Copper foil attached to carrier foil and copper clad laminate using the same

Abstract

The present invention relates to a copper foil attached to a carrier foil having good peel strength under high-temperature press conditions. The present invention provides a copper foil attached to a carrier foil comprising a carrier foil, a peeling layer on the carrier foil, a heat-resistant layer on the peeling layer, and an ultra-thin copper foil on the heat-resistant layer, wherein a buffer layer made of a Ni alloy is interposed between the peeling layer and the heat-resistant layer.

Description

Technology Field

[0001] The present invention relates to a copper foil attached to a carrier foil and a copper foil laminate manufactured using the same, and in particular to a copper foil attached to a carrier foil having good peel strength under high-temperature press conditions and a copper foil laminate using the same. Background Technology

[0002] Conventional copper foil attached to a carrier foil for semiconductor substrates typically consists of a laminated structure having a release layer, a diffusion barrier layer, and an ultra-thin copper foil formed on the carrier foil.

[0003] Conventionally, a press process was performed at 220 to 240°C to bond the copper foil attached to the carrier foil to the resin substrate. However, recently, as high-heat-resistant resin substrates are used, the copper foil attached to the carrier foil is press-formed at a high temperature of 350°C or higher. In such cases, a crater-shaped copper foil blistering phenomenon may occur between the carrier foil and the ultra-thin copper foil, or the diffusion barrier layer may not be able to withstand it, leading to problems such as increased peel strength between the carrier foil and the ultra-thin copper foil. Prior art literature

[0004] (1) KR 10-2316978 B The problem to be solved

[0005] The inventors of the present invention discovered that when press forming at a high temperature of 350°C or higher, if the nickel content of the diffusion barrier layer is insufficient or excessive, the stability of the peel strength between the carrier foil and the thin foil decreases, or a crater-shaped copper foil swelling phenomenon occurs. Accordingly, the present invention aims to provide a copper foil attached to a carrier foil having a laminated structure that suppresses the copper foil swelling phenomenon during high-temperature press forming.

[0006] Meanwhile, the inventors of the present invention discovered that when using a copper foil with a carrier foil attached to the aforementioned laminated structure to suppress copper foil swelling, if the peel strength is 10 gf / cm or less, the carrier foil and the copper foil may separate too easily during the production of the copper foil laminate, causing defects, and if the peel strength is 30 gf / cm or more, it may be difficult to separate the carrier foil during the production of the copper foil laminate, causing defects such as the substrate bending.

[0007] Accordingly, the present invention aims to propose a copper foil lamination structure for maintaining the peel strength between the carrier foil and the thin foil of a copper foil attached to a carrier foil at 10 to 30 gf / cm.

[0008] In addition, the present invention aims to provide a copper foil laminate manufactured using the aforementioned copper foil with attached carrier foil. means of solving the problem

[0009] To achieve the above technical objective, the present invention provides a copper foil attached to a carrier foil comprising a carrier foil, a release layer on the carrier foil, a heat-resistant layer on the release layer, and an ultra-thin copper foil on the heat-resistant layer, wherein a buffer layer made of a Ni alloy is interposed between the release layer and the heat-resistant layer.

[0010] In the present invention, the buffer layer may include a Cu-Ni alloy. At this time, the buffer layer may be plated with a plating solution in which the Cu concentration and Ni concentration are 1:5 to 1:20.

[0011] In addition, in the present invention, the thickness of the buffer layer is preferably 20 to 50 nm.

[0012] In addition, in the present invention, the thickness of the heat-resistant layer is preferably 5 to 50 nm.

[0013] In the present invention, the peeling layer may be an organic peeling layer or an inorganic peeling layer.

[0014] In the present invention, the heat-resistant layer may be a Ni plating layer, and the heat-resistant layer may be plated with a plating solution containing Ni and P.

[0015] It is preferable that the copper foil attached to the carrier foil of the present invention has a 90-degree peel strength of 10 to 30 gf / cm after press processing at 400°C for 60 minutes.

[0016] In addition, to achieve the above other technical objectives, the present invention provides a copper foil laminate comprising a copper foil laminated on a resin substrate, wherein the copper foil is manufactured by bonding a copper foil with a carrier foil attached according to claim 1 to the resin substrate.

[0017] In the present invention, the resin substrate may be one selected from the group consisting of polyimide, fluoropolymer, and LCP. Effects of the invention

[0018] According to the present invention, it is possible to provide a copper foil with a carrier foil attached having a laminated structure that suppresses the copper foil swelling phenomenon during high-temperature press molding at 350°C or higher.

