WO2023219190A1 - Composite release layer for carrier-attached metal foil and metal foil comprising same - Google Patents

Abstract

The present invention relates to a composite release layer for a carrier-attached metal foil and a metal foil comprising same. The present invention provides a composite release layer for a carrier-attached metal foil, the release layer enabling the smooth removal of a carrier from the carrier-attached metal foil, wherein the release layer comprises: a metal-containing release layer formed on the carrier; and an organic and inorganic release layer formed on the metal-containing release layer, the organic and inorganic release layer containing: a heterocyclic compound containing nitrogen; an amine-based compound; and a transition metal compound of groups 3 to 8 of the periodic table.

Description

Composite release layer for carrier-attached metal foil and metal foil containing the same

The present invention relates to a composite release layer for metal foil attached to a carrier and a metal foil containing the same.

Typically, printed circuit boards can be manufactured by combining metal foil and an insulating resin substrate and then forming circuit wiring on the metal foil through an etching process. In order to prevent delamination of the metal foil from occurring in the process of forming the circuit wiring, a metal foil with high work convenience by securing high adhesion and release force between insulating resin substrates is required.

In order to increase the adhesion between the metal foil and the insulating resin substrate, a method has been proposed in the past to form irregularities on the surface of the metal foil by performing roughening treatment on the surface of the metal foil, and to place the insulating resin substrate on the surface of the metal foil with the irregularities formed and bond them by pressing. There is a bar. Specifically, Patent Document 1 discloses that the adhesion between the copper foil and the resin layer is improved by forming particulate protrusions by subjecting the surface of the copper foil on the resin layer side to electrolytic treatment, blast treatment, or oxidation-reduction treatment.

However, since the above method involves performing a separate roughening process on already formed metal foil, there is a problem in that the manufacturing efficiency of the printed circuit board is low. Additionally, there is a problem in that high-frequency signal transmission efficiency is reduced due to irregularities formed on the surface of the metal foil. In other words, in order to process large amounts of information at high speed in accordance with the trend toward higher functionality of portable electronic devices, signal transmission loss must be minimized during the transmission of high-frequency signals. However, when irregularities of high roughness are formed on the surface of the metal foil, they act as an obstacle to high-frequency signal transmission, reducing the efficiency of high-frequency signal transmission.

Meanwhile, due to the thin thickness of the metal foil, wrinkles or bends easily occur during the bonding process with the insulating resin substrate or target substrate. To compensate for this, metal foil is handled by combining a release layer and a carrier on one side. Here, the metal foil to which the release layer and the carrier are bonded must have heat resistance during the bonding process with the insulating resin substrate or the target substrate, and it is required that the carrier be easily peeled off through the release layer after bonding. For this purpose, a technology has been proposed that applies organic components to the release layer or provides a separate layer between the release layer and the metal foil to increase heat resistance.

However, in the case of the organic release layer used in such metal foil, stains may occur during release, and in the case of a release layer made of metal, the metal may diffuse into the copper or the metal may remain on the surface of the copper foil after release, which is the reason for defects. It is being pointed out. Therefore, there is a need to develop a new release layer to overcome the shortcomings of the existing release layer.

In order to solve the above-mentioned problem, the present invention manufactures an organic-inorganic composite release layer by mixing a metal component with an organic release layer, and improves the disadvantage of staining when using the existing organic release layer. The object is to provide a layer and a metal foil containing the same.

In addition, the present invention seeks to provide a composite release layer for metal foil with a carrier that can be applied to copper strike plating by using a metal-containing release layer and an organic-inorganic composite release layer, and a metal foil containing the same.

In order to solve the above-described problem, the present invention provides a release layer that allows the carrier to be smoothly removed from the carrier-attached metal foil, wherein the release layer includes a metal-containing release layer formed on the carrier; and an organic-inorganic release layer formed on the metal-containing release layer, wherein the organic-inorganic release layer includes a heterocyclic compound containing nitrogen; Amine-based compounds; and a composite release layer for metal foil with a carrier containing a transition metal compound of groups 3 to 8.

The heterocyclic compounds include benzotriazole, mercapto benzimidazole, mercapto benzotriazole, sodium mercapto benzotriazole, and 5-carboxybenzotriazole. (5-Carboxybenzotriazole), 3-Amino-5-mercapto-1,2,4-triazole (3-Amino-5-mercapto-1,2,4-triazole), 3-mercapto-1,2, 4-Mercapto-1,2,4-triazole, Triazole-5-carboxylic acid, 1-methyl-3-mercapto-1,2,4-triazole (1-Methyl-3-mercapto-1,2,4-triazole) and 1-Phenyl-5-mercapto tetrazole (1-Phenyl-5-mercapto tetrazole). there is.

In one embodiment, the amine-based compound is ethanolamine, 2-(methylamino)ethanol, 2-methoxyethylamine, 2-amino-1-propanol, alaninol, 2-ethoxyethaneamine, N- At least one selected from the group of ethyl-N-propylamine, tributylamine, 2-(dimethylamino)ethanol, N,N-dimethylbenzenamine, N,N-dibutylbutanamine, and N-ethylpropanamine It can be included.

In one embodiment, the transition metal compound of groups 3 to 8 may be a metal compound containing chromium, molybdenum, tungsten, or titanium.

In one embodiment, the transition metal compound is an oxide of chromium, molybdenum, tungsten, or titanium; Hydroxides of chromium, molybdenum, tungsten or titanium; Sulfates, nitrates, phosphates, hydrochlorides, fluorides or acetates of chromium, molybdenum, tungsten or titanium; Alternatively, it may include compounds derived from oxides of chromium, molybdenum, tungsten, or titanium.

In one embodiment, the transition metal compounds of groups 3 to 8 include chromic acid, chromium (III) picolinate, potassium dichromate, chromium oxide, chromyl chloride, chromium sulfate, tungsten dioxide, tungsten trioxide, tungsten disulfide, It may contain tungsten trisulfide, tungsten dichloride, tungsten hexachloride, tungsten tetrachloride, ditungsten decachloride, tungsten trichloride, titanium tetrachloride, titanium disulfide, titanium halide, molybdenum oxide, molybdenum sulfide or molybdenum hexacarbonyl. there is.

In one embodiment, the metal-containing release layer may include nickel and molybdenum.

In one embodiment, the metal-containing release layer may include 50 to 80% by weight of Ni and 20 to 50% by weight of molybdenum.

In one embodiment, the release layer may have a peel strength of 1 to 20 gf/cm when evaluated according to the IPC-TM-650 standard.

In one embodiment, the metal-containing release layer may have a thickness of 0.01 to 0.2 μm, and the organic-inorganic release layer may have a thickness of 0.001 to 0.01 μm.

The present invention also provides a metal foil attached to a carrier including the composite release layer.

In one embodiment, the metal foil attached to the carrier includes: a carrier; The composite release layer provided on the carrier; and a metal layer provided on the composite release layer, wherein the metal layer may include a metal foil including a plurality of protrusions.

