JP5885054B2 - A treated copper foil for a copper clad laminate, a copper clad laminate obtained by bonding the treated copper foil to an insulating resin substrate, and a printed wiring board using the copper clad laminate. - Google Patents

Description

  The present invention relates to a treated copper foil for a copper-clad laminate, a copper-clad laminate obtained by bonding the treated copper foil to an insulating resin substrate, and a printed wiring board using the copper-clad laminate, and the copper-clad laminate The board is suitable as a printed wiring board material used in electronic equipment.

As is well known, rolled copper foil and electrolytic copper foil used for printed wiring boards are provided with various treatment layers such as a roughening treatment layer, a heat treatment treatment layer, and a rust prevention treatment layer according to the use of the copper foil. (Hereinafter, a copper foil provided with a treatment layer is referred to as “treated copper foil”, and a copper foil provided with no treatment layer is referred to as “untreated copper foil”).
And the treated copper foil used for the printed wiring board which is a typical use of the copper clad laminate formed by bonding the treated copper foil to the insulating resin substrate is firmly bonded to the insulating resin substrate. Therefore, the most effective means for imparting the peel strength property is roughening the surface of the untreated copper foil to be bonded to the insulating resin substrate. It is a means for providing a layer.

   Usually, the roughened layer is made of copper or copper alloy fine particles (hereinafter referred to as “roughened particles”) by electroplating on the surface of the rolled untreated copper foil or electrolytic untreated copper foil bonded to the insulating resin substrate. ) Is deposited and adhered to form a coarse particle aggregate layer (hereinafter referred to as “roughening treatment”), and is strongly peeled by the mechanical anchoring effect of the aggregate layer. As the amount of roughened particles (hereinafter referred to as “roughening amount”) is increased, the surface roughness of the copper foil is increased and the mechanical anchoring effect is increased. Strength is improved.

 However, when manufacturing a printed wiring board, there is a step of etching the treated copper foil to form a copper circuit, and when there is a large amount of roughening treatment of the treated copper foil, etching residue (undissolved residue of roughened particles) ) And the etching factor is reduced, so the surface roughness cannot be increased by increasing the amount of roughening treatment in order to improve the peel strength characteristics. Since fine pitches are progressing as equipment becomes lighter and shorter, it is necessary to suppress the generation of etching residues as much as possible. For this purpose, the surface of the foil surface is reduced by reducing the amount of roughening treatment. Lowering the roughness is an effective means.

  In other words, it is necessary to increase the surface roughness by increasing the amount of roughening treatment in terms of the peel strength for the treated copper foil provided with the roughened layer used for the printed wiring board. From the standpoint of etching characteristics, it is necessary to reduce the surface roughness by reducing the amount of roughening treatment, so that the difficulty of satisfying both characteristics is inherent.

   However, the printed wiring board manufacturing process includes an etching process using an etching solution, a cleaning process using sulfuric acid, hydrochloric acid, and caustic soda, a tin plating process, an electroless nickel plating process, and an electroless gold plating process. When the peel strength of the treated copper foil is weak, the active treatment liquid is soaked from the adhesive interface between the treated copper foil and the insulating resin substrate and the peel strength is reduced ( Degradation) is likely to occur, and if the peel strength is reduced, the printed wiring board produced, especially the fine pitch printed wiring board, is susceptible to circuit peeling and dropping due to thermal and mechanical shocks. There is a need for a treated copper foil that does not decrease the peel strength even after immersion in the liquid and has a small amount of penetration.

  Furthermore, printed wiring boards used in electronic devices tend to be widely used in recent years. For this reason, printed wiring boards are often used in various environments or used for a long time. For this reason, the treated copper foil is subjected to an acceleration test under so-called severe conditions such as a peel strength test after moisture absorption treatment and a peel strength test after heat treatment after molding the copper clad laminate, and after these severe tests There is also a need for a treated copper foil that does not reduce the peel strength.

Among those skilled in the art, research and development are underway to meet the above requirements by overcoming the above-mentioned difficulties inherent in printed wiring boards. For example, in Patent Document 1 described later, a wiring circuit bottom formed on a printed wiring board As a treated copper foil with good linearity and good adhesion resistance (adhesiveness) to the insulating resin base material, as well as chemical resistance and moisture absorption resistance, surface, the following surface roughness Rzjis is 2.5 [mu] m, and the ratio of the 3-dimensional surface area (a) [mu] m ² and the two-dimensional surface area when the two-dimensional surface area measured by a laser method an area of 6550μm ² [(a ) / (6550 μm ² )] is disclosed, and a treated copper foil characterized by a surface area ratio (B) of 1.2 to 2.5 ”is disclosed. in the evaluation areas, zinc - the total amount of zinc and nickel containing nickel layer (C) mg / m ² It is 40 mg / m ² or more "Zinc - discloses that nickel layer is provided.

JP 2008-285751 Japanese Patent Publication No.3-35394 JP 56-118390 A

  The present inventor also overcomes the above-mentioned difficulties inherent in the printed wiring board, meets the above requirements, satisfies both the peeling strength characteristics and the etching characteristics, and the peeling strength decreases even after immersion in the active treatment solution. R & D is underway to provide a treated copper foil that has low penetration after immersion in the active treatment solution and can maintain sufficient peel strength even in accelerated tests under severe conditions However, on the way, when the surface-treated copper foil disclosed in the above-mentioned Patent Document 1 was examined, the treated copper foil was peeled off with an insulating resin base material (FR-4 base material). It is excellent and has a small deterioration rate after treatment with an active treatment solution (diluted hydrochloric acid treatment) and excellent etching properties. However, in the following points, it cannot be said that the above requirements are sufficiently met.

  That is, according to the results of a follow-up experiment conducted by the present inventors, sufficient peel strength characteristics cannot be obtained when the surface area ratio is 1.2 to 1.8, and the deterioration rate of the peel strength after moisture absorption treatment tends to be large. It was.

