JP6297124B2 - Copper foil, copper foil with carrier foil and copper clad laminate - Google Patents

Description

  The present application relates to a copper foil, a copper foil with a carrier foil, and a copper-clad laminate obtained using these copper foils. In particular, the present invention relates to a copper foil provided with a roughening treatment layer having a finer concavo-convex structure on the surface of the copper foil than conventional.

  In general, one of the main uses of copper foil in the market is a circuit formation application of a printed wiring board. In order to improve the adhesiveness with the insulating resin base material, the copper foil for this application is often provided with a shape that exhibits an anchor effect on the surface of the copper foil that serves as an adhesive surface. Conventionally, in order to provide a shape that exerts an anchor effect, “adhesion of fine copper particles” as disclosed in Patent Document 1, etc., “unevenness formation by etching” as disclosed in Patent Document 2, etc. Has been performed on the surface of the copper foil.

  However, in recent years, the demand for the formation of fine pitch circuits is remarkable, and as a result of the great progress in the manufacturing technology of printed wiring boards, as disclosed in Patent Document 3 and Patent Document 4, etc., when forming a fine pitch circuit, In addition, the use of non-roughened copper foil has also increased.

  In Patent Document 3, in order to provide a copper-clad laminate for a printed circuit in which a copper foil and a laminated base material are firmly bonded with a tough and reactive adhesive, In a copper clad laminate in which copper foils are laminated and bonded on both sides, a. A general formula QRSiXYZ (1) (where Q is a functional group that reacts with the following resin composition, R is Q Or a silane coupling agent represented by the general formula T (SH) n..., Or a general formula T (SH) n [2] (wherein T is an aromatic ring, an aliphatic ring, a heterocyclic ring, an aliphatic chain, and n is an integer of 2 or more) through an adhesive base made of a thiol-based coupling agent, b. (1) Acrylic monomer, methacrylic monomer, their polymer or olefin A copolymer of (2) diallyl phthalate, epoxy acrylate or epoxy methacrylate and their oligomer peroxide curable resin composition, and (3) an ethylene butylene copolymer and a styrene copolymer in the molecule A peroxide curable resin composition of thermoplastic elastomer, (4) a resin composition of an olefin copolymer containing a glycidyl group, (5) a resin composition of a polyvinyl butyral resin having a side chain containing an unsaturated group, Or (6) a laminate which is bonded to a laminated substrate with an adhesive comprising a polyvinyl butyral resin and an amino resin having a spiroacetal ring and an epoxy resin, or which also serves as an adhesive for the resin composition It is disclosed that a copper-clad laminate for printed circuits, which is directly bonded to a base material. To have.

  Patent Document 4 provides a copper foil that does not contain chromium in the surface treatment layer and is excellent in the peel strength of the circuit after being processed into a printed wiring board, the chemical resistance deterioration rate of the peel strength, and the like. As an object, “a copper foil provided with a surface treatment layer on a bonding surface of a copper foil used when producing a copper clad laminate by bonding with an insulating resin base material, the surface treatment layer being a bonding surface of the copper foil It is disclosed to employ a copper foil characterized in that it is obtained by adhering a zinc component, a high melting point metal component having a melting point of 1400 ° C. or higher, and further a carbon component. It is disclosed that “the bonding surface of the copper foil is preferably one having a surface roughness (Rzjis) of 2.0 μm or less without being subjected to a roughening treatment”.

  Such a non-roughened copper foil does not have the uneven shape formed by the roughening treatment on the surface bonded to the insulating resin substrate. For this reason, when performing circuit formation by etching the copper foil, it is not necessary to provide an over-etching time for removing the anchor shape (uneven shape) embedded in the insulating resin substrate side. Therefore, if non-roughened copper foil is used, a fine pitch circuit having a good etching factor can be formed.

JP 05-029740 A JP 2000-282265 A Japanese Patent Application Laid-Open No. 09-074273 JP 2008-297569 A

  However, since this non-roughened copper foil does not have an anchor shape (uneven shape) embedded in the insulating resin substrate side, the adhesion of the non-roughened copper foil to the insulating resin substrate is roughened. It tends to be lower than that of the copper foil subjected to.

  Therefore, in the market, there is a demand for a copper foil having better adhesion than that of the non-roughened copper foil and the insulating resin base material and having good etching performance equivalent to that of the non-roughened copper foil. Existed.

  Therefore, as a result of diligent research by the inventors of the present invention, by adopting a copper foil provided with the roughening treatment layer shown below, the nano-anchor effect due to the fine uneven structure of the roughening treatment layer, the insulating resin base material and It was found that a fine pitch circuit having a good etching factor equivalent to the case of using a non-roughened copper foil can be formed. Furthermore, it has also been found that by providing a silane coupling layer on the surface of the roughening treatment layer, the moisture absorption deterioration characteristics equivalent to those of a conventional roughened copper foil are provided. Hereinafter, the copper foil, the copper foil with carrier foil, and the copper clad laminate according to the present application will be described.

Copper foil: The copper foil according to the present application has an average thickness of 100 nm or more and 400 nm having a fine concavo-convex structure formed from a needle-like or plate-like convex portion made of a copper composite compound containing copper oxide and cuprous oxide. The following roughening treatment layer and a surface of the roughening treatment layer are provided with a silane coupling agent treatment layer on at least one surface, and L ^* a ^* b ^* color of the surface of the copper foil on the roughening treatment layer side The value of the lightness L ^{* in} the system is 25 or less, the specific surface area measured by adsorbing krypton on the surface of the roughened layer is 0.035 m ² / g or more, and the rough surface is measured by X-ray photoelectron spectroscopy. When the total area of the peak area of Cu (I) and the peak area of Cu (II) obtained when analyzing the constituent elements of the chemical treatment layer is 100%, the Cu (I) 50% or more of the peak area It is characterized by being 99% or less.

Copper foil with carrier foil: The copper foil with carrier foil according to the present application is characterized in that a carrier foil is provided on one side of the copper foil described above via a bonding interface layer.

Copper-clad laminate: A copper-clad laminate according to the present application is characterized by comprising a copper foil provided with the above-mentioned roughening treatment layer and silane coupling layer or a copper foil with a carrier foil.

  The copper foil or the copper foil with a carrier foil according to the present application is “average thickness having a fine concavo-convex structure formed by needle-like or plate-like convex portions made of a copper composite compound containing copper oxide and cuprous oxide. Is provided with a roughening treatment layer of 100 nm or more and 400 nm or less. For this reason, the surface provided with the roughening treatment layer is used as an adhesive surface with the insulating resin base material, so that the insulating resin base of the non-roughened copper foil can be obtained by the nano-anchor effect by the convex portions forming the fine uneven structure. Good adhesion can be ensured compared to the adhesion to the material. In addition, the roughened layer has an average thickness of 100 nm to 400 nm and is formed of extremely short needle-like or plate-like convex portions, and therefore, when the circuit is formed by etching, By providing an over-etching time of a long time, the convex portion embedded in the insulating resin base material side can be dissolved and removed. Therefore, good etching performance equivalent to that of the non-roughened copper foil can be realized, and a fine pitch circuit having a good etching factor can be formed. Furthermore, by providing a silane coupling agent treatment layer on the surface of the roughening treatment layer, it is possible to realize moisture absorption deterioration resistance equivalent to that of a conventional roughening copper foil.

It is a scanning electron microscope observation image for demonstrating the form of the roughening process layer of the copper foil which concerns on this application. In the copper foil which concerns on this application, it is a scanning electron microscope observation image which shows the surface of each roughening process surface when a roughening process layer is each provided in the electrode surface and precipitation surface of electrolytic copper foil. It is a scanning electron microscope observation image which shows the cross section of the fine concavo-convex structure which the roughening process layer of the copper foil which concerns on this application has. It is a scanning electron microscope observation image which shows the surface of the roughening process layer of the copper foil of the comparative example 2. It is a scanning electron microscope observation image which shows the surface of the reduction | restoration blackening process layer of the copper foil of the comparative example 3.

  Hereinafter, the “form of copper foil”, “form of copper foil with carrier foil” and “form of copper-clad laminate” according to the present application will be described.

Form of copper foil: The copper foil according to the present application was formed on at least one surface of the copper foil from needle-like or plate-like convex portions made of a copper composite compound containing copper oxide and cuprous oxide. A roughening treatment layer having a fine concavo-convex structure with an average thickness of 100 nm to 400 nm and a silane coupling agent treatment layer on the surface of the roughening treatment layer are provided.

