KR20220082767A - Release layer for metal foil with carrier and metal foil comprising the same - Google Patents

Abstract

The present invention relates to a release layer for metal foil with a carrier and a metal foil comprising the same.
The present invention, in the release layer to allow the carrier to be smoothly removed from the metal foil with a carrier, The release layer, a nitrogen-containing heterocyclic compound; and nickel, molybdenum, cobalt, phosphorus, manganese and an inorganic compound comprising at least one selected from the group consisting of iron.

Description

Release layer for metal foil with carrier and metal foil comprising the same

The present invention relates to a release layer for metal foil with a carrier and a metal foil comprising the same.

In general, a printed circuit board may be manufactured by bonding a metal foil and an insulating resin substrate and then forming a circuit wiring on the metal foil through an etching process. In order to prevent peeling of the metal foil from occurring in the process of forming the circuit wiring, it is required to have high adhesion between the metal foil and the insulating resin substrate.

In order to increase the adhesion between the metal foil and the insulating resin substrate, in the prior art, roughening treatment was performed on the surface of the metal foil to form irregularities on the surface of the metal foil, and a method of placing the insulating resin substrate on the surface of the metal foil on which the irregularities were formed and pressing to bond them was proposed. there is a bar Specifically, Patent Document 1 discloses that the surface of the copper foil on the resin layer side is subjected to an electrolytic treatment, a blast treatment, or an oxidation-reduction treatment to form particulate protrusions, thereby improving the adhesion between the copper foil and the resin layer.

However, since the above method performs a separate roughening treatment on the already formed metal foil, there is a problem in that the manufacturing efficiency of the printed circuit board is lowered. In addition, there is a problem in that the high frequency signal transmission efficiency is also lowered due to the unevenness formed on the surface of the metal foil. That is, in order to process a large amount of information at high speed in accordance with the trend toward high functionality of portable electronic devices, signal transmission loss should be minimized in the process of transmitting high-frequency signals. However, when unevenness of high roughness is formed on the surface of the metal foil, it acts as an obstacle to high-frequency signal transmission and thus the high-frequency signal transmission efficiency is lowered.

On the other hand, due to the thin thickness of the metal foil, wrinkles or bends easily occur during bonding with the insulating resin substrate or the target substrate. To compensate for this, the metal foil is handled by combining a release layer and a carrier on one surface thereof. Here, the metal foil in which the release layer and the carrier are bonded must have heat resistance in the bonding process with the insulating resin substrate or the target substrate, and it is required that the carrier is well peeled through the release layer after bonding. To this end, a technique of applying an organic component to the release layer or providing a separate layer capable of increasing heat resistance between the release layer and the metal foil has been proposed.

However, the release layer used in such a metal foil is generally composed of two layers, an organic release layer and an inorganic diffusion prevention layer, and thus requires a lot of cost in manufacturing, and there are cases in which a defect in the separation of the interface of each layer occurs. to be. Therefore, there is a need to develop a new release layer to solve the disadvantages of the release layer.

(0001) Republic of Korea Patent No. 10-1460553 (0002) Republic of Korea Patent Registration No. 10-0869477

In order to solve the above problems, the present invention is to provide a release layer for metal foil with a carrier that can serve as an organic release layer and an inorganic diffusion prevention layer at the same time, and a metal foil comprising the same.

In addition, an object of the present invention is to provide a release layer for metal foil with a carrier, which is composed of a single layer, so that peeling does not occur between each layer, and can reduce cost and time during manufacturing, and a metal foil including the same.

In order to solve the above problems, the present invention provides a release layer to allow a carrier to be smoothly removed from a metal foil with a carrier, wherein the release layer includes: a nitrogen-containing heterocyclic compound; and nickel, molybdenum, cobalt, phosphorus, manganese and an inorganic compound comprising at least one selected from the group consisting of iron.

In one embodiment, the heterocyclic compound is benzotriazole (Benzotriazole), mercapto benzimidazole (Mercapto benzimidazole), mercapto benzotriazole (Mercapto benzotriazole), sodium mercapto benzotriazole (Sodium mercapto benzotriazole), 5-Carboxybenzotriazole, 3-amino-5-mercapto-1,2,4-triazole (3-Amino-5-mercapto-1,2,4-triazole), 3-mer Capto-1,2,4-triazole (3-Mercapto-1,2,4-triazole), triazole-5-carboxylic acid (Triazole-5-carboxylic acid), 1-methyl-3-mercapto-1, 1 selected from the group consisting of 2,4-triazole (1-Methyl-3-mercapto-1,2,4-triazole) and 1-phenyl-5-mercapto tetrazole It may include more than one species.