  Further, as described above, an important characteristic required as a copper foil for a printed wiring board is the peel strength after heat treatment. Particularly in recent years, many types of insulating resin base materials have been used and are diversified. In particular, in a two-layer flexible substrate, this property tends to vary greatly depending on the metal species provided on the surface of the roughened layer. The peeling strength after the heat treatment assumes that the electronic device is used for a long period of time, and an acceleration test is performed by performing the heat treatment.

As the heat treatment conditions, for example, conditions such as 150 ° C.-168 hours are often employed in the above-described two-layer flexible substrate. Also for this, the treated copper foil having the surface area ratio of 1.2 to 2.5 was used, a zinc-nickel layer was provided, and the inventor of the present application conducted a follow-up experiment. With the treated copper foil of the above technique, the peel strength after the heat treatment It has been found that there is room for improvement with a large deterioration rate.

Therefore, the inventor of the present application can obtain a strong peeling strength with the insulating resin base material, a degradation rate of the peeling strength after moisture absorption treatment is small, and a degradation rate of the peeling strength after immersion in the active treatment liquid. As a technical issue, we have obtained a processed copper foil that has a small amount of penetration after immersion in the active treatment solution and has good etching properties. A treated copper foil for copper-clad laminate in which a treated copper foil surface formed by forming a treated layer on the surface of the copper foil is bonded to an insulating resin substrate, and the roughened layer and chromate are formed on the surface of the untreated copper foil. Layer and a silane coupling agent layer are sequentially formed as a treatment layer, and the ten-point average roughness Rz of the treated surface of the treated copper foil is 1.0 μm to 2.7 μm, and by a stylus type surface roughness meter Measured average distance S between local peaks specified in JISB0601-1994 is 0.0230mm or less (However, 0 is not included) The arithmetic average roughness Ra is 0.18 μm to 0.36 μm, and the treated copper foil for a copper clad laminate in which Ra and S have the relationship of the following formula (1) The above-mentioned technical problem has been achieved by obtaining the remarkable knowledge that the above-mentioned can be satisfied.
Formula (1)
50.0 <{(S × 1000) / Ra} ≦ 100.0 (In the formula (1), the unit of S × 1000 is μm)

The technical problem can be solved by the present invention as follows. That is, the treated copper foil according to the present invention is a treated copper foil for a copper clad laminate in which a treated copper foil surface formed by forming a treated layer on the surface of an untreated copper foil is bonded to an insulating resin substrate, A roughened layer, a chromate layer and a silane coupling agent layer are sequentially formed on the surface of the untreated copper foil as a treated layer, and the ten-point average roughness Rz of the treated surface of the treated copper foil is 1.0 μm to 2.7 μm. In addition, the average distance S between local peaks defined by JISB0601-1994 measured by a stylus type surface roughness meter is 0.0230 mm or less (excluding 0), and the arithmetic average roughness Ra is 0.18. The copper foil is a copper clad laminate treated copper foil having a relationship of μm to 0.36 μm and Ra and S having the relationship of the following formula (1).
Formula (1)
50.0 <{(S × 1000) / Ra} ≦ 100.0 (in the formula (1), the unit of S × 1000 is μm) (Claim 1).

In the treated copper foil according to the present invention, a nickel and / or cobalt layer containing molybdenum is formed as a treated layer between the roughened layer and the chromate layer, and the nickel and / or the molybdenum containing the molybdenum and / or or precipitation deposition amount of the cobalt layer is ^{20mg / m 2 ~300mg / m 2} , and claim 1, wherein the remainder content of molybdenum is not more than 10 wt% is a nickel and / or cobalt It is the processing copper foil for copper clad laminated boards of description .
Moreover, this invention is the copper clad laminated board which heat-pressed the process copper foil for copper clad laminated boards of Claim 1 or 2 to the insulating resin base material (Claim 3).
Moreover, this invention is a printed wiring board obtained using the copper clad laminated board of Claim 3. (Claim 4).

According to the present invention, a roughened layer, a chromate layer, and a silane coupling agent layer are sequentially formed on the surface of the untreated copper foil as a treated layer, and the ten-point average roughness Rz of the treated surface of the treated copper foil is By making the average interval S of the local peaks defined in JISB0601-1994 measured by a stylus type surface roughness meter to be 0.0230mm or less (excluding 0), it is 1.0μm to 2.7μm . Strong peel strength with insulating resin base material is obtained, degradation rate of peel strength after moisture absorption treatment is reduced, degradation rate of peel strength after immersion in active treatment solution is reduced, active treatment The amount of penetration after immersion in the liquid is reduced, and a treated copper foil having good etching properties can be obtained.
In addition, the arithmetic average roughness Ra of the treated copper foil surface bonded to the insulating resin base material is 0.18 μm to 0.36 μm, and the arithmetic average roughness Ra and the average interval S between the local peaks are represented by the following formula ( By satisfying the relationship of 1), a stronger peeling strength can be obtained from the insulating resin substrate, and the deterioration rate of the peeling strength after moisture absorption treatment is reduced, and further the peeling after immersion in the active treatment solution is reduced. It is possible to obtain a treated copper foil having a lower strength deterioration rate, a smaller amount of penetration after immersion in the active treatment solution, and a better etching property.
Formula (1)
50.0 < {(S × 1000) / Ra} ≦ 100.0 (In the formula (1), the unit of S × 1000 is μm.)
Further, since a nickel and / or cobalt layer containing molybdenum is formed as a treatment layer between the roughening treatment layer and the chromate layer, the deterioration rate of the peel strength after the heat treatment is reduced.
Therefore, it can be said that the industrial applicability of the present invention is very high.