  Here, the copper foil which concerns on this application should just be equipped with the said roughening process layer in "at least one surface of copper foil", and the double-sided roughening process copper which provided the roughening process layer on both surfaces of copper foil Any of the single side | surface roughening process copper foil provided with the roughening process layer only in one side of foil and copper foil may be sufficient. In the copper foil according to the present application, the copper foil may be an electrolytic copper foil or a rolled copper foil. Also, the thickness of the copper foil at this time is not particularly limited, and it is generally sufficient to recognize the copper foil as having a thickness of 200 μm or less. Furthermore, below, the surface of the copper foil on which the roughening treatment layer and the silane coupling agent layer are provided may be referred to as a roughening treatment surface.

  In the copper foil according to the present application, the roughening treatment layer is formed of needle-like or plate-like convex portions having a maximum length of 500 nm or less made of a copper composite compound containing copper oxide and cuprous oxide. It has a fine concavo-convex structure and has an average thickness of 100 nm to 400 nm. Here, a scanning electron microscope observation image (magnification: 20000 times) showing the surface of the roughened layer when the roughened layer referred to in the present application is provided on the double-side smooth electrolytic copper foil is shown in FIG. Shown in a). As shown in FIG. 1 (a), the fine convex and concave portions protruding in a needle shape or a plate shape are densely adjacent to each other, so that an extremely fine uneven structure is formed on the surface of the electrolytic copper foil, It is observed that these convex portions are provided so as to cover the surface of the electrolytic copper foil along the surface shape of the electrolytic copper foil. FIG. 1 (b) is a further enlarged view of the surface of the roughened layer shown in FIG. 1 (a), and is a scanning electron microscope observation image at a magnification of 50000 times. However, in the present application, the “convex portion” means a protruding portion extending in a needle shape or a plate shape from the surface of the copper foil when the cross section of the copper foil is observed. The projecting portion is composed of a single crystal of a copper composite compound or an aggregate of a plurality of crystals, and the convex portions are densely provided on the surface of the copper foil as shown in FIGS. 1 (a) and 1 (b). It has been.

  Next, in FIG. 2, the observation image of each surface when the said roughening process layer is provided with respect to the electrode surface and precipitation surface of a general electrolytic copper foil, and each surface is shown. As shown in FIG. 2, when observed macroscopically, before and after the roughening treatment layer is provided, the surface shape of each surface of the electrolytic copper foil is finer along the surface shape of each surface before the roughening treatment. It can be confirmed that the concavo-convex structure is formed and the macroscopic surface shape of each surface before the roughening treatment is maintained after the roughening treatment. That is, in the case of the copper foil according to the present application, the roughening treatment layer is formed so that the needle-like or plate-like convex portion of the nm order covers the surface of the copper foil thinly along the surface shape of the copper foil. Since it is densely provided on the surface of the foil, it is considered that the macroscopic surface shape of the copper foil before the roughening treatment can be maintained.

  In this regard, verification is made based on changes in surface roughness before and after forming the roughened layer. Using the non-contact three-dimensional surface shape / roughness measuring machine (model: New-View 6000) manufactured by Zygo Corporation, the deposited surface of the both-side smooth electrolytic copper foil before the roughening treatment described above was used. When measured under the conditions of angle: 2.0, measurement area: 180 μm × 130 μm, Ra = 1.6 nm and Rz = 26 nm. On the other hand, when the surface of the copper foil referred to in the present application shown in FIG. 1A was measured in the same manner as described above, Ra = 2.3 nm and Rz = 39 nm were obtained. That is, in the present application, the roughening treatment layer has an average thickness of 100 nm or more and 400 nm or less, and has a fine concavo-convex structure formed by convex portions of the nm order. The change of the surface roughness of can be suppressed. In other words, by providing the roughened layer on the copper foil having a smooth surface, the surface having the smooth surface before the roughened layer is maintained, and the surface with nano-structures having the fine concavo-convex structure is maintained. An anchor effect can be expressed.

  Next, the maximum length of the convex portion will be described with reference to FIG. FIG. 3 is a scanning electron microscope observation image showing a cross section of the copper foil according to the present application. As shown in FIG. 3, in the cross section of the copper foil, a portion observed in a thin line shape is a convex portion. From FIG. 3, it is confirmed that the surface of the copper foil is covered with innumerable convex portions densely packed with each other, and each convex portion is provided so as to protrude from the surface of the copper foil along the surface shape of the copper foil. Is done. In the present application, the “maximum length of the convex portion” means that when the length from the base end to the tip end of each convex portion observed in the shape of the line (line segment) in the cross section of the copper foil is measured. The maximum value of. The maximum length of the convex portion is preferably 400 nm or less, and more preferably 300 nm or less. As the maximum length of the convex portion becomes shorter, a fine uneven structure can be imparted to the surface of the copper foil, and the surface shape of the copper foil before the roughening treatment can be maintained. The change in height can be suppressed. For this reason, it is possible to obtain good adhesion between the copper foil and the insulating resin base material by the fine nano-anchor effect, and it has a better etching factor equivalent to the case of using a non-roughened copper foil. A fine pitch circuit can be formed.

  Here, in the copper foil according to the present application, the “thickness of the roughening treatment layer” corresponds to the thickness of the fine concavo-convex structure provided in the surface layer portion of the copper foil. The length and the protruding direction of each convex part forming the fine concavo-convex structure are not constant, and the protruding direction of each convex part is not parallel to the thickness direction of the copper foil. Therefore, the length of the convex portion and the height of the convex portion in the thickness direction of the copper foil do not match, and the maximum length of the convex portion and the maximum thickness of the roughening treatment layer also match. Without having a relationship of (thickness of the roughened layer) ≦ (maximum length of the convex portion). Further, since the fine concavo-convex structure is formed by providing the convex portions densely on the surface of the copper foil, the thickness of the roughening treatment layer varies. However, there is a certain correlation between the maximum length of the convex portion and the roughened layer, and as a result of repeated tests by the inventors, the average thickness of the roughened layer is 400 nm. When it is below, the maximum length of the convex portion is 500 nm or less, and when the average thickness of the roughened layer is 100 nm or more, the maximum length of the convex portion is 100 nm or more. In order to obtain good adhesion to the insulating resin substrate, the average thickness of the roughened layer is preferably 100 nm or more, and the average thickness of the roughened layer is within the range of 100 nm to 350 nm. In some cases, it has been determined that it is possible to combine “good adhesion more than the non-roughened copper foil to the insulating resin base material” and “good etching performance equivalent to the non-roughened copper foil”. In FIG. 3, the roughened layer has an average thickness of 250 nm.

  Further, in the copper foil according to the present application, when the surface of the roughened layer is observed planarly at an inclination angle of 45 ° and a magnification of 50000 times or more using a scanning electron microscope, convex shapes adjacent to each other. Among the portions, the length of the tip portion that can be separately observed from other convex portions is preferably 250 nm or less. Here, “the length of the tip portion that can be separately observed from other convex portions (hereinafter, may be abbreviated as“ the length of the tip portion ”)” refers to the length shown below. For example, when the surface of the roughened layer is observed with a scanning electron microscope as described above, the roughened layer is separated from the surface of the copper foil as described above with reference to FIGS. Since the convex part protrudes in the shape of a needle or a plate, and the convex part is provided densely on the surface of the copper foil, the base end part of the convex part from the surface of the copper foil, that is, a copper composite compound The interface between the convex portion and the copper foil cannot be observed. Therefore, when the copper foil is observed in a plane as described above, it is separated from other convex portions among the convex portions adjacent to each other while being densely packed, and exists independently as one convex portion. The portion that can be observed when it is obtained is referred to as the “tip portion that can be observed separately from other convex portions”, and the length of the tip portion refers to the tip of the convex portion (ie, the tip of the tip portion). The length up to the position on the most proximal side that can be separated and observed from other convex portions.

  When the length of the tip portion of the convex portion is 250 nm or less, the maximum length of the convex portion is approximately 500 nm or less, and as described above, due to the nanoanchor effect due to the fine uneven structure of the roughened layer. In addition to being able to obtain good adhesion between the insulating resin base material, it is possible to form a fine pitch circuit having a good etching factor equivalent to the case of using a non-roughened copper foil. In addition, when the length of the tip portion that can be separately observed from other convex portions is 250 nm or less, there is no convex portion that protrudes long from the surface of the copper foil, and the surface of the roughening treatment layer has another surface. Even if an object comes into contact, it is difficult to break. That is, a roughened layer having high scratch resistance can be obtained. Therefore, the copper foil is less prone to so-called powder falling during handling, etc., can maintain a fine concavo-convex structure on the surface, and can prevent copper oxide fine powder from scattering or adhering to the surroundings. it can. Therefore, when the circuit formation of a printed wiring board is performed using the said copper foil, it can be made difficult to produce the insulation defect between wiring resulting from powder fall. From these viewpoints, the length of the tip portion of the convex portion is preferably 200 nm or less, and more preferably 100 nm or less. Moreover, when obtaining favorable adhesiveness with an insulating resin base material, the length of the tip portion of the convex portion is preferably 30 nm or more, and more preferably 50 nm or more.

