Electrodeposited copper foil having preferred orientation of (200) crystal plane and application of the same

Abstract

To provide an electrodeposited copper foil having a preferred orientation of (200) crystal plane and application of the same.SOLUTION: An electrodeposited copper foil having a preferred orientation of (200) crystal plane after heat treatment is disclosed. The electrodeposited copper foil after heat treatment has the same microstructure as that of rolled and annealed copper foil and exhibits excellent mechanical properties. A production method for the electrodeposited copper foil and application of the same are also disclosed. The applications include flexible copper-clad laminates, printed circuit boards, and electronic devices produced from the same.SELECTED DRAWING: Figure 1A

Description

[Technical Field]

[0001] This application relates to electrodeposited copper foils having a preferred orientation of the (200) crystal plane after heat treatment, methods for their manufacture, and flexible copper-clad laminates, printed circuit boards, and electronic devices manufactured therefrom. [Background technology]

[0002] Traditionally, copper foils can be classified into two major categories based on their manufacturing method: rolled and annealed (RA) copper foil and electrodeposited (ED) copper foil. RA copper foil is produced from raw copper sheet by subjecting it to a series of cold and hot rolling processes using rollers, followed by annealing to gradually roll the foil and form a thin copper foil, ultimately resulting in a copper foil typically 6 to 70 μm thick. ED copper foil, on the other hand, is produced from raw copper particles or copper wire by dissolving them in a sulfuric acid solution to form a copper sulfate solution, followed by direct current electroplating to reduce the copper ions in the solution to copper atoms, which then deposit on the negative electrode surface, ultimately forming a copper foil 6 to 70 μm thick. The aforementioned reference to a thickness of 6 to 70 μm for copper foil represents a commonly used specification; copper foils of other thicknesses can be prepared by controlling the rolling process or adjusting the parameters of the electroplating process.

[0003] Although RA copper foil and ED copper foil are prepared by different methods, the base copper foils (i.e., excluding the surface-treated portion) produced by these methods have almost the same chemical composition, which is pure copper with a purity of over 99.9%. However, RA copper foil has mechanical properties that are significantly different from those of electrodeposited copper foil, such as tensile strength, elongation, and bending resistance. The main reason is that RA copper foil has a microstructure with a changed grain arrangement after thermal processing (e.g., oven-baked copper foil, or copper foil after lamination or resin coating).

[0004] Whether it is RA copper foil or electrodeposited copper foil, its grain structure is oriented polycrystalline (with larger and smaller grains of nonuniform size), and the microstructure or texture can be determined and analyzed by X-ray diffraction (XRD) and electron backscatter diffraction (EBSD). Crystal planes are represented by three Miller indices, such as (hkl). XRD diffraction peaks correlate with the interatomic distance, relative position, and number of atoms within the unit cell according to selection rules. Therefore, (hkl), which represent crystal planes in a face-centered cubic (FCC) crystal structure, must be all odd or all even, so that crystal planes including, but not limited to, (200), (220), (111), (311), etc., are present. EBSD signals are derived from Kikuchi patterns generated by diffraction kinematics, and grain orientations are characterized by the {001}, {101}, and {111} crystal plane systems. The advantage of EBSD analysis over XRD analysis is that it is possible to obtain measurements at smaller grain sizes. Although the results of the two analytical methods, XRD and EBSD, are different, they still have reference value for characterizing preferred orientation and grain orientation distribution in electrodeposited copper foils.

[0005] Although RA copper foil and ED copper foil have similar chemical compositions, the grain orientation distribution and grain size of these two categories of copper foil after heat treatment are very different, resulting in different mechanical properties (e.g., elongation, ductility) and electrical properties (e.g., volume resistivity, conductor loss). This also results in the need to use RA copper foil in some special applications. For example, RA copper foil with high elongation and high ductility is used in the manufacture of high-frequency, high-speed printed circuit boards to improve the thermal stability of the product and prevent deformation and warpage. However, because RA copper foil is expensive, using ED copper foil in the manufacture of printed circuit boards has the advantage of reducing production costs. Summary of the Invention [Problem to be solved by the invention]

[0006] Based on the above-mentioned shortcomings of RA copper foil and ED copper foil, one objective of the present application is to provide an ED copper foil with a preferred orientation of the (200) crystal plane. Another objective of the present application is to provide a manufacturing method and its applications. The present application includes flexible copper clad laminates, printed circuit boards, and electronic devices manufactured therefrom. [Means for solving the problem]

[0007] The present application relates to an electrodeposited copper foil having a preferred orientation of the (200) crystal plane after heat treatment, The electrodeposited copper foil before heat treatment has a grain orientation ratio of 20% or less on the (200) crystal plane as determined by XRD analysis, and a grain orientation of less than 20% on the {001} crystal plane system as determined by EBSD analysis; The electrodeposited copper foil after heat treatment has a grain orientation ratio of 50% or more on the (200) crystal plane as determined by XRD analysis, and 20% or more on the {001} crystal plane system as determined by EBSD analysis; and The heat treatment is carried out by heating at 200°C for 2 hours to provide an electrodeposited copper foil.

[0008] In addition, the present application i) supplying an electrolyte solution into an electrolysis cell at a temperature of 20°C to 55°C; ii) 30 A / dm2 to an anode plate and a rotating cathode drum spaced apart in an electrolyte. 2 ~100A / dm 2 applying a current at a current density of; iii) obtaining a copper foil on a rotating cathode drum by electrodeposition; iv) separating the copper foil obtained from step iii); A method for producing the present electrodeposited copper foil, comprising: The electrolyte is with 120g / L to 450g / L copper sulfate; with 30g / L~140g / L sulfuric acid; with 0.01 ppm to 5.00 ppm of chloride ions; At least one additive of 0.01 ppm to 2.50 ppm The present invention provides a method comprising:

[0009] The present application further provides: The electrodeposited copper foil or the electrodeposited copper foil prepared by the method; a dielectric layer provided on at least one surface of the electrodeposited copper foil; A flexible copper clad laminate comprising: The electrodeposited copper foil has a grain orientation ratio of 50% or more on the (200) crystal plane as determined by XRD analysis, and 20% or more on the {001} crystal plane system as determined by EBSD analysis; The dielectric layer has a thickness of 5 μm to 100 μm; and A flexible copper clad laminate is provided in which the dielectric layer is composed of at least one layer of a polymeric material having a thermal decomposition temperature (1%) of 260°C or higher.

[0010] The present application further provides printed circuit boards made from the flexible copper clad laminates.

[0011] The present application still further provides an electronic device including the printed circuit board. [Brief explanation of the drawings]

[0012] [Figure 1A] 1 shows a graph of grain orientation distribution on the M-side of a copper foil obtained by XRD analysis. The test piece is the RA copper foil of Comparative Example 1 of the present application. [Figure 1B] 1 shows a particle orientation distribution graph of the M-plane of a copper foil obtained by XRD analysis. The test piece is the ED copper foil of Comparative Example 3 of the present application. [Figure 2A] 1 shows a grain size photograph of a cross section of a copper foil obtained by EBSD analysis. The test piece is the RA copper foil of Comparative Example 1 of the present application. [Figure 2B] 1 shows a grain size photograph of a cross section of a copper foil obtained by EBSD analysis. The test piece is the ED copper foil of Comparative Example 3 of the present application. [Figure 3]1 illustrates one embodiment of a manufacturing process for the electrodeposited copper foil of the present application. [Figure 4A] 1 shows a particle orientation distribution graph obtained by XRD analysis of an embodiment of the present ED copper foil, which is a specimen of Example 6 of the present application. [Figure 4B] 1 shows a grain size photograph of a cross section of copper foil obtained by EBSD analysis of an embodiment of the present ED copper foil. The ED copper foil is a test piece of Example 6 of the present application. DETAILED DESCRIPTION OF THE INVENTION

[0013] All publications, patent applications, patents, and other references mentioned herein are expressly incorporated by reference herein in their entirety for all purposes as if fully set forth, unless otherwise stated.