Embodiments of the present invention will be described below.
As an untreated copper foil according to the present invention, an electrolytic copper foil formed by depositing on the cathode side by flowing a current between an anode immersed in an electrolytic solution and a cathode, or ingot-shaped copper is rolled. What is necessary is just to use the rolled copper foil etc. which become. In addition, the rolled copper foil does not need to be distinguished from each other because it has no front and back, but it is not necessary to distinguish between the electrolytic copper foil, and any of a precipitation surface and a glossy surface may be used.

  In addition, the thickness of the untreated copper foil is preferably 6 μm to 300 μm, and more preferably 9 μm to 150 μm. Further, the ten-point average roughness Rz of the untreated copper foil surface is preferably 0.1 μm to 2.0 μm, more preferably 0.5 μm to 1.8 μm in consideration of the increase in roughness accompanying the formation of the roughened layer. .

First, the roughening treatment layer and the roughening particles forming the roughening treatment layer will be described in detail.
The roughening treatment layer of the present invention is an aggregate layer of roughening particles having a crystal grain size of 2.0 μm or less obtained by electroplating. The ten-point average roughness Rz (hereinafter referred to as Rz) of the roughened layer is preferably 1.0 μm to 2.7 μm, more preferably 1.2 μm to 2.5 μm. Rz used in the present invention is a ten-point average roughness according to JISB0601-1994.
When Rz is less than 1.0 μm, the roughened layer has small unevenness, so an effective mechanical anchoring effect cannot be obtained, a strong peeling strength cannot be obtained, and a peeling strength after moisture absorption treatment cannot be obtained. The deterioration rate increases, the deterioration rate of the peel strength after immersion in the active treatment solution increases, and the amount of penetration after immersion in the active treatment solution increases. When Rz exceeds 2.7 μm, the roughened layer has large irregularities, so that undissolved coarse particles may occur between the circuits after etching the treated copper foil, and short circuit abnormality may occur.

  Until now, Rz has been frequently used as a parameter representing the roughness of the copper foil surface. On the other hand, depending on the shape and interval of the roughened particles forming the roughened layer, there are many cases where the peel strength differs even when Rz is the same. Therefore, the present inventor paid attention to the average interval S between the local peaks.

  The average interval S (hereinafter referred to as S) of the local summit used in the present invention is also compliant with JISB0601-1994, as is the case with Rz. S is extracted from the roughness curve by the reference length in the direction of the average line, the length of the average line corresponding to the adjacent local peaks is obtained, and the average value between these local peaks is expressed in (mm). Parameter. The smaller the S is, the narrower and denser the local peaks are, while the larger S is the wider and sparsely spaced local peaks.

S is preferably 0.0230 mm or less (excluding 0), more preferably 0.022 mm or less. If S exceeds 0.0230mm, the distance between the tops of the local peaks will be wide, making it difficult to obtain an efficient mechanical anchoring effect, and it will not be possible to obtain a strong peel strength. Deterioration rate of the peel strength after moisture absorption treatment Increases, the rate of degradation of the peel strength after immersion in the active treatment solution increases, and the amount of penetration after immersion in the active treatment solution increases.

The reason why S is smaller is preferable because the distance between the local peaks is close, so there are many local peaks per unit area.Therefore, the surface area of adhesion with the insulating resin substrate is increased, and an efficient mechanical anchoring effect is obtained. can get. As a result, the peel strength improves, the deterioration rate of the peel strength after moisture absorption treatment decreases, the deterioration rate after immersion in the active treatment solution decreases, and the amount of penetration after the active solution immersion decreases.
Next, the arithmetic average roughness Ra (hereinafter referred to as Ra) of the roughened layer is preferably 0.18 μm to 0.36 μm, more preferably 0.20 μm to 0.35 μm. Ra used in the present invention is also compliant with JISB0601-1994. When Ra is less than 0.18μm, the roughened layer has small unevenness, so an effective mechanical anchoring effect cannot be obtained, and strong peeling strength cannot be obtained. Degradation of peeling strength after moisture absorption treatment The rate increases, the deterioration rate of the peel strength after immersion in the active treatment solution increases, and the amount of penetration after immersion in the active treatment solution increases. When Ra exceeds 0.36 μm, the unevenness of the roughening treatment layer is large, so that roughening particles remain undissolved between the circuits after the etching of the treated copper foil, and a short circuit abnormality may occur.

It is also important that Ra and S have the relationship of the following formula (1).
45.0 ≦ {(S × 1000) / Ra} ≦ 100.0 (1)
(In the formula, the unit of S × 1000 is μm.)
More preferably
50.0 ≦ {(S × 1000) / Ra} ≦ 95.0 (2)
(In the formula, the unit of S × 1000 is μm.)
It is.

  When Ra and S have the relationship of formula (1), a stronger peel strength can be obtained, the degradation rate of the peel strength after moisture absorption treatment is reduced, and the peel after immersion in the active treatment solution is further reduced. The deterioration rate of peeling strength is reduced, the amount of penetration after immersion in the active treatment solution is reduced, and the etching property is further improved. On the other hand, when the formula (1) is less than 45.0, undissolved coarse particles may occur between the circuits after etching the treated copper foil, and a short circuit abnormality may occur. When the formula (1) exceeds 100.0, it is difficult to obtain an effective mechanical anchoring effect, a strong peeling strength cannot be obtained, and a deterioration rate of the peeling strength after moisture absorption treatment is increased. The deterioration rate of the peel strength after immersion in the treatment liquid increases, and the amount of penetration after immersion in the active treatment liquid increases.

Next, a treatment method for precipitating roughening particles that form a roughening treatment layer provided on the surface of the untreated copper foil will be described.
The roughening treatment layer of the present invention is formed by two-stage roughening treatment. The first step is a step of attaching a fine dendritic copper powder to the untreated copper foil by passing a current of a limiting current density or higher in an electrolytic solution containing copper ions. The second stage is a process of cover plating so that the fine dendritic copper powder obtained in the first stage does not fall off, and it is formed by flowing a current less than the limit current density in an electrolytic solution containing copper ions. Is done. In the present invention, an aggregate layer of roughened particles obtained by this two-stage electroplating is referred to as a roughened layer.

