TW201940709A - Copper foil with carrier, copper-clad laminate and printed wiring board - Google Patents

Abstract

There is provided a copper foil with a carrier capable of significantly reducing the generation of blisters caused by hot pressing for stacking to a resin substrate. The copper foil with a carrier includes, in sequence, a carrier, a release layer and an extremely thin copper foil. The release layer comprises a carboxyl group-containing compound and a derivative thereof. The number of H2O molecules per unit area in the copper foil with a carrier is 3.44*1016/cm2 or less, and the number of CO2 molecules per unit area in the copper foil with a carrier is 1.39*1016/cm2 or less.

Description

Copper foil, copper laminated board and printed wiring board with carrier

The present invention relates to a copper foil with a carrier, a copper laminate, and a printed wiring board.

As a material for manufacturing a printed wiring board, a copper foil with a carrier has been widely used. The copper foil with a carrier is an insulating resin substrate such as a glass-epoxy substrate, a phenol substrate, or polyimide, which is bonded to a copper laminate by heat and pressure, and is used to produce a printed wiring board.

The copper foil with a carrier is proposed to have a structure which typically has a carrier, a release layer, and an ultra-thin copper foil in this order, and an organic release layer containing an organic compound is used as the release layer. For example, Patent Document 1 (Japanese Patent Application Laid-Open No. 2003-328178) discloses a method for manufacturing a copper foil with a carrier, which comprises using an acid pickling solution containing an organic agent at 50 ppm to 2000 ppm to pickle and dissolve the surface of the carrier, while borrowing The formation of an acid-washed and adsorbed organic film by adsorbing an organic agent as an organic release layer has also been disclosed using carboxybenzotriazole (CBTA) as the organic agent. Furthermore, Patent Document 2 (Japanese Patent No. 5842077) also discloses a copper foil with a carrier using carboxybenzotriazole (CBTA) as an organic release layer.

However, when a copper foil with a carrier is bonded to a resin substrate by heat and pressure, a blister (bubble) occurs between the ultra-thin copper foil and the carrier. Since the pits adversely affect the circuit formation, the yield of the product is reduced. In order to take countermeasures against this problem, a technique has been proposed to reduce the moisture content in the peeling layer. For example, Patent Document 3 (Japanese Laid-Open Patent Publication No. 2015-199355) discloses that a copper foil with a carrier having a moisture content of 160 ppm / g or less generated when heated to 500 ° C at 30 ° C / min is set as The occurrence of moisture can be suppressed and the copper foil with a carrier can suppress the occurrence of pits.
[Prior technical literature]
[Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. 2003-328178
[Patent Document 2] Japanese Patent No. 5842077
[Patent Document 3] Japanese Patent Laid-Open No. 2015-199355

However, as in the prior art disclosed in Patent Document 3, the problem of yield reduction due to the occurrence of pits has not been satisfactorily resolved, and further improvements are expected.

The present inventors have now found that, in a copper foil with a carrier having a release layer of a carboxyl-containing compound and a derivative thereof, the number density of H ₂ O molecules and CO ₂ molecules is reduced to a specific value In the following, the occurrence of pits caused by thermally pressing the resin substrate can be significantly suppressed.

Therefore, an object of the present invention is to provide a copper foil with a carrier that significantly suppresses the occurrence of pits caused by thermally pressing the resin substrate.

According to one aspect of the present invention, there is provided a copper foil with a carrier, which is a copper foil with a carrier having a carrier, a release layer, and an ultra-thin copper foil in order,
The release layer includes a carboxyl-containing compound and a derivative thereof,
The number of H ₂ O molecules per unit area of the aforementioned copper foil with a carrier is 3.44 × 10 ¹⁶ pieces / cm ² or less, and the number of CO ₂ molecules per unit area of the aforementioned copper foil with a carrier is 1.39 × 10 ¹⁶ pieces / cm ² or less.

According to another aspect of the present invention, a copper laminate provided with the aforementioned copper foil with a carrier is provided.

