KR20180135105A - Ultrathin copper foil with carrier and method for manufacturing same, copper-clad laminate, and method for manufacturing printed-wiring board - Google Patents

Abstract

An object of the present invention is to provide an extremely thin copper foil with a carrier capable of both forming a microcircuit and laser workability in the process of producing a copper clad laminate or a printed wiring board.
The ultra-thin copper foil with a carrier according to the present invention comprises a carrier foil, a release layer and an ultra-thin copper foil in this order. The surface of the ultra-thin copper foil on the release layer side has an average distance (Peak spacing) between surface peaks of 20 占 퐉 or less and a maximum elevation difference (Wmax) of bending of 1.0 占 퐉 or less, The maximum height difference (Wmax) of the bending is 1.0 탆 or less.

Description

TECHNICAL FIELD [0001] The present invention relates to an ultra-thin copper foil with a carrier, a method for manufacturing the same, a copper-clad laminate, and a method for manufacturing a printed wiring board,

The present invention relates to an ultra-thin copper foil with a carrier and a method of manufacturing the same.

In recent years, the MSAP (Modified Semi-Adjacent Process) method has been widely adopted as a manufacturing method of printed wiring boards suitable for miniaturization of circuits. The MSAP method is suitable for forming a very fine circuit and is carried out using an ultra-thin copper foil with a carrier foil in order to take advantage of the feature. For example, as shown in Figs. 1 and 2, the ultra-thin copper foil 10 is laminated on an insulating resin substrate 11 having a prepreg 11b on a base substrate (base substrate) 11a (Not shown) is peeled off by using a primer layer 12 on the lower layer circuit 11c (which may include a lower layer circuit 11c), followed by laser piercing (drilling) Thereby forming a via hole 13 (step (b)). Then, after the chemical copper plating 14 is performed (step (c)), masking is performed in a predetermined pattern (step (d)) by exposure and development using the dry film 15, ) (Step (e)). After the dry film 15 is removed to form the wiring portion 16a (step (f)), unnecessary ultra thin copper foil between the adjacent wiring portions 16a and 16a is removed by etching over the entire thickness (Step (g)) to obtain a wiring 17 formed in a predetermined pattern.

Particularly, in recent years, with the miniaturization and lightening of electronic circuits, there has been demanded a copper foil for MSAP method which has better circuit formability (for example, a fine circuit of line / space = 15 μm or less / 15 μm or less can be formed). For example, Patent Document 1 (International Publication No. 2012/046804) discloses a method in which a carrier foil having an average interval (Sm) of concavities and convexities of surface roughening defined by JIS-B-06012-1994 of 25 m or more, A release layer and a copper foil are stacked in this order and the copper foil is peeled off from the carrier foil. By using the copper foil, the linearity of the wiring line up to a very small width of 15 mu m or less in line / So that etching can be performed.

Recently, in the via hole processing of the copper-clad laminate, a direct laser drilling process for forming a via hole by directly irradiating a laser to the ultra-thin copper foil is widely used (see, for example, Japanese Patent Application Laid-Open No. 11-346060 ). In this method, generally, the surface of the ultra-thin copper foil is subjected to a blackening treatment, and then a carbon dioxide gas laser is irradiated to the blackened surface to perforate the ultra-thin copper foil and the insulating layer immediately below it.

International Publication No. 2012/046804 Japanese Patent Application Laid-Open No. 11-346060

However, since the blackening treatment requires time and cost, and the yield can also be lowered, it is preferable that direct laser drilling can be preferably carried out on the surface of the ultra thin copper foil without performing the blackening treatment. However, when the direct laser drilling process is performed on the surface of the ultra-thin copper foil with a carrier described in Patent Document 1, it is difficult to form desired holes in normal irradiation conditions, and it is found that fine circuit formation and laser processability can not be achieved at the same time.

The inventors of the present invention have found that in this ultra-thin copper foil with a carrier, the average distance (Peak spacing) between surface peaks of the surface of the ultra-thin copper foil on the release layer side is 20 탆 or less, It was found that both fine circuit formation and laser processability can be achieved in the process of manufacturing a copper clad laminate or a printed wiring board by giving a surface profile having a maximum level difference Wmax of 1.0 占 퐉 or less.

Therefore, an object of the present invention is to provide an ultra-thin copper foil with a carrier capable of achieving both fine circuit formation and laser processability in the production of a copper clad laminate or a printed wiring board.

According to one aspect of the present invention, there is provided an ultra-thin copper foil with a carrier provided with a carrier foil, a release layer and an ultra-

The surface of the ultra-thin copper foil on the side of the release layer has an average distance (Peak spacing) between surface peaks of 20 占 퐉 or less and a surface of the ultra-thin copper foil on the opposite side of the release layer has a maximum elevation difference (Wmax) An ultra-thin copper foil with a carrier is provided.

