JP5254491B2 - Copper foil for printed circuit board and copper clad laminate for printed circuit board - Google Patents

Description

 The present invention relates to a copper foil for printed circuit boards and a copper clad laminate for printed circuit boards excellent in heat resistance and chemical resistance, in particular, a layer containing nickel, zinc and copper on at least an adhesive surface of the copper foil with a resin ( Hereinafter referred to as “copper nickel zinc layer”), a copper foil for a printed circuit board having a chromate film layer on the same layer and, if necessary, a silane coupling agent layer, and the copper foil. The present invention relates to the produced copper-clad laminate for printed circuit boards.

 A semiconductor package substrate, which is a kind of printed circuit board, is a printed circuit board used for mounting a semiconductor IC chip and other semiconductor elements. Since the circuit formed on the semiconductor package substrate is finer than a normal printed circuit board, a resin base material different from a general printed circuit board is used as the substrate material.

 A semiconductor package substrate is usually manufactured by the following process. First, a copper foil is laminated and bonded to a base material such as a synthetic resin under high temperature and high pressure. This is called a copper clad laminate or simply a laminate. Next, in order to form a target conductive circuit on the laminate, a pattern equivalent to the circuit is printed on the copper foil with a material such as an etching resistant resin. Then, unnecessary portions of the exposed copper foil are removed by an etching process.

After the etching, the printed part is removed and a conductive circuit is formed on the substrate. A predetermined element is finally soldered to the formed conductive circuit to form various printed circuit boards for electronic devices. Finally, it is joined to a resist or a build-up resin substrate.
In general, quality requirements for copper foil for printed circuit boards differ between an adhesive surface (so-called roughened surface) to be bonded to a resin base material and a non-adhesive surface (so-called glossy surface) and satisfy both at the same time. is necessary.

The requirements for the glossy surface are: (1) good appearance and no oxidation discoloration during storage, (2) good solder wettability, (3) no oxidation discoloration when heated at high temperature, (4 ) Good adhesion to the resist is required.
On the other hand, for the roughened surface, mainly (1) no oxidation discoloration during storage, (2) the peel strength from the base material is high temperature heating, wet treatment, soldering, chemical treatment, etc. It is sufficient that (3) there is no so-called lamination stain that occurs after lamination with the substrate and etching.
In recent years, with the miniaturization of circuit print patterns, it has been required to reduce the roughness of the copper foil surface.

Further, in electronic devices such as personal computers and mobile communications, the frequency of electrical signals has been increased with the increase in communication speed and capacity, and printed circuit boards and copper foils that can cope with this have been demanded. . When the frequency of the electric signal is 1 GHz or more, the influence of the skin effect in which the current flows only on the surface of the conductor becomes significant, and the influence that the current transmission path changes due to the unevenness of the surface and the impedance increases cannot be ignored. Also from this point, it is desired that the surface roughness of the copper foil is small.
In order to meet these requirements, many surface treatment methods have been proposed for printed circuit board copper foils.

Although the surface treatment method differs between the rolled copper foil and the electrolytic copper foil, an example of the surface treatment method for the electrolytic copper foil includes the method described below.
That is, first, in order to increase the adhesive strength (peel strength) between copper and the resin base material, in general, after applying fine particles of copper and copper oxide to the surface of the copper foil (roughening treatment), brass is imparted to have heat resistance characteristics. Alternatively, a heat-resistant layer (barrier layer) such as zinc is formed.
Finally, in order to prevent surface oxidation or the like during transportation or storage, the product is subjected to rust prevention treatment such as immersion or electrolysis chromate treatment or electrolytic zinc chromate treatment.

 Of these, the surface treatment method for forming the heat-resistant layer is particularly important as determining the surface properties of the copper foil. For this reason, many copper foils in which a coating layer such as Zn, Cu—Ni alloy, Cu—Co alloy and Cu—Zn alloy is formed as a metal or alloy for forming a heat-resistant layer have been put into practical use (for example, patents). Reference 1).

 Among these, the copper foil formed with a heat-resistant layer made of Cu-Zn alloy (brass) has no stain of the resin layer when used for a printed circuit board made of epoxy resin, etc. Since the copper foil has excellent properties such as little deterioration of peel strength of the copper foil after being held in, it is widely used industrially. The method for forming the heat-resistant layer made of brass is described in detail in Patent Document 2.

 However, in recent years, in the manufacturing process of printed circuit boards, particularly package substrates, in order to improve the adhesion between the resist or build-up resin substrate and the glossy surface of the copper foil as the circuit surface, sulfuric acid and hydrogen peroxide are used. A process of soft etching with a mixed solution to roughen the glossy surface of the copper foil is used, and a printed circuit board using a copper foil on which a known heat-resistant layer described in Patent Document 1 is formed When the copper foil circuit glossy surface is soft-etched with the above mixture of sulfuric acid and hydrogen peroxide, the erosion (circuit erosion) phenomenon of both ends (edge portions) of the circuit pattern formed earlier occurs, and the resin base There is a problem that the peel strength with the material deteriorates.

 This circuit erosion phenomenon is a phenomenon in which the adhesive boundary layer between the copper foil circuit and the resin base material is eroded by the mixed solution of sulfuric acid and hydrogen peroxide, and the peel strength of the copper foil in that portion is significantly deteriorated. Say. If this phenomenon occurs on the entire surface of the circuit pattern, the circuit pattern is peeled off from the substrate, which becomes a serious problem.

 Therefore, it is generally known that a nickel-zinc-copper layer in which nickel is added to brass is effective as a surface treatment layer excellent in preventing a circuit erosion phenomenon. However, although the circuit erosion phenomenon can be prevented by the addition of nickel, depending on the amount of the addition of nickel, such as a decrease in heat resistance (heat-resistant peel strength) and the occurrence of a foot residue during circuit formation, the Cu-Zn alloy (brass) The inventors have found that they may be inferior to the surface layer comprising.

