JP2012207285A - Surface-treated copper foil and manufacturing method therefor, copper-clad laminated board using surface-treated copper foil and manufacturing method therefor, and printed wiring board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a surface-treated copper foil excellent in circuit forming properties of a fine pattern, transmitting properties in a high-frequency range, adhesiveness to a resin base, and chemical resistance.SOLUTION: The surface-treated copper foil has layers formed as follows: a first treatment layer of Ni or Ni-P with a deposition amount of 0.05-1.0 mg/dmis formed on the surface of at least one side of a base copper foil having a surface roughness Ra of ≤0.2 μm or a surface roughness Rz of ≤1.5 μm; a second treatment layer of Zn or Zn-V with a deposition amount of 0.01-0.10 mg/dmis formed on the first treatment layer; a chromate treatment layer with a contact angle θ (hydrophilicity) of 15°-35° is formed on the second treatment layer; a silane coupling treatment layer with a deposition amount of 0.002-0.02 mg/dmis formed on the chromate treatment layer. A method for manufacturing a copper-clad laminated board formed by laminating the surface-treated copper foil and a thermosetting resin board is executed as follows: the surface-treated copper foil and the thermosetting resin board are thermally laminated under the condition that an LMP value shown in a formula 1 is ≤10,660; and a functional group in the outermost silane coupling treatment layer is reacted with a functional group in the thermosetting resin, wherein a formula 1 is LMP=(T+273)*(20+log t), and 20 is a material constant of the copper, T is a temperature(°C), t is a time(hr), and log is a common logarithm.

Description

The present invention relates to a copper foil particularly used for flexible printed wiring boards and the like, and is a surface-treated copper foil excellent in circuit formability in a fine pattern and transmission characteristics in a high frequency region, and excellent in adhesion to a resin base material, and a method for producing the same It is about.
The present invention also relates to a copper clad laminate using the surface-treated copper foil, a method for producing the same, and a printed wiring board using the copper clad laminate.

In recent years, electronic devices are becoming smaller and thinner, and various electronic components used in portable devices such as mobile phones are highly integrated, and include a small and high-density printed wiring board. IC and LSI are used.
Correspondingly, higher density is required for circuit wiring patterns in multilayer printed wiring boards, flexible printed wiring boards, and the like (hereinafter simply referred to as printed wiring boards) used for these. A circuit wiring pattern having a fine width and interval between circuit wirings, that is, a so-called fine pattern printed wiring board is required.

  For example, flexible printed wiring boards are required to have circuit wiring widths and intervals of around 50 μm, respectively, and printed wiring boards used for small ICs have circuit wiring widths and intervals of around 30 μm each. There is a demand for printed wiring boards having fine circuit wiring.

Conventionally, a copper foil used for a printed wiring board has a roughened surface on the side to be thermocompression bonded to a resin base material, and this roughened surface exhibits an anchoring effect on the resin base material. The reliability as a printed wiring board is secured by increasing the bonding strength. (Patent Document 1)
However, in order to increase the information processing speed of electronic devices and to cope with wireless communication, electronic components are required to transmit electric signals at high speed, and application of high-frequency compatible substrates is also in progress. For high-frequency compatible substrates, it is necessary to reduce the transmission loss for high-speed transmission of electrical signals, and in addition to lowering the dielectric constant of the resin base material, it is required to reduce the transmission loss of circuit wiring as a conductor .

  In the high frequency band exceeding several GHz, the current flowing through the circuit wiring is concentrated on the surface of the copper foil due to the skin effect. Therefore, when the copper foil subjected to the conventional roughening treatment is used as the copper foil for the high frequency compatible substrate. There is a problem that the transmission loss in the roughening unit increases and the transmission characteristics deteriorate.