  Furthermore, it is preferable that the length of the tip portion of the convex portion is ½ or less with respect to the maximum length of the convex portion. When the ratio is ½ or less, while separating from other convex portions, the tip portion of the convex portion protrudes from the surface of the copper foil, so that the nano anchor effect can be exhibited, Since the convex portions adjacent to each other on the base end side of the convex portions are densely packed on the copper foil surface while being in contact with each other, the copper foil surface can be densely covered with the fine concavo-convex structure.

  In the case of the copper foil according to the present application, the presence of the silane coupling agent treatment layer on the surface of the roughening treatment layer makes it possible to improve the moisture absorption resistance degradation characteristics when processed into a printed wiring board. The silane coupling agent treatment layer provided on the roughened surface is composed of olefin functional silane, epoxy functional silane, vinyl functional silane, acrylic functional silane, amino functional silane and mercapto functional silane as a silane coupling agent. Either can be used to form. These silane coupling agents are represented by the general formula R—Si (OR ′) n (where R: an organic functional group represented by an amino group, a vinyl group, etc., OR ′: a methoxy group or an ethoxy group) And the like, n: 2 or 3.

  If the silane coupling agent said here is shown more specifically, vinyltrimethoxysilane, vinylphenyltrimethoxylane, mainly using the same coupling agent as used for a glass cloth of a prepreg for a printed wiring board, γ-methacryloxypropyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, 4-glycidylbutyltrimethoxysilane, γ-aminopropyltriethoxysilane, N-β (aminoethyl) γ-aminopropyltrimethoxysilane, Use N-3- (4- (3-aminopropoxy) ptoxy) propyl-3-aminopropyltrimethoxysilane, imidazolesilane, triazinesilane, 3-acryloxypropylmethoxysilane, γ-mercaptopropyltrimethoxysilane, etc. Is possible

  Even if it uses for the adhesion surface with the insulating resin base material of copper foil, the silane coupling agent enumerated here does not have a bad influence on the characteristic after it becomes a subsequent etching process and a printed wiring board. Which type is used in the silane coupling agent can be appropriately selected according to the type of the insulating resin base material, the method of using the copper foil, and the like.

  The silane coupling agent described above contains water as a main solvent, and contains the silane coupling agent component in a concentration range of 0.5 g / L to 10 g / L, thereby setting the temperature to a room temperature level. It is preferable to use an agent treatment liquid. When the concentration of the silane coupling agent in the silane coupling agent treatment liquid is less than 0.5 g / L, the adsorption rate of the silane coupling agent is slow, which is not suitable for general commercial profit, and the adsorption is not uniform. It becomes. On the other hand, even if the concentration of the silane cup agent exceeds 10 g / L, the adsorption rate is not particularly high, and the performance quality such as moisture absorption resistance is not particularly improved. .

  The adsorption method of the silane coupling agent to the copper foil surface using this silane coupling agent treatment liquid can employ an immersion method, a showering method, a spraying method, and the like, and is not particularly limited. That is, any method can be used as long as the copper foil and the silane coupling agent treatment solution can be brought into contact with each other and adsorbed in accordance with the process design.

  After the silane coupling agent is adsorbed on the surface of the roughened layer, sufficient drying is performed, and a condensation reaction between the —OH group on the surface of the roughened layer and the adsorbed silane coupling agent is performed. Promote and completely evaporate the water resulting from the condensation. There is no special limitation regarding the drying method at this time. For example, even if an electric heater is used or a blast method that blows warm air is not particularly limited, a drying method and drying conditions corresponding to the production line may be employed.

On the roughened surface of the copper foil described above, needle-like or plate-like convex portions having a maximum length of 500 nm or less are densely provided adjacent to each other, and between the convex portions. The distance (pitch) is considered to be shorter than the wavelength range of visible light. For this reason, visible light incident on the roughened layer is attenuated as a result of repeated irregular reflection in the fine concavo-convex structure. That is, the roughening treatment layer functions as a light absorbing layer that absorbs light, and the surface of the roughening treatment surface is darkened to blackening, browning, or the like as compared to before the roughening treatment. That is, the roughened surface of the copper foil according to the present application has a special color tone, and the lightness L ^* value of the L ^* a ^* b ^* color system is 25 or less. When the value of the lightness L ^* exceeds 25 and the color tone becomes bright, the maximum length of the convex portion constituting the roughening treatment layer may exceed 500 nm, which is not preferable. Moreover, when the value of L ^* exceeds 25, even if the maximum length of the convex portion is 500 nm or less, the convex portion may not be provided sufficiently densely on the surface of the copper foil. . Thus, when the value of the lightness L ^* exceeds 25, it is considered that the roughening treatment is insufficient or the state of the roughening treatment is uneven. This is not preferable because there is a fear that the above “adhesiveness” cannot be obtained. That is, the value of the lightness L ^* may be used as an indicator of the "surface state of the roughened surface", as the value of the lightness L ^* is less than 25, no relative "insulating resin substrate Arakado It can be considered that the surface state is better in obtaining “adhesiveness better than that of foil”, and if the value of the lightness L ^* is 20 or less, the reliability with respect to the adhesiveness with the insulating resin substrate is high. This is preferable because it improves dramatically. The lightness L ^* in the present application was measured using a spectral color difference meter SE2000 manufactured by Nippon Denshoku Industries Co., Ltd., and the whiteness plate attached to the measuring device was used for the lightness calibration in accordance with JIS Z8722: 2000. . And the measurement of 3 times is performed regarding the same site | part, and the average value of the measurement data of 3 times lightness L ^* is described as the value of the lightness L ^* said to this application. It should be noted that the value of the lightness L ^* of the L ^* a ^* b ^* color system does not vary depending on the presence or absence of the silane coupling agent-treated layer. This is determined only by the surface shape of the fine uneven structure.

  And the roughening layer of the copper foil which concerns on this application WHEREIN: The convex-shaped part which forms a fine uneven structure consists of a copper complex compound. In the present application, the copper composite compound contains copper oxide and cuprous oxide.

  By the way, as described above, conventionally, in order to obtain adhesiveness with the insulating resin base material, roughening treatment such as “adhesion of fine copper particles” and “unevenness formation by etching” is performed on the surface of the copper foil. Has been done. However, when copper foil that has been subjected to such a conventional roughening treatment is used when forming a high-frequency circuit, the uneven structure formed on the surface of the copper foil is a conductor. Signal transmission loss occurs. On the other hand, in the copper foil according to the present application, since the fine concavo-convex structure is formed by the convex portion made of the copper composite compound containing copper oxide and cuprous oxide, the copper foil is provided on the surface of the copper foil. The high frequency signal does not flow through the roughened layer. That is, if the copper foil which concerns on this application is used, the high frequency characteristic equivalent to the non-roughened copper foil which is not provided with the roughening process layer will be shown regarding the transmission loss of a high frequency signal. In addition, the roughened layer has good adhesion to a low dielectric constant and low dielectric loss tangent insulating resin substrate used for a high frequency substrate. Therefore, the copper foil which concerns on this application is very suitable as a high frequency circuit formation material by providing the said roughening process layer with respect to the untreated copper foil which was excellent in the following high frequency characteristics, for example.

  Specifically, a copper foil suitable for a high-frequency circuit forming material can be obtained by providing the roughened layer on an untreated copper foil having the following characteristics. Moreover, the copper foil according to the present application can be suitably used for manufacturing a microstrip line or a strip line by providing the roughening treatment layer for an untreated copper foil having the following characteristics. it can. However, when using the copper foil for microstripline or stripline applications, the surface roughness (Rz) and glossiness (Gs60 °) of the surface in close contact with the insulating resin substrate are within the following ranges, respectively. Preferably there is. That is, when the copper foil is used for stripline use, the insulating resin base material is in close contact with both surfaces, and therefore the surface characteristics of both surfaces are preferably within the following range.

Surface roughness (Rz): 1.5 μm or less, preferably 1.0 μm or less Surface glossiness (Gs 60 °): 100 or more, preferably 300 or more Conductivity of untreated copper foil itself: 99.8% or more untreated Impurity concentration in the copper foil: 100 ppm or less (provided that the impurity means the total content of S, N, C, and Cl)

  Further, in the copper foil according to the present application, Cu obtained when the constituent elements of the roughened layer are analyzed by X-ray photoelectron spectroscopy (hereinafter referred to as “XPS”). The ratio of the peak area of Cu (I) to the total area of the peak area of I) and the peak area of Cu (II) (hereinafter, occupied area ratio) is 50% or more.

