Composite copper foil and method for manufacturing the same

Abstract

The present invention provides a composite copper foil having a thinner thickness and superior quality, as well as a method for manufacturing the same. [Solution] The composite copper foil includes a first copper foil, a second copper foil, and an insulating bonding layer. The insulating bonding layer is located between the first and second copper foils. The thickness of the insulating bonding layer is less than 5 micrometers.

Description

Technical Field

[0001] The present invention relates to a metal foil and a method for manufacturing the same, and more particularly, to a composite copper foil and a method for manufacturing the same.

Background Art

[0002] Existing methods for manufacturing composite copper foils first provide a polymer film (e.g., a polyester (PET) film or a polyimide (PI) film). Next, a first conductive film (usually called a conductive seed layer) is formed on both sides of the aforementioned polymer film by sputtering. Then, the thickness is increased by plating with the first conductive film to form a second conductive film (usually called a plating layer). The composite copper foil formed by the above method is often limited by the thickness of the polymer film and the corresponding conductive film formation method, and it is very difficult to effectively reduce the overall thickness (e.g., at least 6 microns). Also, when directly using a thinner polymer film for double-sided plating, there is a possibility that it cannot be effectively insulated due to the penetration of atoms, particles to be plated, and / or plasma during the plating process (e.g., sputtering or similar plasma deposition plating).

[0003] Therefore, how to manufacture a composite copper foil with a thin thickness and excellent quality has become an actual research issue.

Summary of the Invention

Problems to be Solved by the Invention

[0004] The present invention provides a composite copper foil having a thinner thickness and excellent quality, and a method for manufacturing the same.

Means for Solving the Problems

[0005] The present invention provides a composite copper foil and a method for manufacturing the same, in which the structure and / or the manufacturing method of the composite copper foil is simpler, the thickness can be made thinner, and the composite copper foil has excellent quality.

[0006] The present invention provides a method for manufacturing a composite copper foil, comprising the steps of: providing a first copper foil and a second copper foil having structures separated from each other; forming an insulating bonding material between the first copper foil and the second copper foil; and forming an insulating bonding layer with the insulating bonding material and bonding the first copper foil and the second copper foil with the insulating bonding layer.

[0007] The composite copper foil of the present invention comprises a first copper foil, a second copper foil, and an insulating bonding layer. The insulating bonding layer is located between the first copper foil and the second copper foil. The thickness of the insulating bonding layer is less than 5 micrometers. [Effects of the Invention]

[0008] As described above, the composite copper foil of the present invention has a simpler manufacturing method and / or structure, can be made thinner, and can have excellent quality. [Brief explanation of the drawing]

[0009] [Figure 1] This is a local flowchart of a partial manufacturing method for a composite copper foil according to one embodiment of the present invention. [Figure 2A] This is a local side view of a method for manufacturing a part of a composite copper foil according to one embodiment of the present invention. [Figure 2B] This is a local side view of a method for manufacturing a part of a composite copper foil according to one embodiment of the present invention. [Figure 2C] This is a local side view of a method for manufacturing a part of a composite copper foil according to one embodiment of the present invention. [Figure 2D] This is a local side view of a method for manufacturing a part of a composite copper foil according to one embodiment of the present invention. [Figure 2E] This is a local side view of a method for manufacturing a part of a composite copper foil according to one embodiment of the present invention. [Modes for carrying out the invention]

[0010] The following detailed description includes exemplary embodiments that disclose specific details for illustrative purposes, not limitation, to provide a complete understanding of the various principles of the invention. However, it will be obvious to those skilled in the art that the invention may be carried out in other embodiments different from the specific details disclosed herein. Furthermore, descriptions of well-known apparatus, methods, and materials may be omitted in order to avoid obscuring the description of the various principles of the invention.

[0011] A range may be expressed herein as "about" one specific value to "about" another specific value, or directly as one specific value and / or another specific value. When expressing a range as described above, an alternative embodiment includes that one specific value and / or another specific value. Similarly, when expressing a value as an approximation using the antecedent "about," it is understood that the specific value forms an alternative embodiment. Furthermore, it is understood that each endpoint of a range is either clearly related to or independent of other endpoints.