[0014] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. In case of conflict, the present specification, including definitions, will control.

[0015] Unless otherwise stated, all percentages, parts, ratios, etc. are by weight.

[0016] As used herein, the term "comprising" has the same meaning as "comprising." As used herein, the terms "comprise," "including," "include," "including," "have," "having," "contain," or "containing," or any other variation thereof, are intended to cover a non-exclusive inclusion. For example, a composition, process, method, article, or device that includes a list of elements is not necessarily limited to only those elements and may include other elements not expressly listed or inherent in such composition, process, method, article, or device.

[0017] The transitional phrase "consisting of" excludes any element, step, or ingredient not specified. When in a claim, such a phrase would exclude from the claim the inclusion of materials other than those recited, except for impurities ordinarily associated therewith. When the phrase "consisting of" appears in a clause in the body of a claim, rather than immediately following a preamble, it limits only the elements specified in that clause; other elements are not excluded from the claim as a whole.

[0018] The transitional phrase "consisting essentially of" is used to define a composition, method, or apparatus that includes materials, steps, features, components, or elements in addition to those literally contemplated, provided that these additional materials, steps, features, components, or elements do not materially affect the basic and novel characteristics of the claimed application. The term "consisting essentially of" occupies a middle ground between "comprising" and "consisting of."

[0019] The term "comprising" is intended to include embodiments encompassed by the terms "consisting essentially of" and "consisting of." Similarly, the term "consisting essentially of" is intended to include embodiments encompassed by the term "consisting of."

[0020] When an amount, concentration, or other value or parameter is given as either a range, a preferred range, or a list of upper and lower preferred values, this should be understood to specifically disclose all ranges formed from any pairing of any upper range limit or preferred value with any lower range limit or preferred value, regardless of whether the ranges are separately disclosed. For example, if a range of "1 to 5" is recited, the recited range should be interpreted as including the ranges "1 to 4," "1 to 3," "1 to 2," "1 to 2 and 4 to 5," "1 to 3 and 5," etc. When a range of numerical values ​​is recited herein, unless otherwise specified, the range is intended to include the endpoints thereof, and all integers and fractions within the range.

[0021] Furthermore, unless expressly stated to the contrary, "or" refers to an inclusive "or," not an exclusive "or." For example, a condition A "or" B is satisfied by any one of the following: A is true (or exists) and B is false (or does not exist), A is false (or does not exist) and B is true (or exists), and A and B are both true (or exist).

[0022] "Mol%" or "mole %" means mole percent.

[0023] When referring to the ratio of grain orientation on a particular crystallographic plane or crystallographic plane system, this means the ratio of the indicated particular crystallographic plane or crystallographic plane system to the sum of all crystallographic planes.

[0024] "Twin grain boundary" refers to the boundary between two adjacent grains that exhibit certain symmetrical features. Twins in copper typically occur at a 60 degree angle. When referring to the twin boundary ratio, this refers to the ratio of the total length of the twin boundary to the total length of all grain boundaries.

[0025] The embodiments of the present application described in the Summary may be combined in any manner, including any other embodiment described herein, and the descriptions of variables in the embodiments relate not only to the electrodeposited copper foil of the present application, but also to flexible copper-clad laminates that include the electrodeposited copper foil.

[0026] The present invention will be described in detail below.

[0027] The present application provides an electrodeposited copper foil having a preferred orientation of the (200) crystal plane after heat treatment, wherein the electrodeposited copper foil before heat treatment (i.e., untreated) has a grain orientation ratio of 20% or less on the (200) crystal plane, as determined by XRD analysis; and a grain orientation ratio of less than 20% on the {001} crystal plane system, as determined by EBSD analysis; and the electrodeposited copper foil after heat treatment has a grain orientation ratio of 50% or more on the (200) crystal plane, as determined by XRD analysis; and a grain orientation ratio of 20% or more on the {001} crystal plane system, as determined by EBSD analysis; and the heat treatment is performed by heating at 200°C for 2 hours.

[0028] In one embodiment, the electrodeposited copper foil of the present application before heat treatment has a preferred orientation of the (111) crystal plane, and after heat treatment has a preferred orientation of the (200) crystal plane, with a grain orientation ratio in the (200) crystal plane of 50% or more.

[0029] In the present application, the electrodeposited copper foil before heat treatment has a grain orientation ratio of 20% or less, particularly 5% to 20%, on the (200) crystal plane, as determined by XRD analysis. For example, the grain orientation ratio on the (200) crystal plane before heat treatment can be 5%, 7.5%, 10%, 12.5%, 15%, 17.5%, or 20%, or within any two ranges described herein. In addition, the electrodeposited copper foil before heat treatment has a grain orientation ratio of less than 20%, particularly 5% to 20%, on the {001} crystal plane system, as determined by EBSD analysis. For example, the grain orientation ratio on the {001} crystal plane system before heat treatment can be 5%, 7.5%, 10%, 12.5%, 15%, 17.5%, or 19.5%, or within any two ranges described herein.

[0030] In the present application, the electrodeposited copper foil after heat treatment has a grain orientation ratio on the (200) crystal plane of 50% or more, or 55% or more, or 60% or more, particularly 50% to 90%, as determined by XRD analysis. For example, the grain orientation ratio on the (200) crystal plane after heat treatment can be 50%, 55%, 60%, 65%, 70%, 75%, 80%, 81%, 89%, or 90%, or within any two ranges described herein. In addition, the electrodeposited copper foil after heat treatment has a grain orientation ratio on the {001} crystal plane system of 20% or more, particularly 20% to 45%, as determined by EBSD analysis. For example, the grain orientation ratio on the {001} crystal plane system after heat treatment can be 20%, 25%, 30%, 35%, 40%, or 45%, or within any two ranges described herein.

[0031] In one embodiment, the electrodeposited copper foil of the present application before heat treatment has an average grain size of less than 1.0 μm, particularly 0.5 μm to 1.0 μm, more particularly 0.8 μm to 1.0 μm; the average grain size is determined by EBSD analysis.

[0032] In one embodiment, the electrodeposited copper foil of the present application before heat treatment has a twin boundary ratio of 30% or less, particularly 20% to 30%, more particularly 23% to 28%; the twin boundary ratio is determined by EBSD analysis.

[0033] In one embodiment, the electrodeposited copper foil of the present application after heat treatment has an average grain size of 2.0 μm or more, or 2.5 μm or more, or 3.0 μm or more, particularly 2.0 μm to 5.5 μm, more particularly 2.0 μm to 4.7 μm; the average grain size is determined by EBSD analysis.

[0034] In one embodiment, the electrodeposited copper foil of the present application after heat treatment has a twin boundary ratio of 50% or more, or 55% or more, or 60% or more, particularly 50% to 85%, more particularly 55% to 80%; the twin boundary ratio is determined by EBSD analysis.

[0035] In one embodiment, the electrodeposited copper foil of the present application has a thickness of 3.0 μm to 300 μm, or 3.5 μm to 150 μm, or 4.5 μm to 75 μm, or 5.0 μm to 35 μm.

[0036] In one embodiment, the electrodeposited copper foil of the present application before heat treatment has an M side having a surface roughness (Sz) of 3.0 μm or less, or 2.5 μm or less, or 2.0 μm or less, particularly 1.5 μm to 3 μm, more particularly 2.0 μm to 2.8 μm. In addition, the applicant of the present application has found that the electrodeposited copper foil of the present application before heat treatment has an M side having a surface roughness similar to that after heat treatment, i.e., no significant difference.