  Here, a method for analyzing constituent elements of the fine concavo-convex structure layer by XPS will be described. When the constituent elements of the fine concavo-convex structure layer are analyzed by XPS, each peak of Cu (I) and Cu (II) can be separated and detected. However, when the Cu (I) and Cu (II) peaks are separated and detected, the Cu (0) peak may be observed overlapping the shoulder portion of the large Cu (I) peak. Thus, when the peak of Cu (0) is observed overlappingly, it shall be considered as a Cu (I) peak including this shoulder part. That is, in the present invention, the constituent elements of the copper composite compound that forms the fine concavo-convex structure layer are analyzed using XPS, and Cu (I) and 934 appearing in 932.4 eV corresponding to the binding energy of Cu 2p 3/2, and 934 Each peak obtained by detecting photoelectrons of Cu (II) appearing at .3 eV is separated into waveforms, and the occupied area ratio of the Cu (I) peak is specified from the peak area of each component. However, Quantum 2000 (beam condition: 40 W, 200 μm diameter) manufactured by ULVAC-PHI Co., Ltd. is used as an XPS analyzer, and “MultiPack ver. 6.1A” is used as analysis software to perform state / semi-quantitative narrow measurement. be able to.

The Cu (I) peak obtained as described above is considered to be derived from monovalent copper constituting cuprous oxide (cuprous oxide: Cu ₂ O). And it is thought that a Cu (II) peak originates in the bivalent copper which comprises copper oxide (cupric oxide: CuO). Furthermore, it is considered that the Cu (0) peak is derived from zero-valent copper constituting metallic copper. Therefore, when the occupation area ratio of the Cu (I) peak is less than 50%, the proportion of cuprous oxide in the copper composite compound constituting the roughened layer is smaller than the proportion of copper oxide. Copper oxide has higher solubility in acids such as an etchant than cuprous oxide. Therefore, when the occupied area ratio of the Cu (I) peak is less than 50%, when the roughened surface side of the copper foil is bonded to the insulating resin substrate and the circuit is formed by the etching method, A roughening process layer becomes easy to melt | dissolve and the adhesiveness between copper wiring and an insulating resin base material may fall afterwards. From this viewpoint, it is more preferable that the occupied area ratio of the Cu (I) peak is 70% or more and 80% or more when the constituent elements of the copper composite compound that forms the roughened layer by XPS are analyzed. More preferably it is. As the occupied area ratio of the Cu (I) peak increases, the component ratio of cuprous oxide having higher acid solubility resistance to the etching solution or the like becomes higher than that of copper oxide. Therefore, the acid solubility resistance of the roughened layer to the etching solution is improved, and it becomes possible to reduce the insertion of the etching solution during circuit formation, thereby forming a copper wiring having good adhesion to the insulating resin substrate. be able to. On the other hand, the upper limit value of the occupied area ratio of the Cu (I) peak is not particularly limited, but is 99% or less. As the occupied area ratio of the Cu (I) peak decreases, the adhesiveness between the two surfaces when the roughened surface side of the copper foil is bonded to the insulating resin base material tends to be improved. Therefore, in order to obtain good adhesion between the two, the exclusive area ratio of the Cu (I) peak is preferably 98% or less, and more preferably 95% or less. Note that the occupied area ratio of the Cu (I) peak is calculated by a calculation formula of Cu (I) / {Cu (I) + Cu (II)} × 100 (%).

In the present invention, the specific surface area (hereinafter simply referred to as “specific surface area”) measured by adsorbing krypton on the surface of the roughened layer is preferably 0.035 m ² / g or more. . When the specific surface area measured in this way is 0.035 m ² / g or more, good adhesion is ensured when the roughened surface provided with the roughened layer is bonded to the insulating resin substrate. be able to. Although the upper limit value of the specific surface area is not particularly limited, the fine concavo-convex structure is formed by densely forming needle-like or plate-like convex portions having a maximum length of 500 nm or less. In satisfying the surface shape of the concavo-convex structure, the upper limit value of the specific surface area is calculated to be about 0.3 m ² / g, and actually about 0.2 m ² / g is the upper limit value. In addition, the specific surface area is measured by using a specific surface area / pore distribution measuring device 3Flex manufactured by Micromeritics Co., Ltd. as a pretreatment by heating the sample at 300 ° C. for 2 hours. The above measurement can be performed by using krypton (Kr).

  The roughening treatment layer according to the present application described above can be formed, for example, by subjecting the surface of the copper foil to a roughening treatment by the following wet method. First, a copper compound containing copper oxide (cupric oxide) is formed on the surface of the copper foil by oxidizing the surface of the copper foil by a wet method using a solution. Thereafter, the copper compound is reduced, and a part of the copper oxide is converted into cuprous oxide (cuprous oxide), thereby forming a “needle or plate comprising a copper composite compound containing copper oxide and cuprous oxide. The fine concavo-convex structure formed from the convex portions can be formed on the surface of the copper foil. Here, the “fine concavo-convex structure” itself referred to in the present application is formed of a copper compound containing copper oxide at the stage where the surface of the copper foil is oxidized by a wet method. And when the said copper compound is reduce | restored, a part of copper oxide is converted into a cuprous oxide, maintaining the shape of the fine concavo-convex structure formed with this copper compound, and a copper oxide and a cuprous oxide. It becomes the "fine concavo-convex structure" which consists of a copper complex compound containing. As described above, by performing an appropriate oxidation treatment on the surface of the copper foil by a wet method and then performing a reduction treatment, it is possible to form the “fine concavo-convex structure” of the nm order as described above. In addition, a small amount of metallic copper may be contained in a copper composite compound containing copper oxide and cuprous oxide as main components.

  For example, when performing the wet roughening treatment, an alkali solution such as a sodium hydroxide solution can be used. By oxidizing the surface of the copper foil with an alkaline solution, a convex portion made of a copper compound containing needle-like or plate-like copper oxide can be formed on the surface of the copper foil. Here, when an oxidation treatment is performed on the surface of the copper foil with an alkaline solution, the convex portion grows long, and the maximum length may exceed 500 nm, forming the fine concavo-convex structure referred to in the present application. It becomes difficult. Therefore, in order to form the fine concavo-convex structure, it is preferable to use an alkaline solution containing an oxidation inhibitor capable of finely suppressing oxidation on the copper foil surface.

  An example of such an oxidation inhibitor is an amino silane coupling agent. If the copper foil surface is oxidized using an alkaline solution containing an amino silane coupling agent, the amino silane coupling agent in the alkaline solution is adsorbed on the surface of the copper foil, and the copper foil surface by the alkaline solution Can be finely suppressed. As a result, the growth of copper oxide needle-like crystals can be suppressed, and the roughened layer referred to in the present application having an extremely fine concavo-convex structure on the order of nm can be formed.

  Specific examples of the amino silane coupling agent include N-2- (aminoethyl) -3-aminopropylmethyldimethoxysilane, N-2- (aminoethyl) -3-aminopropyltrimethoxysilane, 3- Use of aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-triethoxysilyl-N- (1,3-dimethyl-butylidene) propylamine, N-phenyl-3-aminopropyltrimethoxysilane, etc. it can. All of these are dissolved in an alkaline solution and are stably held in the alkaline solution, and also exhibit the effect of finely suppressing the oxidation of the copper foil surface described above.

  As described above, the fine concavo-convex structure formed by subjecting the surface of the copper foil to an oxidation treatment with an alkaline solution containing an amino-based silane coupling agent is substantially maintained even after the reduction treatment. The As a result, a roughening treatment layer having a fine concavo-convex structure on the order of nm formed by needle-like or plate-like convex portions having a maximum length of 500 nm or less, comprising copper oxide and cuprous oxide, and having a maximum length of 500 nm or less. Can be obtained. In the reduction treatment, Cu (I) obtained when the constituent elements of the copper composite compound forming the roughening treatment layer are qualitatively analyzed using XPS by adjusting the reducing agent concentration, solution pH, solution temperature, and the like. ) And the total area of the Cu (II) peak area, the occupied area ratio of the Cu (I) peak can be appropriately adjusted. Further, when the constituent elements of the fine uneven structure of the roughened layer formed by the above method are analyzed by XPS, the presence of “—COOH” is detected.

  As described above, since the oxidation treatment and the reduction treatment can be performed by a wet method using each treatment solution, the roughening treatment layer is formed on both sides of the copper foil by a method such as immersing the copper foil in the treatment solution. It can be formed easily. Therefore, when this wet method is used, it becomes possible to easily obtain a double-sided roughened copper foil suitable for forming an inner layer circuit of a multilayer printed wiring board, and both the inner layer circuit and the interlayer insulating layer and the like are good. Adhesion can be ensured.