In order to solve these problems, a method of pasting a smooth copper foil on a resin substrate without roughening as a copper foil used for fine pattern and high frequency printed wiring boards has been studied so far. It has been. (Patent Documents 2, 3, and 4)
However, although these smooth copper foils are excellent in circuit formation of fine patterns and transmission characteristics in a high frequency range, it is not always possible to stably and sufficiently improve the adhesion between the copper foil and the resin base material. In the etching process of circuit wiring or Sn plating process on the edge of circuit wiring, chemical penetration may occur at the interface between the copper foil and the resin base material, and the printed wiring board manufacturing process and products are in use. There is a problem that the adhesiveness is lowered by the heat load. In particular, the printed wiring board that supports fine patterns has a very small bonding area between the circuit wiring (copper foil) and the resin base material. There is a risk that the circuit wiring is peeled off, and a copper foil having good adhesion to a resin base material is desired.

JP 05-029740 A JP 2003-023046 A JP 2007-165694 A JP 2008-007803 A

  The problem of the present application is to provide a surface-treated copper foil that solves the above-mentioned problems, is excellent in rust prevention effect, is excellent in fine circuit formability and transmission characteristics in a high-frequency region, and is excellent in adhesion to a resin base material. In addition, another object is to provide a copper-clad laminate in which the surface-treated copper foil is adhered to a resin substrate, and a printed wiring board using the copper-clad laminate.

As a result of intensive studies, the inventors of the present invention used a copper foil having a surface that was smoothed as necessary to obtain Ra of 0.2 μm or less and Rz of 1.5 μm or less. ~1.0mg / Ni layer dm ² or Ni-P alloy layer (primary treatment layer), Zn layer or Zn-V alloy layer of the deposited amount 0.01～0.10Mg / dm ² (secondary treatment layer) A suitable chromate treatment layer in which the number of hydroxyl groups in the chromate layer is controlled so as to be approximately the same as the number of hydroxyl groups in the silane coupling agent is applied to the surface treatment. By applying and drying a silane coupling agent, surface-treated copper foil with excellent rust prevention effect, fine circuit formability, high frequency transmission characteristics, and excellent adhesion to resin substrates, and its copper The foil was attached to the resin substrate Some have succeeded in providing a clad laminates and printed wiring board using the copper-clad laminate.

The surface-treated copper foil of the present invention is provided with a primary treatment layer of Ni or Ni-P having an adhesion amount of 0.05 to 1.0 mg / dm ^{2 on} at least one surface of a base material copper foil (untreated copper foil). A secondary treatment layer of Zn or Zn-V having an adhesion amount of 0.01 to 0.10 mg / dm ² is provided on the primary treatment layer, and a chromate treatment layer is formed on the secondary treatment layer. A silane coupling treatment layer having an adhesion amount of 0.002 to 0.02 mg / dm ² is provided on the chromate treatment layer.

The surface-treated copper foil of the present invention has an adhesion amount of 0 on at least one surface of a base material copper foil (untreated copper foil) having a surface roughness Ra of 0.2 μm or less or Rz of 1.5 μm or less. A primary treatment layer of 0.05 to 1.0 mg / dm ² of Ni or Ni—P is provided, and an adhesion amount of 0.01 to 0.10 mg / dm ² of Zn or Zn—V is provided on the primary treatment layer. A secondary treatment layer is provided, a chromate treatment layer having a contact angle θ (hydrophilicity) of 15 ° to 35 ° is formed on the secondary treatment layer, and an adhesion amount of 0.002 is formed on the chromate treatment layer. A silane coupling treatment layer of ˜0.02 mg / dm ² is provided.

The manufacturing method of the surface treatment copper foil of this invention is a lamination | stacking method which laminates | stacks the said surface treatment copper foil and a thermosetting resin board | substrate, Comprising: The said surface treatment copper foil and a thermosetting resin board | substrate are shown in Formula 1. It is characterized by laminating by heating under conditions where the LMP value is 10660 or less, and causing the functional group of the outermost surface silane coupling treatment layer of the surface-treated copper foil to react with the functional group of the thermosetting resin.
Formula 1: LMP = (T + 273) * (20 + Logt)
Here, 20 is a copper material constant, T is temperature (° C.), t is time (hr), and Log is a common logarithm.

  It is preferable that the thermosetting resin forming the thermosetting resin substrate is a resin that undergoes a curing reaction under the condition that the LMP value shown in the formula 1 is 10660 or less.