According to another aspect of the present invention, there is provided a method of manufacturing an ultra-

Preparing a carrier foil having a surface having a valley spacing of 15 mu m or less and a maximum height difference (Wmax) of bending of 0.8 mu m or less,

A step of forming a release layer on the surface of the carrier foil,

And a step of forming an ultra-thin copper foil on the release layer.

According to another aspect of the present invention, there is provided a copper clad laminate obtained by using the ultra-thin copper foil with a carrier according to the above aspect.

According to another aspect of the present invention, there is provided a printed wiring board obtained by using the ultra-thin copper foil with a carrier according to the above aspect.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a process flow chart for explaining the MSAP method, which shows the first half of the process (steps (a) to (d)). Fig.
Fig. 2 is a process flow chart for explaining the MSAP process, and Fig. 2 is a diagram showing the latter process (steps (e) to (g)).
3 is a conceptual explanatory view of a method of counting the cross-sectional outline curve of roughened particles and the number of cross-sections of coarse particles at a cut surface at a predetermined height from a basal plane.
4 is a view showing an example of a distribution curve of the number of cross sections of the coarse particles on the cut surface according to the height from the base surface obtained in Example 7. Fig.

Justice

Definitions of the parameters used for specifying the present invention are as follows.

In the present specification, the term " peak spacing " means that the high frequency components of bending are removed from the information about the unevenness of the surface of the sample obtained by using the three-dimensional surface structure analysis microscope, And the average distance between the peaks in the data extracted by the extraction means.

In the present specification, " valley spacing " means that after removing high-frequency bending components from the information on the surface irregularities of the sample obtained by using the three-dimensional surface structure analysis microscope, Refers to the average distance between the bones in the extracted data.

In the present specification, the "maximum difference in bend height (Wmax)" in the present specification refers to a value obtained by dividing the waveform data obtained by extracting the waveform data according to the bend from the information on the surface of the sample obtained by using the three- (The sum of the maximum peak height and the maximum intergrowth depth of the waveform).

Peak spacing between surface peaks, valley spacing between bones, and maximum elevation difference (Wmax) of curvature were all measured using a commercially available three-dimensional surface structure analysis microscope (for example, zygo New View 5032 (Zygo) ) And commercially available analysis software (for example, Metro Pro Ver. 8.0.2), and setting the low-frequency filter to a condition of 11 mu m. At this time, the to-be-measured surface of the foil was fixed in close contact with the sample bed, and a field of view of 108 占 퐉 144 占 퐉 was selected in a range of 1 cm square of the sample piece. It is preferable to employ the average value of the measurement values obtained from the measurement points of the points as representative values.

In the present specification, the " electrode surface " of the carrier foil refers to the side of the carrier foil that was in contact with the rotating cathode when the carrier foil was produced.

In the present specification, the term " precipitated surface " of the carrier foil refers to a surface on the side where the electrolytic copper is precipitated at the time of manufacturing the carrier foil, that is, the side not in contact with the rotating cathode.

carrier  Attach Extreme  Copper foil and manufacturing method thereof

The ultra-thin copper foil with a carrier according to the present invention comprises a carrier foil, a release layer and an ultra-thin copper foil in this order. The surface of the ultra-thin copper foil on the release layer side has an average distance (Peak spacing) between surface peaks of 20 占 퐉 or less and a surface of the ultra-thin copper foil on the opposite side of the release layer has a maximum difference of elevation (Wmax) to be. As a result, both fine circuit formation and laser processability can be achieved in the process of producing a copper clad laminate or a printed wiring board. In addition, in order to secure laser processability, the blackening treatment generally employed so far can be made unnecessary in the present invention.

The microcircuit formation and the laser processability are inherently difficult to achieve, but according to the present invention, they can be made compatible with each other unexpectedly. In order to obtain good microcircuit-forming properties, an ultra-thin copper foil whose surface on the opposite side of the release layer is smooth is required. In order to obtain such an ultra-thin copper foil, an ultra-thin copper foil with a smoother surface on the release layer side is required. The smoother the surface, the easier the laser is to be reflected. . Actually, as described above, when direct laser drilling is performed on the surface of the ultra-thin copper foil with a carrier described in Patent Document 1, it is difficult to drill a desired hole under normal irradiation conditions and the microcircuit formation and laser processability can not be compatible Proved. As a result of the investigation by the inventors of the present invention, it has been found that the main factor that deteriorates the microcircuit formability is the curvature of the surface opposite to the peeling layer of the ultra-thin copper foil. It has been found that controlling the maximum height difference (Wmax) of bending to 1.0 占 퐉 or less is effective in improving the microcircuit forming ability. It has also been found that the factor that lowers the direct laser drilling workability is when the average distance (peak spacing) between surface peaks of the surface of the ultra-thin copper foil on the release layer side exceeds 20 탆. As described above, according to the ultra-thin copper foil with a carrier of the present invention, by controlling the Wmax and the peak spacing in the ultra-thin copper foil (particularly, the ultra-thin copper foil for MSAP), it is possible to form a circuit with a line / space of 15 mu m / The direct laser drilling process can be preferably performed while realizing excellent fine circuit formation.