[0037] In one embodiment, the electrodeposited copper foil of the present application before heat treatment has an elongation of less than 5%, or less than 4.5%, particularly 3% to 4.8%, more particularly 3.5% to 4.5%.

[0038] In one embodiment, the electrodeposited copper foil of the present application after heat treatment has an elongation of 5% or more, or 6% or more, or 7% or more, particularly 5% to 18%, more particularly 6.5% to 15%.

[0039] In one embodiment, the electrodeposited copper foil of the present application after heat treatment has a resistance of 15 Kgf / mm 2 or more than 17Kgf / mm 2 or more than 19Kgf / mm 2 It has a tensile strength of at least 1000kJ / cm2.

[0040] In one embodiment, the electrodeposited copper foil of the present application after heat treatment has a resistance of 25 Kgf / mm 2 or less than 24Kgf / mm 2 or less than 23Kgf / mm 2 It has the following tensile strength:

[0041] Another object of the present application is to provide a method for producing the electrodeposited copper foil of the present application, which is characterized by maintaining a high current density under production conditions, selecting an appropriate additive and controlling its amount in the electrolyte, and adjusting each parameter in the electroplating step, thereby preparing an electrodeposited copper foil having a preferred orientation of the (200) crystal plane after heat treatment. i) providing a formulated electrolyte solution at a temperature between 20°C and 55°C into an electrolysis cell; ii) A current of 30 A / dm is applied to an anode plate (i.e., positive electrode) and a rotating cathode drum (i.e., negative electrode) spaced apart in an electrolyte. 2 ~100A / dm 2 applying a current at a current density of; iii) obtaining a copper foil on a rotating cathode drum by electrodeposition; iv) separating the copper foil obtained from step iii); Including, The electrolyte is with 120g / L to 450g / L copper sulfate; with 30g / L~140g / L sulfuric acid; with 0.01 ppm to 5.00 ppm of chloride ions; At least one additive of 0.01 ppm to 2.50 ppm Includes.

[0042] 3 is a flowchart of one embodiment of the method of the present application. Referring to FIG. 3, this method includes first performing step S100: supplying a formulated electrolyte into an electrolytic cell; then performing step S200: applying a direct current to an anode plate and a rotating cathode drum; thereafter performing step S300: electrodepositing a copper foil on the cathode drum; and finally performing step S400: separating the prepared electrodeposited copper foil. Control conditions for electrodeposition include the temperature of the electrolyte and the current density of the applied direct current.

[0043] The prepared electrodeposited copper foil has two surfaces. The surface that contacts the drum during the manufacturing process is called the "drum side" of the copper foil, and the surface opposite the drum side, i.e., the surface facing the electrolyte, is called the "deposit side." Generally, the "drum side" of the copper foil is its shiny side (S side), and the "deposit side" is its matte side (M side).

[0044] In the method of the present application, the temperature of the electrolyte is generally in the range of 20°C to 55°C, preferably 30°C to 50°C.

[0045] In the method of the present application, the electrodeposition is carried out at 30 A / dm 2 ~100A / dm 2 Generally, electrodeposition is carried out by applying a direct current at a current density in the range of 60 A / dm 2 , or 70A / dm 2 , or 80A / dm 2 Copper foils can be obtained at a current density of 16 μm / min or more, the yield being particularly high when electrodeposition is carried out at a current density of 60 A / dm at the preferred rotation speed of the cathode drum. 2 If carried out as described above, it can meet the standards for industrial high-speed manufacturing.

[0046] In the method of the present application, the electrolyte comprises copper sulfate, sulfuric acid, chloride ions, and at least one additive. The copper sulfate (as a source of copper ions) and sulfuric acid in the electrolyte may be commercially available from various sources and may be used without further purification.

[0047] In one embodiment, the amount of copper sulfate in the electrolyte is 120 g / L to 450 g / L, or 180 g / L to 400 g / L, or 240 g / L to 350 g / L, based on the total volume of the electrolyte.

[0048] In one embodiment, the amount of sulfuric acid in the electrolyte is 30 g / L to 140 g / L, or 50 g / L to 130 g / L, or 70 g / L to 120 g / L, based on the total volume of the electrolyte.

[0049] The chloride ion source may be copper chloride or hydrochloric acid. The chloride ion source may be commercially available and may be used without further purification.

[0050] In one embodiment, the amount of chloride ions in the electrolyte is 0.01 ppm to 5.00 ppm, or 0.05 ppm to 2.50 ppm, or 0.10 ppm to 1.00 ppm, based on the total weight of the electrolyte.

[0051] Suitable additives for use in the electrolyte include gelatin, glue, cellulose, nitrogen-containing cationic polymers, or combinations thereof. There are no particular limitations on the additives used, as long as the electrodeposited copper foil prepared after heat treatment has a preferred orientation of the (200) crystal plane. The aforementioned additives may be used alone or in combination as needed. In one embodiment, the additive is a nitrogen-containing cationic polymer.

[0052] In one embodiment, the additive is a nitrogen-containing cationic polymer, and the nitrogen-containing cationic polymer has a weight average molecular weight of from 500 g / mole to about 12,000 g / mole.

[0053] In another embodiment, the nitrogen-containing cationic polymer is a 1:1 molar ratio of a diamine of formula (I) or an imidazole of formula (II) and an epoxide of formula (III) or a diepoxide of formula (IV):

[0054] [ka]

[0055] (In the formula, R 1 , R 2 , R 3 and R 4 each is independently H or C1-C3 alkyl; R 5 , R 6 , R 7 and R 8 are each independently H or C1-C6 alkyl, and R7 and R 8 are optionally joined to form a saturated ring; R 9 and R 10 are each independently H or C1-C4 alkyl; R 11 is C2-C8 alkylene, C5-C 10 Cycloalkylene and C1-C4 alkylene-C5-C 10 is a divalent linking group selected from cycloalkylene, and R 11 is optionally substituted by C1-C4 alkyl or OH; A is C2-C8 alkylene, C5-C 10 Cycloalkylene, C1-C4 alkylene-C5-C 10 Cycloalkylene-C1-C4 alkylene, C6-C 20 Arylene and C1-C4 alkylene-C6-C 20 a divalent linking group selected from arylene-C1-C4 alkylene, where A is optionally substituted by C1-C4 alkyl or -OH; Y is H or C1-C4 alkyl; X is a halogen; each of p, q, and r is independently an integer from 0 to 10; and and n is an integer of 1 to 20).

[0056] In the method of the present application, the amount of additive in the electrolyte depends on the specific additive selected, the chloride ion concentration in the electrolyte, and the applied current density. In the method of the present application, the amount of additive in the electrolyte is generally 0.01 ppm to 2.50 ppm based on the total weight of the electrolyte.

[0057] In one embodiment, the amount of the additive in the electrolyte is 0.01 ppm to 2.50 ppm, or 0.05 ppm to 1.50 ppm, or 0.10 ppm to 0.50 ppm, based on the total weight of the electrolyte.

[0058] In the method of the present application, the electrolyte may additionally contain one or more other additives, such as a suppressor or a crystal orientation modifier. These other additives may be used alone or in combination as needed. The other additives may generally be present in small amounts (i.e., less than 5 ppm) as long as they do not interfere with the functional properties of the electrodeposited copper foil of the present application.