[0019] In addition, according to the present invention, even when using a copper foil with a carrier foil attached to a laminated structure for suppressing copper foil swelling, the peel strength between the carrier foil and the thin foil can be maintained at 10 to 30 gf / cm. Brief explanation of the drawing

[0020] The accompanying drawings, included as part of the detailed description to aid in understanding the present invention, provide embodiments of the present invention and explain the technical concept of the present invention together with the detailed description. FIG. 1 is a drawing for explaining a copper foil (100) attached to a carrier foil according to one embodiment of the present invention. Figures 2a and 2b are optical microscope images of the peeled surfaces of the samples of the example and comparative example, respectively, after press processing at 350°C and peeling off the carrier foil. Figures 3a and 3b are AES analysis graphs for carrier foil-attached copper foil samples prepared in the examples and comparative examples, respectively. Figure 4 is a graph showing the results of measuring peel strength after pressing at 400°C for samples of the embodiments and comparative examples of the present invention. Figure 5 is a drawing showing the press condition profile when measuring peel strength. Specific details for implementing the invention

[0021] Identical components in each drawing are denoted by the same reference numeral whenever possible. Additionally, detailed descriptions of already known functions and / or configurations are omitted. The following disclosure focuses on the parts necessary for understanding the operation according to various embodiments, and omits descriptions of elements that could obscure the gist of the explanation. Furthermore, some components in the drawings may be exaggerated, omitted, or schematically depicted. The size of each component does not entirely reflect its actual size, and therefore the contents described herein are not limited by the relative sizes or spacing of the components depicted in each drawing.

[0022] In describing the embodiments of the present invention, if it is determined that a detailed description of known technology related to the present invention may unnecessarily obscure the essence of the present invention, such detailed description will be omitted. The terms used in the detailed description of the present invention are intended merely to describe the embodiments of the present invention and should not be limited in any way. Unless explicitly stated otherwise, expressions in the singular form may include the meaning of the plural form. In this description, expressions such as "include" or "comprise" are intended to refer to certain characteristics, numbers, steps, actions, elements, parts or combinations thereof, and should not be interpreted to exclude the existence or possibility of one or more other characteristics, numbers, steps, actions, elements, parts or combinations thereof other than those described.

[0023] Additionally, terms such as first, second, etc., may be used to describe various components, but said components are not limited by said terms, and said terms are used only for the purpose of distinguishing one component from another.

[0024] In the specification of the present invention, lamination means joining at least two layers together. For example, the lamination of a first layer and a second layer includes not only the first layer and the second layer in direct contact but also joining with an additional third layer interposed between the first layer and the second layer.

[0025] FIG. 1 is a drawing for explaining a copper foil (100) attached to a carrier foil according to one embodiment of the present invention.

[0026] Referring to FIG. 1, a copper foil attached to a carrier foil according to one embodiment of the present invention may have a structure in which a carrier foil (110), a release layer (120), a buffer layer (130), a heat-resistant layer (140), and an ultra-thin copper foil (150) are laminated.

[0027] In the present invention, the carrier foil (110) serves as a support (carrier) until the thin copper foil is bonded to an insulating substrate. The carrier foil may be made of aluminum foil, stainless steel foil, titanium foil, copper foil, or copper alloy foil. For example, electrolytic copper foil, electrolytic copper alloy foil, rolled copper foil, or rolled copper alloy foil may be used. Preferably, the carrier foil may be electrolytic copper foil, and the upper surface (100B) of the carrier foil may be either a glossy surface or a matte surface. Additionally, in the present invention, a glazing treatment layer may be formed on the lower surface (100A) of the carrier foil.

[0028] The carrier foil may have a thickness of 1 mm or less. For example, the thickness of the carrier foil may be 10 to 100 μm. As an example, the thickness of the carrier foil may be 12 to 18 μm. If the thickness of the carrier foil is less than 10 μm, it may be difficult to perform the role of a carrier, and if the thickness of the carrier foil is greater than 1 mm, there is no problem in performing the role of a carrier, but when plating continuously to form a release layer and ultra-thin copper foil, it is necessary to increase the tension of the foil within the continuous plating line, and large-scale equipment may be required.