In one embodiment, the metal layer includes: a metal strike layer formed on the release layer; and a metal foil including a plurality of protrusions formed on the metal strike layer. The metal strike layer may be formed under conditions of pH 8 to 11 using metal pyrophosphate.

In one embodiment, the plurality of protrusions may have flat tops.

The composite release layer for metal foil attached to a carrier according to the present invention and the metal foil containing the same are manufactured by mixing metal components in an organic release layer to produce an organic-inorganic composite release layer, which improves the disadvantage that stains may occur when using the existing organic release layer. You can.

In addition, the composite release layer for metal foil attached to a carrier and the metal foil containing the same use a metal-containing release layer and an organic-inorganic composite release layer and can be applied to copper strike plating using a neutral plating solution.

Figure 1 shows a cross section of a conventional carrier-attached metal foil.

Figure 2 shows a cross section of a metal foil attached to a carrier according to an embodiment of the present invention.

Figure 3 shows a bonding structure of an organic-inorganic release layer according to an embodiment of the present invention.

Figure 4 shows the behavior of the organic and inorganic release layer when the release layer is released according to an embodiment of the present invention.

Figure 5 shows the phase equilibrium diagram of a chromium compound according to an embodiment of the present invention.

Figure 6 shows a phase equilibrium diagram of a transition metal compound according to an embodiment of the present invention, where (a) shows molybdenum, (b) shows titanium, and (c) shows tungsten.

Figure 7 shows a plurality of protrusions formed on a metal foil according to an embodiment of the present invention.

Figure 8 shows the appearance of protrusions having various shapes according to an embodiment of the present invention.

Figure 9 shows a photograph showing a protrusion with a flat top formed according to an embodiment of the present invention.

Figure 10 shows a photograph of metal foil after release of the carrier layer according to an embodiment of the present invention.

Figure 11 shows a photograph of metal foil after release of the carrier layer according to an embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail. In describing the present invention, if it is determined that a detailed description of related known technologies may obscure the gist of the present invention, the detailed description will be omitted. Throughout the specification, singular expressions should be understood to include plural expressions, unless the context clearly indicates otherwise, and terms such as “comprise” or “have” refer to the features, numbers, steps, operations, or components being described. , it is intended to specify the existence of a part or a combination thereof, but should be understood as not excluding in advance the possibility of the existence or addition of one or more other features, numbers, steps, operations, components, parts, or combinations thereof. . In addition, when performing a method or manufacturing method, each process forming the method may occur differently from the specified order unless a specific order is clearly stated in the context. That is, each process may occur in the same order as specified, may be performed substantially simultaneously, or may be performed in the opposite order.

Since the present invention can be modified in various ways and can have various embodiments, specific embodiments will be exemplified and explained in detail in the detailed description. However, this is not intended to limit the present invention to specific embodiments, and should be understood to include all transformations, equivalents, and substitutes included in the spirit and technical scope of the present invention.

The technology disclosed in this specification is not limited to the implementation examples described herein and may be embodied in other forms. However, the implementation examples introduced here are provided to ensure that the disclosed content is thorough and complete and that the technical idea of the present technology can be sufficiently conveyed to those skilled in the art. In order to clearly express the components of each device in the drawing, the sizes of the components, such as width and thickness, are shown somewhat enlarged. When describing the drawing as a whole, it is described from the observer's point of view, and when an element is mentioned as being located above another element, this means that the element may be located directly above another element or that additional elements may be interposed between those elements. Includes. Additionally, those skilled in the art will be able to implement the idea of the present invention in various other forms without departing from the technical idea of the present invention. In addition, the same symbols in a plurality of drawings refer to substantially the same elements.

As used herein, the term 'and/or' includes a combination of a plurality of listed items or any of a plurality of listed items. In this specification, 'A or B' may include 'A', 'B', or 'both A and B'.

The present invention relates to a release layer that allows the carrier to be smoothly removed from the carrier-attached metal foil, wherein the release layer includes a metal-containing release layer formed on the carrier; and an organic-inorganic release layer formed on the metal-containing release layer, wherein the organic-inorganic release layer includes a heterocyclic compound containing nitrogen; Amine-based compounds; and a composite release layer for metal foil with a carrier containing a transition metal compound of groups 3 to 8.

Figure 1 shows a carrier adhesive release layer including a conventional release layer.

In the case of the existing release layer ((a) in Figure 1), the release peeling layer 250 and the release layer 240 of a metal component are used, so the metal component diffuses into the copper foil layer or the metal release layer is deposited on the surface of the copper foil during release. The component of (240) is transferred, causing a defect in which the performance of the copper foil is deteriorated. To prevent this, a technique is used to prevent diffusion and transfer of metal components by using an organic release layer 230 or forming an organic diffusion barrier layer on the surface of the metal release layer (FIG. 1(b)). However, these organic components have the disadvantage of not being applicable to strike plating, which is widely used in forming metal foil, because they contain nitrogen.

Figure 2 shows the metal foil with a carrier of the present invention.

In the case of the present invention, a metal-containing release layer is formed on the carrier layer, and an organic-inorganic release layer is formed between the metal-containing release layer and the metal foil to prevent metal diffusion and minimize stains or metal transfer during release. Provides a composite release layer for metal foil with a carrier attached.

For this purpose, the release layer includes a metal-containing release layer formed on the carrier; And it may include an organic-inorganic release layer formed on the metal-containing release layer.

The metal-containing release layer 220 is a layer formed on the carrier 300 to facilitate release of the carrier, and may include nickel and molybdenum.

In the case of the nickel and molybdenum, they can form a dense release layer and stably secure the release force, but they have affinity for copper or aluminum, which are commonly used in metal foil, so when used alone, they diffuse into the metal foil or form part of the metal foil. It is transferred to the surface, causing stains. Therefore, in the case of the present invention, an organic/inorganic release layer 210 can be additionally used to lower the release force of the metal-containing release layer 220, which will be described later.

In the case of the metal-containing release layer 220, a nickel-molybdenum alloy plating layer may be formed by simultaneously plating nickel and molybdenum. Looking at this in detail, the carrier layer can be immersed in a plating solution to form the metal-containing release layer, and the plating solution for forming the metal-containing release layer is nickel sulfate (NiSO ₄ ) and nickel molybdate (Ni ₂ MoO ₄ ) may be included as a source of nickel and molybdenum.

At this time, the mixing ratio of the nickel sulfate and the nickel molybdate may be 1:5 to 5:1 in molar ratio, preferably 1:2 to 2:1 and most preferably 1:1. If mixed outside the above range, the desired release force may not be achieved due to insufficient molybdenum or nickel content, or residue may be generated during release due to excessive release force.

The nickel sulfate and the nickel molybdate may each be included in the plating solution at a ratio of 0.1 to 0.5 M. If it is included in less than the above ratio, a release layer of the desired thickness cannot be formed, and if it exceeds the above range, the surface roughness of the release layer may increase due to excessive precipitation.