[0059] The electrodeposited copper foil prepared by the method of the present application is called a base foil, which is suitable for preparing flexible copper-clad laminates after appropriate surface treatment, such as commonly used copper foil surface treatment processes including pickling, roughening, heat-resistant layer electroplating, oxidation-preventing layer electroplating, and silane treatment. Depending on the application of the copper foil, the surface treatment process can be applied to one or both sides of the base foil. When the electrodeposited copper foil is included in a flexible copper-clad laminate, the side of the copper foil that contacts the dielectric layer is called the "lamination side," and the side opposite the "lamination side" is called the "resist side." To improve adhesion between the copper foil and the dielectric layer, the aforementioned surface treatment process, such as roughening (i.e., forming copper nodules by electroplating) or silane treatment, is applied to at least the lamination side of the copper foil. When roughened copper nodules are attached to the M side of the base foil, the copper foil is generally called a conventionally treated copper foil. When the roughened copper nodules are adhered to the S-side of the base foil, the electrodeposited copper foil is called reverse treated foil (RTF).

[0060] Because the grain size and preferred grain orientation of the electrodeposited copper foil of the present application are related to the microstructure of the base foil, whether the roughened copper nodules are attached to the S-side or the M-side does not affect the various excellent properties exhibited by the base foil.

[0061] Flexible Copper Clad Laminate Another object of the present application is to provide a flexible copper clad laminate (FCCL) comprising the electrodeposited copper foil or the electrodeposited copper foil prepared by the method and a dielectric layer provided on at least one surface of the electrodeposited copper foil, The electrodeposited copper foil has a grain orientation ratio of 50% or more on the (200) crystal plane as determined by XRD analysis, and 20% or more on the {001} crystal plane system as determined by EBSD analysis; The dielectric layer has a thickness of 5 μm to 100 μm; and The object is to provide a flexible copper clad laminate in which the dielectric layer is composed of at least one layer of a polymer material having a thermal decomposition temperature (1%) of 260°C or higher.

[0062] The flexible copper clad laminate of the present application can be a single-sided FCCL or a double-sided FCCL.

[0063] In one embodiment of the present application, the single-sided or double-sided FCCL contains a dielectric layer having a thickness of 5.0 μm to 100 μm, or 10 μm to 75 μm, or 15 μm to 60 μm, or 20 μm to 50 μm. Depending on the specific use of the flexible copper-clad laminate of the present application, the ratio of the thickness of the electrodeposited copper foil to the thickness of the dielectric layer is in the range of 2:1 to 1:10.

[0064] In one embodiment of the present application, the electrodeposited copper foil in the present single-sided or double-sided FCCL contacts the dielectric layer using its S-side as the lamination surface, and the S-side of the electrodeposited copper foil is roughened.

[0065] The flexible copper-clad laminate of the present application is prepared by a method including providing the present electrodeposited copper foil or an electrodeposited copper foil produced by the present method; and coating or laminating at least one layer of a polymeric material or a precursor thereof to form a dielectric layer on at least one surface of the electrodeposited copper foil. The process temperature used in the above method can be up to 260°C to 350°C; therefore, the polymeric material forming the dielectric layer must be able to withstand high temperatures for several hours. Suitable polymeric materials have a thermal decomposition temperature (1%) of 260°C or higher, or 300°C or higher, or 340°C or higher.

[0066] In one embodiment, the dielectric layer included in the flexible copper clad laminate of the present application is composed of at least one layer of polymeric material having a thermal decomposition temperature (1%) of 260°C or higher, or 300°C or higher, or 340°C or higher.

[0067] Those skilled in the art can select appropriate polymer materials for forming the dielectric layers in the flexible copper-clad laminates of the present application that have the above-mentioned properties for the desired application. Suitable polymer materials include polyimide (PI), liquid crystal polymers, or fluorine-based polymers such as poly(tetrafluoroethylene). In one embodiment, the dielectric layers are composed of polyimide.

[0068] In one embodiment, in the flexible copper clad laminate of the present application, the polymer material forming the dielectric layer is polyimide, liquid crystal polymer, or fluorine-based polymer.

[0069] Polyimide When the dielectric layer is made of polyimide, the polyimide precursor is the corresponding polyamic acid, which can be prepared by any method known to those skilled in the art. The steps include adding a diamine component and a dianhydride component to a solution, mixing and stirring at a suitable temperature to obtain a polyimide precursor, i.e., a polyamic acid. The polyimide precursor is cast onto a base film, then baked and cured at a high temperature to provide a polyimide film. The single-sided copper-clad laminate of the present application can be obtained when the aforementioned base film is the surface-treated copper foil of the present application.

[0070] Suitable diamine components include p-phenylenediamine (PPD), m-phenylenediamine (MPD), 2,5-dimethyl-1,4-phenylenediamine (DPX), 2,4-diaminotoluene, 2,5-diaminotoluene, 2,6-diaminotoluene, trifluoromethyl-2,4-diaminobenzene, trifluoromethyl-3,5-diaminobenzene, 4,4'-diaminobiphenyl, 2,2'-dimethyl-4,4'-diaminobiphenyl, 3,3 '-Dimethyl-4,4'-diaminobiphenyl, 2,2'-bis(trifluoromethyl)benzidine (TFMB), 2,2-bis-(4-aminophenyl)propane, 2,2'-bis(4-aminophenyl)hexafluoropropane (6F diamine), 4,4'-diaminobenzophenone, 4,4'-diaminodiphenylmethane (MDA), 4,4'-diaminodiphenyl ether (ODA), 3,4'-diaminodiphenyl ether, 4,4'-di Aminobenzanilide, 2-methoxy-4,4'-diaminobenzanilide, 1,2-bis-(4-aminophenoxy)benzene, 1,3-bis-(4-aminophenoxy)-benzene, 1,4-bis-(4-aminophenoxy)benzene, 1,2-bis-(3-aminophenoxy)benzene, 1,3-bis-(3-aminophenoxy)benzene, 1,4-bis-(3-aminophenoxy)-benzene, 1-(4-aminophenoxy)-3-(3- The amine may be selected from N,N-bis-(4-aminophenoxy)benzene, 1-(4-aminophenoxy)-4-(3-aminophenoxy)benzene, 4,4-bis(aminophenoxy)biphenyl (BAPB), 2,2-bis-(4-[4-aminophenoxy]phenyl)propane (BAPP), 4-aminophenyl-3-aminobenzoate, 4-aminophenyl-4-aminobenzoate, and N,N-bis-(4-aminophenyl)aniline, and combinations thereof.

[0071] Suitable dianhydride components include pyromellitic dianhydride (PMDA), 3,3',4,4'-biphenyltetracarboxylic dianhydride (BPDA), 2,2',3,3'-biphenyltetracarboxylic dianhydride, 2,3,3',4'-biphenyltetracarboxylic dianhydride, 2,2'-bis[4-(4-aminophenoxy)phenyl]tetracarboxylic dianhydride, 3,3',4,4'-benzophenonetetracarboxylic dianhydride (BTDA), 2,2',3,3'-benzophenonetetracarboxylic dianhydride, 2,3,3',4 The dianhydride may be an aromatic dianhydride selected from the group consisting of 2,5-(3',4'-dicarboxydiphenyl ether), 4,4'-oxydiphthalic anhydride (ODPA), bis(3,4-dicarboxyphenyl)sulfide dianhydride, bisphenol A dianhydride (BPADA), bisphenol S dianhydride, 2,2-bis-(3,4-dicarboxyphenyl)-1,1,1,3,3,3-hexafluoropropane dianhydride (6FDA), and combinations thereof. Note that the dianhydride constituting the dianhydride component may be in the form of a dianhydride or in the form of a tetraacid or diester acid halide. However, in some embodiments, the dianhydride component is preferred because it is more reactive than the corresponding acid or ester.

[0072] Examples of solvents used in the polymerization of polyamic acid include dimethylacetamide, N-methylpyrrolidone, 2-butanone, diglyme, or xylene, which may be used alone or in combination of two or more solvents.