[0029] In the present invention, the roughness (R) of the carrier foil z ) may be 1.7 μm or less, 1.5 μm or less, or 1.3 μm or less. In addition, the roughness (R) of the carrier foil z ) may be 0.7 μm or more, 0.9 μm or more, or 1.1 μm or more.

[0030] The peeling layer (120) in the copper foil attached to the carrier foil is a layer to improve peelability when peeling the ultra-thin copper foil and the carrier foil, and is introduced to peel the carrier foil cleanly and easily. The peeling layer is removed integrally with the carrier foil.

[0031] In the present invention, the peeling layer (120) may include a metal or metal alloy having peelability. The peelable metal may include molybdenum or tungsten. Additionally, the peeling layer (130) may include a plating catalyst. For example, the peeling layer (130) may include at least one metal selected from the group consisting of Fe, Co, and Ni.

[0032] In addition, the above-mentioned peeling layer may be an organic peeling layer having peelability. For example, the above-mentioned peeling layer may include at least one organic material selected from the group consisting of benzotriazole (BTA) series.

[0033] In the present invention, the heat-resistant layer (140) may include one or more elements selected from the group consisting of Ni, Co, Fe, Cr, Mo, W, Al, and P. For example, the heat-resistant layer may be a single metal layer, an alloy layer of two or more metals, or a layer of one or more metal oxides.

[0034] For example, nickel plating, cobalt plating, iron plating, aluminum plating, etc. can be used as platings to form a single metal layer. Nickel-cobalt plating, nickel-iron plating, nickel-chromium plating, nickel-molybdenum plating, nickel-tungsten plating, nickel-copper plating, nickel-phosphorus plating, cobalt-iron plating, cobalt-chromium plating, cobalt-molybdenum plating, cobalt-tungsten plating, cobalt-copper plating, cobalt-phosphorus plating, etc. can be used as platings to form a binary alloy layer. As platings forming a ternary alloy layer, nickel-cobalt-iron plating, nickel-cobalt-chromium plating, nickel-cobalt-molybdenum plating, nickel-cobalt-tungsten plating, nickel-cobalt-copper plating, nickel-cobalt-phosphorus plating, nickel-iron-chromium plating, nickel-iron-molybdenum plating, nickel-iron-tungsten plating, nickel-iron-copper plating, nickel-iron-phosphorus plating, nickel-chromium-molybdenum plating, nickel-chromium-tungsten plating, nickel-chromium-copper plating, nickel-chromium-phosphorus plating, nickel-molybdenum-tungsten plating, nickel-molybdenum-copper plating, nickel-molybdenum-phosphorus plating, nickel-tungsten-copper plating, nickel-tungsten-phosphorus plating, nickel-copper-phosphorus plating, cobalt-iron-chromium plating, cobalt-iron-molybdenum plating, cobalt-iron-tungsten plating, and cobalt-iron-copper plating are Plating, cobalt-iron-phosphorus plating, cobalt-chromium-molybdenum plating, cobalt-chromium-tungsten plating, cobalt-chromium-copper plating, cobalt-chromium-phosphorus plating, cobalt-molybdenum-phosphorus plating, cobalt-tungsten-copper plating, cobalt-molybdenum-phosphorus plating, cobalt-tungsten-copper plating, cobalt-tungsten-phosphorus plating, cobalt-copper-phosphorus plating, etc. may be used.

[0035] Preferably, in the present invention, the heat-resistant layer (140) may be a Ni-P plating layer comprising Ni and P.

[0036] The heat-resistant layer (140) suppresses the diffusion of copper into the peeling layer when the copper foil attached to the carrier foil is pressed against an insulating substrate at a high temperature. The diffusion of copper into the peeling layer can create a metallic bond between the carrier foil and the thin copper foil, and due to the strong bonding force between them, it can make it difficult to peel off the carrier foil, and the heat-resistant layer (120) can suppress such a reaction.

[0037] In the present invention, the amount of metal attached to the heat-resistant layer (140) is 50 μg / dm 2 Above, 60 µg / dm 2 Above, or 70 µg / dm 2 It may be more than that, and the above metal adhesion amount is 120 μg / dm 2 ≤110 µg / dm 2 Less than or equal to 100 µg / dm 2 It may be less than or equal to the following. In the present invention, the amount of metal attached to the heat-resistant layer may be the amount of Ni attached.

[0038] Meanwhile, if the nickel content of the heat-resistant layer (140) is low, the peel strength between the carrier foil and the thin foil increases, and if the nickel content increases, a crater-shaped copper foil swelling phenomenon occurs. In the present invention, the aforementioned problem is solved by additionally laminating a buffer layer having a different Ni content from that of the heat-resistant layer.