As described above, the ultra-thin copper foil has a surface with a peak spacing of 20 占 퐉 or less on the surface of the peeling layer side and a surface with a maximum difference of elevation (Wmax) Respectively. By making the two parameters fall within the above range, it is possible to achieve both of the fine circuit formation and the laser processability in the production of a copper clad laminate or a printed wiring board. The average distance (Peak spacing) between surface peaks of the surface of the ultra-thin copper foil on the release layer side is 20 占 퐉 or less, preferably 1 to 15 占 퐉, more preferably 5 to 15 占 퐉, to be. The maximum elevation difference (Wmax) of the bending of the ultra-thin copper foil on the side opposite to the release layer is 1.0 占 퐉 or less, preferably 0.9 占 퐉 or less, and more preferably 0.8 占 퐉 or less. Particularly, in order to form a fine circuit of line / space = 15/15 占 퐉, Wmax of the ultra thin copper foil surface is preferably 0.8 占 퐉 or less. Since the lower limit of Wmax is better, the lower limit is not particularly limited, but Wmax is typically 0.1 占 퐉 or more, and more typically 0.2 占 퐉 or more.

The shaving degree of the ultra-thin copper foil on the release layer side and the maximum height difference (Wmax) of the bending are preferably 1.0 占 퐉 or less, more preferably 0.8 占 퐉, and still more preferably 0.6 占 퐉 or less. With such a low Wmax, the Wmax of the surface opposite to the peeling layer of the ultra-thin copper foil can be suppressed to be low, and the fine circuit forming property is excellent. In particular, in order to form a fine circuit having a line / space of 15/15 m, Wmax is preferably 0.6 m or less. Since the lower the value of Wmax is, the lower the value is, there is no particular limitation. Particularly, when the thickness of the ultra-thin copper foil is reduced (for example, when the thickness is 2.0 占 퐉 or less), Wmax is preferably small. Above all, Wmax is typically at least 0.1 占 퐉, and more typically at least 0.2 占 퐉.

The surface of the ultra-thin copper foil on the side opposite to the release layer is preferably a roughened surface. That is, it is preferable that the one surface of the ultra-thin copper foil is roughened. By doing so, it is possible to improve the adhesion with the resin layer at the time of producing the copper clad laminate or the printed wiring board. This roughening treatment can be carried out by forming coarse particles with a copper or copper alloy on a very thin copper foil. For example, a known plating method which involves at least two types of plating processes including a baking plating process for depositing fine copper grains on the ultra-thin copper foil and a covering plating process for preventing the copper grains from coming off .

Typically, the roughened surface comprises a plurality of roughened particles. Preferably, the plurality of coarsely grained particles have an average height of the coarsened grains from the base surface of 1.0 to 1.4 占 퐉, and a ratio of 1/10 of the distribution curve of the number of cross sections of the coarsened grains on the cross- Is not more than 1.3 탆. These parameters can be obtained by measuring the surface profile of the roughened surface with a desired magnification (for example, 600 to 30000 times) according to the size of the roughening particles, using a three-dimensional roughness analyzer. Here, the " base surface " is a plane parallel to the ultra-thin copper foil, which corresponds to the lowest position among the valley bottoms (valley bottoms) between a plurality of coarse grains as exemplified in Fig. The term " the number of cross-sections of the coarsened grains at the cut surface along the height from the base surface " means that the cross-sectional outline curve of the coarsened grains should be cut by a parallel cut surface at a predetermined height from the base surface Is the number of surface areas to be processed. That is, the cut surfaces are sequentially set while being divided at regular intervals (for example, 0.02 mu m) in the height direction from the base surface to the maximum harmonic grain height, and the number of cross sections of the harmonic grains in each cut surface is counted. The term " height of harmonic particles " means height of harmonic grains from the basal plane, and " average height of harmonic grains " means the distribution of the number of cross-sections of the harmonic grains on the cross- Quot; means the height from the basal plane (the height of harmonic particles) at which the number of cross sections of the coarse particles is the maximum in the curve. 4, the distribution curve of the number of cross-sections of the coarse particles on the cut surface along the height from the base surface is such that the ratio of the cross- Quot; means the distribution width (coarse particle height distribution width) in the value of 1. When the average height of the coarsened grains and the width of 1/10 of the width are within the above range, the height of the coarsened grains is reduced, so that the flash etchability in the vertical direction is improved and the unevenness of the coarsened particles is reduced. The non-uniformity is reduced, so that it is possible to effectively prevent undesired dragging of the substrate at the time of circuit formation. As a result, the circuit formability is improved. If the ratio is within the above range, unevenness of the coarsened grains is reduced. Thus, when the roughened surface is adhered to a resin layer such as a prepreg, unevenness due to the position of the peel strength with the resin layer is reduced. The average height of the coarsened grains is 1.0 to 1.4 mu m, preferably 1.0 to 1.3 mu m. The one-tenth square width is 1.3 탆 or less, preferably 1.0 탆 or less. The smaller the 1/10 tooth width, the better the smaller, but typically 0.1 탆 or more.

