Metal foil carrier, strippable metal foil and circuit board

Abstract

The utility model discloses a metal foil carrier, strippable metal foil and circuit board, the metal foil carrier comprises a support layer and an anti-oxidation layer, two opposite side surfaces of the support layer are provided with a first surface and a second surface, the anti-oxidation layer is arranged on the first surface, the second surface is used for connecting a functional layer, and the anti-oxidation layer is arranged on the second surface. And the anti-oxidation layer comprises a non-metal layer. According to the metal foil carrier, the strippable metal foil and the circuit board disclosed by the utility model, the anti-oxidation layer is arranged in the metal foil carrier, the anti-oxidation layer comprises the non-metal layer, and the melting point, the boiling point and the physical and chemical properties of the non-metal layer are greatly different from those of the metal layer, so that in the recovery process after the metal foil carrier is stripped, the metal foil carrier can be recovered; impurities are easy to separate after copper ions are replaced, so that the recovery efficiency is improved, and the resource waste is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of metal foils, in particular to a metal foil carrier, a peelable metal foil and a circuit board. Background Art

[0002] With the vigorous development of the PCB industry, electrolytic metal foil, as a key material for high-frequency and high-speed printed circuit boards for 5G communications, plays an increasingly important role in the manufacturing of raw materials, copper-clad laminates or PCBs. Ultra-thin metal foil is an important development direction for electrolytic metal foil. At present, the thickness of electrolytic metal foil is gradually developing towards 12μm, 9μm, 5μm, or even thinner. However, due to the low mechanical strength of ultra-thin metal foil, it is difficult to completely peel it off from the cathode roller during preparation, and it is prone to curling, wrinkling or tearing during transportation, which affects subsequent applications. At present, a preparation technology for ultra-thin metal foil with a carrier has been proposed. Since the ultra-thin metal foil has the support of a carrier, its mechanical strength can be improved.

[0003] Peelable metal foil with carrier is widely used to laminate with substrate through hot pressing, and then the metal foil layer and carrier layer are peeled off to be used as copper clad laminate. However, at the use level, the thickness of the metal foil layer is a few to several tens of times that of the carrier layer. After the carrier layer is peeled off, there are many impurities during recycling, which affects the recycling quality of the metal in the carrier layer, the recycling process is cumbersome, the recycling efficiency is low, and the waste of resources is serious. Utility Model Content

[0004] The utility model provides a metal foil carrier, a peelable metal foil and a circuit board. An anti-oxidation layer is arranged in the metal foil carrier, and the anti-oxidation layer includes a non-metallic layer. Since the melting point and boiling point of the non-metallic layer are greatly different from those of the metal layer, impurities can be easily separated after melting during the recycling process after the metal foil carrier is peeled off, which helps to improve the recycling efficiency and reduce resource waste.

[0005] In order to solve the above-mentioned technical problems, the first aspect of an embodiment of the utility model provides a metal foil carrier, wherein the metal foil carrier comprises a supporting layer and an anti-oxidation layer, wherein two opposite sides of the supporting layer are provided with a first surface and a second surface, the anti-oxidation layer is arranged on the first surface, the second surface is used to connect the functional layer, and the anti-oxidation layer comprises a non-metallic layer.

[0006] As a preferred solution, the non-metallic layer includes an organic layer, the organic layer is disposed on the first surface, and the thermal expansion coefficient of the anti-oxidation layer is 12 ppm / °C to 32 ppm / °C.

[0007] As a preferred solution, the non-metallic layer further includes a conductive filler member, the conductive filler member is disposed in the organic layer, and the conductive filler member is a nano-scale oxide.

[0008] As a preferred solution, the thickness of the anti-oxidation layer is 1 nm to 900 nm.

[0009] As a preferred solution, the thickness of the support layer is 15 μm to 50 μm.

[0010] As a preferred solution, the anti-oxidation layer further comprises a conductive support mesh, the conductive support mesh is arranged in the organic layer, and the conductive filler is electrically connected to the conductive support mesh.

[0011] As a preferred solution, the anti-oxidation layer further includes an inorganic metal layer, and the inorganic metal layer is connected to a side of the organic layer facing away from the first surface.

[0012] As a preferred solution, the inorganic metal layer is electrically connected to the conductive support network.

[0013] As a preferred solution, the thickness ratio of the non-metallic layer to the inorganic metal layer is 4:1 to 50:1.