[0039] In the present invention, the thickness of the heat-resistant layer (140) may be 5 nm or more, 7 nm or more, or 10 nm or more. Additionally, it is preferable that the thickness of the heat-resistant layer be 50 nm or less, 30 nm or less, or 20 nm.

[0040] The copper foil attached to the carrier foil of the present invention includes a buffer layer (130) between the peeling layer (120) and the heat-resistant layer (140). In the present invention, the buffer layer (130) protects the peeling layer under high-temperature press conditions of 350°C or higher, suppresses copper diffusion between the carrier foil and the thin foil to prevent swelling, and enables the stability of peel strength.

[0041] In the present invention, the thickness of the buffer layer (130) may be 20 nm or more, or 30 nm or more. Additionally, the thickness of the buffer layer (130) may be 60 nm or less, or 50 nm or less. For example, the thickness of the buffer layer (130) may be 20 to 50 nm. If the thickness of the buffer layer is 20 nm or less, it is ineffective and swelling occurs, and if it is 50 nm or more, the peel strength is significantly lowered, and a lifting phenomenon between the carrier foil and the thin film may occur.

[0042] In the present invention, the thickness ratio of the heat-resistant layer and the buffer layer may be 1:1.5 to 1:5. Preferably, the thickness ratio of the heat-resistant layer and the buffer layer is 1.2 to 1.3.

[0043] In the present invention, the buffer layer (130) is preferably a Ni alloy layer. More preferably, the buffer layer (130) may be a Ni-Cu alloy layer.

[0044] In the present invention, the amount of Ni attached to the buffer layer (130) is 50 μg / dm 2 Above, 60 µg / dm 2 Above, 70 µg / dm 2 Above, 80 µg / dm 2 Above, 90 µg / dm 2 Above, or 100 µg / dm 2 It may be more than that. In addition, the amount of Ni attached to the buffer layer (130) is 300 μg / dm 2 Phosphorus or less, 250 µg / dm³ 2 ≤, 200 µg / dm 2 , or 150 µg / dm 2 The following is desirable.

[0045] In the present invention, the buffer layer (130) is preferably formed by electroplating. In the present invention, the buffer layer of the Ni-Cu alloy can be prepared from a plating solution having a high Ni content ratio. For example, the buffer layer can be electroplated from a plating solution in which the ratio of Cu concentration to Ni concentration is 1:20 to 1:5, preferably 1:15 to 1:7.

[0046] In the present invention, the ultra-thin copper foil (150) may have a thickness of 12 μm or less. Preferably, the ultra-thin copper foil may have a thickness of 1.5 to 5 μm. In addition, in the present invention, it is preferable that the ultra-thin copper foil has a surface roughness (Rz) of 0.5 to 1.5 μm.

[0047] Ultra-thin copper foil can have a harmonized surface and an aharmonized surface depending on the application. The harmonized surface can be formed through nodulation treatment, and the aharmonized surface can be formed by adding a gloss agent and an inhibitor during copper foil formation.

[0048] In the present invention, the surface of the ultra-thin copper foil may be additionally surface-treated. Examples include heat and chemical resistance treatment, chromate treatment, silane coupling treatment, or a combination thereof, and the choice of surface treatment can be appropriately selected according to subsequent processes.

[0049] Heat and chemical resistance treatments can be performed by forming a thin film on a metal foil by sputtering, electroplating, or electroless plating, using any one of the metals such as nickel, tin, zinc, chromium, molybdenum, and cobalt, or alloys thereof. From a cost perspective, electroplating is preferable.

[0050] For the chromate treatment, an aqueous solution containing hexavalent to trivalent chromium ions may be used. While the chromate treatment can be performed by simple immersion, it is preferably carried out by cathodic treatment. For example, the cathodic treatment may be performed using 0.1 to 70 g / L sodium dichromate, a pH of 1 to 13, a bath temperature of 15 to 60 °C, and a current density of 0.1 to 5 A / dm². 2 It is preferable to perform the treatment under conditions of an electrolysis time of 0.1 to 100 seconds. Additionally, it is preferable to perform the chromate treatment on top of the anti-corrosion treatment, thereby further improving moisture resistance and heat resistance.