When plating is performed using a plating solution containing the nickel sulfate and the nickel molybdate in the same ratio as above, the nickel sulfate and the nickel molybdate are 50 to 80% by weight of Ni and 20% by weight of molybdenum in the metal-containing release layer. It may contain ~50% by weight. Also, in this case, the molar ratio of nickel and molybdenum may be about 1:1 to 4:1. Within the above range, the surface roughness of the metal-containing release layer is lowered and plated to a uniform thickness, so that the desired release force can be obtained. However, if it is outside the above range, the desired release force cannot be obtained, or residue may be generated during release due to excessive release force. You can.

The plating solution may include citric acid or tartaric acid in addition to the nickel sulfate and nickel molybdate. The citric acid or tartaric acid may be mixed in the plating solution at a ratio of 0.2 to 0.4 M. If the content is less than the above ratio, the desired plating may not be performed, and if it is more than the above range, the thickness of the plating layer may not be constant, and the surface roughness may increase undesirably.

After the metal-containing release layer 220 is formed as described above, the organic-inorganic release layer 210 may be formed. The organic-inorganic release layer 210 is a layer that prevents the metal contained in the metal-containing release layer 220 from diffusing into the interior of the metal foil, which will be described later, or from being transferred to the surface of the metal foil during release, and is a heterocycle containing nitrogen. It may include compounds, amine compounds, and transition metal compounds of groups 3 to 8.

Since the commonly used organic release layer contains a large amount of nitrogen, stains due to nitrogen may occur during release. In particular, it is known that such stains occur more often when strike plating, which is widely used in forming copper foil, is performed. Therefore, in the case of the present invention, an organic and inorganic release layer can be formed by including a transition metal compound when forming the organic release layer, and through this, stains generated during release can be minimized.

For this purpose, the organic-inorganic release layer includes a heterocyclic compound containing nitrogen, an amine-based compound; and transition metal compounds of groups 3 to 8.

The heterocyclic compound containing nitrogen refers to a compound in which one or more atoms constituting the ring of a cyclic compound are replaced with an atom other than carbon. In the case of the present invention, the carbon atom of the ring is replaced with nitrogen. Heterocyclic compounds can be used.

Looking at this specifically, the heterocyclic compound is a cyclic compound having two or more nitrogen atoms, more specifically, benzotriazole, mercapto benzimidazole, and mercapto benzotriazole. ), Sodium mercapto benzotriazole, 5-Carboxybenzotriazole, 3-Amino-5-mercapto-1,2,4-triazole (3-Amino-5- mercapto-1,2,4-triazole), 3-Mercapto-1,2,4-triazole, triazole-5-carboxylic acid), 1-Methyl-3-mercapto-1,2,4-triazole and 1-phenyl-5-mercaptotetrazole (1 -Phenyl-5-mercapto tetrazole) may include one or more selected from the group consisting of By including such a cyclic compound in the organic-inorganic release layer, the structure of the organic-inorganic release layer can be stably maintained and diffusion between the top and bottom of the organic-inorganic release layer can be prevented.

In addition, the heterocyclic compound may be used as a single component, but two or more types of heterocyclic compounds may be used in combination to facilitate release during peeling. When two types of heterocyclic compounds are included as described above, the mixing ratio of each heterocyclic compound may be 1 to 5: 5 to 1, and is preferably used in a 1:1 ratio, that is, equal amounts can be mixed. . If the heterocyclic compound is mixed in a ratio outside the above range, it is difficult to expect an effect from mixing.

In addition, the heterocyclic compound may be mixed and used in a plating solution at a ratio of 50 to 200 g/L during plating to form the organic-inorganic release layer. If the heterocyclic compound is mixed at a ratio of less than 50 g/L, the peeling strength of the organic-inorganic release layer may be lowered and the carrier may be separated at an undesirable point, and if the heterocyclic compound is mixed at a ratio exceeding 200 g/L, the amine to be described later Defects may occur during plating due to the presence of heterocyclic compounds that are not dissolved by the base compound.

The amine-based compound can be used as a solvent to dissolve the heterocyclic compound and at the same time react with a metal compound to be described later to secure an appropriate mold release force. In the case of the amine-based compound, it refers to a compound in which at least one of the hydrogen atoms of ammonia is replaced with a hydrocarbon. In the case of the present invention, it is preferable to use a primary amine-based compound in which only one of the hydrogen atoms is replaced with a hydrocarbon. More preferably, a primary amine alcohol-based compound having a hydroxy group attached to the hydrocarbon of the primary amine-based compound may be used.

Examples of the primary amine alcohol-based compounds include ethanolamine, 2-(methylamino)ethanol, 2-methoxyethylamine, 2-amino-1-propanol, alaninol, 2-ethoxyethaneamine, N -One or more selected from the group of ethyl-N-propylamine, tributylamine, 2-(dimethylamino)ethanol, N,N-dimethylbenzenamine, N,N-dibutylbutanamine, and N-ethylpropanamine It may include, and most preferably, ethanolamine may be used.

The amine-based compound may be included in an amount of 5 to 20 g/L in the plating solution during plating to form the organic-inorganic release layer. If the amine compound is contained in an amount of less than 5 g/L, the heterocyclic compound may not dissolve smoothly, making it difficult to form a smooth organic-inorganic release layer, and if it is contained in a ratio exceeding 20 g/L, the heterocyclic compound may be difficult to form. The ratio of is relatively low, which may reduce the peel strength.

As described above, the formation of an organic release layer is possible even when using a mixture of the heterocyclic compound and the amine-based compound. However, as seen above, in the case of the organic release layer, nitrogen content remains during release, causing stains in many cases. (see left combination in Figure 3). In addition, in the case of the organic release layer, since it is connected to the upper and lower parts of the release layer through bonds by nitrogen oxygen and hydrogen, it has a disadvantage in that residues may be generated during release due to its high release force.

Therefore, in the case of the present invention, in order to improve the disadvantages of the organic release layer, an organic-inorganic release layer is manufactured by mixing transition metal compounds of groups 3 to 8, thereby minimizing defects caused by residues and controlling the release force. .

Looking at this in detail, the organic-inorganic release layer may exist between the metal foil and the metal-containing release layer formed on the top of the carrier. At this time, the heterocyclic compound used as the organic component may be connected through a bond between the metal-containing release layer and the metal foil by nitrogen oxygen and hydrogen having a strong bonding force. However, in the case of the transition metal compound included in the organic-inorganic release layer, it may be dispersed on the surface of the metal-containing release layer and the surface of the metal foil to form a layer. At this time, the transition metal compound layer formed on the surface of the metal-containing release layer and the transition metal compound layer formed on the surface of the metal foil may be bonded to each other using hydroxy groups (see bond on the right side of Figure 3), but this is hydrogen bonding. It is a type of weak covalent bond, and since only some of the transition metals are bonded, it can have weak bonding strength. That is, if the amount of the transition metal compound included in the organic-inorganic release layer increases, the bond between the transition metal compound layers increases, thereby forming an organic-inorganic release layer with weak release force, and if the amount of the transition metal compound decreases, the bond between the transition metal compound layers increases. As the bonds caused by the heterocyclic compound are increased, a release layer with strong release force can be formed.