The ultra-thin copper foil may have a known constitution adopted for the ultra-thin copper foil with a carrier other than those having the above specific surface profile and is not particularly limited. For example, the ultra-thin copper foil may be formed by a wet film formation method such as an electroless copper plating method and an electrolytic copper plating method, a dry film formation method such as sputtering and chemical vapor deposition, or a combination thereof. The thickness of the ultra-thin copper foil is preferably 0.1 to 5.0 mu m, more preferably 0.5 to 3.0 mu m, and further preferably 1.0 to 2.0 mu m. For example, in order to form a fine circuit of line / space = 15/15 占 퐉, the thickness of the ultra-thin copper foil is particularly preferably 2.0 占 퐉 or less.

The release layer is a layer having a function of suppressing the mutual diffusion that can occur between the carrier foil and the copper foil at the time of press molding at a high temperature by ensuring the stability of the strength by weakening the peel strength of the carrier foil. The release layer is generally formed on one side of the carrier foil, but it may be formed on both sides. The release layer may be either an organic release layer or an inorganic release layer. Examples of the organic component used in the organic release layer include a nitrogen-containing organic compound, a sulfur-containing organic compound, and a carboxylic acid. Examples of the nitrogen-containing organic compound include triazole compounds and imidazole compounds. Among them, triazole compounds are preferable because of their easy peelability. Examples of triazole compounds include 1,2,3-benzotriazole, carboxybenzotriazole, N ', N'-bis (benzotriazolylmethyl) urea, 1H-1,2,4- -1H-1,2,4-triazole, and the like. Examples of the sulfur-containing organic compound include mercaptobenzothiazole, thiocyanuric acid, 2-benzimidazole thiol and the like. Examples of the carboxylic acid include monocarboxylic acid and dicarboxylic acid. On the other hand, examples of the inorganic component used in the inorganic release layer include Ni, Mo, Co, Cr, Fe, Ti, W, P, Zn and a chromate treatment film. The release layer may be formed by bringing the release layer component-containing solution into contact with at least one surface of the carrier foil and fixing the release layer component to the surface of the carrier foil. When the carrier foil is brought into contact with the solution containing the release layer component, the contact may be carried out by immersion in the release layer component-containing solution, spraying of the solution containing the release layer component, and falling of the solution containing the release layer component. Alternatively, a method of forming a film of the release layer component by a vapor phase method such as vapor deposition or sputtering can be employed. The peeling layer component may be fixed to the surface of the carrier foil by adsorption or drying of the solution containing the peeling layer component and electrodeposition of the peeling layer component in the solution containing the releasing layer component. The thickness of the release layer is typically 1 nm to 1 占 퐉, preferably 5 nm to 500 nm.

The carrier foil is a foil for supporting the ultra-thin copper foil and improving its handling property. Examples of the carrier foil include an aluminum foil, a copper foil, a stainless steel (SUS) foil, a resin film whose surface is coated with a metal, and the like, preferably a copper foil. The copper foil may be either a rolled copper foil or an electrolytic copper foil. The thickness of the carrier foil is typically 250 占 퐉 or less, preferably 12 占 퐉 to 200 占 퐉.

The surface of the carrier foil on the release layer side preferably has a valley spacing of 15 mu m or less between the valleys and a maximum height difference (Wmax) of bending of 0.8 mu m or less. Since the ultra-thin copper foil is formed on the side of the release layer side of the carrier foil in the manufacturing process of the ultra-thin copper foil with a carrier, the low valley spacing and Wmax are imparted to the surface of the carrier foil, The above-mentioned preferable surface profile can be given to the surface of the release layer and the surface opposite to the release layer. That is, the ultra-thin copper foil with a carrier according to the present invention is prepared by preparing a carrier foil having a surface having a valley spacing of 15 mu m or less between the valleys and a maximum height difference (Wmax) of bending of 0.8 mu m or less, By forming a peeling layer on the surface of the release layer, and forming an ultra-thin copper foil on the release layer. The valley spacing between the valleys on the release layer side of the carrier foil is preferably 15 占 퐉 or less, more preferably 1 to 10 占 퐉 or less, and further preferably 3 to 8 占 퐉 or less. Further, the maximum height difference (Wmax) of the curvature of the surface of the carrier foil on the release layer side is preferably 0.8 占 퐉 or less, more preferably 0.7 占 퐉 or less, and further preferably 0.6 占 퐉 or less. Since the lower limit of Wmax is better, the lower limit is not particularly limited, but Wmax is typically 0.1 占 퐉 or more, and more typically 0.2 占 퐉 or more. The realization of the low valley spacing and Wmax within the above range on the surface of the carrier foil is achieved by polishing the surface of the rotating cathode used for electrolytic foaming of the carrier foil with a buff of a predetermined number of times, As shown in Fig. That is, the surface profile of the rotated negative electrode thus adjusted is transferred to the electrode surface of the carrier foil, and an ultra-thin copper foil is formed on the electrode surface of the carrier foil thus provided with the preferable surface profile through the separation layer, The above-described surface profile can be imparted to the surface of the substrate. Preferably, the number of buffs is greater than # 1000 and less than # 3000, more preferably # 1500 to # 2500.