(First-stage roughening layer)
Electrolyte composition for electrical plating of the first stage, liquid temperature, additives, electrolysis conditions, as the electrode, Ru include those shown below, for example.
Copper sulfate pentahydrate: 12 g / L to 70 g / L (more preferably 30 g / L to 60 g / L)
Sulfuric acid: 30 g / L to 200 g / L (more preferably 50 g / L to 150 g / L)
Additive: Chlorine ion, Titanium ion, Tungsten ion Liquid temperature: 25C-50C (more preferably 30C-45C)
Current density: 5 A / dm ^{2 to} 100 A / dm ² (more preferably 10 A / dm ^{2 to} 80 A / dm ² )
Electricity: 65 ~ 140C / dm ²
Electrode: Insoluble electrode such as white metal oxide coated titanium plate

(Second-stage roughening layer)
Next, the second-stage electroplating performed as plating for covering the fine dendritic copper powder obtained in the first stage will be described in detail. Examples of the electrolyte composition, liquid temperature, electrolysis conditions, and electrodes for performing the second-stage electroplating include, but are not limited to, the following.
Copper sulfate pentahydrate: 150 g / L to 300 g / L (more preferably 170 g / L to 280 g / L)
Sulfuric acid: 50 g / L to 200 g / L (more preferably 60 g / L to 170 g / L)
Liquid temperature: 25 ° C to 50 ° C (more preferably 30 ° C to 45 ° C)
Current density: 2 A / dm ^{2 to} 60 A / dm ² (more preferably 5 A / dm ^{2 to} 50 A / dm ² )
Electrode: Insoluble electrode such as a white metal oxide-coated titanium plate If necessary, gelatin or the like which is a well-known technique may be added.

  The roughening layer of the treated copper foil according to the present invention and the important parameters representing the shape of the roughening particles forming the roughening layer, the ten-point average roughness Rz, the average interval S of the local peaks, and the arithmetic average roughness The thickness Ra is determined when the roughening layer is formed by the two-stage electroplating. Even if a nickel and / or cobalt layer containing molybdenum according to the present invention and a chromate layer and a silane coupling agent layer, which are well-known techniques, are provided on the surface of the roughened layer, the above parameters do not change.

Moreover, you may give the fine roughening particle layer of the copper obtained from the electrolyte solution which uses the diethylenetriamine pentaacetic acid described in Japanese Patent Publication No. 3-35394 to the said roughening process layer surface as needed.
By providing this processing, the peel strength can be further improved.
Next, the nickel and / or cobalt layer containing molybdenum provided on the surface of the roughened layer will be described in detail.

  By providing a nickel and / or cobalt layer containing molybdenum on the surface of the treated copper foil provided with the roughened layer, the degradation rate of the peel strength after the heat treatment is reduced. In recent years, two-layer flexible printed circuit boards that are frequently used have a direct reaction between polyimide and copper without using an adhesive. Therefore, it is effective to provide cobalt and nickel that are compatible with polyimide on the treated copper foil bonding surface. .

Precipitation deposition of nickel and / or cobalt layer containing molybdenum is preferably ^{20mg / m 2 ~300mg / m 2} , more preferably from ^{30mg / m 2 ~290mg / m 2} . When the deposition amount of the nickel and / or cobalt layer containing molybdenum is less than 20 mg / m ² , the deterioration of the peel strength after the heat treatment becomes large. On the other hand, if it exceeds 300 mg / m ² , nickel is used. However, depending on the molybdenum content and the type of insulating resin substrate, nickel remains on the insulating resin substrate after etching and migration resistance This is not preferable because the property may be lowered. In addition, it is uneconomical because no improvement in properties is observed even if it is further adhered.

  The content of each element in the nickel and / or cobalt layer containing molybdenum is also important. The molybdenum content is preferably 10 wt% or more. More preferably, it is 13 wt% or more. “Wt%” is used as the unit of content, but the sum of the mass of each element used in the nickel and / or cobalt layer containing molybdenum is 100 wt%, and unavoidable impurities are not considered. Please specify. When the molybdenum content is less than 10 wt%, the rate of degradation of the peel strength after heat treatment increases.

  On the other hand, the content of nickel and / or cobalt is preferably 90 wt% or less. More preferably, it is 87 wt% or less. When the nickel content exceeds 90 wt%, although depending on the type of the insulating resin base material, nickel may remain on the insulating resin base material after etching and migration resistance may be deteriorated. Further, the deterioration rate of the peel strength after the heat treatment is increased. When the content of cobalt exceeds 90 wt%, the deterioration rate of the peel strength after heat treatment increases, the deterioration rate of the peel strength after immersion in the active treatment solution increases, and the stain after immersion in the active treatment solution Increasing amount. When the content of nickel and / or cobalt exceeds 90 wt%, the deterioration rate of the peel strength after immersion in the active treatment solution will increase, depending on the content of both. May increase. Further, the deterioration rate of the peel strength after the heat treatment is increased.

Next, a treatment method for depositing a nickel and / or cobalt layer containing molybdenum will be described.
The nickel and / or cobalt layer containing molybdenum of the present invention is formed by electroplating. Examples of the electrolyte composition, solution temperature, pH, electrolysis conditions, and electrodes for forming a nickel and / or cobalt layer containing molybdenum by electroplating include, but are not limited to, the following. .

(Nickel layer containing molybdenum)
Disodium molybdate dihydrate: 1 g / L to 80 g / L (more preferably 5 g / L to 70 g / L)
Nickel sulfate hexahydrate: 10 g / L to 100 g / L (more preferably 20 g / L to 70 g / L)
Trisodium citrate dihydrate: 5 g / L to 100 g / L (more preferably 20 g / L to 70 g / L)
pH: 10.0-12.0 (more preferably 10.5-11.5)
Electrolyte temperature: 20 ° C to 50 ° C (more preferably 25 ° C to 40 ° C)
Current density: 0.1 A / dm ^{2 to} 10.0 A / dm ² (more preferably 0.5 A / dm ^{2 to} 5.0 A / dm ² )
Electrode: Platinum
The pH may be adjusted with ammonia.