According to another aspect of the present invention, there is provided a printed wiring board including the aforementioned copper foil with a carrier.

According to another aspect of the present invention, a method for manufacturing a printed wiring board is provided, which is characterized by using the above-mentioned copper foil with a carrier to manufacture a printed wiring board.

Copper foil with carrier The copper foil with carrier of the present invention has a carrier, a release layer, and an ultra-thin copper foil in this order. The release layer contains a carboxyl group-containing compound (typically an organic compound having a carboxyl group) and a derivative thereof. The number of H ₂ O molecules per unit area of the copper foil with a carrier is 3.44 × 10 ¹⁶ pieces / cm ² or less. In addition, the number of CO ₂ molecules per unit area of the copper foil with a carrier is 1.39 × 10 ¹⁶ pieces / cm ² or less. As described above, in a copper foil with a carrier having a release layer containing a carboxyl group-containing compound and a derivative thereof, by reducing the number density of H ₂ O molecules and CO ₂ molecules to a specific value or less, the accompanying A pit generated by heat-pressing a resin substrate. Since the pits adversely affect the circuit formation, the yield of the product can be improved by reducing the pits.

Although the mechanism of the occurrence of pits is not clear, it can be considered as follows. Figure 2 shows a graph of escaping temperature rise profile of linoleic acid, a carboxyl-containing compound. The temperature rise and drop profile shown in FIG. 2 shows the number of H ₂ O molecules and CO ₂ molecules that are detached from the sample surface at each temperature when the sample (linoleic acid) is heated at a specific rate. As shown in Figure 2, there are three main peaks related to the detachment of water. These are, in order from low temperature, i) the peaks caused by the detachment of water adsorbed on the sample surface (the detachment of adsorbed water), and ii) the cause. The peaks due to the detachment of water that resonates with the carboxyl group (the detachment of the resonant water), and iii) the peaks due to the detachment of water accompanying the dehydration condensation reaction (esterification reaction) of adjacent linoleic acid with each other. On the other hand, the main peak related to the release of carbon dioxide exists at around 180 ° C, which is a peak resulting from the decarbonation reaction of carbon dioxide from the carboxyl group of linoleic acid. Although the temperature at which the decarbonation reaction is caused varies depending on the type of the organic compound, it is generally 150 ° C or higher. In this way, even at a temperature (for example, 110 to 200 ° C) higher than the temperature (for example, about 90 ° C) at which adsorption water is detached from the carboxyl-containing organic compound, a large amount of water and carbon dioxide occur. Therefore, when a copper foil with a carrier including a release layer containing a carboxyl compound is bonded to a resin substrate by heat and pressure, the above-mentioned reaction occurs in the heated release layer, and a large amount of water and carbon dioxide occur. As a result, it is thought that pits caused by water and carbon dioxide gas occurred between the ultra-thin copper foil and the carrier. At this point, according to the present invention, by reducing the number density of H ₂ O molecules and CO ₂ molecules in the copper foil with a carrier to a specific value or less in advance, it is considered that the thermal pressure lamination of the resin substrate can be effectively prevented When the self-stripping layer generates a large amount of water and carbon dioxide, the occurrence of pits can be significantly suppressed.

Therefore, the number of H ₂ O molecules per unit area in the copper foil with a carrier is preferably 3.44 × 10 ¹⁶ pieces / cm ² or less, more preferably 3.38 × 10 ¹⁶ pieces / cm ² or less, and more preferably 3.30 × 10 ¹⁶ pieces / cm ² or less. The lower limit of the number of H ₂ O molecules per unit area is not particularly limited, but is typically 1.00 × 10 ¹⁵ / cm ² or more, more typically 1.50 × 10 ¹⁵ / cm ² or more, and more typically It is 1.04 × 10 ¹⁶ pieces / cm ² or more. The number of CO ₂ molecules per unit area in the copper foil with a carrier is 1.39 × 10 ¹⁶ pieces / cm ² or less, preferably 1.34 × 10 ¹⁶ pieces / cm ² or less, and more preferably 1.32 × 10 ¹⁶ pieces / cm ² or less. The lower limit of the number of CO ₂ molecules per unit area is not particularly limited, but it is typically 1.00 × 10 ¹⁵ / cm ² or more, more typically 1.50 × 10 ¹⁵ / cm ² or more, and even more typically 9.17 × 10 ¹⁵ pieces / cm ² or more. The number of H ₂ O molecules and CO ₂ molecules in the copper foil with a carrier can be better measured by a thermal desorption spectroscopy (TDS: Thermal Desorption Spectrometry) as described in the examples described later.