The surface-treated copper foil of the present invention is excellent in fine pattern circuit formability and transmission characteristics in a high frequency range, and has adhesion and chemical resistance with a resin base material (chemicals at the interface between the copper foil and the resin base material). It is possible to provide a roughened copper foil that is excellent in preventing penetration.
Furthermore, according to the copper clad laminate using the surface-treated copper foil of the present invention, not only is it suitable for a fine pattern or a high-frequency substrate, but also a printed wiring with good adhesion between the resin base material and the copper foil. Board can be provided.

FIG. 1 is a theoretical diagram for explaining the contact angle θ of the present invention.

As the base material copper foil of the present invention, an electrolytic copper foil is preferable, and its surface roughness is Ra 0.2 μm or less, or Rz 1.5 μm or less. When the surface roughness of the untreated copper foil obtained through the foil-making process is outside the above-mentioned roughness range, the copper foil surface is smoothed, for example, using means such as electrolytic polishing and mechanical polishing. Copper foil that fits within the surface roughness range (hereinafter sometimes referred to as base material copper foil or untreated copper foil).
Moreover, you may use the rolled copper foil whose Ra is 0.2 micrometer or less, or Rz is 1.5 micrometer or less as a base material copper foil of this invention.
In the present invention, the surface roughness of the base copper foil is specified to be 0.2 μm or less in Ra, or 1.5 μm or less in Rz. The use is required for high-frequency transmission characteristics or COF (chip-on-film). This is for the purpose of expressing visibility satisfying the purpose of use.

In the present invention, a Ni or Ni-P alloy coating layer is provided as a primary treatment layer on the surface of an untreated copper foil (a copper foil that has not been surface-treated). The primary treatment layer is provided as a plating layer. About Ni of a primary treatment layer, 0.05-1.0 mg / dm < ² > is made to adhere. The amount of adhesion of Ni is specified because it has an influence on the heat resistance and the straightness of the circuit. If the amount of adhesion of Ni is less than 0.05 mg / dm ² , improvement in heat resistance cannot be expected so much, and 1.0 mg / dm ² This is because if the amount is larger, there is a concern that the soft etching property may be adversely affected.
Further, when soft etching is required, it is effective to use a Ni-P alloy.

Moreover, in this invention, Zn or Zn-V alloy which contributes to a rust prevention effect is provided as a secondary treatment layer on the primary treatment layer surface to which the Ni or Ni-P alloy is adhered. Zn deposition amount of the secondary treatment layer and 0.01~0.10mg / dm ^2. The adhesion amount of Zn or Zn—V alloy as Zn is regulated by the fact that the adhesion amount is 0.10 mg / dm ² or more, the etching property is poor, and the acid resistance is 0.01 mg / dm ² or less. This is because the etching of fine patterns cannot be expected.

As the secondary treatment layer, Zn alone has a sufficient rust prevention effect, but by using a Zn-V alloy having a V (vanadium) content of 10% or less, heat resistance and resistance without affecting the fine pattern workability. A synergistic effect of chemical properties can be obtained.
The V (vanadium) content is 10% or less because V is dissolved in a hydrogen peroxide-sulfuric acid-based etching solution used when fine pattern processing is performed on the surface-treated copper foil, and the V dissolved in the etching solution is In order to accelerate the deterioration of hydrogen peroxide by oxidation-reduction reaction with the etching solution, the V content is preferably 10% or less.
Moreover, if the Ni adhesion amount of the primary treatment layer is up to 0.2 mg / dm ² , it is sufficiently brassed with the Zn component and the copper foil surface under a press temperature and heating conditions of about 200 ° C. to 350 ° C., and Ni is mixed. Brass (Cu / Ni / Zn) conversion is possible, and the rust prevention effect of a secondary treatment layer improves further by heating a secondary treatment layer and making it brass.