[0073] Commercially available low dielectric polyimide films suitable for this application include Kapton® manufactured by DuPont Electronics, Inc.; Apical™, Pixio™ BP manufactured by Kaneka Corporation; or Upilex® manufactured by UBE Corporation.

[0074] The flexible copper-clad laminate of the present application can be produced by laminating a thermoplastic film formed from the aforementioned polymer material onto at least one treated surface of the surface-treated copper foil. Alternatively, the flexible copper-clad laminate of the present application can be produced by applying a coating composition containing the aforementioned polymer material or a precursor thereof onto the treated surface of the surface-treated copper foil of the present application. Depending on the polymer material selected for forming the dielectric layer, the polymer composition can contain an appropriate solvent or solvent system. The dielectric layer can be formed by using any suitable preparation method readily implemented by those skilled in the art.

[0075] The coating composition that forms the dielectric layer may be applied by a variety of methods well known in the art, such as spray coating, curtain coating, knife-over-roll coating, air knife coating, slit-die coating, direct gravure printing, reverse gravure printing, offset gravure printing, or roll coating.

[0076] The dielectric layer in the flexible copper-clad laminate of the present application is preferably prepared by directly coating a polymer material-containing solution / dispersion medium liquid for ease of control of thickness and physical properties. The dielectric layer may be formed of only a single layer, but preferably, it may be formed of multiple layers in consideration of adhesion between the dielectric layer and the electrodeposited copper foil of the present application.

[0077] As described above, the dielectric layer can be formed by a single layer or multiple layers. For a single-sided FCCL having a single polyimide layer, the polyimide precursor can be cast directly onto the surface-treated copper foil; for multiple polyimide layers, it can be formed by sequentially applying other polyamic acid solutions onto polyamic acid solutions formed from different components. When a dielectric layer made of polyimide is formed by multiple layers, polyimide precursors of the same composition can be used twice or multiple times.

[0078] In one embodiment, in the case of a double-sided FCCL having multiple polyimide layers as dielectric layers, a polyimide layer having a multiple-layer structure can be first formed and then placed on the first and second surfaces of the electrodeposited copper foil, followed by lamination simultaneously or sequentially.

[0079] After coating, the solvent or solvent mixture may be removed by heating in an oven at a temperature ranging from 100° C. to 200° C. The temperature and duration of heating in the oven will depend on the solvent used and the thickness of the coating layer.

[0080] The process parameters used to prepare the flexible copper clad laminate of the present application, such as temperature, pressure, and time, generally depend on the material properties and preparation method of the substrate, and therefore, those skilled in the art can determine the appropriate process parameters.

[0081] In some embodiments, the flexible copper clad laminates of the present application are manufactured by lamination.

[0082] In some embodiments, lamination is carried out at a temperature ranging from 200°C to 400°C, or from 300°C to about 370°C; at a pressure ranging from 0.5 MPa to 10.0 MPa, or from 1.0 MPa to 5.0 MPa; and for a period ranging from 30 minutes to 300 minutes, or from 60 minutes to 240 minutes.

[0083] Regardless of whether the dielectric layer in the flexible copper-clad laminate of the present application is formed by a coating method or a lamination method, the aforementioned method includes a corresponding heating process, and therefore the electrodeposited copper foil of the present application can be directly used in the manufacture of flexible copper-clad laminates without prior heat treatment. Furthermore, compared with flexible copper-clad laminates using conventional ED copper foil, the present flexible copper-clad laminate exhibits grain size and grain orientation distribution similar to that of FCCL containing RA copper foil due to the ED copper foil contained therein having a microstructure with a preferred orientation of the (200) crystal plane.

[0084] In addition, the flexible copper clad laminate of the present application also has excellent heat resistance and is expected to withstand the welding and reflow steps in the manufacturing process of printed circuit boards. For example, the flexible copper clad laminate of the present application can withstand heat treatment at temperatures of 260°C, 288°C, or even 320°C or higher for at least 30 seconds or more without blistering or delamination.

[0085] printed circuit board The flexible copper clad laminate of the present application may be subjected to known patterning methods, such as subtraction (photolithography) or addition (electroplating), to form a predetermined conductor pattern (i.e., circuit) on the resist surface of the copper foil to produce a printed circuit board (PCB), which may be a flexible printed circuit board (FPCB) or a rigid-flexible printed circuit board (RFPCB). Because the manufacturing processes of FPCB and RFPCB are well known to those skilled in the art, the disclosure thereof is omitted herein for the sake of brevity.

[0086] Flexible printed circuit boards or rigid-flexible printed circuit boards prepared using the flexible copper clad laminates of the present application may be assembled with other components, such as leads or holes, to form various electronic devices, including computer peripherals, such as ribbon leads for hardware drivers; consumer devices, such as laptop computers, tablet computers, electronic readers, portable gaming devices, portable media players, digital cameras, or mobile phones; wearable devices; smart home devices; medical devices; vehicle electronics; manned and unmanned vehicles; aviation facilities, such as unmanned aerial vehicles, airplanes, or aerospace equipment; and the like.

[0087] Without further elaboration, it is believed that one skilled in the art using the preceding description can utilize the present application to its fullest extent. Accordingly, the following examples are to be construed as merely illustrative and not limiting of the present disclosure in any way. [Example]

[0088] The abbreviation "E" stands for "Example" and "CE" stands for "Comparative Example," each followed by a number indicating which electrodeposited copper foil was prepared or used in that example. The Examples and Comparative Examples were prepared and tested in similar manner.

[0089] Some experiments are listed below to demonstrate the practical effects of the present application, but the present application is not limited to the following contents. The raw materials used in the electrolyte, their amounts and ratios, and processing details can be appropriately changed without exceeding the scope of the present application. Therefore, the present application should not be interpreted as being limited based on the experiments described below.

[0090] material Gelatin: Purchased from Jellice Taiwan, catalog number FL-FCC0. NCP-A: A nitrogen-containing cationic polymer obtained from DuPont Electronics, Inc. under the trade name Copper Gleam™ T4. w ranges from 7,000 to 11,000. NCP-B: A nitrogen-containing cationic polymer obtained from DuPont Electronics, Inc. under the trade name Copper Gleam™ T2. w is in the range of 2,000 to 5,000. NCP-C: A nitrogen-containing cationic polymer obtained from DuPont Electronics, Inc. under the trade name Copper Gleam™ T1. w is in the range of 1,000 to 5,000. NCP-D: Nitrogen-containing cationic polymer obtained from DuPont Electronics, Inc. under the trade name Copper Gleam™ T5. w is in the range of 2,000 to 5,000. NCP-E: A nitrogen-containing cationic polymer obtained from DuPont Electronics, Inc. under the trade name Copper Gleam™ T6. wis in the range of 500 to 1,000. HEC: Hydroxyethyl cellulose, purchased from DAICEL Co. Copper sulfate, sulfuric acid, hydrochloric acid, and compounds of unspecified commercial source were purchased from Sigma-Aldrich Co. Copper foil RA1: rolled and annealed copper foil purchased from Taishin copper & aluminum technologies, Co., Ltd., nominal thickness 12 μm, and product number RA501. Copper foil RA2: rolled and annealed copper foil purchased from JX metals corporation, nominal thickness 12 μm, and product number BHM-HAV2. Copper foil ED1: Electrodeposited copper foil purchased from Chang Chun Petrochemical Co. Ltd., nominal thickness 12 μm, and product number RTF2.