In one embodiment, the inorganic compound, nickel, molybdenum, cobalt, phosphorus, manganese and iron sulfate, nitrate, phosphate, hydrochloride, hydrofluoric acid salt or acetate; or salts derived from oxides of nickel, molybdenum, cobalt, phosphorus, manganese and iron.

In one embodiment, the release layer may have a peel strength of 5 to 50 gf/cm when evaluated according to the IPC-TM-650 standard.

In one embodiment, the release layer may have a thickness of 100nm ~ 1㎛.

The present invention also provides a metal foil with a carrier including the release layer.

In one embodiment, the metal foil with a carrier, a carrier; the release layer provided on the carrier; and a metal layer provided on the release layer, wherein the metal layer may include a metal foil including a plurality of protrusions having a flat top.

In one embodiment, the metal layer, an ultra-thin layer formed on the release layer; and a metal foil including a plurality of projections having a flat upper portion formed on the ultra-thin layer, wherein the ultra-thin layer may be formed through an electrolytic plating process.

The present invention can minimize a decrease in high frequency signal transmission efficiency while exhibiting high adhesion to a target substrate (eg, an insulating resin substrate) due to the metal foil having one or more protrusions formed thereon.

In addition, the present invention can provide a metal foil with a carrier excellent in heat resistance while the metal foil is well peeled from the carrier due to the release layer having a single-layer structure (deformation of the metal foil is minimized and peeling is performed without residual impurities).

In addition, the present invention can provide a printed circuit board that is based on an insulating resin substrate or not based on an insulating resin substrate (manufactured by a coreless method) and has excellent high frequency signal transmission efficiency.

1 shows a metal foil with a carrier including a release layer according to an embodiment of the present invention.
2 shows a metal foil with a carrier including a release layer having two conventional layers.
Figure 3 shows the projection structure on the surface of the metal foil according to an embodiment of the present invention.
4 shows protrusions having various shapes according to an embodiment of the present invention.
5 is a SEM photograph of the surface of the metal foil on which the projections are formed according to an embodiment of the present invention.
6 shows a TOF-SIMS analysis result according to an embodiment of the present invention.
7 shows the TOF-SIMS analysis result according to the comparative example 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 a related known technology may obscure the gist of the present invention, the detailed description thereof will be omitted. Throughout the specification, when a part "includes" a certain component, it means that other components may be further included, rather than excluding other components, unless otherwise stated.

Since the present invention can apply various transformations and can have various embodiments, specific embodiments are illustrated and described in detail in the detailed description. However, this is not intended to limit the present invention to specific embodiments, it should be understood to include all modifications, equivalents and substitutes included in the spirit and scope of the present invention.

The technology disclosed herein is not limited to the implementations described herein and may be embodied in other forms. However, the embodiments introduced herein are provided so that the disclosed content may be thorough and complete, and the technical spirit of the present technology may be sufficiently conveyed to those skilled in the art. In order to clearly express the components of each device in the drawings, the sizes such as widths and thicknesses of the components are slightly enlarged. In the description of the drawings as a whole, it has been described from an observer's point of view, and when an element is referred to as being positioned on another element, this means that the element may be positioned directly on the other element or an additional element may be interposed between the elements. include In addition, those of ordinary skill in the art will be able to implement the spirit of the present invention in various other forms without departing from the technical spirit of the present invention. And the same reference numerals in the plurality of drawings refer to elements that are substantially the same as each other.

Terms used in the present invention are only used to describe specific embodiments, and are not intended to limit the present invention. The singular expression includes the plural expression unless the context clearly dictates otherwise. In the present invention, the terms include or have is intended to designate that a feature, number, step, operation, component, part, or combination thereof described in the specification exists, but one or more other features, number, step , it should be understood that it does not preclude in advance the possibility of the presence or addition of an operation, component, part, or combination thereof.

On the other hand, the meaning of the terms described in this specification should be understood as follows. Terms such as “first” or “second” are for distinguishing one component from other components, and the scope of rights should not be limited by these terms. For example, a first component may be termed a second component, and similarly, a second component may also be termed a first component.