[0014] The second aspect of the embodiment of the utility model provides a peelable metal foil, which includes a functional layer, a peeling layer and a metal foil carrier as described in any one of the first aspects, wherein the functional layer is connected to the second surface of the supporting layer in the metal foil carrier through the peeling layer.

[0015] A third aspect of an embodiment of the utility model provides a circuit board, wherein the circuit board comprises the peelable metal foil as described in the first aspect.

[0016] Compared with the prior art, the beneficial effects of the embodiments of the present invention are at least one of the following:

[0017] (1) By providing an anti-oxidation layer in the metal foil carrier, the outer surface of the metal foil carrier is not easily contaminated by moisture, dust and other objects in the air, and can maintain a relatively dry and clean surface state. At the same time, it is not easily oxidized, which can ensure the normal storage and use of the peelable metal foil.

[0018] (2) An anti-oxidation layer is provided in the metal foil carrier, and the anti-oxidation layer includes a non-metallic layer. Since the melting point and boiling point of the non-metallic layer are greatly different from those of the metal layer, it is easy to melt and separate impurities during the recycling process after the metal foil carrier is peeled off, which helps to improve the recycling efficiency and reduce resource waste. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1It is a structural schematic diagram of a preferred embodiment of the metal foil carrier provided by the utility model;

[0020] Figure 2 It is a structural schematic diagram of another preferred embodiment of the metal foil carrier provided by the utility model;

[0021] Figure 3 It is a schematic diagram of the structure of the peelable metal foil in the embodiment of the utility model;

[0022] Among them, 100 is a metal foil carrier; 101 is a support layer; 102 is an anti-oxidation layer; 103 is a non-metallic layer; 104 is an inorganic metal layer; 200 is a peeling layer; and 300 is a functional layer. DETAILED DESCRIPTION

[0023] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. The purpose of providing these embodiments is to make the disclosure of the utility model more thorough and comprehensive. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0024] In the description of this application, the terms "first", "second", "third", etc. are used for descriptive purposes only and are not to be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first", "second", "third", etc. may explicitly or implicitly include one or more of the feature. In the description of this application, unless otherwise specified, "plurality" means two or more.

[0025] In the description of the present application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be a connection between the two elements. The terms "vertical", "horizontal", "left", "right", "upper", "lower" and similar expressions used in this article are only for illustrative purposes, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present utility model. The term "and / or" used in this article includes any and all combinations of one or more related listed items. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0026] In the description of this application, it should be noted that, unless otherwise defined, all technical and scientific terms used in this utility model have the same meanings as those commonly understood by technicians in the technical field of this invention. The terms used in the specification of this utility model are only for the purpose of describing specific embodiments and are not intended to limit this utility model. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood by specific circumstances.

[0027] See also Figure 1 , Figure 1 It is a structural schematic diagram of a metal foil carrier 100 provided in an embodiment of the utility model. In a first aspect, an embodiment of the utility model provides a metal foil carrier 100, wherein the metal foil carrier 100 comprises a support layer 101 and an anti-oxidation layer 102, wherein the support layer 101 has two opposite side surfaces provided with a first surface and a second surface, wherein the anti-oxidation layer 102 is arranged on the first surface, and the second surface is used for connecting the functional layer 300, and the anti-oxidation layer 102 comprises a non-metallic layer 103.

[0028] It is worth mentioning that, in actual application, the metal foil carrier 100 is stacked with other material layers in the metal foil, such as the functional layer 300, to carry and protect the material layer, so that the material layer is not damaged by external contact or collision, etc. and meets the requirements of the production of extremely narrow circuits. After the functional layer 300 is pressed onto the circuit board at high temperature, the metal foil carrier 100 needs to be peeled off.