The peeling layer has a function of making the peeling strength between the carrier and the ultra-thin copper foil weak, ensuring the stability of the strength, and further suppressing the interdiffusion caused between the carrier and the copper foil during hot press molding. The release layer is generally formed on one side of the carrier, but may be formed on both sides. The release layer contains a carboxyl-containing compound and a derivative thereof. Therefore, the release layer is typically an organic release layer, but may be a composite release layer of an organic release layer and an inorganic release layer, or a mixed release layer containing an organic release agent and an inorganic release agent. Here, the so-called carboxyl-containing compound derivative includes a compound in which a part of the molecule of the carboxyl compound is changed by a dissociation reaction or a substitution reaction, or is added to a part of the molecule of the carboxyl compound by an addition reaction or the like. Atom-forming compounds, etc. As examples of these derivatives, compounds containing a carboxyl group to form an acid anhydride (typically a dimer) by dehydration condensation reaction, compounds that desorb CO ₂ molecules from a carboxyl group by decarbonation reaction, and Compounds in which a substituent such as a methyl group is added. Therefore, the release layer may include a carboxyl group-containing compound and a derivative thereof at the beginning of formation of the layer, but it is preferable that a part of the carboxyl group-containing compound is inevitably changed to a derivative after the heat treatment described later. That is, the peeling layer may include a carboxyl group-containing compound initially without accompanying a derivative thereof, and thereafter, a part of the carboxyl group-containing compound may be reacted (for example, a dehydration condensation reaction or a decarbonation reaction) by applying a heat treatment to be described later, and then include Release layer of carboxyl-containing compound and its derivative.

The carboxyl-containing compound is preferably a carboxybenzotriazole (CBTA). Alternatively, the carboxyl-containing compound may be a monocarboxylic acid and / or a dicarboxylic acid. Preferred examples of the monocarboxylic acid include linoleic acid, oleic acid, linolenic acid, thioglycolic acid, 3-mercapto-2-pyridinecarboxylic acid, and the like. Preferred examples of the dicarboxylic acid include thiomalic acid, isopropyl azodicarboxylate, and diethyl azodicarboxylate. By including the carboxyl-containing compound in the release layer, it is possible to further maintain the easy-to-use condition even when hot press molding (for example, 250 ° C or higher) or long-term baking treatment (for example, 200 hours for 8 hours) is applied. The carrier is peeled and removed.

The carrier is a support for supporting ultra-thin copper foil to improve its handleability. A typical carrier includes a metal layer. Examples of such carriers include aluminum foil, copper foil, stainless steel (SUS) foil, resin film or glass coated with a metal such as copper on the surface, and copper foil is preferred. The copper foil may be either a rolled copper foil or an electrolytic copper foil. The thickness of the carrier is typically 250 μm or less, preferably 9 to 200 μm.

The ultra-thin copper foil may have a conventional structure used in an ultra-thin copper foil with a carrier, and is not particularly limited. For example, the ultra-thin copper foil may be formed by a wet film formation method such as electroless copper plating method and electrolytic copper plating method, a dry film formation method such as sputtering and chemical vapor deposition, or a combination thereof. The preferred thickness of the ultra-thin copper foil is 0.1 to 7.0 μm, more preferably 0.5 to 5.0 μm, and still more preferably 1.0 to 3.0 μm.