  In addition, as described above, the roughened layer according to the present application is less prone to so-called powder falling during handling or the like, and can maintain a fine uneven structure on the surface. Accordingly, handling can be facilitated even when a double-side roughened copper foil is used.

Form of copper foil with carrier foil: In the case of copper foil with carrier foil according to the present application, it is possible to apply all of the concepts applied to the copper foil described above. Therefore, only different parts will be described in detail.

  The copper foil with carrier foil according to the present application is a copper foil with carrier foil having a layer configuration of carrier foil / bonding interface layer / copper foil layer, and the outer surface of the carrier foil and the outer surface of the copper foil layer. An average thickness of 100 nm or more and 400 nm having a fine concavo-convex structure formed from needle-like or plate-like convex portions having a maximum length of 500 nm or less made of a copper composite compound on the outer surface of at least the copper foil layer therein The following roughening treatment layer is provided, and a silane coupling agent treatment layer is provided on the surface of the roughening treatment layer. Here, also in the copper foil with carrier foil according to the present application, the surface on which the roughening treatment layer is provided is referred to as a roughening treatment surface. The copper foil with carrier foil according to the present application includes “when both the outer surface of the carrier foil and the outer surface of the copper foil layer are roughened surfaces”. Here, it should be noted that “the outer surface of the carrier foil” is a surface exposed on the surface of the carrier foil constituting the copper foil with the carrier foil, and “the outer surface of the copper foil layer”. "Is the surface exposed on the surface of the copper foil layer constituting the copper foil with carrier foil.

  There is no particular limitation on the material for the carrier foil referred to here. As a carrier foil, copper foil (here, a concept including rolled copper foil, electrolytic copper foil, etc., regardless of its production method), and copper components such as resin foil coated with copper on the surface are present on the surface. As long as it is a foil, it can be used. Judging from the viewpoint of cost, it is preferable to use copper foil. Moreover, there is no limitation in particular also about the thickness as carrier foil. From the industrial point of view, the concept as a foil generally refers to a foil having a thickness of 200 μm or less, and it is sufficient to use this concept.

  Next, with respect to the bonding interface layer, there is no particular limitation as long as it can be a peelable type product from which the carrier foil can be peeled off, as long as the characteristics required for the bonding interface layer are satisfied. Either an inorganic bonding interface layer composed of an agent or an organic bonding interface layer composed of an organic agent can be used. As an inorganic agent which comprises an inorganic joining interface layer, 1 type, or 2 or more types chosen from chromium, nickel, molybdenum, a tantalum, vanadium, tungsten, cobalt, and these oxides can be mixed and used, for example. Moreover, as an organic joining interface layer comprised from an organic agent, what consists of 1 type (s) or 2 or more types selected from a nitrogen containing organic compound, a sulfur containing organic compound, and carboxylic acid can be used. Specifically, examples of the nitrogen-containing organic compound include 1,2,3-benzotriazole, carboxybenzotriazole, N ′, N′-bis (benzotriazolylmethyl) urea, which are triazole compounds having a substituent, and 1H. It is preferable to use -1,2,4-triazole and 3-amino-1H-1,2,4-triazole. As the sulfur-containing organic compound, it is preferable to use mercaptobenzothiazole, thiocyanuric acid, 2-benzimidazolethiol, and the like. As the carboxylic acid, it is particularly preferable to use a monocarboxylic acid, and it is particularly preferable to use oleic acid, linoleic acid, linolenic acid, or the like. In the present application, both of the inorganic bonding interface layer and the organic bonding interface layer can be preferably used. However, when the heat is applied at the time of lamination with the insulating resin base material, the carrier foil has an appropriate peeling strength. From the viewpoint of ensuring the thickness stably, it is more preferable to use an organic bonding interface layer.

  The method for forming the bonding interface layer with this organic agent is to dissolve the above-mentioned organic agent in a solvent and immerse the carrier foil in the solution, or to perform showering, spraying, dripping on the surface on which the bonding interface layer is to be formed. There is no need to employ a particularly limited method. The concentration of the organic agent in the solvent at this time is preferably in the range of a concentration of 0.01 g / L to 10 g / L and a liquid temperature of 20 to 60 ° C. in all the organic agents described above. Further, after the organic bonding interface layer is formed, an auxiliary metal layer such as Ni or Co may be formed on the surface of the organic bonding interface layer in order to improve the heat resistance of the bonding interface layer.

  The copper foil layer is described as including not only a copper foil called an ultrathin copper foil of 12 μm or less but also a layer formed of a copper foil thicker than 12 μm. This is because in the case of a copper foil layer having a thickness of 12 μm or more, the carrier foil may be used to prevent surface contamination.

  The carrier foil according to the present application is provided with the roughening treatment layer and the silane coupling agent treatment layer described in the description of the copper foil on the surface of the copper foil layer of the copper foil with carrier foil described above. It is a copper foil. That is, the copper foil with carrier foil according to the present application is obtained by subjecting the surface of the copper foil layer to roughening treatment (oxidation treatment and reduction treatment) and silane coupling agent treatment. Therefore, the duplicate description here is omitted.

Form of copper clad laminate: The copper clad laminate according to the present application is characterized by comprising a copper foil provided with the above-mentioned roughening treatment layer or a copper foil with a carrier foil. If the copper clad laminate at this time is obtained using a copper foil or a copper foil with a carrier foil according to the present application, the constituent components of the used insulating resin base material, the thickness, the laminating method, etc. There is no special limitation. Moreover, the copper clad laminated board here contains both a rigid type and a flexible type. Strictly speaking, in the case of a copper foil with a carrier foil, a copper clad laminate as a printed wiring board manufacturing material is obtained by removing the carrier foil after the copper foil with a carrier foil and an insulating resin base material are bonded together. Is obtained.

In Example 1, a copper electrolyte solution having the composition described below was used, DSA was used as an anode, and a cathode (a titanium plate electrode whose surface was polished with No. 2000 polishing paper), a liquid temperature of 50 ° C., and a current density of 60 A / dm. Electrolysis was performed under the condition of ² to obtain an electrolytic copper foil having a thickness of 18 μm. The surface roughness (Rz) of the deposited surface of the obtained electrolytic copper foil was 0.2 μm, and the glossiness (Gs60 °) was 600. In addition, the measurement of glossiness and the measurement of surface roughness are as follows.

[Copper electrolyte composition]
Copper concentration: 80 g / L
Free sulfuric acid concentration: 140 g / L
Bis (3-sulfopropyl) disulfide concentration: 5 mg / L
Diallyldimethylammonium chloride polymer concentration: 30 mg / L
Chlorine concentration: 25mg / L

[Glossiness measurement]
Glossiness was measured using a gloss meter PG-1M manufactured by Nippon Denshoku Industries Co., Ltd., in accordance with JIS Z 8741-1997, which is a method for measuring glossiness.

(Measurement of roughness)
KEYENCE LASER MICROSCOPE VK-X100 was used, and the surface roughness was measured with a measurement range of 150 μm square in accordance with JIS B 0601-2001, which is a surface roughness measurement method.

Pretreatment: The electrolytic copper foil produced as described above was immersed in an aqueous sodium hydroxide solution, subjected to alkaline degreasing treatment, and washed with water. And after immersing the electrolytic copper foil which this alkali degreasing process complete | finished in the sulfuric acid type solution whose sulfuric acid concentration is 5 mass% for 1 minute, it washed with water.

Roughening treatment: An oxidation treatment was performed on the copper foil that had been subjected to the preliminary treatment. In the oxidation treatment, the electrolytic copper foil is treated with sodium hydroxide containing a liquid temperature of 70 ° C., pH 12, chlorous acid concentration of 150 g / L, and N-2- (aminoethyl) -3-aminopropyltrimethoxysilane concentration of 10 g / L. It was immersed in the solution for 2 minutes to form a fine concavo-convex structure made of a copper compound on the surface of the electrolytic copper foil. The main component of the copper compound at this time is considered to be copper oxide.

  Next, a reduction treatment was performed on the electrolytic copper foil that had undergone the oxidation treatment. In the reduction treatment, the electrolytic copper foil after the oxidation treatment is immersed in an aqueous solution (room temperature) having a dimethylamine borane concentration of 20 g / L adjusted to pH = 12 using sodium carbonate and sodium hydroxide for 1 minute. And then washed with water and dried. By these steps, a roughening treatment having a fine concavo-convex structure made of a copper composite compound containing copper oxide and cuprous oxide is obtained by reducing a part of the copper oxide to cuprous oxide on the surface of the electrolytic copper foil. A layer was formed.