Japanese Patent Publication No.51-35711 Japanese Patent Publication No.54-6701

The object of the present invention is to obtain various characteristics of a surface layer made of a Cu—Zn alloy (brass) (normal peel strength of a copper foil of a printed circuit board produced by laminating a copper foil and a resin base material, Copper foil suitable for a semiconductor package substrate in which the above circuit erosion phenomenon is reduced without deteriorating the peel strength (hereinafter referred to as heat-resistant peel strength) and chemical resistance (hydrochloric acid) after being held for a predetermined time at Is to develop.
In particular, when copper foil is laminated on the resin base material to greatly improve the heat-resistant peel strength, and when the circuit is soft etched using a sulfuric acid-hydrogen peroxide etchant, the circuit erosion phenomenon caused by the etchant is effective. (Hereinafter referred to as “chemical resistance” if necessary) to establish a copper foil surface treatment technology.

 In order to solve the above-mentioned problems, the present inventors diligently studied the conditions for performing surface treatment on the copper foil. As a result, the following copper foil has improved heat peel strength and chemical resistance, that is, sulfuric acid-hydrogen peroxide etching. It was found that this was effective for erosion resistance (circuit erosion resistance) of the roughened surface during soft etching of the glossy surface of the copper foil.

From the above, the present invention is
1) A copper foil for a printed circuit board provided with a layer containing nickel, zinc and copper (hereinafter referred to as “copper nickel zinc layer”) on the surface of the copper foil, wherein the copper nickel zinc layer per unit area zinc deposition weight 200 [mu] g / dm ² or more and 2000 [mu] g / dm ² or less, the copper nickel zinc layer, Ni is from 1 to 50% by weight, (zinc deposition amount (mass%)) / {100- (copper deposition amount (Mass%))} is 0.3 or more, and (copper adhesion amount (mass%)) / {100- (zinc adhesion quantity (mass%))} is 0.3 or more. For copper foil.

The present invention also provides:
2) The copper foil for a printed circuit board according to 1 above, wherein a chromate film layer is provided on the copper nickel zinc layer. 3) In the chromate film layer, the chromium adhesion weight is 30 μg / dm ² per unit area. The printed circuit board copper foil according to 3 above, which is 100 μg / dm ² or less as described above 4) A silane coupling agent layer is further provided on the chromate film layer. 5) The copper foil for printed circuit board according to 3), wherein the copper foil is an electrolytic copper foil, and the copper nickel zinc layer is formed on a rough surface during electrolytic plating or a glossy surface of the electrolytic copper foil. The copper foil for printed circuit boards according to any one of 1 to 5 above,
6) The copper foil for printed circuit boards according to any one of 1 to 5 above, wherein the copper foil is a rolled copper foil. 7) For the printed circuit board according to any one of 1 to 7 above. Provided is a copper-clad laminate for a printed circuit board produced by bonding a copper foil and a resin for a printed circuit board.

As described above, the copper foil for a printed circuit board according to the present invention uses a copper nickel zinc layer so as not to deteriorate the peel strength of the copper foil after the printed circuit board is held at a high temperature. Thereby, the heat-resistant peel strength of the copper foil can be dramatically improved.
In addition, the circuit erosion phenomenon caused by chemicals can be effectively prevented, and a new characteristic that sulfuric acid-hydrogen peroxide resistance can be improved is provided. Copper foil for printed circuit boards (in particular, This is extremely effective as a copper clad laminate for a semiconductor package substrate) and a copper clad laminate produced by bonding a copper foil and a resin base material (particularly, a copper clad laminate for a semiconductor package substrate). Of course, it can be used as a general copper foil for a printed circuit board.

It is a figure which shows the composition area | region suitable for this invention of a Cu-Ni-Zn ternary alloy.

Next, in order to facilitate understanding of the present invention, the present invention will be described specifically and in detail.
As the copper foil of the present invention, either an electrolytic copper foil or a rolled copper foil can be used. In the case of an electrolytic copper foil, it can be applied to a rough surface during electrolytic plating or a glossy surface of the electrolytic copper foil. Further, these surfaces may be further subjected to a roughening treatment. For example, for the purpose of improving the peeling (peel) strength of the copper foil after lamination with the resin base material, for example, a roughening treatment is performed on the surface of the copper foil after degreasing, for example, “fist-knot” -shaped electrodeposition of copper Is an electrolytic copper foil that can be used as it is.

In general, in a drum-type electrolytic copper foil manufacturing apparatus, one side (drum side) is a glossy surface and the opposite side is a rough surface. In rolled copper foil, all become a glossy rolled surface. In the present invention, the electrolytic copper foil has a rough surface and a glossy surface, but in the case of a rough surface, it can be used as it is. The glossy surface of the electrolytic copper foil can be roughened by applying a roughening treatment to further increase the peel strength.
A roughening treatment is similarly applied to the rolled copper foil. As for the roughening treatment, any known roughening treatment can be used in any case, and there is no particular limitation.
The roughened surface of the present invention means an electrolytic copper foil having a roughened surface during electrolytic plating, or an electrolytic copper foil and a rolled copper foil subjected to a roughening treatment, and can be applied to any copper foil.

As described above, the copper foil for a semiconductor package substrate of the present invention is composed of a copper nickel zinc layer, a chromate film layer, and a silane coupling agent layer as required, which are formed on the surface of the copper foil to be an adhesive surface with the resin. . As the copper foil, the above rolled copper foil or electrolytic copper foil can be used.
As the chromate film layer, an electrolytic chromate film layer or an immersion chromate film layer can be used.

As described above, the present invention forms a layer containing nickel, zinc and copper (hereinafter referred to as “copper nickel zinc layer”) on the surface of a copper foil, for example.
In order for the copper foil not to deteriorate the peel strength after high-temperature heating, the zinc adhesion amount per unit area of the copper foil in the copper nickel zinc layer needs to be 200 μg / dm ² or more. This is because, regardless of the composition of the copper nickel zinc layer, if the zinc adhesion weight is less than 200 μg / dm ² , there is no effect of layer formation and the deterioration of the peel strength after high-temperature heating becomes large. On the other hand, when the zinc adhesion weight exceeds 2000 μg / dm ² , erosion of the circuit end portion by the sulfuric acid-hydrogen peroxide etching solution becomes significant. Therefore zinc coating weight per unit area of the copper foil in the copper-nickel zinc layer is 200 [mu] g / dm ² or more 2000 [mu] g / dm ² or less is preferable.