In addition, the singular expression should be understood to include the plural expression unless the context clearly dictates otherwise, and terms such as “comprise” or “have” refer to the described feature, number, step, operation, component, or part. It is to be understood that this is intended to indicate that there is a combination thereof, but does not preclude the possibility of addition or existence of one or more other features or numbers, steps, operations, components, parts, or combinations thereof. In addition, in performing the method or the manufacturing method, each process constituting the method may occur differently from the specified order unless a specific order is clearly described in context. That is, each process may occur in the same order as specified, may be performed substantially simultaneously, or may be performed in the reverse order.

In this specification, 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, in the release layer to allow the carrier to be smoothly removed from the metal foil with a carrier, The release layer, a nitrogen-containing heterocyclic compound; and an inorganic compound comprising at least one selected from the group consisting of nickel, molybdenum, cobalt, phosphorus, manganese and iron.

The release layer used in the conventional metal foil with a carrier is largely composed of an inorganic diffusion barrier layer 220 and an organic release layer 210 (see FIG. 2 ). In particular, the inorganic diffusion barrier layer 220 serves as a barrier to prevent the components of the carrier 300 from being diffused into the metal foil 100, and serves to prevent changes in the physical properties of the metal foil even when stored for a long time. However, the release layer of such a multi-layer structure has a disadvantage in that it takes a lot of time to manufacture because each layer must be transferred or plated separately, and the interface of each release layer is separated during release, leaving a residue on the metal foil.

Accordingly, in the present invention, by manufacturing the release layer 200 capable of simultaneously performing the roles of the inorganic diffusion barrier layer and the organic release layer, the residues as described above can be minimized, and the production time and cost can be minimized. There is (see Fig. 1).

To this end, the release layer 200 includes an inorganic compound including a metal component and an organic component including a heterocyclic compound at the same time, and serves as an organic release layer and an inorganic diffusion prevention layer of the release layer.

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

Specifically, the heterocyclic compound is a cyclic compound having two or more nitrogen atoms, more specifically, benzotriazole, mercapto benzimidazole, mercapto benzotriazole. , Sodium mercapto benzotriazole (Sodium mercapto benzotriazole), 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-triazole (3-Mercapto-1,2,4-triazole), triazole-5-carboxylic acid (Triazole-5-carboxylic acid) ), 1-methyl-3-mercapto-1,2,4-triazole (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. Since the cyclic compound is included in the release layer, the structure of the release layer may be stably maintained, and diffusion between the upper and lower portions of the release layer may be prevented.

In addition, although one component may be used alone as the organic component, it is more preferable to use a combination of two or more organic components to facilitate release during peeling. In the case of including two kinds of organic components as described above, the mixing ratio of each organic component may be in a ratio of 1 to 5: 5 to 1, preferably in a ratio of 1:1, that is, the same amount may be mixed and used. When the organic component is mixed in a ratio out of the above range, it is difficult to expect an effect by mixing.

In addition, the organic component may be mixed with the plating solution at a ratio of 0.5 to 5 g/L during plating to form the release layer 200 . When the organic component is mixed at a ratio of less than 0.5 g/L, the peel strength of the release layer 200 is lowered, so that the carrier may be separated at an undesired point. Since the component is plated with relatively few components, the diffusion prevention effect may be lowered.

The inorganic component may be an inorganic compound including at least one selected from the group consisting of nickel, molybdenum, cobalt, phosphorus, manganese and iron. This inorganic component is a portion that prevents the component of the lower carrier 300 from being diffused into the upper metal foil 100, and it is preferable to prevent diffusion of copper, which is mainly used for the lower carrier. In addition, in the case of the present invention, the lower carrier is used as copper and the upper metal foil may also be copper. However, when the copper component of the lower carrier diffuses upward, the composition of the upper metal foil may change. In order to prevent this, the inorganic component It is preferable to include

In this case, the inorganic component is preferably an inorganic compound including at least one selected from the group consisting of nickel, molybdenum, cobalt, phosphorus, manganese and iron, and more preferably nickel, molybdenum, cobalt, phosphorus, manganese and iron. sulfate, nitrate, phosphate, hydrochloride, hydrofluoric acid or acetate; or salts derived from oxides of nickel, molybdenum, cobalt, phosphorus, manganese and iron.