[0012] In this specification, non-exclusive terms (e.g., may, may, for example, or other similar terms) may be optional or optional in their implementation, inclusion, addition, or presence.

[0013] Unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as those commonly understood by a person of ordinary skill in the art to which this invention pertains. Furthermore, terms (as defined in commonly used dictionaries) should be interpreted as having the meaning consistent with their meaning in the relevant technical context, and not as idealized or overly formal unless explicitly defined herein.

[0014] In drawings, the thickness of some film layers may be exaggerated for clarity.

[0015] FIG. 1 is a partial flowchart of a method for manufacturing a part of a composite copper foil according to one embodiment of the present invention.

[0016] Referring to FIG. 1, the method for manufacturing a composite copper foil according to one embodiment of the present invention can include the following steps.

[0017] Step S10: Provide a carrier (also referred to as a first carrier).

[0018] Step S20: Form a peelable layer (also referred to as a first peelable layer) on the carrier (e.g., the first carrier).

[0019] Step S30: Form a copper foil (also referred to as a first copper foil) on the peelable layer located on the carrier (e.g., on the first peelable layer located on the first carrier), and constitute a copper foil-containing carrier (e.g., including the peelable layer on the carrier and the copper foil on the peelable layer, also referred to as a first copper foil-containing carrier).

[0020] Step S40: Form an insulating bonding material on the copper foil of the copper foil-containing carrier (e.g., the copper foil of the first copper foil-containing carrier).

[0021] Step S50: Bond the copper foil of another copper foil-containing carrier (e.g., the copper foil of another copper foil-containing carrier different from the first copper foil-containing carrier, also referred to as a second copper foil-containing carrier) and the copper foil-containing carrier having an insulating bonding material thereon (e.g., the first copper foil-containing carrier on which the insulating bonding material is formed on the copper foil) to each other.

[0022] Step S60: Remove at least the carrier to form a composite copper foil.

[0023] FIGS. 2A to 2E are partial side views of a method for manufacturing a part of a composite copper foil according to one embodiment of the present invention. In one embodiment, the steps shown in FIG. 1 can be shown as in FIGS. 2A to 2E.

[0024] Referring to Figure 2A, a first carrier 11 is provided. The present invention does not particularly limit the material or thickness of the first carrier 11, as long as a suitable film layer can be formed on the first carrier 11 and the first carrier 11 is suitable for supporting the film layer formed thereon.

[0025] In one embodiment, the first carrier 11 may be a conductive material, a flexible material, a reusable material, and / or a recyclable material. In one embodiment, the first carrier 11 may be a sheet, plate, or block of metal, such as copper, aluminum, or a combination thereof (e.g., copper-plated aluminum). In a more preferred embodiment, the first carrier 11 may be copper (e.g., a copper sheet, copper plate, or copper block) because the copper material can have the same or similar coefficient of thermal expansion (CTE) and / or the same or similar physical or chemical properties as a copper layer later formed thereon (e.g., a copper plating layer or copper foil).

[0026] In one embodiment, the thickness T11 of the first carrier 11 may be about 10 micrometers (μm) to about 30 μm.

[0027] Continuing to refer to Figure 2A, a first peelable layer 12 is formed on the first carrier 11. The first peelable layer 12 can be temporarily bonded to the first carrier 11 and, in a subsequent appropriate step, can be removed and / or separated from the first carrier 11 by an appropriate method.

[0028] In a more preferred embodiment, the first peelable layer 12 may be formed of an inorganic metal salt, which is considered more preferable because the first peelable layer 12 formed of an inorganic metal salt exhibits excellent temporary bonding to both the first carrier 11 and the later formed film layer (e.g., copper foil).

[0029] In one embodiment, the first peelable layer 12 is also called an inorganic peelable layer. In one embodiment, the first peelable layer 12 is basically free of organic matter.