The outermost surface of the ultra-thin copper foil (that is, the surface away from the release layer side) is preferably a roughened surface. That is, it is preferable to perform roughening treatment on one side of the ultra-thin copper foil. In this way, the adhesiveness with the resin layer at the time of manufacture of a copper laminated board or a printed wiring board can be improved. The roughening treatment is preferably performed according to a conventional plating method including at least two steps including the steps of depositing fine copper particles on an ultra-thin copper foil and sintering the plating, and preventing the fine copper particles. Outside the plating step.

Other functional layers may be provided between the release layer and the carrier and / or the ultra-thin copper foil. An example of such other functional layers is an auxiliary metal layer. The auxiliary metal layer is preferably made of nickel and / or cobalt. By forming the auxiliary metal layer on the surface side of the carrier and / or the surface side of the ultra-thin copper foil, the mutual diffusion caused between the carrier and the ultra-thin copper foil during high-temperature or long-time heat-press forming can be further suppressed, and the carrier can be guaranteed. Stability of peel strength. The thickness of the auxiliary metal layer is preferably 0.001 to 3 μm.

Depending on expectations, anti-rust treatment can also be applied to very thin copper foil. The antirust treatment preferably includes a plating treatment using zinc. The plating treatment using zinc may be any one of a zinc plating treatment and 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 including Ni and Zn, and may further include other elements such as Sn, Cr, and Co. The Ni / Zn adhesion ratio in zinc-nickel alloy plating is preferably 1.2 to 10, more preferably 2 to 7, and even more preferably 2.7 to 4 in terms of mass ratio. The rust prevention treatment preferably further includes a chromate treatment. This chromate treatment is more preferably performed on a plating surface containing zinc after a plating treatment using zinc. If so, the rust prevention property can be further improved. A particularly good antirust treatment is a combination of zinc-nickel alloy plating treatment and subsequent chromate treatment.

According to expectations, the surface of the ultra-thin copper foil may also be treated with a silane coupling agent to form a silane coupling agent layer. This can improve moisture resistance, chemical resistance, adhesion to adhesives, and the like. The silane coupling agent layer can be formed by appropriately diluting the silane coupling agent, coating, and drying. Examples of the silane coupling agent include epoxy-functional silane coupling agents such as 4-glycidylbutyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, and 3-aminopropyltrimethyl Oxysilane, N-2 (aminoethyl) 3-aminopropyltrimethoxysilane, N-3- (4- (3-aminopropyloxy) butoxy) propyl-3-amine Amine-functional silane coupling agents such as propyltrimethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, and thiol-functional silane coupling agents such as 3-mercaptopropyltrimethoxysilane Mixture, or olefin-functional silane coupling agents such as vinyltrimethoxysilane, vinylphenyltrimethoxysilane, etc., or acrylic functional silane coupling agents such as 3-methacryloxypropyltrimethoxysilane Or an imidazole-functional silane coupling agent such as imidazolyl silane or a triazine-functional silane coupling agent such as triazine silane.

Manufacturing method of copper foil with a carrier The copper foil with a carrier of the present invention can be implemented by forming a copper foil with a carrier by sequentially forming layers such as a peeling layer and an ultra-thin copper foil on the carrier according to a conventional method. The two-stage heat treatment step described below promotes the production and discharge of water and carbon dioxide from the peeling layer, and enables better production.