Silane coupling agent treatment: When the reduction treatment is completed, after washing with water, a silane coupling agent treatment liquid (an aqueous solution containing 5 g / L of γ-glycidoxypropyltrimethoxysilane using ion-exchanged water as a solvent) It sprayed on the roughening surface of the electrolytic copper foil after the said roughening process by the showering method, and adsorption | suction of the silane coupling agent was performed. And when adsorption | suction of silane coupling is complete | finished, the water | moisture content of the surface is evaporated in the atmosphere which made the atmospheric temperature 120 degreeC using the electric heater, and the -OH group and the silane coupling agent in the said roughening process surface of The condensation reaction was promoted to obtain a copper foil according to the present application having a silane coupling agent treatment layer on the surface of the roughening treatment layer.

<Evaluation of copper foil>
Shape observation result of roughened surface: Scanning electron microscope image of the copper foil obtained in this example is shown in FIG.

Results of qualitative analysis of roughened surface: When this surface was subjected to qualitative analysis using XPS, the presence of “copper oxide” and “cuprous oxide” was clearly confirmed, and the peak area of Cu (I) The occupied area ratio of the peak of Cu (I) with respect to the total area with the peak area of Cu (II) was 95%. Further, as a result of this qualitative analysis, the presence of “—COO group” was also clearly confirmed on the roughened surface.

Lightness L ^* of the roughened surface: The value of lightness L ^* of the copper foil obtained in this example was 10.

Hygroscopic deterioration performance evaluation result: Using the copper foil of Example 1 and a 100 μm-thick insulating resin base material (MEGTRON4 manufactured by Panasonic Corporation), using a vacuum press, the pressing pressure was 2.9 MPa, the temperature Bonding was performed under the conditions of 190 ° C. and a press time of 90 minutes to produce a copper clad laminate. Next, using this copper-clad laminate, a test substrate having a 3.0 mm width peel strength measuring linear circuit was produced by an etching method. And using this test board | substrate, the normal state peeling strength and the peeling strength after a moisture absorption process were measured, respectively. However, the moisture absorption treatment was performed by boiling the test substrate in boiling ion exchange water for 2 hours. Further, the peel strength of the dried test substrate after the moisture absorption treatment was measured, and the value at this time was defined as the peel strength after the moisture absorption treatment. Based on these measurement results, [moisture resistance degradation rate (%)] = 100 × {[normal peel strength] − [peel strength after moisture absorption]} / [normal peel strength] Thus, the moisture absorption deterioration rate was calculated. As a result, [normal state peeling strength] = 0.68 kgf / cm, [peeling strength after moisture absorption treatment] = 0.58 kgf / cm, [moisture resistance deterioration rate (%)] of the electrolytic copper foil of Example 1 ] = 14.8%.

  In Example 2, a copper foil with a carrier foil using the electrolytic copper foil (untreated copper foil) produced in Example 1 as a carrier foil was produced according to the following procedure.

  First, an organic agent layer was formed as a bonding interface layer on the deposition surface side of the carrier foil. Specifically, the carrier foil was immersed for 30 seconds in an organic material-containing dilute sulfuric acid aqueous solution having a sulfuric acid concentration of 150 g / L, a copper concentration of 10 g / L, a CBTA concentration of 800 ppm, and a liquid temperature of 30 ° C. Thereby, the contaminating component adhering to the surface of the carrier foil was acid-washed, and CBTA was adsorbed on the surface of the carrier foil to form an organic agent layer mainly composed of CBTA.

Next, a nickel layer was formed as a refractory metal layer on the bonding interface layer. Specifically, using a Watts bath having a nickel sulfate (NiSO ₄ · 6H ₂ O) concentration of 330 g / L, a nickel chloride (NiCl ₂ · 6H ₂ O) concentration of 45 g / L, a boric acid concentration of 35 g / L, and a pH of 3, Electrolysis was performed under electrolytic conditions of a liquid temperature of 45 ° C. and a current density of 2.5 A / dm ² to form a nickel layer having a converted thickness of 0.01 μm on the bonding interface layer.

And the electrolytic copper foil layer was formed on the said heat-resistant metal layer. Specifically, using a copper electrolytic solution having a copper concentration of 65 g / L and a sulfuric acid concentration of 150 g / L, electrolysis is performed under electrolytic conditions of a liquid temperature of 45 ° C. and a current density of 15 A / dm ² , and the thickness is formed on the heat-resistant metal layer. A 2 μm electrolytic copper foil layer was formed. At this time, the surface roughness (Rz) on the deposition surface side of this electrolytic copper foil layer was 0.2 μm, and the glossiness [Gs (60 °)] was 600. The surface treatment was performed in the following procedure on the surface of the electrolytic copper foil layer of the electrolytic copper foil with carrier foil formed as described above.

Pretreatment: The copper foil with carrier foil was subjected to alkali degreasing treatment and sulfuric acid treatment in the same manner as in Example 1 and washed with water.

Roughening treatment: The surface of the electrolytic copper foil layer is made of a copper compound by oxidizing the surface of the electrolytic copper foil layer of the copper foil with carrier foil after the preliminary treatment in the same manner as in Example 1. A fine relief structure was formed. Next, the surface on which the copper composite compound of the electrolytic copper foil layer of the copper foil with carrier foil after the oxidation treatment was formed was subjected to reduction treatment in the same manner as in Example 1, and the surface of the electrolytic copper foil layer was subjected to copper oxide and suboxide. A roughening treatment layer having a fine concavo-convex structure made of a copper composite compound containing copper oxide was formed.

Silane coupling agent treatment: When the above reduction treatment was completed, a silane coupling agent treatment was performed in the same manner as in Example 1 to obtain a copper foil with a carrier foil according to the present application.

<Evaluation of copper foil with carrier foil>
Results of observation of shape of roughened surface: Scanning electron microscope image of the roughened surface of the electrolytic copper foil layer of the copper foil with carrier foil obtained in Example 2 has the same form as shown in FIG. I was prepared.

Results of qualitative analysis of the roughened surface: When the qualitative analysis was performed on the electrolytic copper foil layer of the copper foil with carrier foil and the roughened surface of the carrier foil using XPS, the presence of "copper oxide" and "cuprous oxide" Was clearly confirmed, and the occupied area ratio of the peak of Cu (I) with respect to the total area of the peak area of Cu (I) and the peak area of Cu (II) was 92%. Further, as a result of this qualitative analysis, the presence of “—COO group” was also clearly confirmed on the roughened surface.

Lightness L ^* of roughened surface: The value of lightness L ^* of the roughened surface of the electrolytic copper foil layer of the copper foil with carrier foil obtained in Example 2 was 18.

Hygroscopic deterioration performance evaluation results: The roughened surface of the electrolytic copper foil layer of the copper foil with carrier foil of Example 2, and the insulating resin base material (GHPL-830NS, manufactured by Mitsubishi Gas Chemical Co., Ltd.) having a thickness of 100 μm, Using a vacuum press machine, a copper-clad laminate was manufactured by bonding together under the conditions of a pressing pressure of 3.9 MPa, a temperature of 220 ° C., and a pressing time of 90 minutes. Then, the carrier foil on the surface of the copper-clad laminate is removed, and the exposed electrolytic copper foil layer is subjected to electrolytic copper plating so as to have a thickness of 18 μm, and an etching method is used to measure the peel strength. A test substrate with a 4 mm wide linear circuit was produced. Then, using this test substrate, the normal peel strength and the peel strength after the PCT moisture absorption treatment were measured. However, the PCT moisture absorption treatment was performed by holding the test substrate for 24 hours (PCT test) in a high-temperature and high-pressure steam atmosphere of 121 ° C. × 2 atm. Further, the peel strength of the dried test substrate after the PCT treatment was measured, and the value at this time was defined as the peel strength after the PCT moisture absorption treatment. Based on these measurement results, [PCT moisture absorption deterioration rate (%)] = 100 × {[Normal peel strength] − [Peel strength after PCT moisture absorption treatment]} / [Normal peel strength] The anti-PCT moisture absorption deterioration rate was calculated according to the calculation formula. As a result, [normal peel strength] = 0.75 kgf / cm, [peel strength after moisture absorption treatment] = 0.68 kgf / cm, [moisture resistance deterioration rate (%)] of the electrolytic copper foil of Example 1 ] = 9.3%.

  Using the electrolytic copper foil (untreated electrolytic copper foil) produced in Example 1, surface treatment was performed according to the following procedure. The oxidation treatment (oxidation treatment time: 2 minutes) performed in the preliminary treatment and the roughening treatment and the silane coupling agent treatment after the roughening treatment are the same as those in Example 1. And in this Example 3, the pH and dimethylamine borane concentration of the aqueous solution used for the reduction treatment were changed as follows, and these effects were verified.

