a copper foil and a covering plating step for preventing the fine copper grains from falling off. You may follow the method. In this case, in the burn plating step, it is preferable to perform electrolytic precipitation under the above-mentioned roughening treatment conditions. The covering plating step is performed at a temperature of 40 ° C. or higher and 60 ° C. or lower in a copper sulfate solution containing a copper concentration of 60 g / L or more and 80 g / L or less and a sulfuric acid concentration of 100 g / L or more and 300 g / L or less at 1 A / dm ^2. It is preferable to carry out electrolytic precipitation at 70 A / dm ² or less, and this electrolytic precipitation is preferably carried out for 1 second or more and 20 seconds or less.

(3) Rust prevention treatment The copper foil is subjected to rust prevention treatment to form a Zn—Ni—Mo layer. When roughening the copper foil, it is preferable to perform rust preventive treatment on at least the surface of the copper foil on the side where the roughened layer exists, and more preferably, rust preventive treatment is performed on both sides of the copper foil. .. The rust preventive treatment preferably includes a plating treatment using Zn, Ni and Mo. This plating treatment may be performed using a plating solution containing Zn, Ni and Mo. The plating treatment is preferably carried out in a pyrophosphate bath, for example, preferably using potassium pyrophosphate having a concentration of 50 g / L or more and 150 g / L or less. Zinc pyrophosphate, zinc sulfate, or the like is preferably used as the Zn source of the plating solution, and the Zn concentration in the plating solution is preferably 0.1 g / L or more and 10 g / L or less, more preferably 1 g / L or more and 5 g / L. It is as follows. Nickel sulfate, nickel chloride, nickel acetate or the like is preferably used as the Ni source of the plating solution, and the Ni concentration in the plating solution is preferably 0.1 g / L or more and 10 g / L or less, more preferably 1 g / L or more and 5 g. It is less than / L. As the Mo source of the plating solution, sodium molybdate, potassium molybdate, ammonium molybdate or the like is preferably used, and the Mo concentration in the plating solution is preferably 0.1 g / L or more and 10 g / L or less, more preferably 0. It is 5 g / L or more and 5 g / L or less. At a temperature of 20 ° C. or higher 50 ° C. or less by using a plating solution within the above range, it is preferable to perform the electrolysis at 0.1 A / dm ² or more 5.0A / dm ² or less, 30 seconds the electrolyte is at least 1 second It is preferably carried out below.

(4) Chromate Treatment It is preferable to perform chromate treatment on the rust-preventive copper foil to form a chromate layer. Chromate treatment following chromic acid concentration 0.5 g / L or more 8 g / L, pH 1 to 13, is preferably carried out the electrolysis at a current density of 0.1 A / dm ² or more 10A / dm ² or less, the electrolysis is 1 sec It is preferably performed for 30 seconds or less.

(5) Treatment with Silane Coupling Agent It is preferable to treat the copper foil with a silane coupling agent to form a silane coupling agent layer. The silane coupling agent layer can be formed by appropriately diluting the silane coupling agent, applying it, and drying it. Examples of silane coupling agents include epoxy-functional silane coupling agents such as 4-glycidylbutyltrimethoxysilane and 3-glycidoxypropyltrimethoxysilane, or 3-aminopropyltriethoxysilane and N-2 (amino). Amino functions such as ethyl) 3-aminopropyltrimethoxysilane, N-3-(4- (3-aminopropoxy) butoxy) propyl-3-aminopropyltrimethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane A sex silane coupling agent, or a mercapto-functional silane coupling agent such as 3-mercaptopropyltrimethoxysilane, or an olefin-functional silane coupling agent such as vinyltrimethoxysilane or vinylphenyltrimethoxysilane, or 3-methacryloxypropyl. Examples thereof include an acrylic functional silane coupling agent such as trimethoxysilane, an imidazole functional silane coupling agent such as imidazole silane, and a triazine functional silane coupling agent such as triazinesilane.