(Cobalt layer containing molybdenum)
Disodium molybdate dihydrate: 1 g / L to 80 g / L (more preferably 5 g / L to 50 g / L)
Cobalt sulfate heptahydrate: 10 g / L to 100 g / L (more preferably 20 g / L to 70 g / L)
Trisodium citrate dihydrate: 5 g / L to 100 g / L (more preferably 20 g / L to 70 g / L)
pH: 4.0 to 10.0 (more preferably 5.0 to 7.0)
Electrolyte temperature: 20 ° C to 50 ° C (more preferably 25 ° C to 40 ° C)
Current density: 0.1 A / dm ^{2 to} 10.0 A / dm ² (more preferably 0.5 A / dm ^{2 to} 5.0 A / dm ² )
Electrode: Platinum
The pH may be adjusted with sulfuric acid.

(Nickel and cobalt layers containing molybdenum)
Disodium molybdate dihydrate: 1 g / L to 80 g / L (more preferably 5 g / L to 70 g / L)
Nickel sulfate hexahydrate: 10 g / L to 100 g / L (more preferably 20 g / L to 70 g / L)
Cobalt sulfate heptahydrate: 10 g / L to 100 g / L (more preferably 20 g / L to 70 g / L)
Trisodium citrate dihydrate: 5 g / L to 100 g / L (more preferably 20 g / L to 70 g / L)
pH: 4.0 to 10.0 (more preferably 5.0 to 7.0)
Electrolyte temperature: 20 ° C to 50 ° C (more preferably 25 ° C to 40 ° C)
Current density: 0.1 A / dm ^{2 to} 10.0 A / dm ² (more preferably 0.5 A / dm ^{2 to} 5.0 A / dm ² )
Electrode: Platinum
The pH may be adjusted with sulfuric acid.

Next, a chromate layer is provided on the surface of the nickel and / or cobalt layer containing molybdenum based on a known processing method. By providing the chromate layer, properties such as improved peel strength and improved oxidation resistance are imparted. The bath for forming the chromate layer may be a known bath, and may be any bath having hexavalent chromium such as chromic acid, sodium dichromate or potassium dichromate. Further, a chromate layer containing zinc described in JP-A-56-118390 may be used.
Note that the chromium precipitation after the formation of the chromate layer is a mixture of Cr (OH) ₃ and Cr ₂ O _3, which does not contain hexavalent chromium that adversely affects the human body and precipitates in the form of trivalent chromium. doing. The chromic acid solution may be alkaline or acidic.

  Next, a silane coupling agent layer is provided on the surface of the chromate layer based on a known treatment method. By providing a silane coupling agent layer, the wettability between the treated copper foil adhesive surface and the insulating resin base material is improved and the peel strength is improved, and the deterioration rate of the peel strength after moisture absorption treatment is reduced. The characteristics are given. There are various types of silane coupling agents such as epoxy groups, amino groups, mercapto groups, ureido groups, vinyl groups, etc., but they must be provided in consideration of compatibility because they exhibit different characteristics depending on the type of insulating resin substrate.

In addition, the copper clad laminated board which can be used as a printed wiring board can be shape | molded by methods, such as heat-pressing the said process copper foil to an insulating resin base material. As the insulating resin base material, polyimide, phenol, epoxy, polyester, liquid crystal polymer, or the like may be used.
In the present embodiment, each treatment layer is provided only on one side of the untreated copper foil, but each treatment layer may be provided on both sides of the untreated copper foil.

Example 1
An untreated electrolytic copper foil was prepared with the following electrolytic solution composition, additive, electrode, liquid temperature, and electrolysis conditions.
(Method for producing untreated electrolytic copper foil)
Sulfuric acid: 100 g / L, copper sulfate pentahydrate: 280 g / L of sulfuric acid-copper sulfate aqueous solution is prepared, and polyethylene glycol: 20 mg / L (average molecular weight: 20000, manufactured by Sanyo Chemical) as an additive, polyethyleneimine: 20 mg / L (trade name: Epomin, product number: PP-061, average molecular weight: 1200, manufactured by Nippon Shokubai Co., Ltd.), sodium 3-mercapto-1-propanesulfonate: 6 μmol / L, chloride ion: 20 mg / L. An electrolyte containing this additive is filled between an insoluble anode made of titanium coated with a white metal oxide and a cathode cathode made of titanium, which is a cathode, and the current density is 50 A / dm ² and the temperature is 50 ° C. An untreated electrolytic copper foil having a flow thickness of 12 μm was obtained. The ten-point average roughness Rz of the deposited surface of this untreated electrolytic copper foil was 0.93 μm.
Next, a first-stage roughening treatment layer was provided on the deposited surface of the produced untreated electrolytic copper foil under the following electrolytic solution composition, solution temperature, additive, electrode, and electrolysis conditions.

(First-stage roughening layer)
A sulfuric acid-copper sulfate aqueous solution of sulfuric acid: 80 g / L and copper sulfate pentahydrate: 45 g / L was prepared, and the liquid temperature was adjusted to 35 ° C. Titanium ions: 600 mg / L, tungsten ions: 25 mg / L, chlorine ions: 5 mg / L were added as additives. An electrolyte containing this additive is filled between an insoluble anode made of titanium coated with a white metal oxide and an untreated electrolytic copper foil as a cathode, and has a current density of 10 A / dm ² and an electric quantity of 65 C / dm ² . A first-stage roughening treatment layer was provided under electrolytic conditions.