Depending on requirements, another functional layer may be provided between the peeling layer and the carrier foil and / or the ultra-thin copper foil. An example of such another functional layer is an auxiliary metal layer. The auxiliary metal layer is preferably made of nickel and / or cobalt. By forming such an auxiliary metal layer on the surface side of the carrier foil and / or on the surface side of the ultra-thin copper foil, mutual diffusion which may occur between the carrier foil and the ultra-thin copper foil at the time of hot press forming at a high temperature or for a long time is suppressed, The stability of the peel strength can be secured. The thickness of the auxiliary metal layer is preferably 0.001 to 3 mu m.

Depending on the requirement, the ultra-thin copper foil may be rust-inhibited. The rust-preventive treatment preferably includes a plating treatment using zinc. The plating treatment using zinc may be either a zinc plating treatment or a zinc alloy plating treatment, and the zinc alloy plating treatment is particularly preferably a zinc-nickel alloy treatment. The zinc-nickel alloy treatment may be a plating treatment containing at least Ni and Zn, and may further include other elements such as Sn, Cr, and Co. The ratio of Ni / Zn adhesion in the zinc-nickel alloy plating is preferably 1.2 to 10, more preferably 2 to 7, and still more preferably 2.7 to 4 in mass ratio. Further, it is preferable that the rust-preventive treatment further includes a chromate treatment, and it is more preferable that the chromate treatment is performed on the surface of the plating containing zinc after the plating treatment with zinc. This makes it possible to further improve the rustproofing property. A particularly preferable rust-preventive treatment is a combination of a zinc-nickel alloy plating treatment and a subsequent chromate treatment.

The surface of the ultra-thin copper foil may be subjected to a silane coupling agent treatment to form a silane coupling agent layer. As a result, it is possible to improve the moisture resistance, chemical resistance, adhesion with the adhesive, and the like. The silane coupling agent layer can be formed by applying an appropriate dilution of a silane coupling agent, followed by drying. Examples of the silane coupling agent include epoxy functional silane coupling agents such as 4-glycidylbutyltrimethoxysilane and? -Glycidoxypropyltrimethoxysilane, or? -Aminopropyltrimethoxysilane, N-? ( Aminopropyltrimethoxysilane, N-3- (4- (3-aminopropoxy) butoxy) propyl-3-aminopropyltrimethoxysilane, N-phenyl- An amino functional silane coupling agent such as silane coupling agent, an amino functional silane coupling agent such as silane coupling agent, an amino functional silane coupling agent such as silane coupling agent, or a silane coupling agent such as a mercapto functional silane coupling agent such as γ-mercaptopropyltrimethoxysilane or an olefin functional silane coupling agent such as vinyltrimethoxysilane or vinylphenyltrimethoxysilane Or an acryl functional silane coupling agent such as γ-methacryloxypropyltrimethoxysilane, or an imidazole functional silane coupling agent such as imidazole silane, or a triazine functional silane coupling agent such as triazinilane .

Tie Laminates

The ultra-thin copper foil with a carrier according to the present invention is preferably used for producing a copper-clad laminate for a printed wiring board. That is, according to a preferred embodiment of the present invention, there is provided a copper clad laminate obtained by using an ultra-thin copper foil with a carrier. By using the ultra-thin copper foil with a carrier according to the present invention, it is possible to achieve both of the fine circuit formation and the laser processability in the processing of the copper clad laminate. This copper-clad laminate comprises the ultra-thin copper foil with a carrier of the present invention and a resin layer provided in close contact with the surface-treated layer. The ultra-thin copper foil with a carrier may be provided on one side of the resin layer or on both sides thereof. The resin layer comprises a resin, preferably an insulating resin. The resin layer is preferably a prepreg and / or a resin sheet. The prepreg is a generic name of a composite material obtained by impregnating a base material such as a synthetic resin plate, a glass plate, a glass woven fabric, a glass nonwoven fabric, paper or the like with a synthetic resin. Preferable examples of the insulating resin include an epoxy resin, a cyanate resin, a bismaleimide triazine resin (BT resin), a polyphenylene ether resin, and a phenol resin. Examples of the insulating resin constituting the resin sheet include insulating resins such as epoxy resin, polyimide resin and polyester resin. Further, the resin layer may contain filler particles composed of various inorganic particles such as silica and alumina from the viewpoint of improving the insulating property and the like. The thickness of the resin layer is not particularly limited, but is preferably 1 to 1000 占 퐉, more preferably 2 to 400 占 퐉, and still more preferably 3 to 200 占 퐉. The resin layer may be composed of a plurality of layers. A resin layer such as a prepreg and / or a resin sheet may be provided in the ultra-thin copper foil with a carrier through a primer resin layer previously coated on the surface of the copper foil.