In addition, when the organic-inorganic release layer is separated, the covalent bond between the transition metal compound layers is broken, so release layer residues may exist on both sides of the metal foil and the metal-containing release layer, but this only contains a very small amount of organic and inorganic components. Just leaving it on prevents stains on the metal foil and at the same time, it can be easily removed through the etching process (see Figure 4).

The transition metal compounds of groups 3 to 8 may be used without limitation as long as they are compounds containing transition metals belonging to groups 3 to 8, but are preferably metal compounds containing chromium, molybdenum, tungsten or titanium. .

Looking at this in more detail, the transition metal compound may be an oxide of chromium, molybdenum, tungsten or titanium; Hydroxides of chromium, molybdenum, tungsten or titanium; Sulfates, nitrates, phosphates, hydrochlorides, fluorides or acetates of chromium, molybdenum, tungsten or titanium; Alternatively, it may include compounds derived from oxides of chromium, molybdenum, tungsten, or titanium.

In particular, the organic-inorganic release layer has different film formation conditions depending on the type of metal component included in the organic-inorganic release layer, so it is desirable to select and use it appropriately according to each process condition. As an example, in the case of a transition metal compound containing chromium, the hydrous chromium oxide film can be formed between pH 6 and 10 (see Figure 5), and a transition metal compound containing molybdenum can form the hydrous chromium oxide film at pH 3 to 7 (see Figure 6). a)), transition metal compounds containing titanium form a film at pH 2 to 8 ((b) in Figure 6), and transition metal compounds containing tungsten form a film at pH 2 to 4 ((c) in Figure 6). This is possible. Therefore, it is desirable to use a compound containing an appropriate metal according to each process condition.

Additionally, in the case of the transition metal compound, compounds having various forms may be used. As an example, the transition metal compound containing chromium may include chromic acid, chromium (III) picolinate, potassium dichromate, chromium oxide, chromyl chloride, or chromium sulfate.

In the case of chromic acid, it can be most commonly used as a compound produced by dissolving chromium oxide, an oxide of chromium, in water.

Chromium(III) picolinate is a chromium compound that is easily degraded and decomposed, and can be easily used to form a Cr-N film.

Potassium dichromate has excellent oxidizing power and is the most commonly used chromium compound. Chromium trioxide is commonly used as a metal salt in chrome plating solutions, and chromyl chloride can react with hydrochloric acid to form chromium salt. In the case of chromium(III) sulfate, a chromium sulfide film can be formed on the surface of the metal-containing release layer.

That is, as seen in the example of chromium, various transition metal compounds can be used in the organic-inorganic release layer, and can be appropriately selected and used according to each process.

For example, tungsten dioxide, tungsten trioxide, tungsten disulfide, tungsten trisulfide, tungsten dichloride, tungsten hexachloride, tungsten tetrachloride, ditungsten decachloride, tungsten trichloride, titanium tetrachloride, titanium disulfide, titanium halide, molybdenum oxide. Transition metal compounds such as molybdenum sulfide or molybdenum hexacarbonyl can be used.

The transition metal compound may be included in an amount of 20 to 2000 ppm by weight in the plating solution during plating to form the organic-inorganic release layer. If the transition metal compound is included at less than 20ppm, the stain prevention and release force control effects of the transition metal compound may not appear, and if it is included at a rate exceeding 2000ppm, the release force will be weakened and the carrier will separate at an unwanted time. It can be.

The organic-inorganic release layer is preferably performed under conditions of pH 5-7, current density 5-7 ASD, and plating time 20-60 seconds. Within the above range, the organic/inorganic release layer can be formed normally, but if it is outside the above range, the transition metal compound may not be plated on the surface of the carrier layer or it may be difficult to control the release force.

In addition, during the plating process of the organic-inorganic release layer of the present invention, the current efficiency may be 5 to 30%. In the case of such high current plating, a large amount of hydrogen may be generated, but the organic/inorganic release layer can be formed uniformly.

The release layer may have a peel strength of 1 to 20 gf/cm when evaluated according to the IPC-TM-650 standard. If the peel strength of the release layer is less than 1 gf/cm, the carrier may be separated at an undesirable time, and if it exceeds 20 gf/cm, a residue may remain when the carrier is peeled using the release layer.

Additionally, the metal-containing release layer may have a thickness of 0.01 to 0.2 μm, and the organic-inorganic release layer may have a thickness of 0.001 to 0.01 μm. Within the above thickness range, the composite release layer may have a smooth release force. However, if the thickness is less than the above range, the metal component of the carrier may diffuse toward the metal foil, and if the thickness exceeds the above range, after release Release layer components may remain in the metal foil.

The present invention also provides a metal foil attached to a carrier including the organic-inorganic release layer. In the case of the release layer of the present invention, as seen above, it can be composed of a composite release layer of a metal-containing release layer and an organic-inorganic release layer. Accordingly, compared to the existing metal foil attached to a carrier, the release layer can minimize the occurrence of stains during release. It can have the advantage of being able to form .

The metal foil attached to the carrier includes: a carrier; The composite release layer provided on the carrier; and a metal layer provided on the composite release layer, wherein the metal layer may include a metal foil including a plurality of protrusions.

The metal foil 100 according to the present invention includes a plurality of protrusions 10 with flat tops. The protrusions 10 may refer to metal crystal particles protruding vertically upward from the surface of the metal foil 100. Specifically, the protrusion 10 may include a protruding portion 11 and a flat portion 12 (see FIGS. 2 and 7).

The protrusion 11 included in the protrusion 10 is a portion that protrudes from the surface of the metal foil 100 and may have a truncated cone shape or a polygonal pyramid shape. Specifically, as shown in FIG. 2, the protrusion 11 has a truncated cone shape with a flat surface (side surface) or a polygonal pyramid shape with an angulated surface, and as a result, it forms an anchor in close contact with the insulating resin substrate 400. ) The effect is increased, so that the metal foil 100 can be combined with the insulating resin substrate to have high adhesion. More specifically, the protrusion 11 may have one or more shapes selected from the group consisting of a pentagonal pyramid shape, a hexagonal pyramid shape, a heptagonal pyramid shape, and an octagonal pyramid shape among polygonal pyramid shapes.

A plurality of fine protrusions 11a may be formed on the protrusion 11 to increase adhesion to the insulating resin substrate by increasing the surface area. Due to these fine protrusions 11a, the protrusion 11 may have a surface roughness (Ra) of 0.05 to 0.3 ㎛, specifically 0.08 to 0.2 ㎛. Here, the surface roughness (Ra) of the protrusion 11 may be defined as the surface roughness (Ra) of the side surface of the protrusion 11 excluding the flat portion 12.

Meanwhile, the ratio (b/a) of the base length (a) of the protrusion 11 to the height (b) of the protrusion 11 may be 0.4 to 1.5, specifically 0.6 to 1.2. As the ratio (b/a) is within the above range, it is possible to increase the adhesion between the metal foil 100 and the insulating resin substrate and minimize signal transmission loss during high-frequency signal transmission.