Next, a second-stage roughening treatment layer was provided on the surface of the treated copper foil provided with the first-stage roughening treatment layer with the following electrolytic solution composition, liquid temperature, electrode, and electrolysis conditions.
(Second-stage roughening layer)
A sulfuric acid-copper sulfate aqueous solution of sulfuric acid: 120 g / L, copper sulfate pentahydrate: 250 g / L was prepared, and the liquid temperature was adjusted to 45 ° C. The electrolytic solution is filled between an insoluble anode made of titanium coated with a white metal oxide and a treated copper foil provided with a first-stage treatment layer as a cathode, and has a current density of 10 A / dm ² and an electric quantity of 300 C / dm ^2. A second-stage roughening treatment layer was provided under the electrolysis conditions.

Next, a chromate layer was provided on the surface of the treated copper foil provided with the roughening treatment layer under the following electrolyte solution composition, solution temperature, pH, electrode, and electrolysis conditions.
(Chromate layer)
Sodium dichromate dihydrate: 40 g / L, a chromate aqueous solution with a liquid temperature of 35 ° C. was prepared, and adjusted to pH 12.0 using sodium hydroxide. The chromate aqueous solution was filled between platinum used as an anode and the treated copper foil as a cathode, and a chromate layer was provided under electrolytic conditions of a current density of 2.0 A / dm ² and an electric quantity of 10 C / dm ² .

Next, a silane coupling agent layer was provided on the treated copper foil surface provided with the chromate layer with the following liquid composition, liquid temperature, and immersion time.
(Silane coupling agent layer)
An aqueous solution containing 5 mL / L of γ-aminopropyltriethoxysilane was prepared as a silane coupling agent treatment solution. Then, the treated copper foil provided with each treatment was immersed in a silane coupling agent treatment solution at a liquid temperature of 30 ° C. for 10 seconds to give a silane coupling agent treatment.
And after formation of the said silane coupling agent layer was completed, it was naturally dried at normal temperature (25 degreeC), and the process copper foil of this invention was obtained.

Examples 2-6 and Comparative Examples 1-6
(Untreated electrolytic copper foil)
The same untreated electrolytic copper foil used in Example 1 was used.
(First-stage roughening layer)
As shown in Table 1, the same conditions and the same method as in Example 1 except that the concentration of each additive added to the electrolytic solution forming the first-stage roughening treatment layer was changed and the current density and quantity of electricity were changed. Thus, a first-stage roughened layer was obtained.
(Second-stage roughening layer)
A second-stage roughening treatment layer was provided under the same electrolytic solution composition, liquid temperature, electrode, and electrolysis conditions as in Example 1.
(Chromate layer)
A chromate layer was provided with the same electrolytic solution composition, liquid temperature, pH, electrode, and electrolysis conditions as in Example 1.
(Silane coupling agent layer)
A silane coupling agent layer was provided with the same liquid composition, liquid temperature, and immersion time as in Example 1.

Next, the following measurements were performed on the treated copper foils obtained in Examples 1 to 6 and Comparative Examples 1 to 6.
(10-point average roughness roughness Rz)
For the surface provided with each treatment layer, the radius of the tip of the stylus as a stylus on the surf coder SE1700α (manufactured by Kosaka Laboratories) that conforms to the stylus type surface roughness meter specified in JISB0651-2001 A 10 μm average roughness Rz defined in JISB0601-1994 was measured with a roughness curve cut-off value of 0.8 mm and a measurement distance of 4.0 mm. Table 2 shows the measurement results. The ten-point average roughness Rz of the untreated electrolytic copper foil deposition surface was also measured by this method.

(Average distance S between local peaks)
For the surface provided with each treatment layer, the radius of the tip of the stylus as a stylus on the surf coder SE1700α (manufactured by Kosaka Laboratories) that conforms to the stylus type surface roughness meter specified in JISB0651-2001 An average distance S between local peaks defined in JISB0601-1994 was measured with a roughness curve cut-off value of 0.8 mm and a measurement distance of 4.0 mm. Table 2 shows the measurement results.

(Arithmetic mean roughness roughness Ra)
For the surface provided with each treatment layer, the radius of the tip of the stylus as a stylus on the surf coder SE1700α (manufactured by Kosaka Laboratories) that conforms to the stylus type surface roughness meter specified in JISB0651-2001 An arithmetic average roughness Ra defined in JISB0601-1994 was measured using a roughness curve cut-off value of 0.8 mm and a measurement distance of 4.0 mm. Table 2 shows the measurement results.
Formula (1) {(S × 1000) / Ra}
Using Ra and S measured by the above method, calculation was performed by substituting measurement values into the formula (1) {(S × 1000) / Ra} described in claim 1. The calculated results are shown in Table 2.

Next, the copper clad laminated board was produced using the process copper foil of Examples 1-6 and Comparative Examples 1-6.
(Preparation of rigid copper clad laminate using FR-4 substrate (hereinafter referred to as copper clad laminate A))
FR-4 substrate (manufactured by Kyocera Chemical, product name: TLP-551, thickness: 0.18 mm) with the surface provided with various treated layers of the treated copper foils of Examples 1 to 6 and Comparative Examples 1 to 6 as the adherend surface 3), pressure and pressure were set to 40 kgf / cm ² , temperature was set to 170 ° C., and time was set to 60 minutes by heating and pressing with a press machine to obtain a copper-clad laminate A.

Next, the following measurement was performed on the copper-clad laminate A.
(Stripping strength)
An etching machine was used to produce a 1 mm wide copper circuit sample by etching. In accordance with JIS C 6481, the peel strength was measured using a universal testing machine. Table 3 shows the measurement results.