Copper- clad laminate The surface-treated copper foil of the present invention is preferably used for producing copper-clad laminates for printed wiring boards. That is, according to a preferred embodiment of the present invention, there is provided a copper-clad laminate provided with the surface-treated copper foil and an insulating base material provided on at least one surface of the surface-treated copper foil. The surface-treated copper foil may be provided on one side of the insulating base material or may be provided on both sides. The dielectric loss tangent of the insulating base material is preferably 0.004 or less, more preferably 0.003 or less at a frequency of 10 GHz. By doing so, it is possible to reduce the dielectric loss due to the insulating base material when used for a printed wiring board, and therefore it is possible to manufacture a printed wiring board suitable for high frequency applications. The insulating substrate preferably contains an insulating resin. The insulating substrate is preferably a prepreg and / or a resin sheet. Prepreg is a general term for composite materials in which a base material such as a synthetic resin plate, a glass plate, a glass woven fabric, a glass non-woven fabric, or paper is impregnated with a synthetic resin. Preferred examples of the insulating resin impregnated in the prepreg include an epoxy resin, a cyanate resin, a bismaleimide triazine resin (BT resin), a polyphenylene ether resin, a phenol resin and the like. Further, examples of the insulating resin constituting the resin sheet include epoxy resin, polyimide resin, polyester resin and the like. Further, the insulating base material may contain filler particles made of various inorganic particles such as silica and alumina from the viewpoint of improving the insulating property. The thickness of the insulating base material is not particularly limited, but is preferably 1 μm or more and 1000 μm or less, more preferably 2 μm or more and 400 μm or less, and further preferably 3 μm or more and 200 μm or less. The insulating base material may be composed of a plurality of layers. An insulating base material such as a prepreg and / or a resin sheet may be provided on the surface-treated copper foil via a primer resin layer previously applied to the copper foil surface.

The surface-treated copper foil or copper-clad laminate of the present invention is preferably used for producing a printed wiring board. That is, according to a preferred embodiment of the present invention, a method for manufacturing a printed wiring board, which comprises manufacturing a printed wiring board using the above-mentioned surface-treated copper foil or the above-mentioned copper-clad laminate, or the above-mentioned surface treatment. A printed wiring board obtained by using a copper foil or the copper-clad laminate is provided. By using the surface-treated copper foil or copper-clad laminate of the present invention, it is possible to provide a printed wiring board having excellent adhesion reliability between the copper foil and the base material and between the base material and the base material as described above. Can be done. The printed wiring board according to this embodiment includes a layer structure in which an insulating base material and a copper layer are laminated in this order. The insulating base material is as described above for the copper-clad laminate. In any case, a known layer structure can be adopted for the printed wiring board. Specific examples of the printed wiring board include a single-sided or double-sided printed wiring board formed by adhering the surface-treated copper foil of the present invention to one or both sides of a prepreg to form a cured laminate, or a multilayer of these. Examples include printed wiring boards. Further, as another specific example, a flexible printed wiring board, COF, TAB tape, etc., in which the surface-treated copper foil of the present invention is formed on a resin film to form a circuit can be mentioned. As yet another specific example, a copper foil with resin (RCC) obtained by applying the above-mentioned insulating resin to the surface-treated copper foil of the present invention is formed, and the insulating resin is used as an insulating adhesive layer on the above-mentioned printed wiring board. After laminating, the surface-treated copper foil is used as all or part of the wiring layer to remove the build-up wiring board and the surface-treated copper foil whose circuits are formed by methods such as the modified semi-additive (MSAP) method and the subtractive method. Examples thereof include a build-up wiring board in which a circuit is formed by a semi-additive (SAP) method, a direct build-up on wafer in which a copper foil with a resin is laminated and a circuit is formed alternately on a semiconductor integrated circuit.

The present invention will be described in more detail with reference to the following examples.

Examples 1-9
The surface-treated copper foil of the present invention was prepared and evaluated as follows.