The heat treatment step in the first stage is a step carried out by high-temperature treatment of the above-mentioned reaction of water and carbon dioxide. Preferred heat treatment conditions vary depending on the size or shape of the copper foil with a carrier, the type of baking furnace used, and the like. Therefore, it is sufficient to appropriately set the heat treatment conditions that sufficiently generate water and carbon dioxide in accordance with these changing factors, that is, to appropriately set not only the adsorption water but also the resonance water from the carboxyl-containing compound contained in the release layer and the accompanying The heat treatment conditions for the dehydration condensation reaction and decarbonation reaction to generate water and carbon dioxide detachment may be sufficient. Typically, the heat treatment temperature in the first stage is a temperature exceeding 180 ° C, preferably 200 to 280 ° C, and more preferably 220 to 250 ° C. The heat treatment time in the first stage is typically 0.5 to 40 hours, preferably 1 to 30 hours, and more preferably 2 to 24 hours. In this case, water and carbon dioxide can be generated from the copper foil (typically a peeling layer) with a carrier, while effectively preventing deterioration of the copper foil or peeling of the silane coupling agent layer that is set as desired. In particular, performing the heat treatment in the first stage at a temperature close to the heat pressure applied to the resin substrate can effectively suppress the occurrence of pits accompanying the heat pressure build-up. In addition, typically, a part of the carboxyl-containing compound contained in the peeling layer can be changed to a derivative thereof (for example, a dimer or a compound in which CO ₂ molecules are detached) by a high-temperature heat treatment in the first stage.

The heat treatment step in the second stage is a step of discharging water and carbon dioxide generated by the heat treatment step in the first stage from a copper foil with a carrier by a relatively low temperature and long time heat treatment. That is, since water and carbon dioxide generated from the copper foil with a carrier by the heat treatment in the first stage are typically derived from a peeling layer containing a carboxyl-containing compound, the water and carbon dioxide reside in the carrier with the carrier. The copper foil (for example, between the carrier and the ultra-thin copper foil) becomes the cause of the pits. Therefore, it is expected that the water and carbon dioxide residing in the copper foil with a carrier are forced out of the system by the heat treatment in the second stage. As a result, the copper foil with a carrier (especially the release layer) can be modified to a number of H ₂ O molecules per unit area of 3.44 × 10 ¹⁶ units / cm ² or less, and CO ₂ molecules per unit area. The number is 1.39 × 10 ¹⁶ pieces / cm ² or less. At this time, from the viewpoint of further preventing the occurrence of water and carbon dioxide from the peeling layer, the heat treatment temperature in the second stage is preferably lower than the heat treatment temperature in the first stage. Typically, the heat treatment temperature in the second stage is 180 ° C or lower, preferably 90 to 180 ° C, and more preferably 100 to 180 ° C. The heat treatment time in the second stage is typically 3 to 40 hours, preferably 5 to 35 hours, and more preferably 5 to 30 hours. If so, the water and carbon dioxide generated in the first-stage heat treatment can be effectively discharged from the copper foil with a carrier. Also, similar to the heat treatment conditions in the first stage, the preferred heat treatment conditions in the second stage vary depending on the size or shape of the copper foil with a carrier, the type of baking furnace used, and the like.

Copper laminated board The copper foil with a carrier of the present invention is preferably used for a copper laminated board for producing a printed wiring board. That is, according to a preferred aspect of the present invention, a copper laminated board provided with the above-mentioned copper foil with a carrier is provided. The copper laminated board includes the copper foil with a carrier of the present invention and a resin layer provided in close contact with the copper foil with a carrier. The copper foil with a carrier can be provided on one side of the resin layer or on both sides. The resin layer containing resin preferably contains an insulating resin. The resin layer is preferably a prepreg and / or a resin sheet. The so-called prepreg is a general term for a composite material impregnated with a synthetic resin in a substrate such as a synthetic resin plate, a glass plate, a glass woven fabric, a glass nonwoven fabric, or paper. Preferred examples of the insulating resin include epoxy resin, cyanate resin, bismaleimide triazine resin (BT resin), polyphenylene ether resin, and phenol resin. Examples of the insulating resin constituting the resin sheet include insulating resins such as epoxy resin, polyimide resin, and polyester resin. In addition, from the viewpoint of improving the insulation properties of the resin layer, filler particles and the like made of various inorganic particles such as silicon oxide and aluminum oxide may be contained. The thickness of the resin layer is not particularly limited, but is preferably 1 to 1000 μm, more preferably 2 to 400 μm, and even more preferably 3 to 200 μm. The resin layer may be composed of a plurality of layers. The resin layer such as a prepreg sheet and / or a resin sheet may be provided on a copper foil with a carrier through a primer resin layer previously applied on the surface of an ultra-thin copper foil.