(Degradation rate of peel strength after moisture absorption treatment)
A 1 mm wide copper circuit sample was boiled in ion exchange water for 120 minutes. Subsequently, it was washed with water and dried, and then peel strength was measured. The deterioration rate was calculated by substituting the measured value into the following formula (3). The calculated results are shown in Table 3.
Formula (3): Degradation rate of peel strength after moisture absorption treatment (%) = {(value of peel strength before moisture absorption treatment−value of peel strength after moisture treatment) / peel before moisture absorption treatment Peel strength} × 100

(Stripping strength after immersion in active treatment solution)
A 1 mm wide copper circuit sample was immersed in an 18 wt% aqueous hydrochloric acid solution at a liquid temperature of 25 ± 2 ° C. for 60 minutes. Then, after washing with water and drying, the peel strength was measured. The deterioration rate was calculated by substituting the measured value into the following formula (4). The calculated results are shown in Table 3.
Formula (4): Degradation rate of peel strength after immersion in active treatment solution (%) = {(value of peel strength before immersion in hydrochloric acid aqueous solution−value of peel strength after immersion in hydrochloric acid aqueous solution) / hydrochloric acid Value of peel strength before immersion in aqueous solution} × 100

(Penetration amount after immersion in active treatment solution)
A 1 mm wide copper circuit sample was immersed in a 5 wt% aqueous sulfuric acid solution at a liquid temperature of 65 ± 3 ° C. for 30 minutes. Next, after washing with water and drying, the copper circuit was peeled off from the copper-clad laminate A. The peel-treated copper foil surface was observed with an optical microscope, and the amount of penetration of the sulfuric acid aqueous solution (μm) was read. Since the color difference occurs in the portion where the sulfuric acid aqueous solution has permeated, the amount of permeation can be read. The results read are shown in Table 3.

(Etching property: Presence or absence of unmelted copper between circuits)
A positive type liquid resist was applied to the copper foil surface side of the copper clad laminate A and dried in an atmospheric oven set at 70 ° C. for 7 minutes. Next, exposure was performed using a mask film of line / space = 30 μm / 30 μm, followed by development, and the etching resist in the exposed portion was removed. Next, etching is performed without etching resist using etching solution with composition of cupric chloride: 3.2 mol / L, hydrochloric acid: 0.4 mol / L, spray pressure: 0.15 mol / L, and liquid temperature: 50 ° C. The copper foil part was etched. Thereafter, the etching resist on the circuit was removed with sodium hydroxide, followed by drying at 100 ° C. for 10 minutes in an atmospheric oven to obtain a copper circuit of line / space = 30 μm / 30 μm. This sample was subjected to surface analysis of copper with EPMA-1610 manufactured by Shimadzu Corporation to investigate the presence or absence of unmelted copper between circuits. The survey results are shown in Table 3.

  According to the results shown in Table 2 and Table 3, since Examples 1 to 6 satisfy Rz, S and Ra and Formula (1) {(S × 1000 / Ra)} satisfy the requirements of the present invention, A strong peel strength is obtained, the degradation rate of the peel strength after moisture absorption treatment is small, the degradation rate of the peel strength after immersion in the active treatment solution is small, and there is no penetration after immersion in the active treatment solution Etching is good.

  On the other hand, in Comparative Examples 1 to 6, Rz, S, Ra, and formula (1) {(S × 1000 / Ra)} do not satisfy one, two, or three requirements of the present invention. Comparative Examples 1 to 3 and 6 have low peel strength, a large deterioration rate of the peel strength after moisture absorption treatment, a large deterioration rate of the peel strength after immersion in the active treatment solution, and a stain of the active treatment solution Has occurred. Further, in Comparative Examples 4 and 5, there is unmelted copper between the circuits after the treated copper foil etching.

Example 7
(Untreated electrolytic copper foil)
The same untreated electrolytic copper foil used in Example 1 was used.
(First-stage roughening layer)
A first-stage roughening treatment layer was provided with the same electrolyte solution composition, additive, solution temperature, electrode, and electrolysis conditions as in Example 3.
(Second-stage roughening layer)
A second-stage roughening treatment layer was provided under the same electrolytic solution composition, liquid temperature, electrode, and electrolysis conditions as in Example 1.
Next, a nickel layer containing molybdenum was applied to the surface of the second-stage roughening treatment layer according to the following electrolytic solution composition, solution temperature, pH, electrode, and electrolysis conditions.
(Nickel layer containing molybdenum)
Nickel sulfate hexahydrate: 45 g / L, disodium molybdenum (VI) dihydrate: 15 g / L, trisodium citrate dihydrate: 50 g / L, liquid temperature: 35 ° C. nickel-molybdenum aqueous solution The pH was adjusted to 10.5 with aqueous ammonia. This nickel-molybdenum aqueous solution is filled between platinum used as an anode and a treated copper foil provided with a roughening layer as a cathode, and is subjected to electrolytic conditions of a current density of 1.0 A / dm ² and an electric charge of 2.0 C / dm ^2. A nickel layer containing molybdenum was provided.
(Chromate layer)
A chromate layer was provided with the same electrolyte solution composition, solution temperature, pH, and electrolysis conditions as in Example 1.
(Silane coupling agent layer)
A silane coupling agent layer was provided with the same liquid composition, liquid temperature, and immersion time as in Example 1.

Examples 8-13 and Comparative Examples 7-9
(Untreated electrolytic copper foil)
The same untreated electrolytic copper foil used in Example 1 was used.
(First-stage roughening layer)
A first-stage roughened layer was obtained with the same electrolyte solution composition, additive, solution temperature, electrode and electrolysis conditions as in Example 7 (Example 3).
(Second-stage roughening layer)
A second-stage roughening treatment layer was provided under the same electrolytic solution composition, liquid temperature, electrode, and electrolysis conditions as in Example 1.
(Nickel and / or cobalt layer containing molybdenum)
A nickel and / or cobalt layer containing molybdenum was formed under the electrolytic solution composition, liquid temperature, pH, and electrolysis conditions shown in Table 4.