(1) Preparation of electrolytic copper foil Using a copper sulfate solution having the composition shown below as the copper electrolytic solution, using a rotating electrode made of titanium for the cathode, and using DSA (dimensionally stable anode) for the anode. Electrolysis was performed at a solution temperature of 45 ° C. and a current density of 55 A / dm ² to obtain an electrolytic copper foil having a thickness of 18 μm. When the maximum height Sz of the precipitation surface and the electrode surface of the electrolytic copper foil was measured using a laser microscope (manufactured by KEYENCE CORPORATION, VK-X100) in accordance with ISO25178, the Sz of the precipitation surface was 0.5 μm and the electrode. The Sz of the surface was 1.2 μm. This measurement was performed by measuring the surface profiles of the precipitation surface and the electrode surface of the electrolytic copper foil in a region of 22500 μm ² (150 μm × 150 μm), respectively, and no measurement area filter was used.
<Composition of sulfuric acid acidic copper sulfate solution>
-Copper concentration: 80 g / L
-Sulfuric acid concentration: 260 g / L
-Bis (3-sulfopropyl) disulfide concentration: 30 mg / L
-Diallyldimethylammonium chloride polymer concentration: 50 mg / L
-Chlorine concentration: 40 mg / L

(2) Roughing Treatment Condition A (1 step plating, Examples 1 to 3 and 5-9) or Condition B (2 step plating, eg) shown below with respect to the precipitation surface side of the obtained electrolytic copper foil. The roughening treatment according to 4) was performed.

<Condition A (1 step plating)>
The electrolytic copper foil is immersed in a copper sulfate solution having a copper concentration of 10 g / L and a sulfuric acid concentration of 100 g / L, and roughened under the conditions of a liquid temperature of 30 ° C. and a current density of 40 A / dm ² , and the electrolytic copper foil is deposited on the precipitation surface side. A roughened layer was formed in.

<Condition B (2-step plating)>
The electrolytic copper foil was immersed in a copper sulfate solution having a copper concentration of 4 g / L and a sulfuric acid concentration of 200 g / L, and the first-step roughening treatment was performed under the conditions of a liquid temperature of 30 ° C. and a current density of 30 A / dm ² . Then, as the second step of roughening treatment, the mixture is immersed in a copper sulfate solution having a copper concentration of 69 g / L and a sulfuric acid concentration of 240 g / L, covered with plating under the conditions of a liquid temperature of 50 ° C. and a current density of 10 A / dm ² , and electrolyzed. A roughened layer was formed on the precipitation surface side of the copper foil.

(3) Rust prevention treatment The electrolytic copper foil after the roughening treatment is subjected to a one-step (Examples 1 to 7) or two-step (Examples 8 and 9) rust prevention treatment to form a roughened layer of the electrolytic copper foil. A Zn-Ni-Mo layer was formed on the formed surface. Specifically, the first-step treatment is pyrophosphate containing zinc pyrophosphate (Zn source), nickel sulfate (Ni source) and sodium molybdate (Mo source) at the Zn, Ni and Mo concentrations shown in Table 1. The electrolytic copper foil was immersed in a pyrophosphate bath having a potassium acid concentration of 100 g / L, and Zn—Ni—Mo was electrodeposited at a liquid temperature of 40 ° C. and the current density and treatment time shown in Table 1. In the second step, the electrolytic copper foil that has undergone the first step is immersed in a pyrophosphate bath containing zinc pyrophosphate (Zn source) at the Zn concentration shown in Table 1 and having a potassium pyrophosphate concentration of 145 g / L. Then, Zn was electrodeposited at a liquid temperature of 30 ° C., a current density and a treatment time shown in Table 1. At this time, by appropriately changing the Zn concentration, Ni concentration, Mo concentration, current density and processing time as shown in Table 1, the Zn adhesion amount, the Ni adhesion amount, the Mo adhesion amount and the Mo adhesion amount in the Zn—Ni—Mo layer and Various samples with different Ni / (Zn + Ni + Mo) were prepared.

(4) Chromate Treatment Both sides of the electrolytic copper foil subjected to the above rust prevention treatment were subjected to chromate treatment to form a chromate layer on the Zn—Ni—Mo layer. This chromate treatment was carried out under the conditions of a chromic acid concentration of 1 g / L, a pH of 11, a liquid temperature of 25 ° C., and a current density of 1 A / dm ² .

(5) Treatment with Silane Coupling Agent The copper foil on which the chromate layer was formed was washed with water, and then immediately treated with a silane coupling agent to form a silane coupling agent layer on the chromate layer on the roughened surface. In this silane coupling agent treatment, pure water is used as a solvent, a solution having a 3-aminopropyltrimethoxysilane concentration of 3 g / L is used, and this solution is sprayed on the roughened surface by showering to adsorb. went. After adsorbing the silane coupling agent, the water was finally evaporated by an electric heater to obtain a surface-treated copper foil having a thickness of 18 μm.