A chromate treatment layer (film) is further formed on the surface of the secondary treatment layer. After the secondary treatment layer and the chromate treatment layer made of Zn or Zn-V alloy prevent the copper foil surface from being oxidized, the initial adhesion between the copper foil and the resin base material is improved, and after being exposed to a high temperature and high humidity atmosphere There is an effect of preventing a decrease in adhesion strength.
In particular, by reducing the contact angle θ of the chromate treatment layer, the adhesion with the resin base material is further improved.

The contact angle θ of the chromate treatment layer will be described with reference to FIG.
For the measurement of the contact angle, the θ / 2 method is generally used.
In the θ / 2 method, as shown in FIG. 1, measurement is performed with a droplet amount that can ignore the influence of gravity on the assumption that the droplet is a part of a sphere.
In the θ / 2 method, the angle of the straight line connecting the left and right end points and the vertex of the droplet with respect to the solid surface is θ1, and twice the contact angle θ is obtained. If there is a scale like a protractor, it can be measured by direct reading, and can also be measured by simple calculation even with analysis by a personal computer.

By reducing the contact angle θ of the chromate treatment layer, the adhesion with the resin base material is improved. The contact angle θ (hydrophilicity) was experimentally found to decrease the contact degree θ by increasing the current density when the chromate treatment layer is provided on the secondary treatment layer.
Table 1 shows the results of obtaining the contact angle θ shown in FIG. 1 by providing a Ni layer as a base plating on the copper foil surface, providing a Zn layer thereon, and applying a chromate layer on the surface with various current densities. .
As is apparent from Experimental Examples 1 to 9 shown in Table 1, as the current density increases, the amount of deposited Cr increases, but the contact angle θ also increases.

In the surface-treated copper foil of the present invention, a silane coupling agent is applied to the surface of the chromate treatment layer and dried by heating to provide a silane coupling treatment layer.
Various types of silane coupling agents are commercially available, but each has its characteristics, and it is necessary to select a silane coupling agent suitable for the resin base material to be bonded. Aminosilane-based or methacrylic-based materials are effective for high-frequency compatible resin substrates. In addition, it is effective to use mainly an epoxy phenol resin or an epoxy resin for a rigid wiring board or a printed wiring board for IC.

The silane coupling agent hydrolyzes when it comes into contact with water, and the generated silanol groups are adsorbed by hydrogen bonding to the hydroxyl groups on the surface of the chromate layer by self-condensation, and the heat (thermal energy) applied in the subsequent drying treatment. Thus, it is considered that a dehydration (condensation reaction) reaction occurs from the hydroxyl group present on the surface of the chromate layer and the silanol group, and the rust prevention effect is enhanced.
That is, by controlling the number of hydroxyl groups generated on the surface of the chromate layer, the number of hydroxyl groups that cannot be hydrogen bonded can be reduced by combining the number of hydroxyl groups that are hydrogen bonded to the silane coupling agent. Thereby, through a drying process, an excess hydroxyl group decreases, as a result, adhesion of an oxide decreases on the copper foil surface, and the rust prevention effect on the copper foil surface is obtained.

  If the heating and drying temperature is low during the process of applying and drying the silane coupling agent, the bond energy of the hydrogen bond between the hydroxyl group of the chromate layer and the silanol group of the silane coupling agent is low, and the effect of the silane coupling treatment is effective. I can't get it. On the other hand, if it is heated too much, the bonded silane coupling agent is decomposed by heat, which becomes a fragile interface and adversely affects the adhesion to the resin substrate, which is not preferable. Although the drying temperature and the drying time depend on the configuration of the apparatus and the processing speed (work time) of the manufacturing process, a preferable range is a drying temperature of 70 to 200 ° C. and a drying time of 15 to 35 seconds.

Based on the above considerations, the degree of oxidation of the copper foil surface (rust prevention effect) and the peel of the thermosetting resin depending on the Cr adhesion amount (contact angle θ) of the chromate treatment layer and the silane coupling agent adhesion amount of the silane coupling treatment layer Table 1 shows the results of the study on strength.
As can be seen from Table 1, the peel strength after heat resistance is 5 in which the contact angle θ of the chromate treatment layer is 15 ° to 35 ° and the adhesion amount of the silane coupling agent is 0.002 to 0.02 mg / dm ^2. Shows satisfactory results.
The evaluation method will be described later.