[0051] As a silane coupling agent used for silane coupling treatment, one or more substances or mixtures selected from the group consisting of epoxy functional silanes such as 3-glycidoxypropyl trimethoxysilane and 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, amino functional silanes, olefin functional silanes, acrylic functional silanes, methacrylic functional silanes, and mercapto functional silanes may be used. For example, the silane coupling agent is dissolved in a solvent such as water at a concentration of 0.1 to 15 g / L and applied to a metal foil at a temperature of room temperature to 70 ℃, or adsorbed by electrodeposition. After silane coupling treatment, a stable bond can be formed by heating, ultraviolet irradiation, etc. Heating may be performed at a temperature of 100 to 200 ℃ for 2 to 60 seconds.

[0052] Although an example of a structure in which a carrier foil, a release layer, a buffer layer, a heat-resistant layer, and an electrode foil constituting a carrier foil-attached copper foil are laminated while in sequential contact has been described above, additional layers may be added between each layer forming the laminated structure as needed.

[0053] For example, a diffusion barrier layer may be added between the carrier foil and the release layer. The diffusion of copper from the carrier foil to the release layer can create metallic bonds, and the strong bonding force between them can make it difficult to peel off the carrier foil. Therefore, additionally, a diffusion barrier layer may be introduced to facilitate this reaction.

[0054] Meanwhile, in the present invention, the copper foil attached to the carrier foil can be manufactured into a copper foil laminate by bonding it with a resin having low dielectric properties, such as polyimide, fluoropolymer, LCP resin, etc., and such a copper foil laminate can be used to manufacture a printed circuit board.

[0055] The present invention will be described in more detail below with reference to examples. However, these are presented as preferred examples of the present invention and should not be interpreted in any way as limiting the present invention.

[0057] <Example 1>

[0058] A copper foil with carrier foil attached was manufactured using the following method.

[0060] A. Carrier Box

[0061] Electrolytic copper foil with a surface roughness of 1.2㎛ and a thickness of 18㎛ was used.

[0063] B. Delamination layer

[0064] An organic peeling layer was formed under the following conditions.

[0065] - Carboxybenzotrisol concentration: 1–5 g / L, Copper concentration: 5–15 g / L, H2SO4 concentration: 150 g / L

[0066] - Temperature: 40 ℃, Dipping time: 25 seconds

[0068] C. Buffer layer

[0069] A buffer layer was formed on a carrier foil under the plating bath and plating conditions below. The thickness of the formed buffer layer was 35 nm.

[0070] -Copper concentration: 5~10g / L, Nickel concentration: 50~100g / L, Boric acid concentration: 20~50g / L

[0071] - Temperature: 30℃, Current density: 2.0A / dm 2 , Plating time: 2.5 seconds

[0073] D. Heat-resistant layer

[0074] A heat-resistant layer was formed under the plating bath and plating conditions below. The Ni deposition amount of the formed heat-resistant layer was 90 μg / dm² 2 was.

[0075] - Ni concentration: 15~25 g / L, P concentration: 10~20 g / L

[0076] - pH: 4.0, Temperature: 30 ℃, Current density: 0.5 A / dm² 2 , Plating time: 6 seconds

[0078] E. Ultrasonic copper

[0079] An ultra-thin copper foil was formed under the plating bath and plating conditions below. The plating thickness was set to 2 μm.

[0080] - CuSO4-5H2O: 250g / L, H2SO4: 100g / L

[0081] - Temperature: 35 ℃, Current density: 20 A / dm 2 , Plating time: 30 seconds

[0082] Subsequently, heat and chemical resistance treatments, chromate treatment, and silane coupling treatment were additionally performed on the surface of the ultra-thin copper foil.

[0084] <Example 2>

[0085] A carrier foil-attached copper foil was manufactured in the same manner as in Example 1, except that the buffer layer was formed to a thickness of 25 nm. The plating conditions for the buffer layer are as follows.

[0086] - Copper concentration: 5~10g / L, Nickel concentration: 50~100g / L, Boric acid concentration: 20~50g / L

[0087] - Temperature: 30℃, Current density: 2.0A / dm 2 , Plating time: 1.8 seconds

[0089] <Example 3>

[0090] A carrier foil-attached copper foil was manufactured in the same manner as in Example 1, except that the buffer layer was formed to a thickness of 45 nm. The plating conditions for the buffer layer are as follows.