Specifically, as the sulfate, iron sulfate, nickel sulfate, ammonium sulfate, manganese sulfate, molybdenum disulfide, and cobalt sulfate may be used, and as the nitrate, iron nitrate, nickel nitrate, molybdenum nitrate, cobalt nitrate, and manganese nitrate may be used. can Similarly, phosphate salts such as iron phosphate, nickel phosphate, molybdenum phosphate, cobalt phosphate, manganese phosphate, nickel chloride, molybdenum chloride, cobalt chloride, and manganese chloride may be used, and hydrofluoric acid salts or acetates may also be used.

In addition, the salt derived from the oxide refers to a salt in which sodium, potassium, calcium, magnesium, etc. are combined with a base made of oxides of nickel, molybdenum, cobalt, phosphorus, manganese and iron.

In addition, it is more preferable to use the inorganic component by mixing two or more inorganic components (first component and second component) in order to increase the diffusion prevention effect in the same way as the organic component. In particular, when a compound containing nickel is used as the inorganic component, it is possible to prevent the metal component of the carrier from diffusing to the upper portion of the release layer, and when a compound containing molybdenum is used, the organic component, that is, a heterocyclic ring By activating the compound so that the inorganic components can be smoothly combined, residues during release can be minimized.

Here, the ratio (a:b) of the first component (a) and the second component (b) may be a weight ratio of 30 to 80:70 to 20, specifically 40 to 70:60 to 30 by weight. . As the ratio of the first component to the second component is within the above range, diffusion of the component of the carrier into the metal layer may be prevented, and the carrier may be peeled off so that impurities do not remain in the metal layer. In addition, a required bonding strength (peel strength) before and after peeling may be imparted to the release layer. In addition, even if the metal foil with the carrier foil is heat treated at 200° C. or higher for the manufacture of a laminate for forming a printed wiring board combined with a resin substrate, the bonding strength (peel strength) between the carrier and the release layer is stably maintained, so that the carrier can be easily peeled off. have.

On the other hand, when the release layer includes two kinds of inorganic components as described above, the agent containing at least one selected from the group consisting of cobalt (Co), phosphorus (P), manganese (Mn) and iron (Fe) It may further include 3 components. As the release layer further includes a third component, the bonding strength between the inorganic and organic components constituting the release layer can be increased, and the bonding strength (peel strength) can be stably heated even when the metal foil with a carrier is heat treated at 200° C. or higher. can keep Here, when the release layer further includes the third component (c), the ratio (a:b:c) of the first component (a), the second component (b), and the third component (c) is 30 to 60 It may be a weight ratio of: 25 to 50: 1 to 40.

In addition, the inorganic component may be mixed with the plating solution at a ratio of 50 to 150 g/L during plating to form the release layer. When the inorganic component is mixed at a ratio of less than 50 g/L, the diffusion prevention effect may be reduced, and when the inorganic component is mixed at a ratio exceeding 150 g/L, the ratio of the organic component is relatively low and peel strength may be decreased.

The release layer prepared by combining the organic component and the inorganic component as described above may have a thickness of 100 nm to 1 μm, preferably 100 to 500 nm, more preferably 150 to 250 nm. When the release layer has a thickness of less than 100 nm, the release layer becomes too thin, so it is difficult to peel off and at the same time to prevent diffusion of the carrier layer. this can remain

In addition, electroplating may be performed to form the release layer 200 as described above, and the electrolytic plating may be performed for 10 to 60 seconds at an intensity of 2 to 5 ASD. When the electrolytic plating is performed for an intensity of less than 2 ASD or for a time period of less than 10 seconds, the thickness of the release layer 200 may be less than 100 nm, and an intensity exceeding 5 ASD or when performed for a time exceeding 60 seconds If the thickness of the release layer exceeds 1 μm or the amount of current is too strong, the release layer may be carbonized.

The release layer 200 may have a peel strength of 5 to 50 gf/cm when evaluated according to the IPC-TM-650 standard. If the peel strength is less than 5 gf / cm, the carrier may be separated during storage or movement, and defects may occur.

The present invention also provides a metal foil with a carrier including the release layer. In the case of the release layer of the present invention, as described above, it may be composed of a single layer, and thus may have the advantage of being able to form the release layer at a lower cost and in less time than the conventional metal foil with a carrier.

The said metal foil with a carrier, a carrier; the release layer provided on the carrier; and a metal layer provided on the release layer, wherein the metal layer may include a metal foil including a plurality of protrusions having a flat top.

The metal foil 100 according to the present invention includes a plurality of projections 10 having a flat top. The projections 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 protrusion 11 and a flat portion 12 .