 Furthermore, the inventors have an important balance of the composition of each metal in the copper nickel zinc layer. By forming the copper nickel zinc layer in the region X shown in the composition region of the Cu—Ni—Zn ternary alloy in FIG. It was found that the peel strength after high-temperature heating and chemical resistance (hydrochloric acid resistance, sulfuric acid-hydrogen peroxide resistance) were excellent. The details will be described below.

 Addition of nickel is inevitable for chemical resistance, and the nickel ratio in the copper nickel zinc layer may be 1% or more. If it is less than 1%, the circuit erosion phenomenon cannot be effectively prevented. However, it is preferable that the nickel ratio in the copper nickel zinc layer exceeds 50% because the balance of zinc and copper in the copper nickel zinc layer described later is lost, the heat-resistant peel strength is lowered, and the foot residue during circuit formation frequently occurs. Absent. Therefore, the nickel ratio in the copper nickel zinc layer is preferably 1% or more and 50% or less.

 Furthermore, when the nickel ratio in the copper nickel zinc layer is 1% or more and 50% or less, the ratio of the adhesion amount of zinc and copper in the copper nickel zinc layer affects the heat peel strength or chemical resistance (hydrochloric acid). Specifically, it is necessary to satisfy the following formula. That is, (Zinc adhesion amount (% by mass)) / {100- (Copper adhesion amount (% by mass))} (Formula 1) is 0.3 or more, (Copper adhesion amount (% by mass)) / {100- (Zinc Adhesion amount (mass%))} (Formula 2) must be 0.3 or more (region X in FIG. 1). In order to facilitate understanding, (Expression 1) and (Expression 2) are added to the above expressions, respectively.

For example, when there is too much zinc adhesion amount, (zinc adhesion amount (mass%)) / {100- (copper adhesion amount (mass%))} (Formula 1) will be 0.3 or more, but copper adhesion amount is Since it decreases, copper adhesion amount (mass%)) / {100- (zinc adhesion quantity (mass%))} (Formula 2) may be less than 0.3 (region c in FIG. 1). In this case, since the copper adhesion amount is smaller than the zinc adhesion amount, the chemical resistance (hydrochloric acid) is lowered.
On the other hand, when there is too much copper adhesion amount, (copper adhesion amount (mass%)) / {100- (zinc adhesion amount (mass%))} (Formula 2) becomes 0.3 or more, (Mass%)) / {100- (copper adhesion amount (mass%))} (formula 1) may be less than 0.3 (region b in FIG. 1).

 In this case, since the zinc adhesion amount is smaller than the copper adhesion amount, the heat-resistant peel strength is lowered. Therefore, about the ratio of the adhesion amount of zinc and copper in the copper nickel zinc layer (zinc adhesion amount (mass%)) / {100- (copper adhesion amount (mass%))} (formula 1) is 0.3 or more, It is preferable that (copper adhesion amount (% by mass)) / {100- (zinc adhesion amount (% by mass))} (Formula 2) satisfies both formulas of 0.3 or more (region X in FIG. 1).

The copper nickel zinc layer is usually formed under the following conditions. However, zinc deposition weight per unit area of the copper nickel zinc layer, 200 [mu] g / dm ² or more and 2000 [mu] g / dm ² or less, the copper nickel zinc layer, Ni is 1-50 wt%, (zinc deposition amount ( Mass%)) / {100- (copper adhesion amount (mass%))} (Formula 1) is 0.3 or more, (copper adhesion amount (mass%)) / {100- (zinc adhesion amount (mass%)) } (Equation 2) is not particularly limited as long as the electroplating conditions can achieve 0.3 or more, and other electroplating conditions can also be used.

(Plating solution composition)
Ni: 0.1 g / L to 30 g / L, Zn: 0.1 g / L to 12 g / L, Cu: 0.1 g / L to ₂ g / L, sulfuric acid (H ₂ SO ₄ ): 0.1 g / L to 10 g / L is a basic bath. Also, other inorganic acids or organic carboxylic acids (citric acid, malic acid, etc.) can be used instead of sulfuric acid.
(Current density) 3-25 A / dm ²

Next, regarding the chromate treatment, any of an electrolytic chromate treatment, an immersion chromate treatment, and a zinc chromate treatment containing zinc in a chromate bath can be applied to produce the chromate film layer.
In any case, if the chromium adhesion weight is less than 30 μg / dm ² , the effect of increasing acid resistance and heat resistance is small, so the chromium adhesion weight is 30 μg / dm ² or more. On the other hand, if the chromium adhesion weight exceeds 100 μg / dm ² , the effect of chromate treatment is saturated and the chromium adhesion weight does not increase any more. When these are put together, it can be said that the chromium adhesion weight per unit area in the chromate treatment layer is preferably 30 to 100 μg / dm ² .

Examples of conditions for forming the chromate film layer are described below. However, as described above, it is not necessary to be limited to this condition, and any known chromate treatment can be used.
In general, in the case of the immersion chromate treatment, a chromium adhesion weight of 30 to 40 μg / dm ² per unit area can be achieved. In the case of electrolytic chromate treatment, a chromium adhesion weight per unit area of 30 to 100 μg / dm ² can be achieved.
This rust prevention treatment is one of the factors affecting the acid resistance and heat resistance of the copper foil, and is effective because the chromate treatment improves the chemical resistance and heat resistance of the copper foil.