[0030] In one embodiment, a first peelable layer 12 can be formed on the first carrier 11 by a plating method. The electrolyte used in the aforementioned plating may include electrolyte compounds of manganese, cobalt, nickel, molybdenum, iron, and / or tungsten. For example, it may be sulfates, nitrates, phosphates, chlorides, salts derived from oxides of the aforementioned metals, and / or hydrates of the aforementioned salts of manganese, cobalt, nickel, molybdenum, iron, and / or tungsten. In one embodiment, the aforementioned manganese-containing compound may include, for example, manganese sulfate, manganese nitrate, manganese phosphate, or manganese chloride. In one embodiment, the aforementioned cobalt-containing compound may include, for example, cobalt sulfate, cobalt nitrate, cobalt phosphate, cobalt chloride, or cobalt 1 chloride. In one embodiment, the aforementioned nickel-containing compound may include, for example, nickel sulfate, nickel ammonium sulfate, nickel nitrate, or nickel chloride. In one embodiment, the aforementioned molybdenum-containing compound may include, for example, sodium molybdate, potassium molybdate, molybdenum disulfide, molybdenum nitrate, molybdenum phosphate, or molybdenum chloride. In one embodiment, the aforementioned iron-containing compound may include, for example, ferrous sulfate, ferrous nitrate, ferrous phosphate, or ferrous chloride. In one embodiment, the aforementioned tungsten-containing compound may include, for example, sodium tungstate or potassium tungstate. In one embodiment, the solvent for the aforementioned electrolyte may include water.

[0031] In one embodiment, the electrolyte can be brought to a corresponding pH value by adding an acid or base agent. In one embodiment, the pH value of the electrolyte may be about 2.5 to 4.5. In one embodiment, the added acid agent may include sulfuric acid, nitric acid, hydrochloric acid, or phosphoric acid.

[0032] In one embodiment, the electrolysis temperature may be in the range of about 20°C to 60°C. In one embodiment, the electrolysis current density is about 0.1 A / dm 2 ~50A / dm 2 It may be within the range of [a certain limit].

[0033] In one embodiment, the concentration of the metal ions to be plated in the electrolyte may be about 0.005 M (molar, mol / L) to 0.5 M.

[0034] In one embodiment, the conductivity of the electrolyte can be adjusted by adding other non-plating electrolytes. The metals contained in the aforementioned "non-plating electrolytes" are essentially not reduced and are not plated onto the first carrier 11. The aforementioned "non-plating electrolytes" may include, for example, the corresponding potassium salt or sodium salt.

[0035] In one embodiment, the plating time can be adjusted according to demand (e.g., the corresponding thickness) or corresponding conditions (e.g., current density, plating temperature, and / or concentration of metal ions being plated).

[0036] In one embodiment, the plating layer formed on the first carrier 11 is also essentially called the first peelable layer 12.

[0037] In one embodiment, the first carrier 11 can be subjected to appropriate pre-treatment before forming the first peelable layer 12 on the first carrier 11. The aforementioned pre-treatment may include (but is not limited to) acid cleaning, alkaline cleaning, degreasing, and / or electrolytic cleaning, thereby allowing the first carrier 11 to have an outer surface that adheres more cleanly and / or more easily to the first peelable layer 12.

[0038] In one embodiment, after plating, more preferably, the first carrier 11 and the plating layer located thereon may be appropriately heated to form the corresponding first peelable layer 12. This is considered more preferable because it is thought that the bonding strength between the first peelable layer 12 and the first carrier 11 can be improved by promoting the formation of a corresponding eutectic mixture between the metal in the first peelable layer 12 and the metal in the first carrier 11. This is also considered more preferable because it is thought that the bonding strength between the first peelable layer 12 and a later formed film layer (e.g., copper foil) can be improved by promoting the oxidation and / or roughening of the outer surface of the first peelable layer 12 (i.e., the surface that does not come into contact with the first carrier 11 and is exposed to the outside).