In Comparative Example 9, a zinc-nickel layer was provided with the following electrolyte solution composition, solution temperature, pH, electrode, and electrolysis conditions.
(Zinc-nickel layer)
Nickel pyrophosphate: 8 g / L, zinc pyrophosphate: 20 g / L, potassium pyrophosphate: 80 g / L, liquid temperature: 40 ° C. A zinc-nickel aqueous solution was adjusted to adjust the pH to 9.5. This zinc-nickel aqueous solution is filled between platinum used as an anode and a treated copper foil provided with a roughening treatment layer as a cathode, and zinc is electrolyzed under a current density of 0.5 A / dm ² and an electric quantity of 2 C / dm ^2. -A nickel layer was provided.

(Chromate layer)
A chromate layer was provided with the same electrolyte solution composition, solution temperature, pH, and electrolysis conditions as in Example 1.
(Silane coupling agent layer)
A silane coupling agent layer was provided with the same liquid composition, liquid temperature, and immersion time as in Example 1.

Next, the following measurements were performed on the treated copper foils obtained in Examples 7 to 13 and Comparative Examples 7 to 9.
(Deposition deposition amount of nickel and / or cobalt layer containing molybdenum)
Using RIX2000 made by Rigaku Denki Co., Ltd., the deposition amount of each element of the nickel and / or cobalt layer containing molybdenum was measured, and the sum of each element was taken as the deposition amount. In Comparative Example 9 as well, RIX2000 was used to measure the deposition amount of zinc and nickel, and the sum was taken as the deposition amount. Table 5 shows the measurement results.
(Content of each element of nickel and / or cobalt layer containing molybdenum)
Using the deposition deposition amount of each element obtained from the deposition deposition amount of the nickel and / or cobalt layer containing molybdenum, the content (wt%) of each element was substituted into the following formula (5). In addition, the zinc-nickel layer of Comparative Example 9 is also replaced with the denominator of the formula (5) by (precipitated deposit amount of zinc-nickel layer), and the molecule is replaced by the deposited deposit amount of zinc or the deposited deposit amount of nickel. The rate was calculated. The calculated results are shown in Table 5.
Formula (5): Content of each element (wt%) = {(precipitation amount of each element) / (precipitation amount of cobalt or nickel layer containing molybdenum)} × 100

Next, the copper clad laminated board was produced using the process copper foil of Examples 7-13 and Comparative Examples 7-9.
(2-layer flexible copper clad laminate using polyamic acid (hereinafter referred to as copper clad laminate B))
The surface provided with various treatment layers of the treated copper foils of Examples 7 to 13 and Comparative Examples 7 to 9 was coated with a pyromellitic acid type polyimide precursor with a clearance of 350 μm.
425g of N, N-dimethylacetamide was sampled in a separable flask, 0.18mol of pyromellitic anhydride, 0.18mol of 4,4'-diaminodiphenyl ether was dissolved with stirring, and this polyimide precursor was polymerized by stirring for 4 hours. It was obtained by performing. Next, the treated copper foil after application of the polyimide precursor was volatilized with an inert dryer at 130 ° C-12 minutes, 160 ° C-2 minutes, 220 ° C-2 minutes, 250 ° C-2 minutes, and then inerted. A copper clad laminate B was obtained by performing a heat curing treatment at 360 ° C. for 2 minutes with a dryer.

Next, the following measurement was performed on the copper-clad laminate B.
(Stripping strength)
An etching machine was used to produce a 1 mm wide copper circuit sample by etching. In accordance with JIS C 5016, the peel strength at 90 ° was measured using a universal testing machine. Table 6 shows the measurement results.
(Degradation rate of peel strength after heat treatment)
A 1 mm wide copper circuit sample was subjected to a heat treatment using an atmospheric oven under conditions of temperature: 150 ° C. and time: 168 hours, and the peel strength was measured. The deterioration rate was calculated by substituting a value into the following formula (6). The calculated results are shown in Table 6.
Equation (6): Degradation rate of peel strength after heat treatment (%) = {(Peel strength value before heat treatment−Peel strength value after heat treatment) / Peel before heat treatment Peel strength} × 100

According to the results shown in Table 5 and Table 6, Examples 7 to 13 provided with a nickel and / or cobalt layer containing molybdenum provided a strong peel strength, and the peel strength after heat treatment was obtained. The deterioration rate is small.
On the other hand, when the deposition amount of the cobalt layer containing molybdenum is small as in Comparative Example 7, when the molybdenum content of nickel containing molybdenum is less than 10 wt% as in Comparative Example 8, as in Comparative Example 9 In the case of a zinc-nickel layer, strong peeling strength is obtained, but the deterioration rate of the peeling strength after heat treatment is large.

Claims (4)

A treated copper foil for a copper clad laminate in which a treated copper foil surface formed by forming a treated layer on the surface of an untreated copper foil is bonded to an insulating resin substrate, and a roughened treated layer on the surface of the untreated copper foil The chromate layer and the silane coupling agent layer are sequentially formed as a treatment layer, the ten-point average roughness Rz of the treated surface of the treated copper foil is 1.0 μm to 2.7 μm, and the stylus surface roughness The average distance S between local peaks defined by JISB0601-1994 measured by a meter is 0.0230 mm or less (excluding 0), the arithmetic average roughness Ra is 0.18 μm to 0.36 μm, and the Ra A copper foil for copper-clad laminate, wherein S and S have the relationship of the following formula (1).
Formula (1)
50.0 <{(S × 1000) / Ra} ≦ 100.0 (in the formula (1), the unit of S × 1000 is μm) A nickel and / or cobalt layer containing molybdenum is formed as a treatment layer between the roughening layer and the chromate layer, and the deposition amount of the nickel and / or cobalt layer containing molybdenum is 20 mg / m. ² is a to 300 mg / m ^2, and nickel remainder content of molybdenum is not more than 10 wt% and / or cobalt der Ru請 Motomeko 1 copper clad laminate for treated copper foil according. Claim 1 or 2 copper clad laminate of the copper-clad laminate for treated copper foil was heat-pressed in the insulating resin base material according. Help printed wiring board obtained using the copper-clad laminate of claim 3 wherein.