Printed wiring board The copper foil with a carrier of the present invention is preferably used for manufacturing a printed wiring board. That is, according to a preferred aspect of the present invention, a printed wiring board provided with the above-mentioned copper foil with a carrier or a manufacturing method thereof is provided. The printed wiring board of this aspect includes a layer formed by laminating a resin layer and a copper layer in this order. The resin layer is as described above for the copper laminate. In short, the printed wiring board can be constructed using a conventional layer. Specific examples of the printed wiring board include, for example, one side or both sides of the prepreg, followed by the ultra-thin copper foil of the present invention and hardened to form a laminated body, and then a single-sided or double-sided printed wiring board of a circuit is formed or the like. Multi-layered multilayer printed wiring boards, etc. In addition, as other specific examples, a flexible printed wiring board, a COF, a TAB tape, etc., in which the ultra-thin copper foil of the present invention is formed on a resin film to form a circuit are also exemplified. As another specific example, the resin-coated copper foil (RCC) formed by coating the resin layer on the ultra-thin copper foil of the present invention is used as an example, and the resin layer is laminated on the printed wiring board as an insulating adhesive, and then The ultra-thin copper foil is used as the whole or a part of the wiring layer to form a circuit-added wiring board by a method such as the improved and semi-additive (MSAP) method or the subtractive method, or the ultra-thin copper foil is removed and the semi-additive method is used ( (SAP) forming a circuit build-up wiring board, repeating direct buildup on wafers formed by laminating resin copper foil and circuits formed on a semiconductor integrated circuit. The copper foil with a carrier of the present invention can also be suitably used for a manufacturing method of a coreless build-up method in which an insulating resin layer and a conductor layer are alternately laminated without using a so-called core substrate.

[Example]

The present invention is further specifically described by the following examples.

Examples 1, 2 and 4 to 8
Production and evaluation of the copper foil with a carrier were performed as follows.

(1) Preparation of the carrier An electrolytic copper foil having a thickness of 18 μm, which is classified by the IPC standard as Class 3, is prepared as a carrier. The electrolytic copper foil used as the carrier is a copper foil (so-called green foil) in a state of being electrolytically produced, and has not been subjected to a surface treatment such as rust prevention treatment or roughening treatment. A pickling process is performed to remove the grease components or the surface oxide film attached to the surface of the carrier.

(2) Formation of the peeling layer The electrode surface of the pickled carrier is placed in a CBTA (carboxybenzobenzotriazole) concentration of 1 g / L, a sulfuric acid concentration of 150 g / L, and a copper concentration of 10 g / L in an aqueous solution of CBTA at a liquid temperature of 30 Immerse at 30 ° C for 30 seconds to adsorb the CBTA component to the electrode surface of the carrier. In this way, a CBTA layer is formed on the surface of the electrode surface of the carrier as a release layer.

(3) Auxiliary metal layer formation The carrier with the release layer is immersed in a solution of nickel concentration of 20 g / L made of nickel sulfate, and the release layer is formed at a temperature of 45 ° C, a pH of 3, and a current density of 5 A / dm ² . Nickel was deposited on the substrate in an amount corresponding to a thickness of 0.001 μm. In this way, a nickel layer is formed on the release layer as an auxiliary metal layer.

(4) Formation of ultra-thin copper foil The carrier forming the auxiliary metal layer is immersed in a copper sulfate solution having a copper concentration of 60 g / L and a sulfuric acid concentration of 200 g / L, and is electrolyzed at a liquid temperature of 50 ° C and a current density of 5 to 30 A / dm ² An extremely thin copper foil having a thickness of 1.5 μm is formed on the auxiliary metal layer.