Next, the resin base material was laminated | stacked on the surface treatment copper foil which performed the surface treatment, and the copper clad laminated board was created.
As the resin base material, polymer materials of various components can be used. However, in the present invention, in order to better bond the inorganic material and the organic material, the hydrophilicity (contact angle) of the chromate treatment layer, which is an inorganic material, is limited, and a curable resin that is cured at a relatively low temperature is selected. By limiting the contact angle of the chromate treatment layer of the surface-treated foil and selecting a curable resin that cures at a relatively low temperature, even when the surface of the copper foil is in a smooth state, bonding is performed with high peel strength. A copper-clad laminate can be created.
In order to produce a copper-clad laminate, a curable resin that is cured at a relatively low temperature is selected as described above. As the curable resin that cures at a relatively low temperature, it is desirable to select a thermosetting resin that thermosets at 260 ° C. or less for 1 hour or under the condition that the LMP value represented by Formula 1 is 10660 or less.
Formula 1: LMP = (T + 273) * (20 + Logt)
Here, 20 is a copper material constant, T is temperature (° C.), t is time (hr), and Log is a common logarithm.

  As a curable resin that is cured at a relatively low temperature and laminated with the surface-treated copper foil, for example, a recently developed soluble polyimide resin is most desirable because it can be bonded to the copper foil at a curing temperature of 200 ° C. or lower. In addition, even with a photo-curing, moisture-curing, or two-component curing resin or adhesive, the heat treatment load is small. Therefore, if the characteristics of the resin itself can be satisfied, the present invention is consistent with the gist of the present invention. It is.

Also, for example, polymer, thermoplastic polyimide, and resin polyether ether ketone (PEEK) resin that can form an optically anisotropic melt phase are directly laminated with copper foil because the molding temperature exceeds 350 ° C. Although it is not desirable, it can be laminated with a surface-treated copper foil via a thermosetting adhesive to form a copper-clad laminate. In addition, polyethylene terephthalate (PET) resin and polyethylene naphthalate (PEN) resin, which have relatively low molding temperatures, have few groups that react with the functional groups of the silane coupling agent. Although it is difficult to do, a copper-clad laminate can be obtained by laminating a surface-treated copper foil with a curable resin that cures at a relatively low temperature as an adhesive.
As a method of laminating (laminating) the surface-treated copper foil and the resin base material, a casting method, a heat press method, a continuous roll laminate method, a continuous belt press method, or the like can be used. Thermocompression bonding is also possible.
As another method, a method in which a resin-containing material dissolved in a solvent and having fluidity is applied to the surface of the surface-treated copper foil and then the resin is cured by heat treatment can be applied.

  Recently, the surface of the copper foil is coated with an adhesive resin such as epoxy resin or polyimide in advance, and the resin-coated copper foil in which the adhesive resin is semi-cured (B stage) is used as a copper foil for circuit formation. A multilayer printed wiring board and a flexible printed wiring board are also manufactured by thermocompression bonding the resin side for adhesion to a resin base material. Since this method can enhance the adhesion between the surface-treated copper foil and the resin substrate, a copper-clad laminate with good adhesion can be produced by combining with the present invention, and is more effective.

Hereinafter, the present invention will be described in more detail based on examples, but the present invention is not limited thereto.
The surface treatment process of the copper foil of the present invention will be described in order from the foil making process.

Examples 1-4
(1) Foil-making process A base material copper foil (untreated copper foil) was prepared under the following plating bath and plating conditions.
(Plating bath and plating conditions)
Copper sulfate: 50-80 g / L as copper concentration
Sulfuric acid concentration: 30-70 g / L
Chlorine concentration: 0.01-30ppm
Liquid temperature: 35-45 degreeC
Current density: 20 to 50 A / dm ²
Ra of the produced copper foil was 0.2 micrometer or less, and Rz was 1.5 micrometers or less.