print Wiring board

The ultra-thin copper foil with a carrier according to the present invention is preferably used for producing a printed wiring board. That is, according to a preferred embodiment of the present invention, there is provided a printed wiring board obtained using the ultra-thin copper foil with a carrier. By using the ultra-thin copper foil with a carrier according to the present invention, both fine circuit formation and laser processability can be achieved in the production of printed wiring boards. The printed wiring board according to the present embodiment comprises a resin layer and a layer structure in which a copper layer is laminated in this order. The copper layer is a layer derived from the ultra-thin copper foil of the ultra-thin copper foil with a carrier of the present invention. The resin layer is as described above for the copper clad laminate. In any case, a known layer structure can be employed for the printed wiring board, except that the ultra-thin copper foil with a carrier of the present invention is used. Specific examples of the printed wiring board include a single-sided or double-sided printed wiring board formed by forming a laminate obtained by adhering the ultra-thin copper foil of the present invention to one side or both sides of a prepreg and curing it, and a multilayer printed wiring board obtained by multilayering these. As another specific example, a flexible printed wiring board, a COF, a TAB tape, or the like which forms a circuit by forming the ultra-thin copper foil of the present invention on a resin film can be used. As another specific example, the resin-coated copper foil (RCC) coated with the resin layer described above is formed on the ultra-thin copper foil of the present invention, and the resin layer is laminated on the above-described printed board as an insulating adhesive layer, A build-up wiring board in which a circuit is formed by a method such as a modulated semi-insulating (MSAP) method or a subtractive method, a build-up wiring board in which a circuit is formed by a semi- And a direct build-up wafer in which the lamination of the resin-coated copper foil and the circuit formation are alternately repeated on the circuit. As a more practical example, an antenna element formed by stacking the above resin-coated copper foil on a substrate, an electronic element for a panel / display or an electronic material for a window glass in which a pattern is formed by laminating on a glass or resin film through an adhesive layer, And an electromagnetic shielding film obtained by applying a conductive adhesive agent to the ultra-thin copper foil of the present invention. In particular, the ultra-thin copper foil with a carrier of the present invention is suitable for the MSAP method. For example, when a circuit is formed by the MSAP method, the configurations shown in Figs. 1 and 2 can be employed.

[Example]

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

Examples 1 to 5

A peeling layer and an ultra-thin copper foil layer were formed in order on the electrode face side of the carrier foil, and then a rust-preventive treatment and a silane coupling agent treatment were carried out to produce an ultra-thin copper foil with a carrier. The resulting ultra-thin copper foil with a carrier was evaluated variously. The concrete procedure is as follows.

(1) Preparation of carrier foil

Using the same electrolyte, a rotating anode and a cathode as a DSA (dimensionally stable anode) of the composition shown below, and electrolytic solution temperature to 50 ℃, a current density of 70A / dm ^2, the copper foil as a carrier foil thick electrolytic 18㎛ . At this time, the surface was polished with a buff of # 2500 (Example 1), # 2000 (Example 2), # 1500 (Example 3), # 1000 (Example 4), or # 3000 (Example 5) The adjusted electrode was used.

<Composition of copper electrolytic solution>

- Concentration: 80g / L

- sulfuric acid concentration: 300 g / L

- Chlorine concentration: 30 mg / L

- Glucose concentration: 5 mg / L

(2) Formation of release layer

The electrode surface of the pickling treated carrier foil was immersed in a CBTA aqueous solution having a CBTA (carboxybenzotriazole) concentration of 1 g / L, a sulfuric acid concentration of 150 g / L and a copper concentration of 10 g / L for 30 seconds at a liquid temperature of 30 ° C , And the CBTA component was adsorbed on the electrode surface of the carrier foil. Thus, a CBTA layer was formed as an organic release layer on the electrode surface of the carrier foil.

(3) Formation of auxiliary metal layer

The carrier foil is peeled off the organic layer is formed, it is immersed in a solution containing a nickel concentration of 20g / L produced by using the nickel sulfate, at a liquid temperature of 45 ℃, pH3, the conditions of a current density of 5A / dm ^2, with a thickness equivalent 0.001㎛ An amount of nickel was adhered onto the organic release layer. Thus, a nickel layer was formed as an auxiliary metal layer on the organic peeling layer.

(4) Formation of ultra-thin copper foil

The carrier foil having the auxiliary metal layer formed thereon was immersed in a copper solution having the composition shown below, and electrolyzed at a solution temperature of 50 캜 and a current density of 5 to 30 A / dm ² to form an ultra-thin copper foil having a thickness of 2 탆 on the auxiliary metal layer.