(6) Evaluation The produced surface-treated copper foil was measured and evaluated as shown below.

(A) Measurement of maximum height Sz Using a laser microscope (manufactured by KEYENCE CORPORATION, VK-X100), the surface of the surface-treated copper foil on the Zn-Ni-Mo layer side (that is, the silane coupling agent) in accordance with ISO25178. The maximum height Sz of the surface of the layer) was measured. The Sz on the surface on the Zn—Ni—Mo layer side largely reflects the Sz on the surface of the roughened layer. This measurement was performed by measuring the surface profile of a region (150 μm × 150 μm) having an area of 22500 μm ^{2 on} the outermost surface of the surface-treated copper foil, and a measurement area filter was not used. The results are as shown in Table 2.

(B) Measurement of Adhesion Amount of Each Element in Zn-Ni-Mo Layer A region of 25 cm ² (5 cm x 5 cm) in area on the surface of the surface-treated copper foil on the Zn-Ni-Mo layer side was dissolved with acid to obtain the result. The concentrations of Zn, Ni and Mo in the solution were analyzed by the ICP emission analysis method, and the amount of Zn adhered, the amount of Ni adhered and the amount of Mo adhered were measured. From the obtained measurement results, Ni / (Zn + Ni + Mo), which is the ratio of the Ni adhesion amount to the total amount of the Zn adhesion amount, the Ni adhesion amount and the Mo adhesion amount, was calculated. The results are as shown in Table 2.

(C) Evaluation of Adhesion Reliability between Copper Foil and Base Material In order to evaluate the adhesion of surface-treated copper foil in various states (for example, normal state, after heat load and after chemical immersion) to the insulating base material, the normal state The peel strength, the peel strength after the solder flow, and the peel strength after the acid treatment (hydrochloric acid deterioration resistance) were measured as follows. The results are as shown in Table 2.

(C-1) Normal Peeling Strength Two prepregs (thickness 100 μm) containing polyphenylene ether, triallyl isocyanurate, and bismaleimide resin as main components were prepared and stacked as an insulating base material. The prepared surface-treated copper foil was laminated on the stacked prepregs so that the roughened surface was in contact with the prepreg, and pressed at 32 kgf / cm ² at 205 ° C. for 120 minutes to prepare a copper-clad laminate. .. Next, a circuit was formed on this copper-clad laminate by an etching method to prepare a test substrate having a linear circuit having a width of 3 mm. The linear circuit thus obtained was peeled off from the insulating base material according to the method A (90 ° peeling) of JIS C 5016-1994, and the normal peeling strength (kgf / cm) was measured. The results are as shown in Table 2.

(C-2) Peeling Strength After Solder Flow Prior to measuring the peeling strength, a test substrate equipped with a linear circuit was floated in a solder bath at 288 ° C. for 300 seconds, but the procedure was the same as the normal peeling strength described above. The peel strength (kgf / cm) after the solder flow was measured. The results are as shown in Table 2.

(C-3) Peeling strength after acid treatment (hydrochloric acid deterioration resistance)
The peel strength before acid treatment (kgf / cm) was measured by the same procedure as the normal peel strength described above except that the circuit width was 0.4 mm. Further, (i) the circuit width was set to 0.4 mm, and (ii) the test substrate equipped with the linear circuit was immersed in 4 mol / L hydrochloric acid at 60 ° C. for 90 minutes prior to the measurement of the peel strength. Except for the above, the peel strength (kgf / cm) after the acid treatment was measured by the same procedure as the normal peel strength described above. The hydrochloric acid deterioration resistance rate (%) was calculated from the peel strength before and after the acid treatment thus obtained.