(2) Surface treatment-1
The primary treatment layer was applied in the following plating bath and plating conditions.
(Ni plating)
Nickel sulfate hexahydrate: 240 g / L
Ammonium persulfate: 40 g / L
Boric acid: 30 g / L
Liquid temperature: 50 ° C
Current density: 0.5 A / dm ²

(Ni-P plating)
Nickel sulfate hexahydrate: 240 g / L
Ammonium persulfate: 40 g / L
Sodium hypophosphite: 5 g / L
Boric acid: 30 g / L
Liquid temperature: 50 ° C
Current density: 0.5 A / dm ²
The adhesion amount of Ni in the Ni or Ni—P alloy applied in the surface treatment-1 is in the range of 0.05 to 1.0 mg / dm ² .

(3) Surface treatment-2
The secondary treatment layer was applied with the following plating bath and plating conditions.
(Zn plating)
Zinc sulfate heptahydrate: 24 g / L
Sodium hydroxide: 85 g / L
Liquid temperature: 25 ° C
Current density: 0.4 A / dm ²

(Zn-V plating)
Zinc sulfate heptahydrate: 24 g / L
Sodium hydroxide: 85 g / L
Ammonium metavanadate: 5 g / L
Liquid temperature: 25 ° C
Current density: 0.4 A / dm ²
Adhesion amount of Zn in the Zn or Zn-V alloy was subjected surface treatment -2 ranges 0.01 to 0.1 mg / dm ^2.

(4) Chromate treatment After the metal plating layer treatment, Cr plating was performed using the following plating bath and plating conditions.
(Cr plating)
Chromic anhydride: 0.1 g / L to 100 g / L
Liquid temperature: 20-50 degreeC
Current density: 1-2 A / dm ²

(5) Silane coupling treatment Silane species: 3-aminopropyltrimethoxysilane Silane concentration: 0.1 g / L to 10 g / L
Liquid temperature: 20-50 degreeC

Comparative Example 1
(Ni-Zn alloy plating)
When Ni plating was applied, Zn plating was applied thereon, and when Ni—Zn plating was applied, Zn plating was not applied.
Nickel sulfate: Nickel concentration of 20 g / L to 60 g / L,
Zinc sulfate: 0.05 g / L to 50 g / L as the zinc concentration,
Liquid temperature: 20-60 degreeC
pH: 2-7
Current density: 0.3 to 10 A / dm ²

Comparative Example 2
(Ni-Zn-P alloy plating)
Nickel sulfate: Nickel concentration of 20 g / L to 60 g / L,
Zinc sulfate: 0.05 g / L to 50 g / L as the zinc concentration,
Ammonium persulfate: 20 g / L to 40 g / L
Sodium hypophosphite: 5 g / L
Boric acid: 30 g / L
Liquid temperature: 20 to 60 ° C
Current density: 0.5 A / dm ^{2 to} 8.5 A / dm ²

Examples 5-8
Various resin base materials shown in Table 3 were bonded to the surface-treated copper foil prepared in Example 1 to prepare a copper-clad laminate.

Comparative Examples 3 and 4
The surface-treated copper foil created in Comparative Example 1 was laminated with a resin base material shown in Table 3 to produce a copper-clad laminate.

Preparation of test piece The copper foil or laminated substrate prepared in the above Examples and Comparative Examples was processed into sizes and forms suitable for various evaluations to obtain test pieces.

Characteristic Evaluation of Test Pieces Various measurements and evaluations were performed on the test pieces, and the results are shown in Tables 1 to 3.
(1) Measurement of metal adhesion amount It analyzed with the fluorescent-X-ray-analysis apparatus (Rigaku Co., Ltd. product ZSX Primus, analysis diameter: 35 (PHI)).

(2) Measurement of surface roughness It measured with the contact-type surface roughness measuring machine (SE1700 by Kosaka Laboratory).