[0091] Examples 1 to 8 and Comparative Examples 1 to 6 Example 1 A base electrolyte solution containing 260 g / L copper sulfate, 100 g / L sulfuric acid, 0.1 ppm chloride ion, and 0.1 ppm gelatin as an additive was formulated. A rotating electrode apparatus was used, which had a titanium drum as the cathode (i.e., negative electrode) and a dimensionally stable anode (DSA) plate (i.e., positive electrode), and was equipped with a DC power supply. The space between the cathode and anode was filled with the electrolyte. Then, a current of 60 A / dm was applied. 2 Electrodeposited copper foils having a thickness of 12 μm were formed directly on the surface of the titanium drum by electroplating for 45 seconds at a current density of 1000 kJ / s, an electrolyte temperature of 40°C, and a cathode rotation speed of 400 rpm. After electrodeposition was completed, the electrodeposited copper foils were removed from the titanium drum for surface treatment, i.e., immersed in a copper protective agent for 5 seconds. The copper protective agent was purchased from DuPont Electronics, Inc. under the trade name CUPROTEC™. The electrodeposited copper foils were then removed and dried by blowing compressed air onto them, followed by the corresponding tests. The test results are shown in Tables 1 and 2, respectively.

[0092] Examples 2 to 6 The same base electrolyte as in Example 1 was prepared, containing 260 g / L copper sulfate, 100 g / L sulfuric acid, 0.1 ppm chloride ion, and 0.1 ppm additives. The additives used in each example are listed in Tables 1 and 2. Then, using the same equipment and electrodeposition conditions as in Example 1, a 60 A / dm 2 Electroplating was performed for 45 seconds at a current density of 1000 kJ / cm, an electrolyte temperature of 40°C, and a cathode rotation speed of 400 rpm, thereby forming an electrodeposited copper foil having a thickness of 12 μm directly on the surface of the titanium drum. After electrodeposition was completed, the electrodeposited copper foil was removed from the titanium drum and subjected to the same surface treatment steps and subsequent corresponding tests as in Example 1. The test results are shown in Tables 1 and 2, respectively.

[0093] Example 7 The same base electrolyte as in Example 1 was prepared, containing 260 g / L of copper sulfate, 100 g / L of sulfuric acid, 0.1 ppm of chloride ions, and 0.1 ppm of NCP-A as an additive. Then, using the same equipment and electrodeposition conditions as in Example 1, a 60 A / dm 2 A 210 μm thick electrodeposited copper foil was formed directly on the surface of the titanium drum by electroplating for 780 seconds at a current density of 1000 kJ / cm, an electrolyte temperature of 40°C, and a cathode rotation speed of 400 rpm. After electrodeposition was completed, the electrodeposited copper foil was removed from the titanium drum and subjected to the same surface treatment steps and subsequent corresponding tests as in Example 1. The test results are shown in Tables 1 and 2, respectively.

[0094] Example 8 The same base electrolyte as in Example 1 was prepared, containing 260 g / L of copper sulfate, 100 g / L of sulfuric acid, 0.1 ppm of chloride ions, and 0.1 ppm of NCP-A as an additive. Then, using the same equipment and electrodeposition conditions as in Example 1, a current of 80 A / dm 2 A 12 μm thick electrodeposited copper foil was formed directly on the surface of the titanium drum by electroplating for 34 seconds at a current density of 1000 kJ / cm, an electrolyte temperature of 40°C, and a cathode rotation speed of 400 rpm. After electrodeposition was completed, the electrodeposited copper foil was removed from the titanium drum and subjected to the same surface treatment steps and subsequent corresponding tests as in Example 1. The test results are shown in Tables 1 and 2, respectively.

[0095] Comparative Examples 1 to 3 The copper foils used in Comparative Examples 1 to 3 were commercially available, and among them, the RA copper foil of CE1 was RA1, the RA copper foil of CE2 was RA2, and the ED copper foil of CE3 was ED1. The sample collection method, test equipment, measurement method, and analysis method were the same as those used for the samples of Examples 1 to 9, and the test results are shown in Tables 1 and 2, respectively.

[0096] Comparative Example 4 The electrolyte used in this comparative example contained 260 g / L of copper sulfate and 100 g / L of sulfuric acid, and contained no chloride ions or additives. 2 A 12 μm thick electrodeposited copper foil was formed directly on the surface of the titanium drum by electroplating for 45 seconds at a current density of 1000 kJ / cm, an electrolyte temperature of 40°C, and a cathode rotation speed of 400 rpm. After electrodeposition was completed, the electrodeposited copper foil was removed from the titanium drum and subjected to the same surface treatment steps and subsequent corresponding tests as in Example 1. The test results are shown in Tables 1 and 2, respectively.

[0097] Comparative Example 5 The electrolyte used in this comparative example contained 260 g / L copper sulfate, 100 g / L sulfuric acid, and 0.1 ppm chloride ions, but no additives. 2 A 12 μm thick electrodeposited copper foil was formed directly on the surface of the titanium drum by electroplating for 45 seconds at a current density of 1000 kJ / cm, an electrolyte temperature of 40°C, and a cathode rotation speed of 400 rpm. After electrodeposition was completed, the electrodeposited copper foil was removed from the titanium drum and subjected to the same surface treatment steps and subsequent corresponding tests as in Example 1. The test results are shown in Tables 1 and 2, respectively.

[0098] Comparative Example 6 The electrolyte used in this comparative example contained 260 g / L of copper sulfate, 100 g / L of sulfuric acid, and 0.1 ppm of NCP-A as an additive, but did not contain chloride ions. Then, using the same equipment and electrodeposition conditions as in Example 1, a current of 60 A / dm2 A 12 μm thick electrodeposited copper foil was formed directly on the surface of the titanium drum by electroplating for 45 seconds at a current density of 1000 kJ / cm, an electrolyte temperature of 40°C, and a cathode rotation speed of 400 rpm. After electrodeposition was completed, the electrodeposited copper foil was removed from the titanium drum and subjected to the same surface treatment steps and subsequent corresponding tests as in Example 1. The test results are shown in Tables 1 and 2, respectively.

[0099] Details of each test method are shown below.

[0100] Test Method XRD analysis Two test specimens (10 cm × 10 cm) were cut from the electrodeposited copper foil prepared in each example, one of which was kept in an untreated state (i.e., before heat treatment), and the other was heat-treated by baking in an oven at 200°C (atmospheric pressure, under air) for 2 hours. The grain orientation ratio and grain size distribution of the test specimens were measured and calculated using XRD analysis.

[0101] The specimen under test was placed with the S-plane facing a low background noise carrier, and diffraction data were obtained using a Bruker AXS D8 Advance X-ray diffraction instrument equipped with a LynxEye detector (at a wavelength of 1.5418 Å) under measurement conditions of 0.025 degrees for each step and 2θ angles of 40 to 95 degrees. The background noise was subtracted from the data using EVA software, and the texture coefficient (Tc(hkl)) was calculated using the following formula using the Miller indices (111), (200), (220), and (311) crystal plane diffraction intensities: Tc(hkl)=[I(hkl) / I0(hkl)] / (1 / N)[Σ N I(hkl) / I0(hkl)] (Tc: texture coefficient; I: diffraction intensity of the sample relative to the (hkl) surface; I0: reference diffraction intensity; N: number of Miller indices, diffraction intensity of the reference material (I0)). Tc(111), Tc(200), Tc(220), and Tc(311) were obtained, and the sum of each Tc(hkl) was used as the denominator and each Tc(hkl) as the numerator. The grain orientation ratio of the sample on each crystal plane was obtained by multiplying by 100, and the results for each example and comparative example are recorded in Table 1.

[0102] EBSD analysis Two test pieces (10 cm × 10 cm) were cut from the electrodeposited copper foil prepared in each example, one of which was kept in an untreated state (i.e., before heat treatment), and the other was heat-treated by baking in an oven at 200°C (atmospheric pressure, under air) for 2 hours. Measurements were performed using EBSD analysis, and the obtained data was analyzed by software to obtain the values ​​of the average grain size, twin boundary ratio, and grain orientation ratio.