The protrusion 11 included in the protrusion 10 is a portion protruding from the surface of the metal foil 100 and may have a truncated cone shape or a polygonal truncated 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 truncated pyramid shape with an angulate surface. is increased, so that the metal foil 100 may be coupled to the insulating resin substrate to have high adhesion. More specifically, the protrusion 11 may have at least one shape selected from the group consisting of a pentagonal truncated pyramid shape, a hexagonal truncated pyramid shape, a heptagonal truncated pyramid shape, and an octagonal truncated pyramid shape.

A plurality of fine protrusions 11a may be formed on the protrusion 11 to increase adhesion to the insulating resin substrate due to an increase in surface area. Due to the fine protrusions 11a, the protrusion 11 may have a surface roughness Ra of 0.05 to 0.3 μm, specifically 0.08 to 0.2 μm. 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 part 12 .

Meanwhile, the ratio (b/a) of the length (a) of the base 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 minimize signal transmission loss in the high frequency signal transmission process while increasing the adhesion between the metal foil 100 and the insulating resin substrate.

The flat portion 12 included in the protrusion 10 is a flat surface provided on the upper end of the protrusion 11 . The flat portion 12 may mean an upper surface of the protrusion 11 having a truncated cone shape or a polygonal truncated pyramid shape. Here, unlike the prior art in which high-frequency signal transmission loss occurred due to the formation of particles (formation of irregularities with high roughness) to protrude sharply or roundly to increase adhesion, the present invention provides a flat portion in which the upper part (upper part) of the protrusion 10 is a flat surface. As (12) is formed, the surface of the metal foil 100 exhibits relatively low illuminance, thereby minimizing the occurrence of high-frequency signal transmission loss. Specifically, the flat portion 12 may have a circular, oval, or polygonal shape. On the other hand, even if the fine unevenness is formed on the surface, it can be seen that the case where the fine unevenness is densely formed to form a flat surface is included in the scope of the flat portion 12 of the present invention.

In the protrusion 10, the ratio (c/a) of the length (a) of the base 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 minimize the occurrence of signal transmission loss in the high frequency signal transmission process while increasing the adhesion between the metal foil 100 and the insulating resin substrate. The length c of the flat portion 12 may mean the longest length in the plane forming the flat portion 12 .

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

The protrusion 10 may be formed by electroless plating. Specifically, the metal foil 100 according to the present invention is manufactured by electroless plating, and after the metal seed foil is formed during the electroless plating process, crystal grains continuously grow on the metal seed foil so that a plurality of protrusions 10 are formed on the surface. The metal foil 100 present in the can be manufactured. Here, unlike the conventional method of forming irregularities by performing a separate roughening treatment on the metal foil, in the present invention, since a plurality of protrusions 10 that are roughened surfaces are naturally formed in the manufacturing process of the metal foil 100, a separate roughening treatment is performed This process may be omitted, thereby improving the manufacturing efficiency of the metal foil 100 and/or the printed circuit board. In addition, as the metal foil 100 is manufactured by electroless plating, it is possible to provide the metal foil 100 having a thinner thickness and porosity than the metal foil manufactured by electroplating.

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

Specifically, the metal ion source may be at least one copper ion source selected from the group consisting of copper sulfate, copper chloride, copper nitrate, copper hydroxide, and copper sulfamate. The concentration of the 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 to form a plurality of projections 10 on the surface of the metal seed foil formed by the metal ion source. The nitrogen-containing compound is specifically 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 -Pyryl ketone, N,N,N',N'-tetraethylenediamine, 1,8-naphthyridine, 1,6-naphthyridine, and may be at least one selected from the group consisting of terpyridine. The concentration of the nitrogen-containing compound 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 adjusting agent, and a reducing agent.

The chelating agent is specifically 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 group consisting of hydantoin, 5,5-dimethylhydantoin, nitriloacetic acid, triethanolamine, ethylenediaminetetraacetic acid, tetrasodiumethylenediaminetetraacetate, N-hydroxyethylenediaminetriacetate and pentahydroxypropyldiethylenetriamine It may be one or more selected from. The concentration of the chelating agent may be 0.5 to 600 g/L, specifically 300 to 450 g/L, and more specifically 400 to 430 g/L.

Specifically, the pH adjusting agent may be at least one selected from the group consisting of sodium hydroxide, potassium hydroxide and lithium hydroxide. Such a pH adjusting agent 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.