The flat portion 12 included in the protrusion 10 is a flat surface provided at the top of the protrusion 11. The flat portion 12 may refer to the upper surface of the protrusion 11 having a truncated cone shape or a polygonal pyramid shape. Here, unlike the prior art, where high-frequency signal transmission loss occurred by forming particles (forming irregularities of high roughness) to protrude sharply or roundly to increase adhesion, the present invention has a flat portion where the top (top) of the protrusion 10 is a flat surface. As it is composed of (12), the surface of the metal foil 100 exhibits relatively low illumination, thereby minimizing high-frequency signal transmission loss. Specifically, the flat portion 12 may have a circular, oval, or polygonal shape (see FIG. 8). Meanwhile, even if fine irregularities are formed on the surface, a case where the fine irregularities are densely formed to form a flat surface can be considered to be included in the category of the flat portion 12 of the present invention.

In this protrusion 10, the ratio (c/a) of the base length (a) of the protrusion 11 to the length (c) of the flat portion 12 may be 0.1 to 0.7, specifically 0.2 to 0.6. As the ratio (c/a) is within the above range, it is possible to increase the adhesion between the metal foil 100 and the insulating resin substrate and minimize signal transmission loss during high-frequency signal transmission. The length (c) of the flat part 12 may mean the longest length on the surface forming the flat part 12.

The number of such protrusions 10 is per unit area (1 ㎛ ² ) of the metal foil 100, considering the adhesion between the metal foil 100 and the insulating resin substrate, high-frequency signal transmission efficiency, and circuit wiring resolution of the metal foil 100. It may be 25 or less, specifically 5 to 20, and more specifically 7 to 15 (see FIG. 9).

The protrusions 10 may be formed by electroless plating. Specifically, the metal foil 100 according to the present invention is manufactured by electroless plating. After the metal seed foil is formed in the electroless plating process, crystal grains continue to grow on the metal seed foil, and a plurality of protrusions 10 are formed on the surface. The metal foil 100 present in can be manufactured. Here, unlike the conventional method of forming irregularities by performing a separate roughening process on the metal foil, the present invention performs a separate roughening process because a plurality of protrusions 10, which are roughened surfaces, are naturally formed during the manufacturing process of the metal foil 100. The process can be omitted, thereby improving the manufacturing efficiency of the metal foil 100 or/and the printed circuit board. In addition, as the metal foil 100 is manufactured by electroless plating, it is possible to provide a metal foil 100 that is thinner and more porous than the metal foil manufactured by electrolytic plating.

The electroless plating solution used during the electroless plating to manufacture the metal foil 100 according to the present invention is not particularly limited, but may be an electroless plating solution containing a metal ion source and a nitrogen-containing compound.

The metal ion source may specifically be one or more copper ion sources selected from the group consisting of copper sulfate, copper chloride, copper nitrate, copper hydroxide, and copper sulfamate. The concentration of this metal ion source may be 0.5 to 300 g/L, specifically 100 to 250 g/L, and more specifically 190 to 200 g/L.

The nitrogen-containing compound diffuses metal ions so that a plurality of protrusions 10 are formed on the surface of the metal seed foil formed by the metal ion source. The nitrogen-containing compounds specifically include purine, adenine, guanine, hypoxanthine, xanthine, pyridazine, methylpiperidine, 1,2-di-(2-pyridyl)ethylene, 1,2-di-(pyridyl) ) Ethylene, 2,2'-dipyridylamine, 2,2'-bipyridyl, 2,2'-bipyrimidine, 6,6'-dimethyl-2,2'-dipyridyl, di-2 -It may be one or more selected from the group consisting of pyryl ketone, N,N,N',N'-tetraethylenediamine, 1,8-naphthyridine, 1,6-naphthyridine, and terpyridine. The concentration of these nitrogen-containing compounds may be 0.001 to 1 g/L, specifically 0.01 to 0.1 g/L.

The electroless plating solution may further include one or more additives selected from the group consisting of a chelating agent, a pH adjuster, and a reducing agent.

The chelating agent specifically includes tartaric acid, citric acid, acetic acid, malic acid, malonic acid, ascorbic acid, oxalic acid, lactic acid, succinic acid, potassium sodium tartrate, dipotassium tartrate, hydantoin, 1-methylhydantoin, 1,3-dimethyl. A group consisting of hydantoin, 5,5-dimethylhydantoin, nitriloacetic acid, triethanolamine, ethylenediaminetetraacetic acid, tetrasodium ethylenediaminetetraacetate, N-hydroxyethylenediaminetriacetate and pentahydroxy propyldiethylenetriamine. There may be one or more types selected from. The concentration of this chelating agent may be 0.5 to 600 g/L, specifically 300 to 450 g/L, and more specifically 400 to 430 g/L.

The pH adjuster may specifically be one or more selected from the group consisting of sodium hydroxide, potassium hydroxide, and lithium hydroxide. This pH adjuster may be included in the electroless plating solution so that the pH of the electroless plating solution is adjusted to 8 or more, specifically 10 to 14, and more specifically 11 to 13.5.

The reducing agent may be one or more selected from the group consisting of formaldehyde, sodium hypophosphite, sodium hydroxymethane sulfinate, glyoxylic acid, boron hydride, and dimethylamine borane. The concentration of this reducing agent may be 1 to 20 g/L, specifically 5 to 20 g/L.

Plating conditions for manufacturing the metal foil 100 by electroless plating with the electroless plating solution can be appropriately adjusted depending on the thickness of the metal foil 100. Specifically, the electroless plating temperature may be 20 to 60°C, specifically 25 to 40°C, and the electroless plating time may be 2 to 30 minutes, specifically 5 to 20 minutes.

In this way, the thickness of the metal foil 100 of the present invention manufactured by electroless plating may be 5 ㎛ or less, specifically 0.1 to 1 ㎛. In addition, the components that make up the metal foil 100 of the present invention are not particularly limited as long as they are known metals that can form the circuit layer of a printed circuit board, and specifically, they are selected from the group consisting of copper, silver, gold, nickel, and aluminum. There may be more than one type.

The carrier 300 included in the metal foil attached to the carrier according to the present invention prevents the metal layer from being deformed during movement or use of the metal attached to the carrier, and includes metals such as copper, aluminum, etc.; Alternatively, it may be made of polymers such as polyethylene terephthalate (PET), polyphenylene sulfide (PPS), Teflon, etc. The thickness of this carrier may specifically be 10 to 50 ㎛.

The metal foil attached to a carrier according to the present invention may further include a rust prevention layer provided on the metal layer to protect the metal layer. The rust prevention layer may include zinc, chromium, etc.

Additionally, the metal layer may include: a metal strike layer formed on the release layer; And it may include a metal foil including a plurality of protrusions formed on the metal strike layer.

The metal layer may largely be composed of a metal strike layer formed on the release layer and a metal foil on which the plurality of protrusions are formed. The metal strike layer is formed on the release layer and serves as a base for forming the metal foil, and may be formed using a strike plating process.