Reduction treatment: The electrolytic copper foil after the oxidation treatment is adjusted to three levels of pH = 11, 12, and 13 using sodium carbonate and sodium hydroxide, and the dimethylamine borane concentrations are 5 g / L, 10 g / L, and 20 g / L. The copper foil which concerns on this application was obtained by immersing for 1 minute in each of nine types of aqueous solution (room temperature) which combined these three levels, performing a reduction process, washing with water, and drying. The copper foils obtained when the aqueous solution used for the reduction treatment had pH = 11 were designated as “Execution Sample 11-a, Implementation Sample 11-b, Implementation Sample 11-c”. Further, the copper foils obtained when the aqueous solution used for the reduction treatment had a pH of 12 were designated as “Execution Sample 12-a, Implementation Sample 12-b, Implementation Sample 12-c”. And the copper foil obtained when the aqueous solution used for a reduction process was pH = 13 was set to "Execution sample 13-a, Implementation sample 13-b, Implementation sample 13-c". In addition, the “−a” display when indicating each of the implementation samples is when the dimethylamine borane concentration in the aqueous solution used for the reduction treatment is 5 g / L. And "-b" display is a case where the dimethylamine borane density | concentration in the aqueous solution used for a reduction process is 10 g / L. “−c” is indicated when the concentration of dimethylamine borane in the aqueous solution used for the reduction treatment is 20 g / L.

  Scanning electron microscope observation images of all the working samples obtained in Example 3 were in the same form as shown in FIG. Then, when the state of the “fine irregularities made of a copper composite compound” on the surface of the roughened layer of each of the implementation samples is analyzed using XPS, the presence of “copper oxide” and “cuprous oxide” is clearly confirmed. Table 3 shows the occupation area ratio of the peak of Cu (I) with respect to the total area of the peak area of Cu (I) and the peak area of Cu (II). Further, as a result of this qualitative analysis, the presence of “—COO group” was also clearly confirmed on the roughened surface. Further, in the same manner as in Example 1, a test substrate was produced using each sample. Then, using this test substrate, the normal peel strength and the peel strength after moisture absorption treatment were measured in the same manner as in Example 1. These results are shown together in Table 3.

Comparative example

[Comparative Example 1]
The copper foil of Comparative Example 1 is obtained by omitting the silane coupling agent treatment in the copper foil of Example 1. In contrast to the copper foil described in Example 1, the presence or absence of the silane coupling agent treatment is It is for confirming the influence which it has on moisture absorption degradation performance. Therefore, except for the silane coupling agent treatment, other manufacturing conditions are the same as those in the example, and therefore, a duplicate description is omitted and only the evaluation results are described below.

<Evaluation of copper foil>
Shape observation result of roughened surface: The scanning electron microscope image of the copper foil obtained in Comparative Example 1 was the same as that shown in FIG.

Results of qualitative analysis of roughened surface: When this surface was subjected to qualitative analysis using XPS, the presence of “copper oxide” and “cuprous oxide” was clearly confirmed, and the peak area of Cu (I) The occupied area ratio of the peak of Cu (I) with respect to the total area with the peak area of Cu (II) was 95%. Further, as a result of this qualitative analysis, the presence of “—COO group” was also clearly confirmed on the roughened surface.

Lightness L ^* of the roughened surface: The value of the lightness L ^* of the copper foil obtained in Comparative Example 1 was 10.

Hygroscopic deterioration performance evaluation results: Using the copper foil of Comparative Example 1, a test substrate was produced in the same manner as in Example 1. Then, using this test substrate, the normal peel strength and the peel strength after moisture absorption treatment were measured in the same manner as in Example 1. As a result, [normal peel strength] = 0.65 kgf / cm, [peel strength after moisture absorption treatment] = 0.40 kgf / cm, [moisture resistance deterioration rate (%)] of the electrolytic copper foil of Comparative Example 1 ] = 38.6%.

[Comparative Example 2]
The copper foil with carrier foil of Comparative Example 2 is obtained by subjecting the copper foil with carrier foil used in Example 2 to roughening treatment, rust prevention treatment, and silane coupling agent treatment according to the following procedure. Here, in contrast to the copper foil with carrier foil described in Example 2, it is for confirming the influence of the difference in the roughening treatment layer on the PCT moisture absorption deterioration rate. Therefore, regarding the manufacturing conditions, portions different from those in the second embodiment will be described, and redundant description will be omitted.

Roughening treatment: In the roughening treatment step, fine copper particles were deposited on the surface of the electrolytic copper foil layer of the copper foil with carrier foil. At this time, a burn plating condition in which a copper sulfate solution (sulfuric acid concentration 100 g / L, copper concentration 18 g / L), liquid temperature 25 ° C., current density 10 A / dm ² , and energization time 10 seconds was adopted. In order to prevent the fine copper particles from falling off, as the covering plating, a copper sulfate solution (sulfuric acid concentration 150 g / L, copper concentration 65 g / L), liquid temperature 45 ° C., current density 15 A / dm ² , energization time 20 By adopting second smooth plating conditions, fine copper particles were fixed on the surface of the electrolytic copper foil layer.

Rust prevention treatment: Here, the surface of the electrolytic copper foil layer of the carrier foil-attached copper foil having been subjected to the roughening treatment was subjected to a rust prevention treatment using zinc as a rust prevention element. At this time, the rust prevention treatment layer uses a zinc sulfate bath, uses a zinc sulfate solution having a sulfuric acid concentration of 70 g / L and a zinc concentration of 20 g / L, a liquid temperature of 40 ° C., a current density of 15 A / dm ² , and an energization time of 20 The zinc anticorrosive treatment layer was formed using the second condition.

  Hereinafter, similarly to Example 2, the silane coupling agent treatment and drying were performed to obtain a copper foil with a carrier foil of Comparative Example 2.

<Evaluation of copper foil with carrier foil>
Result of Observation of Shape on Roughened Surface: A scanning electron microscope image of the roughened surface of the electrolytic copper foil layer of the copper foil with carrier foil obtained in Comparative Example 2 is shown in FIG.

Results of qualitative analysis of roughened surface: When this roughened surface was qualitatively analyzed using XPS, the zinc component was detected, while “copper oxide”, “cuprous oxide” and “—COO group” were It was hardly confirmed.

Lightness L ^* of roughened surface: The value of lightness L ^* of the copper foil obtained in Comparative Example 2 was 46.

Hygroscopic deterioration performance evaluation results: A test board was prepared in the same manner as in Example 2 using the copper foil of Comparative Example 2. Then, using this test substrate, the normal peel strength and the peel strength after moisture absorption treatment were measured in the same manner as in Example 2. As a result, [normal state peeling strength] = 0.59 kgf / cm, [peeling strength after moisture absorption treatment] = 0.46 kgf / cm, [moisture resistance deterioration rate (%)] of the electrolytic copper foil of Comparative Example 2 ] = 22.0%.

[Comparative Example 3]
In Comparative Example 3, the same pretreatment as in Example 1 was performed using the same electrolytic copper foil as in Example 1, and instead of the roughening process in Example, blackening treatment and reduction treatment were performed to obtain Comparative Sample 3. It was. Hereinafter, the blackening process and the reduction process will be described.

Blackening treatment: 10% by volume of “PRO BOND 80A OXIDE SOLUTION”, which is an oxidation treatment solution manufactured by Rohm & Haas Electronic Materials Co., Ltd. A general blackening treatment was formed on the surface by immersing in an aqueous solution containing 20 vol% and having a liquid temperature of 85 ° C. for 5 minutes.

Reduction treatment: The electrolytic copper foil that has been subjected to oxidation treatment is reduced to 6.7 vol% for "CIRCUPOSIT PB OXIDE CONVERTER 60C", which is a reduction treatment solution manufactured by Rohm & Haas Electronic Materials Co., Ltd., and 1.5 vol for "CUPOSIT Z". 5% immersion in an aqueous solution having a liquid temperature of 35 ° C., washed with water, and dried to obtain a comparative sample having a reduction blackening treatment layer shown in FIG.

  When the surface of the roughened layer of the surface-treated copper foil (comparative sample) obtained in this comparative example was analyzed using XPS, the presence of “Cu (0)” was confirmed. In addition, the presence of “Cu (II)” and “Cu (I)” was also confirmed, and the peak of Cu (I) relative to the total area of the peak area of Cu (I) and the peak area of Cu (II) was confirmed. The occupied area ratio is as shown in Table 3. However, as a result of this qualitative analysis, the presence of a “—COO group” was not confirmed on the roughened surface.

[Contrast between Example and Comparative Example]
Comparison between Example 1 and Comparative Example 1 The comparison between Example 1 and Comparative Example 1 is for confirming the effect of the silane coupling agent treatment. The evaluation results of Example 1 and Comparative Example 1 are shown in Table 1 below.