Specifically, the reducing agent may be at least one selected from the group consisting of formaldehyde, sodium hypophosphite, sodium hydroxymethane sulfinate, glyoxylic acid, borohydride, 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 may be appropriately adjusted according to the thickness of the metal foil 100 . Specifically, the electroless plating temperature may be 20 to 60 ℃, specifically 25 to 40 ℃, the electroless plating time may be 2 to 30 minutes, specifically 5 to 20 minutes.

As described above, the thickness of the metal foil 100 of the present invention manufactured by electroless plating may be 5 μm or less, specifically 0.1 to 1 μm. In addition, the component constituting the metal foil 100 of the present invention is not particularly limited as long as it is a known metal capable of forming a circuit layer of a printed circuit board, and specifically, it is 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 with a carrier according to the present invention is to prevent the metal layer from being deformed in the process of movement or use of the metal with a carrier, metal such as copper, aluminum; Alternatively, it may be made of a polymer such as polyethylene terephthalate (PET), polyphenylene sulfide (PPS), or Teflon. The thickness of such a carrier may be specifically 10 to 50 μm.

The metal foil with a carrier according to the present invention may further include a rust prevention layer provided on the metal layer for protection of the metal layer. The rust prevention layer may include zinc, chromium, and the like.

In addition, the metal layer, an ultra-thin layer formed on the release layer; and a metal foil including a plurality of projections having a flat upper portion formed on the ultra-thin layer.

The metal layer may be largely composed of an ultra-thin layer formed on the release layer and the metal foil having the plurality of protrusions. The ultra-thin layer is formed on the release layer to serve as a base for forming the metal foil, and may be formed using an electrolytic plating process.

Specifically, in order to form a metal layer on the release layer, an electrolytic plating process must be used. However, since the metal foil of the present invention is formed by electroless plating as described above, it may be difficult to form directly on the release layer. Therefore, since the release layer is formed by using an electrolytic plating process to form the ultra-thin layer, the metal foil using the electroless plating method can be smoothly formed.

At this time, for smooth bonding with the metal foil, the ultra-thin layer may include at least one selected from the group consisting of copper, silver, gold, nickel and aluminum, and more preferably, the ultra-thin layer is the same as the metal foil. It may be made of metal.

The ultra-thin layer may be manufactured using an electrolytic plating process as described above. In this case, sulfates of copper, silver, gold, nickel and aluminum may be used as a source of metal ions, and an aqueous solution containing sulfuric acid may be used as the electrolyte solution.

In addition, the electrolytic plating process may be used by properly distributing process conditions according to the thickness of the ultra-thin layer, but may be performed at a temperature of 20 to 30° C. for 1 to 50 seconds. Within the above range, a normal ultra-thin layer may be formed, but if it is less than the above range, the thickness of the ultra-thin layer may be thin, so it may be difficult to form the metal foil. can increase

In addition, the electroplating process for forming the ultra-thin layer may be performed under a current density of 1 to 5 ASD. When a current less than the current density is supplied, the formation of the ultra-thin layer may not be performed, and when a current exceeding the above range is supplied, the ultra-thin layer is oxidized and a defect may occur.

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, or the like.

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, and the metal circuit layer is derived from the above-described metal foil, 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. Such a metal circuit layer is obtained through the process of forming circuit wiring on the above-described metal foil, and the present invention can provide a printed circuit board showing fine and high resolution by the above-described metal foil. Specifically, the printed circuit board according to the present invention is manufactured by performing an etching process on a laminate in which an insulating resin substrate and the above-mentioned metal foil are combined, and forming circuit wiring on the metal foil, wherein the metal foil has high adhesion with the insulating resin substrate. Since the thickness is relatively thin while being coupled, it is possible to form fine and high-resolution circuit wiring on metal foil. In addition, by the above-described metal foil, the present invention can provide a printed circuit board exhibiting high adhesion between the circuit wiring and the insulating resin substrate.

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

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

The printed circuit board according to the present invention may be manufactured using an insulating resin substrate or may be manufactured by a coreless method in which the insulating resin substrate is excluded. The coreless method may not be particularly limited as long as it is a commonly known method.

Hereinafter, the present invention will be described in more detail by way of Examples. However, the following examples are intended to illustrate the present invention, and it is apparent to those skilled in the art that various changes and modifications can be made within the scope and spirit of the present invention, and the scope of the present invention is not limited thereto.