[0039] In one embodiment, the thickness T12 of the first peelable layer 12 may be about 20 nanometers (nm) to 100 nanometers. More preferably, it may be about 40 nanometers to 60 nanometers.

[0040] Referring to Figure 2B, the first copper foil 13 is formed on the first peelable layer 12 located on the first carrier 11, thereby constituting the first copper foil-containing carrier 10 including the first copper foil 13.

[0041] In one embodiment, the corresponding first copper foil 13 can be formed on the first peelable layer 12 by sputtering, plating, post-sputtering plating, or other suitable or commonly used methods.

[0042] In one embodiment, the thickness T11 of the first carrier 11 may be 5 to 30 times the thickness T13 of the first copper foil 13. In one embodiment, the thickness T13 of the first copper foil 13 may be 15 to 50 times the thickness T12 of the first peelable layer 12.

[0043] In one embodiment, the thickness T13 of the first copper foil 13 may be less than 6 micrometers (μm), more preferably less than or approximately equal to 4.5 micrometers, for example, about 1 to 2 micrometers.

[0044] In one embodiment, if necessary, the first copper foil-containing carrier 10 including the first copper foil 13 can be cut by an appropriate method. In one embodiment, if necessary, the first copper foil-containing carrier 10 including the first copper foil 13 can be temporarily stored by an appropriate method (e.g., winding).

[0045] Referring to Figure 2C, an insulating bonding material 39 is formed on the first copper foil 13 of the first copper foil-containing carrier 10.

[0046] In one embodiment, the insulating bonding material 39 may include epoxy resin, polyamide (PA), ether polymer (e.g., polyethersulfone (PES) or polyetheretherketone (PEEK)), polyolefin (e.g., polyethylene (PE)), ethylene vinyl acetate (EVA), polyimide (PI), or combinations or mixtures thereof.

[0047] In one embodiment, the corresponding insulating bonding material 39 can be formed on the first copper foil 13 by spray coating, roll coating, impregnation, spraying, or other suitable method. In one embodiment, the corresponding insulating bonding material 39 can be partially cured by a suitable method (e.g., heating and / or standing) if necessary.

[0048] Referring to Figure 2D, a second copper foil-containing carrier 20 is provided, and the second copper foil 23 of the second copper foil-containing carrier 20 and the first copper foil 13 of the first carrier foil are placed facing each other, and the second copper foil-containing carrier 20 and the first carrier foil are joined to each other by an insulating bonding layer 33 through an appropriate procedure.

[0049] In one embodiment, the second copper foil-containing carrier 20 and the first carrier foil may have the same or similar structure (e.g., thickness or shape), material, and / or method of formation. For example, the second copper foil-containing carrier 20 may include a second carrier 21, a second peelable layer 22, and a second copper foil 23, and the first carrier foil may include a first carrier 11, a first peelable layer 12, and a first copper foil 13, and the second carrier 21 and the first carrier 11 may have the same or similar structure, material, and / or method of formation, the second peelable layer 22 and the first peelable layer 12 may have the same or similar structure, material, and / or method of formation, and / or the second copper foil 23 and the first copper foil 13 may have the same or similar structure, material, and / or method of formation.

[0050] Referring to Figures 2C and 2D, in one embodiment, the insulating bonding layer 33 (shown in Figure 2D) can be formed by an insulating bonding material 39 (shown in Figure 2C). For example, the second copper foil 23 of the second copper foil carrier 20 can be brought into contact with the insulating bonding material 39 (which may be uncured or semi-cured) on the first copper foil 13, and then the insulating bonding material 39 can be cured by an appropriate method (e.g., heating, light irradiation, and / or standing) to form an insulating bonding layer 33 that contacts and bonds the first copper foil 13 and the second copper foil 23.

[0051] In one embodiment, before the insulating bonding material 39 is completely cured, the distance between the first copper foil 13 and the second copper foil 23 may be further reduced by an appropriate method (e.g., pressing), but without bringing them into contact with each other. That is, the thickness T33 of the insulating bonding layer 33 can be made even thinner compared to the thickness T39 of the insulating bonding material 39. In this way, the resulting composite copper foil 80 (shown in Figure 2E) can be made even thinner.