[0103] EBSD samples were prepared by first polishing them with an ion milling cross-section polisher and then placed in a SEM (JEOL-IT800SHL) cavity equipped with a 50° pretilt bracket. The stage was then tilted 20°. The accelerating voltage was set to 15-20 kV using high current mode. EBSD data were collected using an Oxford Symmetric EBSD detector. EBSD data collection parameters were set as follows: 3000x magnification, acquisition step size was 0.1 μm.

[0104] For grain size analysis, the EBSD data was loaded into AZtecCrystal software and special grain boundaries were identified by the copper phase, crystallographic axes / angles. <111> The scanning angle was set to 60°, and the deviation angle was set to 5°. The particle size (equivalent circle diameter, ECD) and particle distribution were automatically output by the software. The equivalent circle diameter was selected to calculate the average particle size, and particles with a diameter of less than 0.5 μm were excluded from the calculation as they were considered to be errors caused by the scan, thereby obtaining the average particle size. The results for each example and comparative example are recorded in Table 2.

[0105] For twin boundary ratio analysis, the EBSD data were loaded into AZtecCrystal software and output as BandContrast+ special grain boundary diagram was selected. The parameters for the special grain boundary diagram were set as follows: minimum angle 10°, copper phase, crystal axis / angle. <111> / 60°, and deviation angle 1°. The twin boundary ratios of each example and each comparative example are recorded in Table 2.

[0106] For the grain orientation ratio of the {001} crystal plane system, the EBSD data was loaded into AZtecCrystal software, the texture components were analyzed, and the output was selected to obtain the grain orientation ratio and the inverse polarity value of the {001} crystal plane. Because the sample was a cross-section, 001 / / ND was set as the 001 direction parallel to the Y1 direction (defined as red), 101 / / ND was set as the 101 direction parallel to the Y1 direction (defined as green), and 111 / / ND was set as the 111 direction parallel to the Y1 direction (defined as blue). To obtain a larger area ratio, the deviation angle was set to 20°. The results for each example and comparative example are recorded in Table 1.

[0107] Copper foil thickness According to the standard method of IPC-TM-650 2.2.12, the copper foil was cut before heat treatment and the copper foil thickness was measured by the weighing method.

[0108] surface roughness The M side of the copper foil sample before heat treatment was measured in five areas using a laser scanning microscope (Olympus, Model No. 5000) at an objective magnification of 100x without a cutoff filter. Roughness was measured at various spots according to the ISO 25178 method, and the measurement data were averaged. Sz is defined as the sum of the top 10 maximum peak heights and the top 10 maximum valley depths within a defined area.

[0109] Elongation and tensile strength Two test pieces (5 cm x 15 cm) were cut from the electrodeposited copper foil prepared or used in each example. One of the test pieces was kept in an untreated state (i.e., before heat treatment), while the other was subjected to heat treatment by placing it in an oven at 200°C (atmospheric pressure, under air) and baking for 2 hours. The two test pieces were measured for tensile strength and elongation at ambient temperature using a tensile testing machine (Shimadzu Corporation, Model No. AGS-X) according to the method of IPC-TM-650 2.4.18B. The results for each example and comparative example are recorded in Table 2.

[0110] [Table 1]

[0111] The XRD grain orientation distribution ratio data in Table 1 reveal that the RA copper foils CE1 and CE2 each had a preferred orientation of the (220) crystal plane before heat treatment, a preferred orientation of the (200) crystal plane after heat treatment, and grain orientation ratios in the (200) crystal plane of 66% and greater than 99%, respectively. The commercially available electrodeposited copper foil CE3 had a preferred orientation of the (220) crystal plane before and after heat treatment. The electrodeposited copper foils CE4, CE5, and CE6 each had a preferred orientation of the (200) crystal plane after heat treatment, but the grain orientation ratios in the (200) crystal plane for these examples were less than 50%. In contrast, the ED copper foils E1 to E8, which are embodiments of the present electrodeposited copper foil, each had a preferred orientation of the (200) crystal plane after heat treatment, and each had a grain orientation ratio in the (200) crystal plane of 50% or greater. It can be seen that the electrodeposited copper foil of the present application after heat treatment has a preferred orientation similar to that of the RA copper foil, with the grain orientation ratio in the (200) crystal plane being 50% or more.

[0112] From the EBSD grain orientation data in Table 1, it can be seen that the RA copper foils CE1 and CE2 had a grain orientation ratio of 20% or more in the {001} crystal plane system after heat treatment. The ED copper foils CE3 to CE6 had a crystal orientation ratio of less than 20% in the {001} crystal plane system after heat treatment. In contrast, the ED copper foils E1 to E8 had a crystal orientation ratio of 20% or more in the {001} crystal plane system after heat treatment.

[0113] In conclusion, the electrodeposited copper foil after heat treatment has a preferred orientation of the (200) crystal plane similar to that of RA copper foil; it has a grain orientation ratio of 50% or more in the (200) crystal plane as measured by XRD analysis, and a grain orientation ratio of 20% or more in the {001} crystal plane system as measured by EBSD analysis.

[0114] [Table 2]

[0115] From the surface roughness (Sz) data in Table 2, it can be seen that the ED copper foils E1 to E8 each had a surface roughness (Sz) of 3.0 μm or less on the M side before heat treatment. In addition, when comparing the electrical conductivity data of E1 to E8 with that of CE3, the ED copper foils E1 to E8 after heat treatment each had a surface roughness of 57.0 × 10 6 The conductivity is 55.20×10 S / m or more, and the conductivity is 55.20×10 S / m or more. 6 S / m) and was equivalent to the CE2 RA copper foil.

[0116] From the data in Table 2, it can be seen that the ED copper foils E1 to E8 each had an average grain size of less than 1.0 μm before heat treatment, and the average grain size increased to 2.0 μm or more after heat treatment. In addition, the ED copper foils E1 to E8 each had a twin boundary ratio of 30% or less before heat treatment, and the twin boundary ratio increased to 50% or more after heat treatment. Furthermore, from the data in Table 2, the ED copper foils E1 to E8 each had an elongation of 5% or more and a yield strength of 15 kgf / mm after heat treatment. 2 ~25Kgf / mm 2 It can be seen that the tensile strength was

[0117] Generally, RA copper foils have a grain arrangement with a preferred orientation likely lying on the (200) crystal plane, and as shown in Figures 1A and 2A, the grains clearly grew to a diameter of more than 2.0 μm. Figure 1A is a graph showing the grain orientation distribution of an RA copper foil specimen of Comparative Example 1 of the present application after heating at 200°C for 2 hours. From Figure 1A, it is clear that the RA copper foil has a grain arrangement with a preferred orientation of the (200) crystal plane. Figure 2A is an EBSD photograph showing the grain size of the specimen of Comparative Example 1. From the photograph in Figure 2A and its reference scale, it is clear that the RA copper foil has an average grain size of more than 2.0 μm. The actual measured average grain size is 4.56 μm.

[0118] In contrast, ED copper foils are generally produced by electroplating with high current densities, e.g., direct currents exceeding 50 ASD, to achieve industrial mass production. However, under high current density conditions, copper atoms in the copper deposit layer readily grow along the loosely arranged (220) and / or (311) crystal planes. Even after heat treatment, the electrodeposited copper foils have a crystalline arrangement with a preferred orientation primarily on the (111) and / or (220) crystal planes, rather than the (200) crystal plane, and have relatively small grain sizes, typically less than 2.0 μm, as shown in Figures 1B and 2B, which represent the sample of Comparative Example 3 of the present application.