Examples 1-15

A carrier foil made of a copper foil having a thickness of about 18 μm was immersed in 5 wt% sulfuric acid to be pickled, and then washed with pure water. A release layer was formed by electroplating the washed carrier foil with a plating solution containing nickel sulfate, sodium molybdate, 3-mercapto-1,2,4-triazole (MT) and 5-Carboxybenzotriazole (CBTA). At this time, the concentration of the nickel sulfate, sodium molybdate, MT and CBTA, and the current density and the plating time were changed to observe the change in the release layer according to the change in the plating conditions. The composition, current and degree of the plating solution used and the plating time are shown in Table 1 below.

Plating solution composition (g/L) current density
(ASD) plating time
(candle) nickel sulfate sodium molybdate MT CBTA Example 1 50 60 One One 3.5 30 Example 2 25 75 One One 3.5 30 Example 3 70 40 One One 3.5 30 Example 4 15 25 One One 3.5 30 Example 5 70 90 One One 3.5 30 Example 6 50 60 1.5 0.5 3.5 30 Example 7 50 60 0.5 1.5 3.5 30 Example 8 50 60 0.2 0.2 3.5 30 Example 9 50 60 3 3 3.5 30 Example 10 50 60 One One 2 30 Example 11 50 60 One One 4.5 30 Example 12 50 60 One One 5.5 30 Example 13 50 60 One One 3.5 15 Example 14 50 60 One One 3.5 50 Example 15 50 60 One One 3.5 70

Comparative Example 1

As in the conventional method, a release layer prepared by forming a metal alloy layer on the carrier and then forming an organic material layer was used.

Specifically, a carrier foil made of 18 μm thick copper foil was immersed in 5 wt% sulfuric acid to be pickled, and then washed with pure water. Electrolytic plating with a plating solution (nickel sulfate 50 g/L, sodium molybdate 60 g/L and citric acid 50 g/L aqueous solution) containing nickel (first component) and molybdenum (second component) on the washed carrier foil Thus, an alloy layer (nickel: molebdenum ratio = 60:40 weight ratio) having a thickness of 200 nm was formed. At this time, the electrolytic plating was performed at 5 ASD for 30 seconds while maintaining a pH of 10 or higher.

After washing the carrier foil on which the alloy layer is formed, it is immersed in a coating solution at 30° C. consisting of 1 part by weight of sodium mercaptobenzotriazole and 99 parts by weight of pure water for 30 seconds to form an organic layer having a thickness of 1 to 10 nm on the alloy layer. formed.

Experimental Example 1

An ultra-thin layer and a metal foil layer were formed on the release layer formed in Examples 1 to 15 as follows.

1) Ultra-thin layer formation

An ultra-thin layer was formed on the formed release layer. The ultra-thin layer was formed through electroplating, and was made using an electrolytic plating solution containing 250 g/L of copper sulfate and 50 g/L of sulfuric acid under conditions of a temperature of 25 degrees and a current density of 3 ASD to form a thickness of about 1 μm.

2) Formation of metal foil layer

After the formation of the ultra-thin layer was completed, the laminate was put into an electroless plating bath and electroless plating was performed to form a metal foil (copper foil) having a thickness of 1 μm on the release layer. At this time, metal ion source (CuSO ₄ ·5H ₂ 0) 190-200 g/L, nitrogen-containing compound (Guanine) 0.01-0.1 g/L, chelating agent (potassium sodium tartrate) 405-420 g/L, pH adjusting agent An electroless plating solution containing (NaOH) and a reducing agent (28% formaldehyde) was used, and the electroless plating was performed at 30° C. for 10 minutes.

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

The formed metal foil (including a single release layer) / craft paper / SUS plate (plate) was laminated in this order and pressed under vacuum at 200 ° C. for 100 minutes at a pressure of 3.5 MPa 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 IPC-TM-650 standard (BMSP-90P Peel tester, Test speed). : 50 mm/min, Test speed: 90°).

In addition, the thickness of the release layer prepared in Examples 1 to 15 was measured in order to confirm the thickness of the release layer according to the conditions of each of the Examples.