&Lt; Composition of Solution >

- Concentration: 60g / L

- sulfuric acid concentration: 200 g / L

(5) Harmonization processing

The surface of the ultra-thin copper foil thus formed was subjected to coarsening treatment. This roughening treatment is composed of a baking plating process for depositing fine coarse pebbles on the thin ultra thin copper foil and a covering plating process for preventing the fine copper coils from falling off. The burn plating process, the copper concentration using an acidic copper sulfate solution comprising 10g / L and a sulfuric acid concentration of 120g / L, the liquid temperature was subjected to roughening treatment with 25 ℃, a current density of 15A / dm ^2. In the plating process after the icing, copper concentration using an acidic copper sulfate solution comprising 70g / L and a sulfuric acid concentration of 120g / L, the deposition was carried out in a smooth plating conditions of a liquid temperature of 40 ℃ and a current density of 15A / dm ^2.

(6) Rust treatment

The surface of the roughened treatment layer of the resulting ultra-thin copper foil with a carrier was subjected to a rust-proofing treatment comprising a zinc-nickel alloy plating treatment and a chromate treatment. First, in the zinc concentration 0.2g / L, the nickel concentration 2g / L and the potassium pyrophosphate concentrations of 300g / L by using an electrolyte solution of a liquid temperature of 40 ℃, current density of 0.5A / dm ^2, the roughened layer and the carrier foil And the surface was subjected to a zinc-nickel alloy plating treatment. Next, chromate treatment was performed on the surface of zinc-nickel alloy plating treatment under the conditions of pH 10 and current density of 5 A / dm ² using a 3 g / L aqueous solution of chromic acid.

(7) Treatment with silane coupling agent

an aqueous solution containing 2 g / L of? -glycidoxypropyltrimethoxysilane was adsorbed on the surface of the ultra-thin copper foil of the ultra-thin copper foil with a carrier, and the water was evaporated by an electric heater to perform a silane coupling agent treatment. At this time, the silane coupling agent treatment was not performed on the carrier foil side.

(8) Evaluation

With respect to the ultra-thin copper foil with a carrier thus obtained, various properties were evaluated as follows.

&Lt; Surface property parameter &

As the measuring instrument, zygo New View 5032 (manufactured by Zygo Co.) was used, and as analysis software Metro Pro Ver. 8.0.2 was used and the low frequency filter was set to a thickness of 11 mu m so that the maximum height difference (Wmax) of curvature, the peak spacing between the surface peaks and the average distance between the valleys spacing) was measured. At this time, an ultra-thin copper foil or carrier foil was fixed in close contact with the sample bed, and 6 fields of view of 108 占 퐉 144 占 퐉 were selected in a range of 1 cm square of the sample piece. The average value of the measurement values obtained from six measurement points was It was adopted as a representative value. Further, regarding the surface of the ultra-thin copper foil on the release layer side, the copper clad laminate for evaluation of laser workability described later was prepared and then measurement was carried out.

In Example 2, the surface profile of the area of 10800 mu m ² (120 mu m x 90 mu m) on the surface (rough surface side) of the ultra-thin copper foil was measured with a three-dimensional roughness analyzer (ERA-8900, manufactured by Erison, ) Was used to determine the mean coarsened particle height and the 1 / 10th tooth width by analyzing under the conditions of a measurement magnification: 1000 times, an acceleration voltage: 10 kV, and a Z axis interval: 0.02 mu m. In this surface analysis, the cut surfaces were sequentially set while being partitioned at a constant interval (0.02 占 퐉) in the height direction from the lowest position (corresponding to the base surface) to the maximum coarse particle height among the valleys between the coarse particles, By counting the number of cross sections of the coarsely grained particles. The larger the number of sections, the greater the number of harmonic particles, and vice versa. The ordinate is taken as the section number on the cut surface, and the abscissa is plotted as the height from the basal plane. Based on this distribution curve and the above definition, the average coarsely grained particle height and 1 / 10th measured width were determined.

&Lt; Laser processability >

A copper clad laminate was produced using the ultra-thin copper foil with a carrier, and the laser processability was evaluated. First, the ultra-thin copper foil of the ultra-thin copper foil with a carrier was laminated on the surface of the inner-layer substrate through a prepreg (830NX-A, thickness 0.1 mm, manufactured by Mitsubishi Gas Kagaku Co., Ltd.) After hot pressing for minutes, the carrier foil was peeled off to produce a copper clad laminate. Thereafter, by using a carbon dioxide gas laser, the copper clad laminate was subjected to laser processing under the conditions of a pulse width of 14 microseconds, a pulse energy of 6.4 mJ, and a laser beam of 108 micrometers. At that time, it was judged that the diameter of the hole after machining was 60 탆 or more, and that of the hole was less than 60 탆.

<Circuit Formability>

Evaluation of the circuit formability was carried out as follows. First, a dry film was attached to the surface of the copper clad laminate, and exposure and development were carried out to form a plating resist. Electrolytic copper plating was formed on the surface of the copper-clad laminate on which the plating resist was not formed to a thickness of 18 탆. Next, the plating resist was peeled off, and the ultra thin copper foil remaining between the circuits was dissolved and removed by treating with an etching solution (CPE800, manufactured by Mitsubishi Gas Kagaku Co., Ltd.) using hydrogen peroxide and sulfuric acid to prepare a line / space = A wiring pattern of 15 mu m was formed. At this time, it was judged that the wiring pattern width was ± 2 μm or less and S, ± 2 μm or more and 5 μm or less was A, and the other was B.