(A) Example of immersion chromate treatment CrO ₃ or K ₂ Cr ₂ O ₇ : 1 to 12 g / L, Zn (OH) ₂ or ZnSO ₄ · 7H ₂ O: 0 to 10 g / L, Na ₂ SO ₄ : 0 20 g / L, pH 2.5 to 12.5, Temperature: 20 to 60 ° C., Time: 0.5 to 20 seconds (b) Example of electrolytic chromate treatment CrO ₃ or K ₂ Cr ₂ O ₇ : 1 12 g / L, Zn (OH) ₂ or ZnSO ₄ .7H ₂ O: 0 to 10 g / L, Na ₂ SO ₄ : 0 to 20 g / L, pH 2.5 to 12.5, temperature: 20 to 60 ° C, current density 0.5 to 5 A / dm ² , time: 0.5 to 20 seconds

As a silane coupling agent used for the copper foil for printed circuit boards of this invention, it is desirable to contain 1 or more types of alkoxysilane provided with the functional group which has the reactivity of at least tetraalkoxysilane and resin, for example. . Although the selection of this silane coupling agent is arbitrary, the selection considering the adhesiveness with the resin is desirable.
Further, the present invention provides a copper clad produced by laminating the printed circuit board copper foil according to any one of 1) to 7) above and the printed circuit board copper foil according to 8) and a resin base material. Provide a laminate.

Next, a silane coupling agent treatment (after application and drying) was performed on the rust preventive layer.
The conditions for the silane coupling agent treatment are as follows.
An aqueous solution containing 0.5% by volume of epoxysilane was applied after adjusting to pH 7 and then dried.

(Test method)
The following two types of resin base materials to be laminated with the copper foil were used.
FR-4 resin (glass cloth base epoxy resin)
BT resin (triazine-bismaleimide resin, trade name: GHPL-830 manufactured by Mitsubishi Gas Chemical)
The BT resin is a material having high heat resistance and being used for a printed circuit board for a semiconductor package.

(1) Measurement of normal peel strength and heat-resistant peel strength using an FR-4 substrate A copper foil on a laminate produced by laminating a surface of a copper foil on which a copper nickel zinc layer is formed and an FR-4 resin base material. Etching forms a 10 mm wide copper foil circuit on the laminate.
The circuit is peeled and the normal peel strength is measured. Next, the peel strength (hereinafter referred to as heat-resistant peel strength) after heating the laminate having the copper foil circuit having a width of 10 mm for 2 days in the air at 180 ° C. and the relative deterioration rate from the normal peel strength. (Loss%) was measured. The FR-4 substrate is inferior in heat resistance compared to the BT substrate.
Therefore, if it has a good heat-resistant peel strength and a low deterioration rate when using the FR-4 substrate, it has a sufficient heat-resistant peel strength and deterioration rate even when using the BT substrate.

(2) Measurement of normal peel strength and hydrogen peroxide resistance using a BT substrate Etching the copper foil on a laminated board prepared by laminating the copper nickel zinc layer surface of the copper foil and the BT resin base material Then, a 0.4 mm wide copper foil circuit is formed on the laminate. The circuit is peeled and the normal peel strength is measured. Next, a sulfuric acid-hydrogen peroxide resistance test and a hydrochloric acid resistance test were performed using the laminate on which the 0.4 mm-wide copper foil circuit was formed.

In the sulfuric acid-hydrogen peroxide resistance test, after the copper foil circuit on the laminate was immersed in an etching solution containing 5 to 20% by volume of sulfuric acid and 1 to 10% by volume of hydrogen peroxide, the thickness of the copper foil circuit was etched by 2 μm. The relative deterioration rate (loss%) from the peel strength and its normal peel strength is measured.
The measurement of the peel strength in this case can be said to be in a harsh environment, and is a more severe condition than the chemical resistance evaluation generally performed when using the FR-4 substrate.
Accordingly, if the BT substrate has good sulfuric acid-hydrogen peroxide resistance, the FR-4 substrate also has sufficient chemical resistance (particularly sulfuric acid-hydrogen peroxide resistance).
In the hydrochloric acid resistance test, the peel strength after immersing the copper foil circuit on the laminated board in a 60 ° C solution containing 12% by weight of hydrochloric acid for 90 minutes and the relative deterioration rate (loss%) from the normal peel strength are measured. .

(3) Measurement of nickel and zinc plating adhesion weight per unit area A laminate is prepared by laminating with an FR-4 resin base material so that the surface of the copper foil on which the copper nickel zinc layer is formed is exposed. Next, measure the adhesion weight of zinc per unit area by dissolving the copper nickel zinc layer exposed on the laminate surface and the copper of its mother layer with hydrochloric acid or nitric acid and conducting chemical analysis of the zinc concentration in the solution. did.

(4) Analysis of abundance ratio of zinc, nickel and copper Using XPS (X-ray photoelectron spectroscopy), the abundance ratio of nickel, zinc and copper contained in the copper nickel zinc layer was measured. The measurement is performed intermittently from the outermost surface to the copper layer which is the base of the copper nickel zinc layer while etching the copper foil thickness by argon ion sputtering, and the abundance ratio of nickel, zinc and copper obtained at each depth Was integrated with the depth from the outermost surface, and the average abundance ratio of nickel, zinc and copper in the entire copper nickel zinc layer was calculated.
The instrument used for the measurement was AXIS-HS manufactured by KRATOS, and the output of argon ion sputtering was 52.5W. Under this condition, the copper foil thickness is etched by about 20 mm per minute. The sputtering time was 15 to 100 minutes.

Next, examples and comparative examples will be described. The results are shown in the following tables. In addition, a present Example shows a suitable example, This invention is not limited to these Examples. Accordingly, all modifications and other examples or aspects included in the technical idea of the present invention are included in the present invention.
In addition, the comparative example was published for contrast with this invention.

(Example 1-9)
Using an electrolytic copper foil having a thickness of 12 μm, a copper nickel zinc layer was formed by electroplating on the roughened surface (surface average roughness: 3.8 μm) of this copper foil under the conditions shown below. Table 1 shows the abundance ratios of nickel, zinc, and copper.