[0091] - Copper concentration: 5~10g / L, Nickel concentration: 50~100g / L, Boric acid concentration: 20~50g / L

[0092] - Temperature: 30℃, Current density: 2.0A / dm 2 , Plating time: 3.3 seconds

[0094] <Example 4>

[0095] A copper foil attached to a carrier foil was manufactured in the same manner as in Example 1, except that an inorganic release layer was formed as the release layer. The release layer was formed by Mo-Ni-Fe plating. The adhesion amount of the formed release layer was 0.9 mg / dm² 2 The composition of the exfoliated layer was Mo 60.31 wt%, Ni 31.6 wt%, and Fe 8.09 wt%. .

[0096] - Mo concentration: 10–30 g / L, Ni concentration: 3–10 g / L, Fe concentration: 1–5 g / L, Sodium citrate: 100–200 g / L

[0097] - pH: 10.2 (30 ml / L ammonia solution added), Temperature: 30 ℃, Current density: 8 A / dm² 2 , Plating time: 6 seconds

[0099] <Comparative Example 1>

[0100] A copper foil with carrier foil attached was manufactured in the same manner as in Example 1, except that the buffer layer was omitted.

[0102] <Comparative Example 2>

[0103] A copper foil with carrier foil attached was manufactured using the following method.

[0105] A. Carrier Box

[0106] Electrolytic copper foil with a surface roughness of 1.2 μm and a thickness of 18 μm was used for the carrier foil.

[0108] B. Diffusion barrier layer

[0109] A diffusion barrier layer was formed on the carrier foil by Ni plating. The plating bath and plating conditions were as follows. The deposition amount of the formed diffusion barrier layer was 352 ug / dm³, with a metal (Ni) deposition amount. 2 was.

[0110] - Ni concentration: 15~25g / L, P concentration: 10~20g / L, pH: 4.0

[0111] - Temperature: 30 ℃, Current density: 1.5 A / dm² 2 , Plating time: 2 seconds

[0113] C. Formation of peeling layer

[0114] A stripping layer was formed by Mo-Ni-Fe plating. The adhesion amount of the formed stripping layer was 0.9 mg / dm². 2 The composition of the peeling layer was Mo 60.31 wt%, Ni 31.6 wt%, and Fe 8.09 wt%.

[0115] - Mo concentration: 10~30g / L, Ni concentration: 3~10g / L, Fe concentration: 1~5g / L, Sodium citrate: 100~200g / L,

[0116] - pH: 10.2 (30 ml / L ammonia solution added), Temperature: 30 ℃, Current density: 8 A / dm² 2 , Plating time: 6 seconds

[0118] D. Formation of a heat-resistant layer

[0119] A heat-resistant layer was formed under the plating bath and plating conditions below. The Ni deposition amount of the formed heat-resistant layer was 33 μg / dm² 2 was.

[0120] - Ni concentration: 15~25 g / L, P concentration: 10~20 g / L

[0121] - pH: 4.0, Temperature: 30 ℃, Current density: 0.5 A / dm² 2 , Plating time: 2 seconds

[0123] E. Formation of thin copper foil

[0124] An ultra-thin copper foil was formed under the plating bath and plating conditions below. The plating thickness was set to 2 μm.

[0125] - CuSO4-5H2O: 250g / L, H2SO4: 100g / L

[0126] - Temperature: 35 ℃, Current density: 20 A / dm 2 , Plating time: 30 seconds

[0128] Subsequently, heat and chemical resistance treatments, chromate treatment, and silane coupling treatment were additionally performed on the surface of the ultra-thin copper foil.

[0130] <Comparative Example 3>

[0131] A copper foil with a carrier foil attached was manufactured in the same manner as in Example 1, except that the thickness of the buffer layer (anti-swelling layer) was 15 nm.

[0132] The buffer layer plating conditions are as follows.

[0133] - Copper concentration: 5~10g / L, Ni concentration: 50~100g / L, Boric acid concentration: 20~50g / L

[0134] - Temperature: 30℃, Current density: 2.0A / dm2, Plating time: 1.5 seconds

[0136] <Comparative Example 4>

[0137] A copper foil with a carrier foil attached was manufactured in the same manner as in Example 1, except that the thickness of the buffer layer (anti-swelling layer) was 70 nm.

[0138] - Copper concentration: 5~10g / L, Ni concentration: 50~100g / L, Boric acid concentration: 20~50g / L

[0139] - Temperature: 30℃, Current density: 2.0A / dm 2 , Plating time: 1.5 seconds

[0141] <Characteristics Evaluation>

[0142] The characteristics of the carrier foil-attached copper foil specimens prepared in the examples and comparative examples were evaluated. The evaluation method is as follows.