Example 6 (comparative)

A peeling layer and an ultra-thin copper foil layer were formed in this order on the side of the deposition of the carrier foil, and then rust-proofing treatment and silane coupling agent treatment were carried out to produce an ultra-thin copper foil with a carrier. The resulting ultra-thin copper foil with a carrier was evaluated variously. The concrete procedure is as follows.

(1) Preparation of carrier foil

The electrolytic copper foil having a thickness of 18 탆 was electrolyzed at a solution temperature of 50 캜 and a current density of 60 A / dm ² using a copper electrolytic solution having the composition shown below, a rotating cathode, and a DSA (dimensionally stable anode) . At this time, as the rotating cathode, an electrode whose surface was polished with a buff of # 1000 to adjust the surface roughness was used.

<Composition of copper electrolytic solution>

- Concentration: 80g / L

- sulfuric acid concentration: 280 g / L

- Diallyldimethylammonium chloride Polymer concentration: 30 mg / L

Bis (3-sulfopropyl) disulfide concentration: 5 mg / L

(2) Formation of release layer

The pickling treated carrier foil was immersed in a CBTA aqueous solution having a concentration of 1 g / L of CBTA (carboxybenzotriazole), a sulfuric acid concentration of 150 g / L and a copper concentration of 10 g / L for 30 seconds at a liquid temperature of 30 DEG C, Lt; / RTI &gt; Thus, a CBTA layer was formed as an organic release layer on the deposition surface of the carrier foil.

(3) Follow-up process and evaluation

The formation of the auxiliary metal layer, the formation of the ultra-thin copper foil, the roughening treatment, the anti-rust treatment, the anti-corrosion treatment, and the anti-corrosion treatment were carried out on the organic peel layer formed on the precipitation surface side of the carrier foil in the same procedure as described in (3-5) Silane coupling treatment, and various evaluations.

Example 7

The baking plating process in the roughening treatment was carried out by using an acidic copper sulfate solution containing copper concentration of 10 g / L, sulfuric acid concentration of 120 g / L and carboxybenzotriazole of 2 mg / L at a liquid temperature of 25 캜 and a current density of 15 A / dm ² , The preparation and evaluation of the ultra-thin copper foil with a carrier were carried out in the same manner as in Example 2. The distribution curve of the number of cross sections of the coarse particles on the cut surface along the height from the base was as shown in Fig.

result

The evaluation results obtained in Examples 1 to 7 were as shown in Table 1.

[Table 1]

Claims (11)

The ultra-thin copper foil with a carrier comprising a carrier foil, a release layer and an ultra-thin copper foil in this order,
The surface of the ultra-thin copper foil on the release layer side has an average distance (Peak spacing) between surface peaks of 20 占 퐉 or less and a maximum elevation difference (Wmax) of bending of 1.0 占 퐉 or less, , And the maximum elevation difference (Wmax) of bending is 1.0 占 퐉 or less. The method according to claim 1,
Wherein the surface of the ultra-thin copper foil on the release layer side has an average distance (Peak spacing) between the surface peaks of 1 to 15 占 퐉. The method according to claim 1,
Wherein the surface of the ultra-thin copper foil on the opposite side of the release layer is a maximum elevation difference (Wmax) of bending of 0.8 占 퐉 or less. The method according to claim 1,
Wherein the surface of the ultra-thin copper foil on the opposite side of the peeling layer is a roughened surface. 5. The method of claim 4,
Wherein the roughened surface has a plurality of roughed grains and the plurality of roughed grains have an average roughened particle height from a base surface (base surface) of 1.0 to 1.4 m, and the roughened surface of the roughened surface Which is parallel to the ultra-thin copper foil, wherein the one-tenth square width of the distribution curve of the number of cross-sections of the particles is 1.3 占 퐉 or less and the basal plane corresponds to the lowest position among the valleys between the plurality of coarse particles, Copper foil. The method according to claim 1,
Wherein the ultra-thin copper foil has a thickness of 0.1 to 5.0 mu m. 7. A method for producing an ultra-thin copper foil with a carrier according to any one of claims 1 to 6,
Preparing a carrier foil having a surface having a valley spacing of 15 mu m or less and a maximum height difference (Wmax) of bending of 0.8 mu m or less,
A step of forming a release layer on the surface of the carrier foil,
And forming an ultra-thin copper foil on the release layer. 8. The method of claim 7,
Wherein the surface of the carrier foil has a valley spacing between 1 and 10 mu m. 8. The method of claim 7,
Wherein the surface of the carrier foil has a maximum height difference (Wmax) of bending of 0.1 to 0.7 mu m. A copper clad laminate comprising the ultra-thin copper foil with a carrier according to any one of claims 1 to 6. A process for producing a printed wiring board characterized by producing a printed wiring board using the ultra-thin copper foil with a carrier according to any one of claims 1 to 6.

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