(Electroplating solution composition of Example 1)
Ni: 3 g / L, Zn: 6 g / L, Cu: 0.5 g / L, sulfuric acid (H ₂ SO ₄ ): 7.5 g / L
(Electroplating solution composition of Example 2)
Ni: 20 g / L, Zn: 3 g / L, Cu: 0.2 g / L, sulfuric acid (H ₂ SO ₄ ): 8.5 g / L
(Electroplating solution composition of Example 3)
Ni: 13 g / L, Zn: 1 g / L, Cu: 2 g / L, sulfuric acid (H ₂ SO ₄ ): 8.5 g / L
(Electroplating solution composition of Example 4)
Ni: 10 g / L, Zn: 12 g / L, Cu: 0.2 g / L, sulfuric acid (H ₂ SO ₄ ): 8.5 g / L
(Electroplating solution composition of Example 5)
Ni: 28 g / L, Zn: 8 g / L, Cu: 0.5 g / L, sulfuric acid (H ₂ SO ₄ ): 8.5 g / L
(Electroplating solution composition of Example 6)
Ni: 10 g / L, Zn: 5 g / L, Cu: 1.0 g / L, sulfuric acid (H ₂ SO ₄ ): 8.5 g / L
(Electroplating solution composition of Example 7)
Ni: 0.3 g / L, Zn: 0.3 g / L, Cu: 2.0 g / L, sulfuric acid (H ₂ SO ₄ ): 8.5 g / L
(Electroplating solution composition of Example 8)
Ni: 28 g / L, Zn: 1 g / L, Cu: 0.8 g / L, sulfuric acid (H ₂ SO ₄ ): 8.5 g / L
(Electroplating solution composition of Example 9)
Ni: 7 g / L, Zn: 10 g / L, Cu: 0.5 g / L, sulfuric acid (H ₂ SO ₄ ): 8.5 g / L
(Current density) 5 A / dm ² or 10 A / dm ²

Further, chromate treatment was performed on the copper nickel zinc layer to form a rust preventive layer. The processing conditions are shown below.
CrO ₃ : 4.0 g / L, ZnSO ₄ · 7H ₂ O: 2.0 g / L, Na ₂ SO ₄ : 15 g / L, pH: 4.2, temperature: 45 ° C, current density 3.0A / dm ² , time: 1.5 seconds

Example 1
In Example 1, the adhesion amount of zinc (Zn) in the plating film was 924 μg / dm ² , and in the plating film, Ni: 9 mass%, Zn: 42 mass%, Cu: 49 mass%, and the formula 1 ( Zinc adhesion (mass%)) / {100- (copper adhesion (mass%))} is 0.83, Formula 2 (copper adhesion (mass%)) / {100- (zinc adhesion (mass%)) )} Was 0.85, and both were within the range of the conditions of the present invention. As a result, in Example 1, the peel strength of the normal BT substrate in the FR substrate was 1.47 kN / m, the peel strength after aging for 2 days was 1.20 kN / m, and the deterioration rate was 18%.
Further, the normal peel strength on a normal BT substrate (in a harsh environment) is 1.05 kN / m, the peel strength after hydrochloric acid treatment is 0.85 kN / m, the deterioration rate is 20%, and sulfuric acid-hydrogen peroxide resistant The peel strength was 0.98 kN / m and the deterioration rate was 7%, both of which were good results.
The results are shown in Table 1.

(Example 2)
In Example 2, the zinc (Zn) adhesion amount in the plating film was 320 μg / dm ² , and in the plating film, Ni: 31 mass%, Zn: 34 mass%, Cu: 36 mass%, and the formula 1 ( Zinc adhesion (mass%)) / {100- (copper adhesion (mass%))} is 0.52, Formula 2 (copper adhesion (mass%)) / {100- (zinc adhesion (mass%) )} Was 0.54, both of which were within the range of the present invention. As a result, in Example 2, the peel strength of the normal BT substrate in the FR substrate was 1.56 kN / m, the peel strength after aging for 2 days was 1.42 kN / m, and the deterioration rate was 9%.
In addition, the normal peel strength on a normal BT substrate (in a harsh environment) is 0.99 kN / m, the peel strength after treatment with hydrochloric acid is 0.89 kN / m, the deterioration rate is 10%, and sulfuric acid-hydrogen peroxide resistant The peel strength was 0.86 kN / m and the deterioration rate was 14%, both of which were good results.
The above results are similarly shown in Table 1.

(Example 3)
In Example 3, the zinc (Zn) adhesion amount in the plating film was 465 μg / dm ² , and in the plating film, Ni: 18 mass%, Zn: 12 mass%, Cu: 70 mass%, and the formula 1 ( Zinc adhesion (mass%)) / {100- (copper adhesion (mass%))} is 0.39, Formula 2 (copper adhesion (mass%)) / {100- (zinc adhesion (mass%)) )} Was 0.79, both of which were within the range of the present invention. As a result, in Example 3, the peel strength of the normal BT substrate in the FR substrate was 1.55 kN / m, the peel strength after aging for 2 days was 1.53 kN / m, and the deterioration rate was 2%.
In addition, the normal peel strength on a normal BT substrate (in a harsh environment) is 0.99 kN / m, the peel strength after hydrochloric acid treatment is 0.93 kN / m, the deterioration rate is 6%, and sulfuric acid-hydrogen peroxide resistant The peel strength was 0.88 kN / m and the deterioration rate was 11%, both of which were good results.
The above results are similarly shown in Table 1.

Example 4
In Example 4, the adhesion amount of zinc (Zn) in the plating film was 390 μg / dm ² , and in the plating film, Ni: 2 mass%, Zn: 93 mass%, Cu: 5 mass%, and Formula 1 ( Zinc adhesion (mass%)) / {100- (copper adhesion (mass%))} is 0.98, Formula 2 (copper adhesion (mass%)) / {100- (zinc adhesion (mass%)) )} Was 0.77, both of which were within the range of the present invention. As a result, in Example 4, the peel strength of the normal BT substrate in the FR substrate was 1.46 kN / m, the peel strength after aging for 2 days was 1.28 kN / m, and the deterioration rate was 12%.
Further, the normal peel strength on a normal BT substrate (in a harsh environment) is 1.01 kN / m, the peel strength after hydrochloric acid treatment is 0.86 kN / m, the deterioration rate is 15%, and sulfuric acid-hydrogen peroxide resistant The peel strength was 0.92 kN / m and the deterioration rate was 9%, both of which were good results.
The above results are similarly shown in Table 1.