(5) Roughening treatment Roughening the surface of the ultra-thin copper foil. This roughening process is performed by the following two-stage plating. The first-stage plating step is electroplating using an acidic copper sulfate solution containing copper 10 g / L and sulfuric acid 120 g / L under plating conditions at a liquid temperature of 40 ° C and a current density of 30 A / dm ² . The second-stage plating step was performed by using an acidic copper sulfate solution containing copper 70 g / L and sulfuric acid 120 g / L under plating conditions of a liquid temperature of 40 ° C. and a current density of 30 A / dm ² .

(6) Anti-rust treatment Both sides of the copper foil with a carrier after roughening treatment are subjected to anti-rust treatment by inorganic anti-rust treatment and chromate treatment. As an inorganic antirust treatment, zinc-nickel was performed using a pyrophosphate bath at a potassium pyrophosphate concentration of 80 g / L, a zinc concentration of 0.2 g / L, a nickel concentration of 2 g / L, a liquid temperature of 40 ° C, and a current density of 0.5 A / dm ² . Alloy antirust treatment. Next, as a chromate treatment, a chromate layer was formed after the zinc-nickel alloy antirust treatment. This chromate treatment was performed at a chromic acid concentration of 1 g / L, a pH of 11, a liquid temperature of 25 ° C, and a current density of 1 A / dm ² .

(7) Silane coupling agent treatment The copper foil to which the rust prevention treatment has been applied is washed with water, and then the silane coupling agent treatment is immediately performed to adsorb the silane coupling agent on the rust prevention treatment layer of the roughened surface. This silane coupling agent treatment is performed by using pure water as a solvent and a solution of 3-aminopropyltrimethoxysilane with a concentration of 3 g / L, and blowing the solution onto the roughened surface using an eluent ring for adsorption treatment. And proceed. After the silane coupling agent was adsorbed, water was finally evaporated by an electric heater to obtain a copper foil with a carrier having a roughened copper foil having a thickness of 1.5 μm and a carrier.

(8) Heat treatment The copper foil with a carrier thus obtained was subjected to a one-stage or two-stage heat treatment in an atmosphere in an oven under the conditions shown in Table 1. At this time, the heating conditions in each of Examples 1, 2, and 4 to 8 were appropriately changed as shown in Table 1, and various samples having different moisture content and carbon dioxide content in the peeling layer were prepared. In addition, the heat treatment conditions vary depending on the size of the sample, the type of the baking oven, and the like, of course, the present invention is not limited by these conditions.

(9) Evaluation of copper foil with carrier The following evaluations were performed on the obtained copper foil with carrier.

<Evaluation 1: Measurement of moisture and carbon dioxide>
Thermal Desorption (TDS: Thermal Desorption
Spectrometry) The moisture and carbon dioxide contained in the obtained copper foil with a carrier (particularly a release layer) were measured as follows. First, in order to remove the moisture adsorbed on the surface of the copper foil with a carrier subjected to heat treatment in the above (8), a vacuum constant temperature dryer was used to perform vacuum drying at 50 ° C for 7 days under atmospheric pressure of -0.1 MPa. . Next, the copper foil with a carrier that has been vacuum-dried was punched into a size of 1 cm in diameter by a punch to make a test piece, and the weight of the test piece was quickly measured. The test piece was set in a state where the carrier was separated from the ultra-thin copper foil (that is, the state where the peeling layer was exposed) in a chamber of a temperature rising separation analysis device (manufactured by Electronic Science Co., Ltd., TDS1200II). Evacuate for 5 minutes. Subsequently, the test piece was irradiated with light, and the test piece was heated to 400 ° C at a temperature increase rate of 30 ° C / min by light absorption, and the gas generated from the test piece was qualitatively and quantitatively analyzed by a mass spectrometer. At this time, m / z = 18 was used as the H ₂ O gas, and m / z = 44 was used as the CO ₂ gas. The H ₂ O molecules and the 1 cm diameter circle in the copper foil with the carrier were obtained. Each number of CO ₂ molecules. By dividing the value thus obtained by a circle area (0.785 cm ² ) with a diameter of 1 cm, the respective numbers of H ₂ O molecules and CO ₂ molecules per unit area were calculated. The results are summarized in Table 1 and FIG. 1. In Table 1, for reference, the H of the copper foil with a carrier calculated by dividing each weight of H ₂ O and CO ₂ (converted from the number of molecules) by the weight of the test piece is also shown. The respective weight ratios (ppm) of ₂ O and CO ₂ .