Peel strength (gf/cm) Thickness (nm) Example 1 14.7 201 Example 2 8.4 226 Example 3 11.4 218 Example 4 41.4 125 Example 5 4.1 318 Example 6 11.2 218 Example 7 10.1 199 Example 8 3.5 98 Example 9 52.8 359 Example 10 19.1 108 Example 11 10.9 318 Example 12 6.8 481 Example 13 19.8 84 Example 14 9.1 455 Example 15 4.4 1046 Comparative Example 1 15.1 251

As shown in Table 2, in the case of Example 1 of the present invention, it was found that a release layer having a thickness of 200 nm can be formed while having an appropriate peel strength. In particular, there was almost no difference in physical properties from Comparative Example 1 prepared by the conventional method, and since the release layer could be formed in one step, it was found that the manufacturing time and cost were significantly reduced.

Experimental Example 2

Residue testing was performed after peeling using Example 1 and Comparative Example 1. 100 5cmX5cm specimens were prepared in the same manner as in Experimental Example 1, and then each of them was peeled off, and it was visually confirmed that residues remained on the surface of the metal foil.

Number of Residue Checks (pcs) Example 1 One Example 2 2 Example 3 One Example 4 One Example 5 3 Example 6 6 Example 7 8 Example 8 9 Example 9 4 Example 10 2 Example 11 3 Example 12 2 Example 13 2 Example 14 One Example 15 2 Comparative Example 1 11

As shown in Table 3, in the case of the Example of the present invention, it was found that less residue was left compared to the Comparative Example prepared by the conventional method.

Experimental Example 3

TOF-SIMS analysis was performed to compare the components of Example 1 and Comparative Example 1. This TOF-SIMS is a method of analyzing the components of the shaved layer while scraping the surface to a certain thickness, and it is an analysis method that can observe the change in composition according to the thickness. 6 is an analysis result of Example 1, and FIG. 7 is an analysis result of Comparative Example 1. As shown in FIG. 7 , in the case of Comparative Example 1 having a release layer composed of an alloy layer and an organic layer as in the conventional method, it was confirmed that the organic material content decreased as the depth increased. That is, in the case of Comparative Example 1, it means that the composition is changed according to the depth, which means that a non-uniform release layer is formed. As shown in FIG. 6 , in the case of Example 1 of the present invention, there is little change in each component even when the depth is changed, which means that each component is evenly distributed in a single layer.

100: metal foil
10: turn
11: protrusion
11a: microprotrusions
12: flat part

Claims (8)

In the release layer that allows the carrier to be smoothly removed from the metal foil with a carrier,
The release layer is
heterocyclic compounds containing nitrogen; and
an inorganic compound comprising at least one selected from the group consisting of nickel, molybdenum, cobalt, phosphorus, manganese and iron;
A release layer for metal foil with a carrier, comprising:
According to claim 1,
The heterocyclic compound is benzotriazole, mercapto benzimidazole, mercapto benzotriazole, sodium mercapto benzotriazole, 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-triazole (3-Mercapto-1,2,4-triazole), triazole-5-carboxylic acid (Triazole-5-carboxylic acid), 1-methyl-3-mercapto-1,2,4-triazole (1-Methyl-3-mercapto-1,2,4-triazole) and 1-phenyl-5-mercaptotetrazole (1-Phenyl-5-mercapto tetrazole) comprising at least one selected from the group consisting of A release layer for metal foil with a carrier, characterized in that.
According to claim 1,
The inorganic compound is
sulfate, nitrate, phosphate, hydrochloride, hydrofluoric acid or acetate salts of nickel, molybdenum, cobalt, phosphorus, manganese and iron; or
salts derived from oxides of nickel, molybdenum, cobalt, phosphorus, manganese and iron;
A release layer for metal foil with a carrier, comprising:
According to claim 1,
The release layer is a release layer for a metal foil with a carrier, characterized in that the peel strength is 5 ~ 50gf / cm when evaluated according to the IPC-TM-650 standard.
2. The method of claim 1
The release layer is a release layer for a metal foil with a carrier, characterized in that it has a thickness of 100nm ~ 1㎛.
Metal foil with a carrier containing the mold release layer of any one of Claims 1-5.
7. The method of claim 6,
The metal foil with a carrier,
carrier;
The release layer of any one of claims 1 to 5 provided on the carrier; and
a metal layer provided on the release layer;
to provide
The metal layer is a metal foil with a carrier, characterized in that it comprises a metal foil including a plurality of projections with a flat top.
8. The method of claim 7
The metal layer is
an ultra-thin layer formed on the release layer; and
a metal foil including a plurality of projections having a flat upper portion formed on the ultra-thin layer;
includes
The ultra-thin layer is metal foil with a carrier, characterized in that formed through an electrolytic plating process.

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