Looking at this specifically, in order to form the metal layer 100 on the composite release layer, an electroplating process must be used. However, in the case of the present invention, since the metal foil is formed using an electroless plating process, the metal strike layer 110 can be formed on the release layer to facilitate the formation of the metal foil (see Figure 2).

The metal strike layer 110 may be formed by a strike plating process, which refers to a process in which plating is performed for a short time under a high current density to increase the adhesion of plating with low adhesion. In most plating, the main plating process can be performed after the strike plating process, and in the case of the present invention, the metal foil can be formed using the electroless plating process as discussed above.

However, in the case of the present invention, in order to prevent surface stains caused by the composite release layer, it is preferable that the metal strike layer is formed under conditions of pH 8 to 11 using metal pyrophosphate.

Looking at this in detail, if the composite release layer of the present invention is formed and then acidic copper electroplating used in conventional plating is performed, the metal contained in the organic-inorganic release layer may be oxidized by the acid, resulting in many stains. In addition, in the case of such stains, since the surface of the organic-inorganic release layer is neutral, it may become worse if acid electroplating is performed. Therefore, in the case of the present invention, it is preferable to perform the metal strike plating using a neutral plating solution.

Looking at this in detail, the metal strike plating uses metal pyrophosphate as a metal source and can be performed at a current density of 2 to 6 ASD and a temperature of 50 to 60 ° C. As seen above, sulfate, which is used as a metal source in existing plating solutions, can form an acidic plating solution, so in the case of the present invention, it is preferable to use metal pyrophosphate as a metal source.

The metal layer formed by strike plating may be a copper or aluminum layer. Therefore, it is preferable that the metal pyrophosphate is copper pyrophosphate or aluminum pyrophosphate. The metal pyrophosphate may be included in the plating solution for the strike plating in an amount of 80 to 110 g/L, preferably 90 g/L. If the metal pyrophosphate is included at less than 80 g/L, it may be difficult to form the metal strike layer, and if it is added at a rate exceeding 110 g/L, the surface roughness of the metal strike layer may increase and defects may occur. .

In addition, potassium pyrophosphate may be added to form a buffer solution separately from the metal pyrophosphate. This potassium pyrophosphate can maintain the pH of the plating solution appropriately by forming a buffer solution, thereby allowing the strike plating to be performed under neutral conditions.

The potassium pyrophosphate is preferably mixed in the plating solution for strike plating at a ratio of 250 to 400 g/L, preferably 290 to 370 g/L, and most preferably 340 g/L. If the potassium pyrophosphate is contained in less than 250 g/L, it may be difficult to maintain pH during strike plating, and if it is contained in a ratio exceeding 400 g/L, potassium may precipitate and cause defects during plating.

The strike plating is preferably performed under a current density of 2 to 6 ASD, preferably 3 to 5 ASD, and most preferably 4 ASD. If the current density is less than 2ASD, strike plating may not be performed, resulting in defective plating having a nodule shape. If the current density is more than 6ASD, the roughness may increase on the surface of the strike plating layer, creating a dark red matte surface. In addition, within the above current density range, the current efficiency may be more than 80%, but if it exceeds 6ASD, the current efficiency may rapidly decrease to less than 35%.

Additionally, the strike plating is preferably performed under pH 8.0 to 11.0, preferably pH 8.7 conditions. If the strike plating is performed below pH 8.0, stains may occur on the surface in contact with the release layer as seen above, and if pH exceeds 11.0, the surface shape may have a nodule or spherical shape and defects may occur.

Additionally, the strike plating may be performed at a temperature of 50 to 60°C, preferably 55°C. If the plating temperature is less than 50°C, current efficiency may be reduced, and if it exceeds 60°C, the roughness of the strike layer surface may increase.

The metal foil with a carrier according to the present invention may further include an antioxidant layer provided between the release layer and the metal layer. The antioxidant layer may include nickel, phosphorus, etc.

The present invention provides a printed circuit board manufactured using the above-described metal foil. Specifically, the printed circuit board according to the present invention includes a metal circuit layer and an insulating resin layer 400, and the metal circuit layer is derived from the metal foil described above, which will be described as follows.

The metal circuit layer included in the printed circuit board according to the present invention is a layer on which circuit wiring is formed. This metal circuit layer is obtained through the process of forming circuit wiring on the above-described metal foil. By using the above-described metal foil, the present invention can provide a fine and high-resolution printed circuit board. Specifically, the printed circuit board according to the present invention is manufactured by performing an etching process on a laminate combining the insulating resin base and the above-described metal foil to form circuit wiring in the metal foil, and the metal foil has high adhesion to the insulating resin base. Although they are combined, their thickness is relatively thin, making it possible to form fine, high-resolution circuit wiring in metal foil. In addition, by using the above-described metal foil, the present invention can provide a printed circuit board that exhibits high adhesion between circuit wiring and an insulating resin substrate.

The method of forming the circuit wiring is not particularly limited and includes subtractive process, additive process, full additive process, semi additive process, Alternatively, it may be a modified semi additive process.

The insulating resin layer 400 included in the printed circuit board according to the present invention is an insulating layer provided on a metal circuit layer. This insulating resin layer 400 may be made of a commonly known insulating resin substrate. Specifically, the insulating resin layer may be made of a resin substrate (eg, prepreg) having a structure in which inorganic fibers or organic fibers are impregnated with a commonly known resin.

The printed circuit board according to the present invention can be manufactured using an insulating resin base material, or can also be manufactured using a coreless method excluding the insulating resin base material. The coreless method may not be particularly limited as long as it is a commonly known method.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings so that those skilled in the art can easily implement them. Additionally, in describing the present invention, if it is determined that a detailed description of a related known function or known configuration may unnecessarily obscure the gist of the present invention, the detailed description will be omitted. Additionally, some features presented in the drawings are enlarged, reduced, or simplified for ease of explanation, and the drawings and their components are not necessarily drawn to appropriate scale. However, those skilled in the art will easily understand these details.

Examples 1 to 19

An experiment was conducted to confirm the effect of the formation conditions of the metal-containing release layer.

A carrier foil made of copper foil (Cu foil) with a thickness of about 18 ㎛ was immersed in 5% by weight sulfuric acid, pickled, and then washed with pure water.

The treated carrier foil was immersed in a plating solution containing nickel sulfate (NiSO ₄ ), sodium molybdate (Na ₂ MoO ₄ ), and citric acid (Citrate), and then plating was performed.

At this time, the conditions used for forming the metal-containing release layer are shown in Table 1 below.