[0052] In one embodiment, during the process of bringing the distance between the first copper foil 13 and the second copper foil 23 closer (e.g., a pressing process), the corresponding structure can be placed in a low-pressure atmosphere (e.g., less than 1 atmosphere or less than 0.1 atmosphere). For example, the aforementioned process can be carried out in a cavity in a low-pressure atmosphere. In this way, it is possible to make it easier to evacuate gas between the first copper foil 13 and the second copper foil 23 and reduce the number and / or volume of bubbles embedded in the insulating bonding material 39 (or the corresponding insulating bonding layer 33).

[0053] In one embodiment, when the distance between the first copper foil 13 and the second copper foil 23 is further reduced, some of the insulating bonding material 39 may overflow from between the first copper foil 13 and the second copper foil 23. The overflowed portion of insulating bonding material 39 can be scraped off or removed by other suitable means before curing, and / or the overflowed portion of insulating bonding material 39 can be cut or removed by other suitable means after curing.

[0054] In one embodiment, the thickness T33 of the insulating bonding layer 33 may be less than 5 micrometers, more preferably less than or approximately equal to 4.5 micrometers, for example, about 2 to 4.5 micrometers.

[0055] In one embodiment, if necessary, the structure shown in Figure 2D can be appropriately cut. In one embodiment, if necessary, the structure shown in Figure 2D can be appropriately wound up.

[0056] Referring to Figures 2D and 2E, the upper surface of the first copper foil 13 (the upper surface in the figure) and the lower surface of the second copper foil 23 (the lower surface in the figure) can be exposed to the outside by appropriate methods. For example, the first carrier 11 and / or the second carrier 21 can be removed by a peeling method. If a portion of the first peelable layer 12 remains on the upper surface of the first copper foil 13 (the upper surface in the figure), and / or if a portion of the second peelable layer 22 remains on the lower surface of the second copper foil 23 (the lower surface in the figure), it can be removed by etching, wiping, washing, or other appropriate methods.

[0057] The manufacturing process described above can be used to almost complete the production of the composite copper foil 80 of this embodiment. The composite copper foil 80 described above includes a first copper foil 13, a second copper foil 23, and an insulating bonding layer 33. The insulating bonding layer 33 is located between the first copper foil 13 and the second copper foil 23. Opposite sides of the insulating bonding layer 33 (for example, the upper and lower sides) may be in contact with the first copper foil 13 and the second copper foil 23, respectively.

[0058] In one embodiment, the thickness of the first copper foil 13 and / or the thickness of the second copper foil 23 may be less than 6 micrometers (μm), more preferably less than or approximately equal to 4.5 micrometers, for example, about 1 to 2 micrometers.

[0059] In one embodiment, the material of the insulating bonding layer 33 is a polymer. In one embodiment, the insulating bonding layer 33 is a homogeneous material, and the said homogeneous material cannot be further separated into different single materials by mechanical means (e.g., crushing, shearing, cutting, sawing, polishing, etc.). In one embodiment, there may be no interfaces formed by different materials within the insulating bonding layer 33. In one embodiment, there may be no interfaces formed by different manufacturing processes (e.g., bonding) within the insulating bonding layer 33.

[0060] In one embodiment, the composite copper foil 80 is composed of a first copper foil 13, a second copper foil 23, and an insulating bonding layer 33. In other words, there are no other film layers within the composite copper foil 80 that are different from the first copper foil 13, the second copper foil 23, and the insulating bonding layer 33.