(Example 5)
In Example 5, the zinc (Zn) adhesion amount in the plating film was 378 μg / dm ² , and in the plating film, Ni: 40 mass%, Zn: 36 mass%, Cu: 24 mass%, and the formula 1 ( Zinc adhesion (mass%)) / {100- (copper adhesion (mass%))} is 0.47, Formula 2 (copper adhesion (mass%)) / {100- (zinc adhesion (mass%)) )} Was 0.37, both of which were within the range of the present invention. As a result, in Example 5, the peel strength of the normal BT substrate in the FR substrate was 1.48 kN / m, the peel strength after aging for 2 days was 1.43 kN / m, and the deterioration rate was 3%.
Further, the normal peel strength on a normal BT substrate (in a harsh environment) is 1.04 kN / m, the peel strength after hydrochloric acid treatment is 0.91 kN / m, the deterioration rate is 13%, and sulfuric acid-hydrogen peroxide resistant The peel strength was 0.93 kN / m and the deterioration rate was 11%, both of which were good results.
The results are shown in Table 1.

(Example 6)
In Example 6, the zinc (Zn) adhesion amount in the plating film was 617 μg / dm ² , and in the plating film, Ni: 18 mass%, Zn: 12 mass%, Cu: 70 mass%, and the formula 1 ( Zinc adhesion (mass%)) / {100- (copper adhesion (mass%))} is 0.39, Formula 2 (copper adhesion (mass%)) / {100- (zinc adhesion (mass%)) )} Was 0.79, both of which were within the range of the present invention. As a result, in Example 6, the peel strength of the normal BT substrate in the FR substrate was 1.45 kN / m, the peel strength after aging for 2 days was 1.42 kN / m, and the deterioration rate was 2%.
Further, the normal peel strength on a normal BT substrate (harsh environment) was 1.10 kN / m, the peel strength after hydrochloric acid treatment was 0.87 kN / m, the deterioration rate was 21%, and sulfuric acid-hydrogen peroxide resistance The peel strength was 0.98 kN / m and the deterioration rate was 11%, both of which were good results.
The above results are similarly shown in Table 1.

(Example 7)
In Example 7, the zinc (Zn) adhesion amount in the plating film was 1860 μg / dm ² , and in the plating film, Ni: 7 mass%, Zn: 9 mass%, Cu: 84 mass%, and the formula 1 ( Zinc adhesion (mass%)) / {100- (copper adhesion (mass%))} is 0.56, Formula 2 (copper adhesion (mass%)) / {100- (zinc adhesion (mass%) )} Was 0.92, and both were within the range of the conditions of the present invention. As a result, in Example 7, the peel strength of the normal BT substrate in the FR substrate was 1.48 kN / m, the peel strength after aging for 2 days was 1.40 kN / m, and the deterioration rate was 5%.
Further, the normal peel strength on a normal BT substrate (in a harsh environment) is 1.02 kN / m, the peel strength after hydrochloric acid treatment is 0.98 kN / m, the deterioration rate is 4%, and sulfuric acid-hydrogen peroxide resistant The peel strength was 0.96 kN / m and the deterioration rate was 2%, both of which were good results.
The above results are similarly shown in Table 1.

(Example 8)
In Example 8, the zinc (Zn) adhesion amount in the plating film was 746 μg / dm ² , and in the plating film, Ni: 47 mass%, Zn: 30 mass%, Cu: 23 mass%, and the formula 1 ( Zinc adhesion (mass%)) / {100- (copper adhesion (mass%))} is 0.39, Formula 2 (copper adhesion (mass%)) / {100- (zinc adhesion (mass%)) )} Was 0.33, both of which were within the range of the present invention. As a result, in Example 8, the peel strength of the normal BT substrate in the FR substrate was 1.47 kN / m, the peel strength after aging for 2 days was 1.46 kN / m, and the deterioration rate was 1%.
Further, the normal peel strength on a normal BT substrate (harsh environment) is 1.03 kN / m, the peel strength after hydrochloric acid treatment is 0.95 kN / m, the deterioration rate is 8%, and the sulfuric acid-hydrogen peroxide resistant The peel strength was 0.95 kN / m and the deterioration rate was 0%, both of which were good results.
The results are shown in Table 1.

Example 9
In Example 9, the zinc (Zn) adhesion amount in the plating film was 220 μg / dm ² , and in the plating film, Ni: 20 mass%, Zn: 69 mass%, Cu: 11 mass%, and the formula 1 ( Zinc adhesion (mass%)) / {100- (copper adhesion (mass%))} is 0.78, Formula 2 (copper adhesion (mass%)) / {100- (zinc adhesion (mass%)) )} Was 0.35, and both were within the range of the conditions of the present invention. As a result, in Example 9, the peel strength of the normal BT substrate in the FR substrate was 1.45 kN / m, the peel strength after aging for 2 days was 1.42 kN / m, and the deterioration rate was 2%.
Further, the normal peel strength on a normal BT substrate (in a harsh environment) is 1.06 kN / m, the peel strength after hydrochloric acid treatment is 0.92 kN / m, the deterioration rate is 13%, and sulfuric acid-hydrogen peroxide resistant The peel strength was 0.98 kN / m and the deterioration rate was 11%, both of which were good results.
The above results are similarly shown in Table 1.

As described above, the plating layers of Examples, adhesion weight of zinc per unit area 220μg ^/ dm ² ~1860μg ^/ dm 2, and the normal peel strength at FR-4 substrate is 1.45kN / m~1.56kN / M, the heat-resistant peel strength is 1.20 kN / m to 1.53 kN / m, and the deterioration rate is in the range of 18% or less, and both showed good normal peel strength and heat-resistant peel strength.
Further, the normal peel strength on the BT substrate was in the range of 0.99 kN / m to 1.10 kN / m. The peel strength after treatment with hydrochloric acid / sulfuric acid / hydrogen peroxide solution is 0.85 kN / m to 0.93 kN / m and 0.86 kN / m to 0.98 kN / m, respectively, and the deterioration rate is 4% to 21%, respectively. 0% to 14%, showing good properties.

(Comparative Example 1-7)
The plating bath composition was changed under the conditions shown below to form a copper nickel zinc layer. Table 2 shows the zinc adhesion amount per unit area and the abundance ratio of nickel, zinc, and copper in the plating film.