[0144] A. Evaluation of swelling characteristics

[0145] After press processing at each temperature (220℃, 350℃, 400℃) and peeling off the carrier foil, the peeled surface was visually inspected. If even one crater-shaped bulging phenomenon was found, it was judged to be a bulging defect.

[0147] B. AES Analysis

[0148] Analysis was performed using the PHI 700™ (Scanning Auger Nanoprobe) as the analytical instrument. The analysis conditions are as follows.

[0149] - Beam Size (10keV 10nA): 20nm

[0150] - Analysis area (㎛ or point): 10㎛ x 10㎛, Area

[0151] - Tilt(°) / Stage Normal(°): 30° / 60°

[0152] - Analyzer: CMA (Cylindrical Mirror Analyzer)

[0154] C. Optical Microscope Analysis

[0155] HIROX's HK7700 was observed at a magnification of 200x.

[0157] D. Evaluation of peel strength

[0158] Teflon resin from Mirae EMC (thickness: 50㎛) was prepared, and a copper foil specimen with a width of 30mm was prepared and pressed onto the resin at temperatures of 220℃, 350℃, and 400℃ to prepare samples (press conditions: pressure 4.9Mpa, held for 60 minutes). The press condition profile is shown in Fig. 5.

[0159] The peel strength of the prepared samples was measured using the 90° peel method in accordance with JIS C 6471 8.1.

[0161] Table 1 below summarizes the results of swelling characteristics and peel strength.

[0162] division Buffer layer thickness 220℃ Press (Crater occurrence / Peel strength) 350℃ Press (Crater occurrence / Peel strength) 400℃ (presence of crater / peel strength) Example 1 35nm Good / 15gf / cm Good / 16gf / cm Good / 21gf / cm Example 2 25nm Good / 14gf / cm Good / 18gf / cm Good / 26gf / cm Example 3 45nm Good / 12gf / cm Good / 15gf / cm Good / 19gf / cm Example 4 35nm Good / 14gf / cm Good / 14gf / cm Good / 28gf / cm Comparative Example 1 X Good / 21gf / cm Generation / 87gf / cm No occurrence / peeling Comparative Example 2 X Good / 18gf / cm Occurrence / 79gf / cm No occurrence / peeling Comparative Example 3 15nm Good / 17gf / cm Occurrence / 28gf / cm Occurrence / 84gf / cm Comparative Example 4 70nm Good / 4gf / cm Good / 6gf / cm Good / 7gf / cm

[0163] In the case of Example 1, no swelling occurred even when pressed at 350°C and 400°C, and it was confirmed that the peel strength between the carrier foil and the ultra-thin copper foil was very good, at 15gf / cm at 220°C, 16gf / cm at 350°C, and 21gf / cm at 400°C.

[0164] In the case of Example 2, no swelling occurred after pressing at 350°C and 400°C, and the peel strength between the carrier foil and the ultra-thin copper foil was confirmed to be very good, at 14gf / cm at 220°C, 18gf / cm at 350°C, and 26gf / cm at 400°C.

[0165] In the case of Example 3, no swelling occurred after pressing at 350°C and 400°C, and it was confirmed that the peel strength between the carrier foil and the ultra-thin copper foil was very good, at 12gf / cm at 220°C, 15gf / cm at 350°C, and 18gf / cm at 400°C.

[0166] In the case of Example 4, no swelling occurred after pressing at 350°C and 400°C, and the peel strength between the carrier foil and the ultra-thin copper foil was confirmed to be very good, at 14gf / cm at 220°C, 14gf / cm at 350°C, and 28gf / cm at 400°C.

[0167] In the case of Comparative Example 1, no swelling occurred after pressing at 220°C, and the peel strength between the carrier foil and the thin copper foil was good at 21 gf / cm at 220°C. However, swelling occurred at 350°C, and the peel strength was 87 gf / cm, which caused a problem where it was difficult to separate the carrier foil and the thin foil. In addition, at 400°C, swelling occurred and it was impossible to peel the carrier foil and the thin foil.

[0168] In the case of Comparative Example 2, no swelling occurred after pressing at 220°C, and the peel strength between the carrier foil and the thin copper foil was good at 18 gf / cm at 220°C. However, swelling occurred at 350°C, and the peel strength was 79 gf / cm, which caused a problem where it was difficult to separate the carrier foil and the thin foil. In addition, at 400°C, swelling occurred and it was impossible to peel the carrier foil and the thin foil.