[0061] In one embodiment, the first copper foil 13 and the second copper foil 23 of the composite copper foil 80 are not formed on an insulating bonding layer 33. That is, structurally, the physical first copper foil 13 and the second copper foil 23 are formed first, and then the insulating bonding layer 33 is formed between the first copper foil 13 and the second copper foil 23 by an appropriate method (for example, by curing the insulating bonding material between the first copper foil 13 and the second copper foil 23 to form the insulating bonding layer 33). The method for forming the insulating bonding layer 33 may be as described above, and therefore the thickness of the composite copper foil 80 can be made thinner (compared to the composite copper foil formed when the method of the embodiment of the present invention is not used), while still being able to have excellent quality. [Industrial applicability]

[0062] In one embodiment, the composite copper foil 80 is suitable for manufacturing electronic components (e.g., circuit boards). In one embodiment, the composite copper foil 80 can be applied to electrodes and is suitable for manufacturing batteries (e.g., lithium battery electrodes).

[0063] As described above, the composite copper foil of the present invention has a simpler manufacturing method and / or structure, can be made thinner, and can have excellent quality.

[0064] The composite copper foil of the present invention is suitable for the manufacture of electronic components (e.g., circuit boards), and is suitable for the manufacture of batteries (e.g., lithium battery electrodes). [Explanation of symbols]

[0065] 80 Composite copper foil 10 Copper foil-containing carrier 11. First Carrier 12. First peelable layer 13 First copper foil 20 Copper foil-containing carrier 21. Second Carrier 22 Second peelable layer 23 Copper foil 33 Insulating bonding layer 39. Insulating bonding materials Thickness: T11, T12, T13, T33, T39 S10, S20, S30, S40, S50, S60 Step

Claims

1. The steps include providing a first copper foil and a second copper foil whose structures are separated from each other, The steps include forming an insulating bonding material between the first copper foil and the second copper foil, The steps include forming an insulating bonding layer with the insulating bonding material and bonding the first copper foil and the second copper foil with the insulating bonding layer, A method for manufacturing composite copper foil containing [a specific component].

2. The first carrier having a first peelable layer thereon is provided, and the first copper foil is formed on the first peelable layer, The second carrier having a second peelable layer thereon is provided, and the second copper foil is formed on the second peelable layer, A method for producing a composite copper foil according to claim 1, further comprising:

3. The steps include forming the insulating bonding material on at least one of the first copper foil or the second copper foil, The steps include placing the first copper foil and the second copper foil facing each other, and arranging the insulating bonding material between the first copper foil and the second copper foil, A method for producing a composite copper foil according to claim 2, further comprising:

4. The first peelable layer and the second peelable layer are made of an inorganic material. The method for manufacturing a composite copper foil according to claim 2, wherein the insulating bonding material is an organic material.

5. The thickness of the first carrier is 5 to 30 times the thickness of the first copper foil. The thickness of the second carrier is 5 to 30 times the thickness of the second copper foil. The thickness of the second carrier is 5 to 30 times the thickness of the first copper foil, and / or The method for manufacturing a composite copper foil according to claim 2, wherein the thickness of the first carrier is 5 to 30 times the thickness of the second copper foil.

6. The thickness of the first copper foil is 15 to 50 times the thickness of the first peelable layer. The thickness of the second copper foil is 15 to 50 times the thickness of the second peelable layer. The thickness of the second copper foil is 15 to 50 times the thickness of the first peelable layer, and / or The method for manufacturing a composite copper foil according to claim 2, wherein the thickness of the first copper foil is 15 to 50 times the thickness of the second peelable layer.

7. The method for manufacturing a composite copper foil according to claim 1, further comprising the step of curing the insulating bonding material after the insulating bonding material has come into contact with the first copper foil and the second copper foil to form the insulating bonding layer.

8. The method for manufacturing a composite copper foil according to claim 1, wherein the thickness of the insulating bonding layer is thinner than the thickness of the insulating bonding material.

9. First copper foil and, The second copper foil and, An insulating bonding layer located between the first copper foil and the second copper foil, A composite copper foil comprising the above, wherein the thickness of the insulating bonding layer is less than 5 micrometers.

10. The composite copper foil according to claim 9, comprising the first copper foil, the second copper foil, and the insulating bonding layer.

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