(3) Initial peel strength (measurement of initial adhesion strength)
The adhesion strength between the surface-treated copper foil and the resin base material was measured. A commercially available thermosetting polyimide resist was used as the resin substrate.
Curing conditions: 260 ° C., 1 hour (LMP value = 10660)
Adhesion strength is tensilon tester (manufactured by Toyo Seiki Seisakusho Co., Ltd.), after bonding copper foil and resin base material, the test piece is etched into 1mm wide circuit wiring, and the resin side is a stainless steel plate with double-sided tape The circuit wiring was peeled off at a rate of 50 mm / min in the 90 degree direction. Initial adhesion determined that 0.8 kN / m or more was acceptable (◯) and less than that was unacceptable (x).

(4) Heat resistance (measurement of adhesion strength after heat treatment)
About the test piece, the adhesive strength after heat-processing at 150 degreeC for 168 hours was measured.
As for heat resistance, 50% or more of the initial peel strength was determined to be acceptable (◯), and less than that was determined to be unacceptable (x).

(5) Chemical resistance 5-1. Acid resistance 30 minutes (measurement of adhesion strength after acid treatment)
In the chemical resistance evaluation, pass / fail was determined by measuring the peel strength by a measurement method defined in JIS-C-6481, which is used for measurement of peel adhesion to a substrate. First, the peel strength (initial value) KN / m of the test circuit patterned to 1 m / m width in the same manner as the peel strength measurement shown in Table 1, the test circuit is hydrochloric acid: water = 1: 2. From those having no degradation value of peel measured after 30 minutes of immersion in a diluted hydrochloric acid solution, less than 10% was judged to be acceptable, and 10% or more was judged to be unacceptable (x).
5-2. Acid resistance 60 minutes (with or without chemicals)
About the test piece, after immersing in a hydrochloric acid solution of water: hydrochloric acid = 1: 1 at room temperature for 1 hour, the interface between the copper foil and the resin base material was observed for the presence of 1 μm or more so as to pass the sample without soaking (○ ), And those that were soaked were judged as rejected (x).

(6) Circuit formability (measurement of remaining copper at the end of circuit wiring)
The test piece was etched into 1 mm-wide circuit wiring, and the width of the remaining copper at the interface between the copper foil and the resin substrate was measured.
The circuit formability was determined to be 3.0 μm or less as acceptable (◯).

(7) Transmission characteristics (measurement of transmission loss at high frequency)
Transmission loss in the high frequency band was measured with a test piece for measuring transmission characteristics. As the resin base material, copper-clad laminates were prepared using various resins having the requirements shown in Table 3, and processed into test pieces for measuring transmission characteristics.
For the evaluation of transmission measurement, a known stripline resonator method (microstrip structure: dielectric thickness 50 μm, conductor length 1.0 mm, conductor thickness 12 μm, conductor circuit width 120 μm, suitable for measurement in the 1 to 25 GHz region, The transmission loss (dB / 100 mm) at a frequency of 5 GHz was measured using a method of measuring the S21 parameter with a characteristic impedance of 50Ω and no coverlay film.
Regarding the transmission characteristics, a transmission loss of less than 25 dB / 100 mm was determined to be acceptable (◯), and more than that was determined to be unacceptable (x).

(8) Copper foil oxidation test The test piece was heated in air at 250 ° C for 1 hour, and the surface-treated surface of the copper foil was observed. In the evaluation, within the 25 × 25 cm range of the test piece, the area ratio seen as oxidation of the copper foil was determined to be 20% or less as acceptable (◯), and more than that was determined as unacceptable (×).

(9) Measurement of contact angle Contact angle (theta) shown in FIG. 1 was measured using DM-701 by Kyowa Interface Science.
The measured values were measured at five locations on the surface of each test piece, and the average value was taken.

As described above, the surface-treated copper foil of the present invention satisfies the initial adhesion with a resin base material (resin base material cured at LMP10600 or less), heat resistance, circuit formability, and transmission characteristics, and is industrially excellent. It is a surface-treated copper foil.
Moreover, according to the manufacturing method of the surface treatment copper foil of this invention, the outstanding surface treatment copper foil which is excellent in adhesiveness with a resin base material, and is satisfied industrially can be manufactured.
Furthermore, according to the copper clad laminate and the printed wiring board of the present invention, the adhesive strength between the resin base material and the copper foil is strong, and the chemical resistance is excellent in circuit formation.