<Evaluation 2: Measurement of pits>
A 100 μm-thick prepreg (GHPL-830NSF, manufactured by Mitsubishi Gas Chemical Co., Ltd.) was prepared as a resin substrate. The copper foil with a carrier subjected to the heat treatment in the above (8) was laminated on the resin substrate so that the ultra-thin copper foil side was in contact with the resin substrate, and the temperature was 90 at a pressure of 2.4 MPa and a temperature of 250 ° C. After the one-minute hot press molding, a baking furnace was further subjected to a baking treatment at a temperature of 200 ° C. for 8 hours to obtain a copper laminate sample. After removing the carrier from the copper laminate sample, the depression formed on the surface of the ultra-thin copper foil was calculated using an optical microscope (VHX-5000, manufactured by KYENCE Co., Ltd.) at a magnification of 20 times and a measuring field of view of 18 mm × 13.5 mm. The number of pits is the average value of the three fields of view. That is to say, since the depression formed on the surface of the copper laminate sample (that is, the surface of the ultra-thin copper foil) after the carrier is peeled off is a trace caused by the pits occurring between the carrier and the ultra-thin copper foil, the number of depressions is considered The number of pits that occurred. The results are summarized in Table 1.

Example 3 (comparative)
A copper foil with a carrier was produced and evaluated in the same manner as in Example 1 except that the copper foil with a carrier was not subjected to heat-treated water. The results are summarized in Table 1 and FIG. 1.

Example 9 (comparative)
Except that in the step of forming the release layer, instead of the CBTA aqueous solution, a linoleic acid aqueous solution having a linoleic acid concentration of 1,000 ppm by weight was used, and a carrier-made copper foil was produced and evaluated in the same manner as in Example 2. The results are summarized in Table 1 and FIG. 1.

FIG. 1 is a graph plotting the respective numbers of H ₂ O molecules and CO ₂ molecules per unit area of the copper foil with a carrier of Examples 1 to 9. FIG.

Fig. 2 is a graph showing the temperature rise off profile of linoleic acid.

Claims (8)

A copper foil with a carrier is a copper foil with a carrier having a carrier, a release layer, and an ultra-thin copper foil in this order. The peeling layer includes a compound containing a carboxyl group and a derivative thereof, and the aforementioned copper foil with a carrier. The number of H ₂ O molecules per unit area is 3.44 × 10 ¹⁶ units / cm ² or less, and the number of CO ₂ molecules per unit area of the aforementioned copper foil with a carrier is 1.39 × 10 ¹⁶ units / cm 2 ² or less. For example, the copper foil with a carrier according to claim 1, wherein the aforementioned carboxyl-containing compound is carboxybenzotriazole (CBTA). The copper foil with a carrier according to claim 1, wherein the aforementioned carboxyl-containing compound is a monocarboxylic acid and / or a dicarboxylic acid. The copper foil with a carrier according to any one of claims 1 to 3, wherein the aforementioned carrier comprises a metal layer. The copper foil with a carrier according to any one of claims 1 to 4, further comprising an auxiliary metal layer between the peeling layer and the carrier and / or the ultra-thin copper foil. A copper laminated board comprising the copper foil with a carrier according to any one of claims 1 to 5. A printed wiring board provided with the copper foil with a carrier as described in any one of Claims 1 to 5. A method for manufacturing a printed wiring board, which is characterized in that the printed wiring board is manufactured using a copper foil with a carrier as in any one of claims 1 to 5.