[0169] In the case of Comparative Example 3, no swelling occurred after pressing at 220°C, and the peel strength between the carrier foil and the thin copper foil was good at 17 gf / cm at 220°C. However, swelling occurred at 350°C, and the peel strength was good at 28 gf / cm. In addition, at 400°C, swelling occurred, and the peel strength between the carrier foil and the thin foil was 84 gf / cm, which caused a problem where it was difficult to separate the carrier foil and the thin foil.

[0170] In the case of Comparative Example 4, no swelling occurred after pressing at 220℃, 350℃, and 400℃, but the peel strength between the carrier foil and the ultra-thin copper foil was 4gf / cm at 220℃, 6gf / cm at 350℃, and 7gf / cm at 400℃, showing significantly low peel strength values.

[0172] Figures 2a and 2b are optical microscope images of the peeled surface of the ultra-thin copper foil side after peeling off the carrier foil following press processing of the samples of Example 1 and Comparative Example 1 at 350°C, respectively.

[0173] Referring to the drawings, it can be seen that in the case of Example 1, the peeled surface is clean, whereas in the case of Comparative Example 1, a crater is formed on the peeled surface. It can be seen that this is due to swelling near the peeled layer during pressing.

[0174] Figures 3a and 3b are AES analysis graphs for carrier foil-attached copper foil samples prepared in Example 1 and Comparative Example 1, respectively.

[0175] Referring to the drawings, in the case of Example 1 compared to Comparative Example 1, peaks showing Cu peaks and Ni peaks that appear to be due to what is contained in the buffer layer can be observed.

[0177] Figure 4 is a graph plotting the results of peel strength measurements after pressing at 400°C for samples of the embodiments and comparative examples of the present invention.

[0178] Referring to FIG. 4, it can be seen that Examples 1 to 4 fall within a stable peel strength range of 10 to 30 kg / cm.

[0180] As described above, the present invention has been explained by specific details such as specific components, limited embodiments, and drawings; however, this is provided merely to aid in a more comprehensive understanding of the invention, and the invention is not limited to the above embodiments. A person skilled in the art to which the invention pertains will be able to make various modifications and variations within the scope of the essential characteristics of the invention. Accordingly, the concept of the present invention should not be limited to the described embodiments, and all technical concepts that are equivalent to or have equivalent variations to the claims set forth below, as well as the claims themselves, should be interpreted as being included within the scope of the rights of the present invention. Explanation of the symbols

[0182] 110 suitcase box 120 release layer 130 buffer layer 140 heat-resistant layer 150 ultra-thin copper foil

Claims

Claim 1 A copper foil attached to a carrier foil comprising a carrier foil, a peeling layer on the carrier foil, a heat-resistant layer on the peeling layer, and an ultra-thin copper foil on the heat-resistant layer, wherein a buffer layer made of a Ni alloy is interposed between the peeling layer and the heat-resistant layer, the buffer layer having a thickness of 20 to 50 nm including a Ni-Cu alloy, and the heat-resistant layer being a Ni-P plating layer including Ni and P. Claim 2 delete Claim 3 A copper foil attached to a carrier foil according to claim 1, characterized in that the buffer layer is plated with a plating solution having a Cu concentration and a Ni concentration of 1:5 to 1:

20. Claim 4 delete Claim 5 A copper foil attached to a carrier foil according to claim 1, characterized in that the thickness of the heat-resistant layer is 5 to 50 nm. Claim 6 A copper foil attached to a carrier foil, characterized in that, in claim 1, the release layer is an organic release layer. Claim 7 A copper foil attached to a carrier foil, characterized in that, in claim 1, the peeling layer is an inorganic peeling layer. Claim 8 delete Claim 9 delete Claim 10 A copper foil attached to a carrier foil according to claim 1, characterized in that the 90-degree peel strength after press processing at 400℃ for 60 minutes is 10 to 30 gf / cm. Claim 11 A copper foil laminate comprising a copper foil laminated on a resin substrate, wherein the copper foil is a copper foil laminate manufactured by bonding a carrier foil-attached copper foil according to claim 1 to the resin substrate. Claim 12 A copper foil laminate according to claim 11, characterized in that the resin substrate is one selected from the group consisting of polyimide, fluoropolymer, and LCP.

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