[0119] Furthermore, EBSD analysis was performed to obtain directionality-imaging inverse pole figures (hereinafter referred to as inverse pole figures or IPFS) of the cross sections of the RA copper foil specimen of Comparative Example 1 and the ED copper foil specimen of Comparative Example 3. When comparing the grain size and grain orientation distribution between the RA copper foil and the ED copper foil, the same conclusion can be drawn: the RA copper foil has a significantly larger grain size than the ED copper foil. Furthermore, the inverse pole figure of the RA copper foil specimen shows that the predominant grain orientation is the {001} crystal plane system, which includes all crystallographically equivalent crystal planes, i.e., crystal planes such as (001), (100), and (010); the inverse pole figure of the ED copper foil specimen shows that the predominant grain orientation is the {101} crystal plane system, which includes crystal planes such as (101), (011), and (110).

[0120] 4A and 4B show a grain orientation distribution graph obtained by XRD analysis of an embodiment of the present ED copper foil, and a grain size photograph of a cross section of the copper foil obtained by EBSD analysis, respectively. The ED copper foil is a specimen of Example 6 of the present application. Unlike the more conventional ED copper foil of Comparative Example 3, this ED copper foil has a grain arrangement with a preferred orientation of the (200) crystal plane and a much larger grain size. An inverse pole figure of the ED copper foil of Example 6 shows that the predominant grain orientation is the {001} crystal plane system, very similar to the RA copper foil specimen of Comparative Example 1.

[0121] While the present application has been illustrated and described in exemplary embodiments, it is not intended to be limited to the details shown, since various modifications and substitutions are possible without departing from the spirit of the present application. Accordingly, modifications and equivalents of the present application disclosed herein may occur to those skilled in the art using no more than routine experimentation, and all such modifications and equivalents are deemed to be within the spirit and scope of the present invention as defined by the following claims. [Explanation of symbols]

[0122] 001 Crystal plane system 111 crystal face 200 crystal faces 220 Crystal Faces 311 Crystal Faces

Claims

1. 1. An electrodeposited copper foil having a preferred orientation of the (200) crystal plane after heat treatment, The electrodeposited copper foil, prior to heat treatment, has a grain orientation ratio of 20% or less on (200) crystallographic planes as determined by XRD analysis, and a grain orientation ratio of less than 20% on the {001} crystallographic plane system as determined by EBSD analysis; The electrodeposited copper foil after heat treatment has a grain orientation ratio of 50% or more on the (200) crystal plane as determined by XRD analysis, and a grain orientation ratio of 20% or more on the {001} crystal plane system as determined by EBSD analysis; and The electrodeposited copper foil, wherein the heat treatment is carried out by heating at 200°C for 2 hours.

2. The electrodeposited copper foil before heat treatment has an average grain size of less than 1.0 μm and a twin boundary ratio of 30% or less; The electrodeposited copper foil after heat treatment has an average grain size of 2.0 μm or more and a twin boundary ratio of 50% or more; and 2. The electrodeposited copper foil of claim 1, wherein the average grain size and twin boundary ratio are determined by EBSD analysis.

3. The electrodeposited copper foil of claim 1, wherein the electrodeposited copper foil has a thickness of 3.0 μm to 300 μm.

4. 2. The electrodeposited copper foil according to claim 1, wherein the electrodeposited copper foil has a surface roughness (Sz) of 3.0 μm or less on the M side before heat treatment.

5. The electrolytic copper foil after the heat treatment had a thickness of 57.0 × 10 ６ 2. The electrodeposited copper foil of claim 1, having a conductivity of S / m or greater.

6. The electrodeposited copper foil before heat treatment has an elongation of less than 5%; and The electrodeposited copper foil after heat treatment has an elongation of 5% or more and a compressibility of 15 kgf / mm ２ ~25 kgf / mm ２ 2. The electrodeposited copper foil of claim 1, having a tensile strength of

7. i) providing an electrolyte solution at a temperature of 20°C to 55°C in the electrolysis cell; ii) A current of 30 A / dm2 was applied to the anode plate and the rotating cathode drum, which were spaced apart from each other in the electrolyte. ２ ~100 A / dm ２ applying a current at a current density of iii) obtaining a copper foil on said rotating cathode drum by electrodeposition; and iv) separating the copper foil obtained from step iii); The method for producing an electrodeposited copper foil according to claim 1, comprising: The electrolyte solution comprises: 120 g / L to 450 g / L copper sulfate; 30 g / L to 140 g / L sulfuric acid; 0.01 ppm to 5.00 ppm of chloride ions; and 0.01 ppm to 2.50 ppm of at least one additive A method comprising:

8. The method of claim 7 , wherein the additive comprises gelatin, glue, cellulose, a nitrogen-containing cationic polymer, or a combination thereof.

9. 8. The method of claim 7, wherein the additive is a nitrogen-containing cationic polymer, the nitrogen-containing cationic polymer having a weight average molecular weight of 500 g / mole to 12,000 g / mole.

10. The nitrogen-containing cationic polymer is a compound obtained by mixing, in a 1:1 molar ratio, a diamine of formula (I) or an imidazole of formula (II) with an epoxide of formula (III) or a diepoxide of formula (IV): 【Chemical 1】 (In the formula, R １ , R ２ , R ３ and R ４ each independently represents H or C １ ~C ３ is alkyl; R ５ , R ６ , R ７ and R ８ each independently represents H or C １ ~C ６ alkyl, and R ７ and R ８ are optionally joined to form a saturated ring; R ９ and R １０ are each independently H or C １ ~C ４ is alkyl; R １１ is C ２ ~C ８ Alkylene, C ５ ~C １０ Cycloalkylene, and C １ ~C ４ Alkylene-C ５ ~C １０ is a divalent linking group selected from cycloalkylene, and R １１ is optionally C １ ~C ４ substituted by alkyl or —OH; A is C ２ ~C ８ Alkylene, C ５ ~C １０ Cycloalkylene, C １ ~C ４ Alkylene-C ５ ~C １０ Cycloalkylene-C １ ~C ４ Alkylene, C ６ ~C ２０ Arylene and C １ ~C ４ Alkylene-C ６ ~C ２０ Arylene-C １ ~C ４ A is a divalent linking group selected from alkylene, and A is optionally C １ ~C ４ substituted by alkyl or —OH; Y is H or C １ ~C ４ is alkyl; X is a halogen; each of p, q, and r is independently an integer from 0 to 10; and and n is an integer from 1 to 20.

11. The electrodeposited copper foil according to claim 1, and a dielectric layer provided on at least one surface of said electrodeposited copper foil; A flexible copper clad laminate comprising: The electrodeposited copper foil has a grain orientation ratio of 50% or greater on the (200) crystal plane as determined by XRD analysis, and a grain orientation ratio of 20% or greater on the {001} crystal plane system as determined by EBSD analysis; the dielectric layer has a thickness of 5 μm to 100 μm; and A flexible copper clad laminate wherein said dielectric layer is composed of at least one layer of a polymeric material having a thermal decomposition temperature (1%) of 260°C or greater.

12. 12. The flexible copper clad laminate of claim 11, wherein the polymer material is a polyimide, a liquid crystal polymer, or a fluorine-based polymer.

13. Providing the surface-treated copper foil of claim 1; and coating or laminating at least one layer of a polymeric material or precursor thereof to form a dielectric layer on at least one surface of said electrodeposited copper foil; The method for producing the flexible copper clad laminate of claim 11, comprising:

14. 12. A printed circuit board manufactured from the flexible copper clad laminate of claim 11, wherein the printed circuit board is a flexible printed circuit board (FPCB) or a flexible-rigid printed circuit board (FRPCB).

15. An electronic device comprising the printed circuit of claim 14.

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