  On the other hand, as shown in Comparative Examples 1 and 2, when a Ni—Zn alloy is used for the base plating, a sufficient peel strength cannot be obtained, and a resin that has few groups that react with the functional group of the silane coupling agent as a resin substrate. As shown in Comparative Example 3, a sufficient peel strength was not obtained, and a peel strength was not satisfactory as shown in Comparative Example 4 with a resin base material having a high curing temperature.

The surface-treated copper foil of the present invention is provided with a primary treatment layer of Ni or Ni-P alloy having an adhesion amount of 0.05 to 1.0 mg / dm ^{2 on} at least one surface of a base material copper foil (untreated copper foil). A secondary treatment layer of Zn or Zn-V alloy having an adhesion amount of 0.01 to 0.10 mg / dm ² is provided on the primary treatment layer, and a chromate treatment layer is provided on the secondary treatment layer. Since a silane coupling treatment layer having an adhesion amount of 0.002 to 0.02 mg / dm ² is applied on the chromate treatment layer, as shown in Table 3, peel strength, circuit moldability, A surface-treated copper foil excellent in acid resistance, transmission characteristics, and chemical resistance can be provided, and an excellent copper-clad laminate can be provided by laminating a resin substrate having a relatively low curing temperature to the surface-treated copper foil. Providing fine-pitch printed wiring boards using this laminate Rukoto can.

Claims (7)

A primary treatment layer of Ni or Ni-P having an adhesion amount of 0.05 to 1.0 mg / dm ² is provided on at least one surface of the base material copper foil (untreated copper foil), on the primary treatment layer. A secondary treatment layer of Zn or Zn-V having an adhesion amount of 0.01 to 0.10 mg / dm ² is provided, a chromate treatment layer is formed on the secondary treatment layer, and the chromate treatment layer is formed on the chromate treatment layer. A surface-treated copper foil provided with a silane coupling treatment layer having an adhesion amount of 0.002 to 0.02 mg / dm ² . Ni having an adhesion amount of 0.05 to 1.0 mg / dm ^{2 on} at least one surface of a base copper foil (untreated copper foil) having a surface roughness Ra of 0.2 μm or less or Rz of 1.5 μm or less. Further, a primary treatment layer of Ni—P is provided, and a secondary treatment layer of Zn or Zn—V having an adhesion amount of 0.01 to 0.10 mg / dm ² is provided on the primary treatment layer. A chromate treatment layer having a contact angle θ (hydrophilicity) of 15 ° to 35 ° is formed on the treatment layer, and a silane coupling having an adhesion amount of 0.002 to 0.02 mg / dm ² on the chromate treatment layer. A surface-treated copper foil provided with a treatment layer.   The surface-treated copper foil whose Zn content rate in the Zn-V alloy which forms the secondary treatment layer of Claim 1 or 2 is 90% or more. A method for producing a copper-clad laminate in which the surface-treated copper foil according to claim 1 or 2 and a thermosetting resin substrate are laminated,
The surface-treated copper foil and the thermosetting resin substrate are heated and laminated under the condition that the LMP value shown in Formula 1 is 10660 or less, and the functional group of the silane coupling treatment layer of the surface-treated copper foil is changed to that of the thermosetting resin. The manufacturing method of the copper clad laminated board made to react with a functional group.
Formula 1: LMP = (T + 273) * (20 + Logt)
Here, 20 is a copper material constant, T is temperature (° C.), t is time (hr), and Log is a common logarithm. The method for producing a copper clad laminate according to claim 4, wherein the thermosetting resin forming the thermosetting resin substrate is a resin that undergoes a curing reaction under the condition of an LMP value of 10660 or less shown in Formula 1.
Formula 1: LMP = (T + 273) * (20 + Logt)
Here, 20 is a copper material constant, T is temperature (° C.), t is time (hr), and Log is a common logarithm.   The copper clad laminated board manufactured with the manufacturing method of the copper clad laminated board of Claim 4 or 5.   A printed wiring board using the copper clad laminate according to claim 6.

Images