As apparent from Table 1, since the copper foil of Comparative Example 1 is obtained by omitting the silane coupling agent treatment of the copper foil of Example 1, the “roughening treatment surface shape”, “roughening treatment” The same evaluation results are shown in “Qualitative analysis of surface” and “Lightness L ^* of roughened surface”. As for the peel strength, there is no significant difference between Example 1 and Comparative Example 1 with respect to “normal peel strength”. However, as for “stripping strength after moisture absorption treatment”, the value of Comparative Example 1 is lower than the value of Example 1. As a result, while the moisture resistance deterioration rate of Example 1 is 14.8%, the humidity resistance deterioration rate of Comparative Example 1 is reduced to 38.6%. Therefore, it is clear that the copper foil of Comparative Example 1 is not suitable for manufacturing a printed wiring board that is exposed to a large amount of water or various aqueous solutions.

Comparison between Example 2 and Comparative Example 2: The comparison between Example 2 and Comparative Example 2 is that the copper foil with carrier foil according to the present application is a conventional copper foil with carrier foil subjected to roughening treatment and the like. On the other hand, it is for confirming what superiority is exhibited. The evaluation results of Example 2 and Comparative Example 2 are shown in Table 2 below.

The copper foil with carrier foil of Comparative Example 2 is different from the copper foil with carrier foil of Example 2 in the roughening treatment method. As a result, as is apparent from Table 2, the “roughening surface shape” is Different. Moreover, since the roughening method differs in Example 2 and Comparative Example 2, the components which comprise a roughening process layer differ. Specifically, from the roughened surface of the copper foil with carrier foil of Example 2, “copper oxide”, “cuprous oxide”, and “—COO group” were detected by XPS. These components are hardly detected from the roughened surface, and the roughened layer of the comparative example is composed of fine copper grains electrodeposited on the surface of the copper foil, so that the main component is mainly “copper” or “ Copper alloy ". And since the value of the lightness L ^* of Example 2 is smaller than the value of the lightness L ^* of Comparative Example 2, in the roughening process layer of Example 2, the needle-shaped or plate-shaped convex which consists of a copper complex compound It can be seen that the concavo-convex structure formed by the shaped portions is finer than the concavo-convex structure formed by the fine copper particles attached to the surface of the copper foil in the roughening treatment layer of Comparative Example 2.

  Moreover, when "normal peeling strength" is seen, compared with the case where circuit formation is performed using the copper foil with a carrier foil of the comparative example 2, circuit formation is performed using the copper foil with a carrier foil of Example 2. Indicates a higher peel strength. This is also clear from the difference in the roughened state of the surface in FIG. 1 as an example and FIG. 4 as a comparative example. That is, it is considered that the roughened layer of Example 2 is formed with fine convex portions and has a larger specific surface area than the roughened layer of Comparative Example 2. And the value of Comparative Example 2 is also lower than the value of Example 2 for “stripping strength after moisture absorption treatment”. As a result, the moisture resistance deterioration rate of Example 2 is 9.3%, while the humidity resistance deterioration rate of Comparative Example 2 is reduced to 22.0%. Therefore, it is clear that the copper foil with carrier foil of Comparative Example 2 is not suitable for manufacturing printed wiring boards that are exposed to much water or various aqueous solutions as compared with the copper foil with carrier foil of Example 2.

Comparison between Example 3 and Comparative Example 3: Next, referring to Table 3 below, Example 3 and Comparative Example 3 are compared.

  In Table 3, paying attention to the occupied area ratio of the Cu (I) peak, the surface-treated copper foils obtained when the aqueous solution used for the reduction treatment is pH = 11 (Example 11-a, Example 11-b, Example) Sample 11-c), surface-treated copper foil (implementation sample 12-a, implementation sample 12-b, implementation sample 12-c) obtained when the aqueous solution used for the reduction treatment is pH = 12, and reduction treatment Looking at the surface-treated copper foils (Example 13-a, Example 13-b, Example 13-c) obtained when the aqueous solution used was pH = 13, the occupied area ratio of the Cu (I) peak was 59% to 99%. On the other hand, even in the comparative sample, the occupied area ratio of the Cu (I) peak is 83%. Therefore, in the occupied area ratio of the Cu (I) peak, it can be seen that there is no difference between Example 3 and Comparative Example 3. However, when the state analysis by XPS described above is used, the detected components are different. The presence of “—COO group” was not confirmed on the roughened surface of the sample. On the other hand, when planar observation of the roughened surface of the comparative sample 3 is performed, a long and thick needle-like convex portion is observed, and the shape of the convex portion formed by the blackening treatment is an oxidation treatment performed on the implementation sample. Unlike the shape of the convex part formed later, the tip part is sharply pointed. The thickness of the concavo-convex structure layer formed by the blackening treatment was 700 nm. However, when the reduction blackening process was performed by performing the reduction process, the tip of the convex part was rounded, and the uneven shape of the surface was greatly changed by the reduction process. When the cross section after the reduction treatment was observed for the comparative sample 3, it was confirmed that the needle-like convex portions formed after the blackening treatment were thin and finely broken by the reduction treatment. On the other hand, in the working samples of Example 3 and the like, it was confirmed that the surface shape of the fine concavo-convex structure formed by the oxidation treatment was maintained after the reduction treatment. That is, it can be predicted that the convex portion formed in the comparative sample is very fragile as compared with the working sample, and a so-called problem of powder falling occurs.

  Therefore, the peel strength of the surface-treated copper foil obtained in Example 3 and Comparative Example 3 will be compared. As a result, the peel strength of the implementation sample is 0.69 kgf / cm to 0.81 kgf / cm. On the other hand, the peeling strength of the comparative sample was 0.33 kgf / cm, which was confirmed to be lower than the working sample.

  The copper foil or the copper foil with carrier foil according to the present application described above is “a fine concavo-convex structure formed from a needle-like or plate-like convex portion made of a copper composite compound containing copper oxide and cuprous oxide. It has a roughened layer having an average thickness of 100 nm to 400 nm. For this reason, the surface provided with the roughening treatment layer is used as an adhesive surface with the insulating resin base material, so that the insulating resin base of the non-roughened copper foil can be obtained by the nano-anchor effect by the convex portions forming the fine uneven structure. Good adhesion can be ensured compared to the adhesion to the material. Further, since the fine concavo-convex structure is formed by extremely short needle-like or plate-like convex portions having a maximum length of 500 nm or less, a slight over-etching time is required when forming a circuit by etching. By providing, the convex part of the state embedded in the insulating resin base material side can be dissolved and removed. Therefore, good etching performance equivalent to that of the non-roughened copper foil can be realized, and a fine pitch circuit having a good etching factor can be formed. Furthermore, by providing a silane coupling agent treatment layer on the surface of the roughening treatment layer, it is possible to realize moisture absorption deterioration resistance equivalent to that of a conventional roughening copper foil. Therefore, it can be usefully used as all printed wiring board manufacturing materials. In addition, as described above, the copper foil according to the present application can be provided with a roughening treatment layer on both sides of the copper foil, and powder formation is suppressed, so that the inner layer circuit formation of the multilayer printed wiring board is achieved. It can be set as the double-side roughening copper foil suitable for.

Claims (5)

A roughening treatment layer having an average thickness of 100 nm or more and 400 nm or less having a fine concavo-convex structure formed from needle-like or plate-like convex portions made of a copper composite compound containing copper oxide and cuprous oxide, and the roughening The surface of the treatment layer is provided with a silane coupling agent treatment layer on at least one surface,
The value of the lightness L ^* in the L ^* a ^* b ^* color system of the roughening layer side surface of the copper foil is 25 or less,
The specific surface area measured by adsorbing krypton on the surface of the roughening treatment layer is 0.035 m ² / g or more,
With respect to the total area of the peak area of Cu (I) and the peak area of Cu (II) obtained when the constituent elements of the roughened layer are analyzed by X-ray photoelectron spectroscopy, the Cu (I) The copper foil characterized by the ratio which a peak area occupies from 50% to 99%.   When the surface of the roughened layer is observed with a scanning electron microscope at an inclination angle of 45 ° and a magnification of 50000 times or more, it can be observed separately from other convex portions among adjacent convex portions. The copper foil according to claim 1, wherein the length of the leading end portion is 250 nm or less. The silane coupling agent treatment layer is formed using any one of olefin functional silane, epoxy functional silane, vinyl functional silane, acrylic functional silane, amino functional silane and mercapto functional silane. Claim | item 1 or the copper foil of Claim 2 . A copper foil with a carrier foil comprising a carrier foil on one side of the copper foil according to any one of claims 1 to 3 via a bonding interface layer. The copper clad laminated board provided with the copper foil as described in any one of Claims 1-3 .

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