(D) Evaluation of Adhesion Reliability between Base Material and Base Material The adhesion between the base material and the base material in the multilayer laminate produced by etching and removing the copper foil was evaluated as follows. First, the surface-treated copper foil 112 is roughened on both sides of an insulating base material 110 in which two prepregs (thickness 100 μm) containing polyphenylene ether, triallyl isocyanurate, and bismaleimide resin as main components are stacked. It was laminated so as to be in contact with the insulating base material 110, and pressed at 32 kgf / cm ² at 205 ° C. for 120 minutes to obtain a first copper-clad laminate 114 (FIG. 1 (a)). Both sides of the first copper-clad laminate 114 are etched with a cupric chloride etching solution having an acid concentration of 3 mol / L at a bath temperature of 50 ° C. to dissolve and remove the surface-treated copper foil 112 existing on both sides. Then, an insulating base material 110'in which the shape of the roughened surface of the surface-treated copper foil 112 was transferred to the surface was obtained (FIG. 1 (b)). This etching was performed by performing the operation of passing the first copper-clad laminate 114 through the etching tank having a length of about 50 cm in 23 seconds (speed 1.3 m / min) twice in total. Next, pure water cleaning, dilute hydrochloric acid (concentration 10% by volume) cleaning, and pure water cleaning were performed on the insulating base material 110'after the etching treatment in this order. The washed insulating substrate 110'was dried in a clean oven at 80 ° C. for 20 minutes. The above-mentioned 100 μm-thick prepreg 116 and surface-treated copper foil 112 were laminated in this order on both sides of the dried insulating base material 110', and pressed at 32 kgf / cm ² at 205 ° C. for 120 minutes to form a second copper-clad laminate 118. (Fig. 1 (c)). Both sides of the second copper-clad laminate 118 are etched with a cupric chloride etching solution having an acid concentration of 3 mol / L at a bath temperature of 50 ° C. to dissolve and remove the surface-treated copper foil 112 existing on both sides. Then, the evaluation sample 120 was prepared (FIG. 1 (d)). Two test pieces having a size of 5 cm × 10 cm were cut out from this evaluation sample 120. These test pieces were put into a PCT (Pressure Cooker Test) tester and allowed to absorb moisture at 2 atm, 121 ° C., and 100% RH for 50 minutes. The test piece after moisture absorption was taken out from the PCT tester, the moisture was wiped off, and then the solder dip was performed within 10 minutes after taking out. This solder dip was performed by immersing the test piece in a solder bath at 288 ° C. for 20 seconds a total of 20 times. After the solder dip, the presence or absence of blister on the test piece (that is, the bubble-like gap caused by the peeling between the base materials inside the laminate) is visually confirmed, and blister occurs on at least one of the two test pieces. If it is, it is judged that there is blistering. Further, it was considered that the generated blisters were caused by the residue of the rust preventive treatment layer remaining after the etching of the copper foil. The results are as shown in Table 2.

Claims (7)

With copper foil
Provided on at least one surface of the copper foil, the Zn adhesion amount is 3 mg / m ² or more and 100 mg / m ² or less, the Ni adhesion amount is 5 mg / m ² or more and 60 mg / m ² or less, and the Mo adhesion amount is 2.0 mg / m. Ni / (Zn + Ni + Mo), which is m ² or more and 40 mg / m ² or less and is the ratio of the Ni adhesion amount to the total amount of the Zn adhesion amount, the Ni adhesion amount, and the Mo adhesion amount, is 0.40 or more and 0. With a Zn-Ni-Mo layer of .80 or less,
With surface-treated copper foil. The surface-treated copper foil according to claim 1, further comprising a roughened layer composed of a plurality of roughened particles between the copper foil and the Zn—Ni—Mo layer. The surface-treated copper foil according to claim 1 or 2, wherein the maximum height Sz of the surface of the surface-treated copper foil on the Zn-Ni-Mo layer side, which is measured in accordance with ISO25178, is 7.0 μm or less. .. The surface-treated copper foil according to any one of claims 1 to 3, further comprising a chromate layer and / or a silane coupling agent layer on the surface of the Zn—Ni—Mo layer. The surface-treated copper foil according to any one of claims 1 to 4,
An insulating base material provided on at least one surface of the surface-treated copper foil, and
A copper-clad laminate with. The copper-clad laminate according to claim 5, wherein the dielectric loss tangent of the insulating base material is 0.004 or less at a frequency of 10 GHz. Manufacture of a printed wiring board, which comprises manufacturing a printed wiring board using the surface-treated copper foil according to any one of claims 1 to 4 or the copper-clad laminate according to claim 5 or 6. Method.

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