	Nickel sulfate (M)	Sodium molybdate (M)	Citric acid (M)	pH	Current density (ASD)	Plating time (seconds)
Example 1	0.3	0.05	0.3	6	6	40
Example 2	0.3	0.1	0.3	6	6	40
Example 3	0.3	0.3	0.3	6	6	40
Example 4	0.3	0.5	0.3	6	6	40
Example 5	0.3	0.8	0.3	6	6	40
Example 6	0.05	0.3	0.3	6	6	40
Example 7	0.1	0.3	0.3	6	6	40
Example 8	0.5	0.3	0.3	6	6	40
Example 9	0.8	0.3	0.3	6	6	40
Example 10	0.3	0.3	0.2	6	6	40
Example 11	0.3	0.3	0.4	6	6	40
Example 12	0.3	0.3	0.3	4	6	40
Example 13	0.3	0.3	0.3	8	6	40
Example 14	0.3	0.3	0.3	6	4	40
Example 15	0.3	0.3	0.3	6	8	40
Example 16	0.3	0.3	0.3	6	6	10
Example 17	0.3	0.3	0.3	6	6	20
Example 18	0.3	0.3	0.3	6	6	60
Example 19	0.3	0.3	0.3	6	6	70

As shown in Table 1, a metal-containing release layer was formed by changing the contents of nickel sulfate, sodium molybdate, and citric acid and each process condition.

As a result, a uniform surface plating could be formed only when the molar ratio of nickel and molybdenum was 1:1 to 4:1 (Examples 2 to 4), and in particular, Example 3, where the same amount of moles was used, showed the most uniform surface. It was confirmed that it had . When different ratios were used (Examples 1, 5 to 9), it was confirmed that the surface was not uniform or the thickness of the metal-containing release layer varied depending on each point.

In addition, it was confirmed that the formation of the metal-containing release layer was not smooth under pH conditions below 4 and above 8, and that a large amount of hydrogen gas was generated when a current density of 8ASD was used. Although the amount of hydrogen generated was reduced under the condition of a current density of 4ASD, the plating rate was significantly reduced and an uneven metal-containing mold layer was formed.

As a result, it was confirmed that the conditions of Example 3 were the most suitable conditions for forming the metal-containing release layer, and in the examples to be described later, the metal-containing release layer manufactured by the method of Example 3 was used.

Examples 20-31

An experiment was conducted to form an organic-inorganic release layer on the metal-containing release layer manufactured as in Example 3.

To form an organic-inorganic release layer on top of the carrier + metal-containing release layer prepared in Example 3, it was immersed in a solution for forming an organic-inorganic release layer. At this time, the optimal organic-inorganic release layer was selected by varying the composition of the solution for forming the organic-inorganic release layer.

First, an experiment was conducted to select a transition metal compound used in the organic-inorganic release layer. The transition metal compounds (ppm) shown in Table 2 below were added to a solution containing CBTA (5-carboxybenzotriazole, 100 g/L) and ethanolamine (10 g/L), and then immersed for 40 seconds at pH 9 and a temperature of 30°C. Thus, an organic-inorganic release layer was formed.

	chromic acid	molybdic acid	titanic acid	tungstic acid	Potassium dichromate	sulfuric acid chrome	sulfuric acid magnesium	Nickel sulfate
Example 20	5	-	-	-	-	-	-	-
Example 21	20	-	-	-	-	-	-	-
Example 22	300	-	-	-	-	-	-	-
Example 23	2000	-	-	-	-	-	-	-
Example 24	2500	-	-	-	-	-	-	-
Example 25	-	300	-	-	-	-	-	-
Example 26	-	-	300	-	-	-	-	-
Example 27	-	-	-	300	-	-	-	-
Example 28	-	-	-	-	300	-	-	-
Example 29	-	-	-	-	-	300	-	-
Example 30	-	-	-	-	-	-	300	-
Example 31	-	-	-	-	-	-	-	300

After the organic-inorganic release layer prepared in Examples 20 to 31 was formed, copper strike plating was performed on the release layer.

The copper strike plating was performed under the plating conditions shown in Table 3 below.

	condition
Copper pyrophosphate (g/L)	90
Potassium pyrophosphate (g/L)	340
Ammonia water (ml/L)	3
Temperature (℃)	55
pH	8.7
Current density (ASD)	4
cathode material	Hamin-dong

After the formation of the copper strike layer was completed, the prepared laminate was placed in an electroless plating bath and electroless plated to form a metal foil (copper foil) with a thickness of 1 μm on the release layer. At this time, metal ion source (CuSO ₄ 5H ₂ O) 190-200 g/L, nitrogen-containing compound (Guanine) 0.01-0.1 g/L, chelating agent (potassium sodium tartrate) 405-420 g/L, pH adjuster An electroless plating solution containing (NaOH) and a reducing agent (28% formaldehyde) was used, and electroless plating was performed at 30°C for 10 minutes.

The following process was performed to confirm the adhesion and peel strength of the formed metal foil.

The formed metal foil (including a single release layer)/Kraft paper/SUS plate was laminated in that order and pressed at 3.5 MPa pressure for 100 minutes at 200°C under vacuum to prepare a laminate.

After removing the kraft paper and SUS plate through the release layer from the manufactured laminate, the peel strength between the copper foil carrier foil (including a single release layer) and the ultra-thin layer was measured according to the IPC-TM-650 standard (BMSP-90P Peel tester, Test speed). : 50 mm/min, Test speed: 90°).

In addition, after the peel strength evaluation was completed, it was also evaluated whether stains occurred on the surface and whether stains occurred after the desmear process.

	Peel strength (gf/cm)		Stains occur	Occurrence of stains (after desmear)
	Press exhibition	After press
Example 20	22.17	23.11	X	O
Example 21	18.74	19.21	X	X
Example 22	6.57	6.62	X	X
Example 23	2.45	3.08	X	X
Example 24	0.27	0.94	X	X
Example 25	6.84	6.95	X	X
Example 26	5.59	5.95	X	X
Example 27	7.18	7.22	X	X
Example 28	6.89	7.01	X	X
Example 29	6.48	6.57	X	X
Example 30	0.48	0.55	O	O
Example 31	-	-	O	O

As shown in Table 4, Example 22, which is judged to be the optimal condition, has an appropriate peel strength and does not cause staining (Figure 10 (a)), but when 5 ppm of the transition metal compound is used, the It was found that the mold release force control effect was poor, resulting in high mold release force, and it was also confirmed that the nitrogen component of CBTA used as a heterocyclic compound remained, causing stains after desmear (Figure 10(b)). In addition, when the chromic acid exceeded 2000 ppm (Example 24), it was confirmed that the release force rapidly decreased due to excessive transition metal compounds.

In addition, Examples 25, 26, and 27 using transition metals other than chromium were found to have appropriate release force, and Examples 28 and 29 using other compounds of chromium also showed appropriate release force. It was confirmed that However, when metal compounds other than transition metal compounds of groups 3 to 8 are used, the release force becomes very weak and stains due to metal components occur (Example 30, Figure 10 (c)). There were cases where it was glued without being molded (Example 31), making it impossible to use.

Next, an experiment was conducted to confirm the effect of the organic components contained in the organic-inorganic composite layer and the plating conditions.