(Electroplating solution composition of Comparative Example 1)
Ni: 13 g / L, Zn: 5 g / L, Cu: 0 g / L, sulfuric acid (H ₂ SO ₄ ): 8.5 g / L
(Electroplating solution composition of Comparative Example 2)
Ni: 13 g / L, Zn: 0 g / L, Cu: 6.5 g / L, sulfuric acid (H ₂ SO ₄ ): 8.5 g / L
(Electroplating solution composition of Comparative Example 3)
Ni: 0 g / L, Zn: 5 g / L, Cu: 0.5 g / L, sulfuric acid (H ₂ SO ₄ ): 8.5 g / L
(Electroplating solution composition of Comparative Example 4)
Ni: 13 g / L, Zn: 15 g / L, Cu: 0.9 g / L, sulfuric acid (H ₂ SO ₄ ): 8.5 g / L
(Electroplating solution composition of Comparative Example 5)
Ni: 15 g / L, Zn: 0.1 g / L, Cu: 3 g / L, sulfuric acid (H ₂ SO ₄ ): 8.5 g / L
(Electroplating solution composition of Comparative Example 6)
Ni: 3 g / L, Zn: 16 g / L, Cu: 0.1 g / L, sulfuric acid (H ₂ SO ₄ ): 1 g / L
(Composition of electroplating solution of Comparative Example 7)
Ni: 13 g / L, Zn: 3 g / L, Cu: 0.5 g / L, sulfuric acid (H ₂ SO ₄ ): 1 g / L
(Electroplating solution composition of Comparative Example 8)
Ni: 40 g / L, Zn: 3 g / L, Cu: 0.1 g / L, sulfuric acid (H ₂ SO ₄ ): 1 g / L
(Electroplating solution composition of Comparative Example 9)
Ni: 32 g / L, Zn: 0.05 g / L, Cu: 3.4 g / L, sulfuric acid (H ₂ SO ₄ ): 1 g / L
(Electroplating solution composition of Comparative Example 10)
Ni: 25 g / L, Zn: 16 g / L, Cu: 0.05 g / L, sulfuric acid (H ₂ SO ₄ ): 1 g / L
(Current density)
2.5 A / dm ^{2 to} 30 A / dm ²

(Comparative Example 1)
In Comparative Example 1, copper does not exist in the plating film, and the abundance ratio of nickel in the plating film exceeds 50% by mass, thus deviating from the present invention. Moreover, although Formula 1 (Zinc adhesion amount (mass%)) / {100- (Copper adhesion amount (mass%))} is 0.49, Formula 2 (Copper adhesion amount (mass%)) / {100- (Zinc adhesion amount (mass%))} is 0.00, which is not within the range of the present invention.
In Comparative Example 1, the peel strength of the normal BT substrate of the FR substrate was 1.50 kN / m, the peel strength after aging for 2. days was 1.47 kN / m, and the deterioration rate was 2%. Further, the normal peel strength on a normal BT substrate (in a harsh environment) was 0.98 kN / m, but the peel strength after hydrochloric acid treatment was 0.15 kN / m, and the deterioration rate was significantly reduced to 85%. Furthermore, the peel strength with sulfuric acid-hydrogen peroxide was 0.75 kN / m, the deterioration rate was 24%, and the chemical resistance was greatly lowered in all cases. The results are shown in Table 2.

(Comparative Example 2)
In Comparative Example 2, zinc does not exist in the plating film, and the abundance ratio of nickel in the plating film exceeds 50% by mass, thus deviating from the present invention. Moreover, although Formula 2 (copper adhesion amount (mass%)) / {100- (zinc adhesion amount (mass%))} is 0.45, Formula 1 (zinc adhesion amount (mass%)) / {100- (Copper adhesion amount (mass%))} is 0.00, which is not within the range of the present invention.
In Comparative Example 2, the peel strength of the normal BT substrate in the FR substrate was 1.51 kN / m, the peel strength after aging for 2 days was 1.06 kN / m, and the degradation rate was 30%. The heat peel strength of the steel was greatly reduced. The above results are similarly shown in Table 2.

(Comparative Example 3)
In Comparative Example 3, the adhesion amount of zinc (Zn) in the plating film is 620 μg / dm ² , but nickel does not exist in the plating film and deviates from the present invention. Formula 1 (Zinc adhesion amount (% by mass)) / {100- (Copper adhesion amount (% by mass))} is 1.00, Formula 2 (Copper adhesion amount (% by mass)) / {100- (Zinc adhesion amount ( Mass%))} is 1.00.
In Comparative Example 3, the normal peel strength on a normal BT substrate (in a harsh environment) was 0.96 kN / m, but the peel strength after hydrochloric acid treatment was 0.65 kN / m, and the deterioration rate was 32%. Furthermore, the peel strength with sulfuric acid-hydrogen peroxide was 0.69 kN / m, the deterioration rate was 28%, and the chemical resistance was greatly reduced. The above results are similarly shown in Table 2.

(Comparative Example 4)
In Comparative Example 4, the adhesion amount of zinc per unit area is 2564 μg / dm ² , which is a departure from the present invention. In Comparative Example 4, the normal peel strength on a normal BT substrate (in a harsh environment) was 1.02 kN / m, but the peel strength after hydrochloric acid treatment was 0.20 kN / m and the deterioration rate was 80%. Furthermore, the peel strength with sulfuric acid-hydrogen peroxide was 0.62 kN / m, the deterioration rate was 39%, and the chemical resistance was greatly reduced in all cases.
The above results are similarly shown in Table 2.

(Comparative Example 5)
In Comparative Example 5, the amount of copper present in the plating film was as large as 80% by mass, zinc was 4% by mass, and nickel was 16% by mass. (Zinc adhesion amount (% by mass)) / {100- (copper adhesion amount ( Mass%))} is 0.2, which is out of the scope of the present invention. In Comparative Example 5, the normal peel strength on the FR-4 substrate was 1.12 kN / m, but the peel strength after hydrochloric acid treatment was 1.12 kN / m, the degradation rate was 25%, and FR-4 The heat-resistant peel strength on the substrate was greatly reduced.
The above results are similarly shown in Table 2.