In Example 22, instead of the combination of 5-carboxybenzotriazole (100 g/L) and ethanolamine (10 g/L), a heterocyclic compound and an amine compound were added in combination at the ratios shown in Table 5 below, and the current density and plating The effect was measured by changing the time. (CBTA: 5-carboxybenzotriazole, MT: 3-mercapto-1,2,4-triazole, EA: ethanolamine, AP: 2-amino-1-propanol )

	Plating solution composition (g/L)
	CBTA	MT	EA	AP
Example 32	50	-	10	-
Example 33	100	-	10	-
Example 34	200	-	10	-
Example 35	-	100	10	-
Example 36	100	-	5	-
Example 37	100	-	10	-
Example 38	100	-	20	-
Example 39	100	-	-	10

A laminate was manufactured and tested in the same manner as in Example 22, except that the conditions of Examples 32 to 45 were used.

	Peel strength (gf/cm)		Stains occur	Occurrence of stains (after desmear)
	Press exhibition	After press
Example 32	1.42	1.54	O	O
Example 33	6.57	6.62	X	X
Example 34	18.18	18.27	X	O
Example 35	7.16	7.55	X	X
Example 36	17.48	18.11	O	O
Example 37	6.57	6.62	X	X
Example 38	1.15	1.28	X	O
Example 39	6.48	6.58	X	X

As shown in Table 6, Example 33, which is the optimal condition for the present invention, has appropriate peel strength and does not cause staining (Figure 11 (a)), but as the content of CTBA, a heterocyclic compound, increases, the peel strength decreases. It was confirmed that was rising. In addition, at 200 g/L of this heterocyclic compound, some staining occurred after desmearing, and therefore, it was confirmed that staining occurred at concentrations above this level. Additionally, when 50 g/L was used (Example 32), the content of the heterocyclic compound was reduced, confirming that the metal component of the metal-containing release layer was transferred to the strike copper layer (FIG. 11(b)).

In addition, in Example 35 using a different type of heterocyclic compound, results similar to those of the present invention were seen.

In the case of amine-based compounds, it was confirmed that as the content increases, the ratio of heterocyclic compounds relatively decreases and the release force decreases. However, in the case of Example 36 using 5 g/L, stains occurred ((c in Figure 11) )) appears, which appears to be the effect of the heterocyclic compound not being completely dissolved by the amine-based compound. In addition, in the case of Example 38 in which an excessive amount of an amine compound was used, it was confirmed that stains due to nitrogen components occurred after pressing (Figure 11 (d)).

Additionally, Example 39 using AP showed similar results.

As the specific parts of the present invention have been described in detail above, it is clear to those skilled in the art that these specific techniques are merely preferred embodiments and do not limit the scope of the present invention. will be. Accordingly, the substantial scope of the present invention will be defined by the appended claims and their equivalents.

Claims (14)

1. In the release layer that allows the carrier to be smoothly removed from the carrier-attached metal foil,

   The release layer is,

   A metal-containing release layer formed on the carrier; and

   An organic-inorganic release layer formed on the metal-containing release layer;

   Includes,

   The organic-inorganic release layer is,

   Heterocyclic compounds containing nitrogen;

   Amine-based compounds; and

   Transition metal compounds of groups 3 to 8;

   A composite release layer for metal foil attached to a carrier, comprising:
2. According to paragraph 1,

   The amine compounds include ethanolamine, 2-(methylamino)ethanol, 2-methoxyethylamine, 2-amino-1-propanol, alaninol, 2-ethoxyethaneamine, and N-ethyl-N-propylamine. , for metal foil with a carrier containing at least one member selected from the group of tributylamine, 2-(dimethylamino)ethanol, N,N-dimethylbenzenamine, N,N-dibutylbutanamine, and N-ethylpropanamine. Composite release layer.
3. According to paragraph 1,

   The heterocyclic compounds include benzotriazole, mercapto benzimidazole, mercapto benzotriazole, sodium mercapto benzotriazole, and 5-carboxybenzotriazole. (5-Carboxybenzotriazole), 3-Amino-5-mercapto-1,2,4-triazole (3-Amino-5-mercapto-1,2,4-triazole), 3-mercapto-1,2, 4-Mercapto-1,2,4-triazole, Triazole-5-carboxylic acid, 1-methyl-3-mercapto-1,2,4-triazole (1-Methyl-3-mercapto-1,2,4-triazole) and 1-Phenyl-5-mercapto tetrazole (1-Phenyl-5-mercapto tetrazole). A composite release layer for metal foil with a carrier, characterized by:
4. According to paragraph 1,

   The transition metal compounds of groups 3 to 8 are,

   A composite release layer for metal foil with a carrier, which is a metal compound containing chromium, molybdenum, tungsten or titanium.
5. According to paragraph 4,

   The transition metal compound is;

   oxides of chromium, molybdenum, tungsten or titanium;

   Hydroxides of chromium, molybdenum, tungsten or titanium;

   Sulfates, nitrates, phosphates, hydrochlorides, fluorides or acetates of chromium, molybdenum, tungsten or titanium; or

   Compounds derived from oxides of chromium, molybdenum, tungsten or titanium;

   A composite release layer for metal foil attached to a carrier comprising a.
6. According to clause 5,

   The transition metal compounds of groups 3 to 8 include chromic acid, chromium (III) picolinate, potassium dichromate, chromium oxide, chromyl chloride, chromium sulfate, tungsten dioxide, tungsten trioxide, tungsten disulfide, tungsten trisulfide, and tungsten dioxide. Composite release layer for metal foil with carrier containing chloride, tungsten hexachloride, tungsten tetrachloride, ditungsten decachloride, tungsten trichloride, titanium tetrachloride, titanium disulfide, titanium halide, molybdenum oxide, molybdenum sulfide or molybdenum hexacarbonyl .
7. According to paragraph 1,

   The metal-containing release layer is a composite release layer for metal foil with a carrier containing nickel and molybdenum.
8. In clause 7,

   The metal-containing release layer is a composite release layer for metal foil attached to a carrier containing 50 to 80% by weight of Ni and 20 to 50% by weight of molybdenum.
9. According to paragraph 1,

   The release layer is a composite release layer for metal foil attached to a carrier, characterized in that the peel strength is 1 to 20 gf/cm when evaluated according to the IPC-TM-650 standard.
10. According to paragraph 1,

    The metal-containing release layer has a thickness of 0.01-0.2㎛, and the organic-inorganic release layer has a thickness of 0.001-0.01㎛. A composite release layer for metal foil attached to a carrier.
11. According to paragraph 1,

    A metal foil attached to a carrier comprising the composite release layer of any one of claims 1 to 10.
12. According to clause 11,

    The metal foil attached to the carrier is,

    carrier;

    The composite release layer provided on the carrier; and

    A metal layer provided on the composite release layer;

    Equipped with

    A metal foil with a carrier, characterized in that the metal layer includes a metal foil including a plurality of protrusions.
13. In paragraph 12

    The metal layer is,

    a metal strike layer formed on the release layer; and

    A metal foil including a plurality of protrusions formed on the metal strike layer;

    Includes

    The metal strike layer is a metal foil attached to a carrier formed under conditions of pH 8 to 11 using metal pyrophosphate.
14. According to clause 12,

    A metal foil attached to a carrier, wherein the plurality of protrusions have flat tops.

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