(Comparative Example 6)
In Comparative Example 6, since the zinc present in the plating film is as large as 70% by mass and the copper is as small as 6% by mass, (copper adhesion amount (% by mass)) / {100- (zinc adhesion amount (% by mass)) is In Comparative Example 6, the normal peel strength on the BT substrate was 1.04 kN / m, but the peel strength after hydrochloric acid treatment was 0.16 kN / m. The deterioration rate was as high as 85%, and the chemical resistance (hydrochloric acid) was greatly reduced.

(Comparative Example 7)
In Comparative Example 7, the adhesion amount of zinc per unit area is as small as 150 μg / dm ^2, which deviates from the present invention. In Comparative Example 7, the peel strength after aging for 2 days on the FR-4 substrate was 1.01 kN / m, the deterioration rate was as large as 31%, and the heat resistance was greatly reduced.
The above results are similarly shown in Table 2.

(Comparative Example 8)
In Comparative Example 8, the abundance ratio of nickel in the plating film exceeds 50% by mass, and (Zinc adhesion amount (% by mass)) / {100- (Copper adhesion amount (% by mass))} is 0.27. It deviates from the scope of the present invention. In Comparative Example 8, the peel strength after aging for 2 days on the FR-4 substrate was 1.10 kN / m, the deterioration rate increased to 23%, and the heat-resistant peel strength on the FR-4 substrate was greatly reduced. The above results are similarly shown in Table 2.

(Comparative Example 9)
In Comparative Example 9, (zinc adhesion amount (mass%)) / {100- (copper adhesion quantity (mass%))} is 0.25, which is out of the scope of the present invention. In Comparative Example 9, the peel strength after aging for 2 days on the FR-4 substrate was 1.19 kN / m, the deterioration rate increased to 22%, and the heat-resistant peel strength on the FR-4 substrate was greatly reduced. The above results are similarly shown in Table 2.

In Comparative Example 10, the copper adhesion amount (% by mass)) / {100- (Zinc adhesion amount (% by mass)) is 0.28, which departs from the scope of the present invention. The normal peel strength on the substrate was 1.01 kN / m, but the peel strength after hydrochloric acid treatment was 0.71 kN / m, the deterioration rate was as high as 30%, and the chemical resistance (hydrochloric acid) was greatly reduced.
The above results are similarly shown in Table 2.

From the above, the plating bath conditions for producing the copper nickel zinc layer of the present invention are: Ni: 0.1 g / L to 30 g / L, Zn: 0.1 g / L to 12 g / L, Cu: 0.00. The basic bath is preferably 1 g / L to ₂ g / L, sulfuric acid (H ₂ SO ₄ ): 0.1 g / L to 10 g / L.
When the concentration of nickel, zinc or copper is out of the range of these concentrations and the concentration of nickel, zinc or copper is increased, the waste water treatment is hindered. If the component concentration is too low, it is difficult to manage the plating bath due to factors such as concentration change due to plating, and the current efficiency is extremely reduced.

 In the above description, the case of applying to the roughened surface of the electrolytic copper foil has been described, but it goes without saying that the same applies to the electrolytic copper foil in which the roughened surface is subjected to the roughening treatment. The same applies to the rolled copper foil subjected to the roughening treatment. If the roughened surface of electrolytic copper foil and rolled copper foil is used, the absolute value of normal peel strength may differ depending on the shape of the roughening treatment and the surface roughness, but the heat-resistant peel strength and sulfuric acid -The relative deterioration rate from the normal peel of the peel strength after the hydrogen peroxide treatment can be reduced.

In the copper foil for printed circuit boards according to the present invention, it is a central subject of the invention to select the optimum conditions for the copper nickel zinc layer. As a result, the heat-resistant peel strength of the copper foil is drastically improved, the circuit erosion phenomenon is effectively prevented, and the sulfuric acid / hydrogen peroxide resistance is constantly and stably exerted.
Therefore, it should be easily understood that the selection of the electrolytic copper foil and the rolled copper foil or the selection of the roughened surface can be arbitrarily selected according to the purpose.

 As shown above, the copper foil for printed circuit boards of the present invention uses a copper nickel zinc layer so as not to deteriorate the peel strength with the resin after high-temperature heating, and the heat-resistant peel strength of the copper foil is reduced. It can be improved dramatically. In addition, this has given new characteristics that the circuit erosion phenomenon can be effectively prevented and the chemical resistance (sulfuric acid-hydrogen peroxide system resistance) can be constantly and stably exerted. For printed circuit board copper foil (especially copper foil for semiconductor package board) and printed circuit board (especially semiconductor package board) produced by bonding copper foil and resin base material while fine pattern and high frequency of printed circuit are progressing It is useful as a copper clad laminate.

Claims (7)

A copper foil for a printed circuit board comprising a layer containing nickel, zinc and copper (hereinafter referred to as “copper nickel zinc layer”) on the surface of the copper foil, and the zinc adhesion per unit area of the copper nickel zinc layer weight 200 [mu] g / dm ² or more and 2000 [mu] g / dm ² or less, the copper nickel zinc layer, Ni is 1-50 wt%, (zinc deposition amount (mass%)) / {100- (copper deposition amount (mass %))} Is 0.3 or more, and (copper adhesion amount (mass%)) / {100- (zinc adhesion amount (mass%))} is 0.3 or more. Foil.  The printed circuit board copper foil according to claim 1, further comprising a chromate film layer on the copper nickel zinc layer. 3. The copper foil for a printed circuit board according to claim 2, wherein in the chromate film layer, a chromium adhesion weight is 30 μg / dm ² or more and 100 μg / dm ² or less per unit area.  The printed circuit board copper foil according to claim 2, further comprising a silane coupling agent layer on the chromate film layer.  5. The copper foil is an electrolytic copper foil, and the copper nickel zinc layer is formed on a rough surface at the time of electrolytic plating or a glossy surface of the electrolytic copper foil. Copper foil for printed circuit boards.   The copper foil for printed circuit boards according to any one of claims 1 to 5, wherein the copper foil is a rolled copper foil.  The copper clad laminated board for printed circuit boards produced by bonding together the copper foil for printed circuit boards and the resin for printed circuit boards as described in any one of Claims 1-6.