[0029] In this embodiment, first of all, considering that the strippable metal foil only uses a relatively thin functional layer 300 when in use, for example, the strippable copper foil only uses a thin copper layer of about 1 μm when in use, the metal foil carrier 100 is usually discarded or recycled after stripping, and there are often many impurities when the metal foil carrier 100 is recycled, thereby affecting the recovery quality of the metal in the metal foil carrier 100, and the purification process is cumbersome, and the recycling cost is high. Taking the metal foil carrier 100 as an example of a copper foil carrier, in order to reduce resource waste, it is necessary to recycle the copper in the copper foil carrier after the copper foil carrier is stripped, but there are many impurities during recycling, resulting in low copper recovery quality, and the purification process is cumbersome, which increases the recycling cost. Of course, the metal foil carrier 100 is not limited to a copper foil carrier, and it can also be made of other metal materials, such as aluminum, magnesium, titanium, lead, zinc, silver, nickel, cadmium, iron, chromium, cobalt, gold, etc. Different metals correspond to different application scenarios, and this embodiment is not specifically limited here. In order to solve the problem that the metal foil carrier 100 has a large number of impurities and is difficult to recycle, an anti-oxidation layer 102 is provided on the first surface of the support layer 101 of the metal foil carrier 100 in this embodiment, and the anti-oxidation layer 102 includes a non-metallic layer 103. Since the physicochemical properties of the non-metallic layer 103 are quite different from those of the metal layer, it usually does not react with the sulfuric acid-containing recovery liquid. Therefore, during the recovery process of the metal foil carrier 100, the non-metallic antioxidant material is easier to chemically dissolve and separate the impurities than the metallic antioxidant material, thereby improving the recovery quality of the metal in the metal foil carrier 100, helping to improve the recovery efficiency, and reduce resource waste and recovery costs.

[0030] Specifically, the waste copper foil recycling method is a method of recycling waste copper foil electroplated with one or more heavy metals by chemical dissolution and crystallization purification with a solution containing sulfuric acid; the waste copper foil is dissolved in a sulfuric acid solution to produce a copper sulfate solution, and after stabilizing its concentration, the copper sulfate solution is crystallized, that is, separated into two parts: crystals and mother liquor. At this time, the heavy metals on the waste copper foil have been transferred to the mother liquor, and then the crystals are separated from the mother liquor by washing with clean water, and the resulting copper sulfate crystals are sent to the electroplating tank for dissolution to complete the recovery of the copper foil. Secondly, this embodiment takes into account that during the application process of the strippable metal foil, the outer surface of the metal foil carrier 100 is exposed to the air environment, and is easily contaminated by moisture, dust and other objects in the air, and then an oxidation reaction occurs, and the storage time is greatly shortened. At the same time, the severely oxidized metal foil carrier 100 will also greatly increase the oxidation probability of the functional layer 300 it carries. In addition, due to the oxidation of the metal foil carrier 100, the brittleness increases during the stripping process, and the oxidized powder falls off from its surface, causing an increase in pollutants such as dust in the space during the stripping process, and the surface of the stripped functional layer 300 adsorbs the above pollutants. In addition, if the outer surface of the metal foil carrier 100 is severely oxidized, it is difficult to protect the functional layer 300 well. For example, when the strippable metal foil is in a high-temperature pressing process, due to the high hardness of the oxidation point of the metal foil carrier 100, pits and protrusions are formed on the surface of the functional layer 300 during the pressing process, causing the surface of the functional layer 300 to be uneven, which may cause a large line transmission loss in subsequent applications, and also cause the functional layer 300 to have poor adhesion when pressed with the application carrier such as the circuit substrate, causing the functional layer 300 to be tilted, bubbling and wrinkled. In addition, the oxidation point may fall off during the pressing process and adhere to the surface of the pressing plate of the press, causing pollution to the press, thereby affecting the subsequent pressing process. Therefore, in this embodiment, an anti-oxidation layer 102 is provided in the metal foil carrier 100, so that the outer surface of the metal foil carrier 100 is not easily contaminated by moisture, dust and other objects in the air, and can maintain a relatively dry and clean surface state. At the same time, it is not easily oxidized, which can ensure the normal storage and use of the peelable metal foil, which is conducive to extending the storage time.

[0031] As a preferred solution, the non-metallic layer 103 includes an organic layer, the organic layer is disposed on the first surface, and the thermal expansion coefficient of the anti-oxidation layer 102 is 12 ppm / °C to 32 ppm / °C.

[0032] Specifically, the non-metallic layer 103 in the present embodiment includes an organic layer, and the material of the organic layer is a polymer organic material such as polyimide, PET, etc. Taking polyimide as an example, polyimide has excellent high temperature stability and chemical stability, and has good bonding with the functional layer 300 (such as copper foil). By coating a polyimide solution or suspension on the surface of the functional layer 300 (such as copper foil) and undergoing heat treatment, a uniform anti-oxidation layer 102 can be formed. Such an anti-oxidation layer can effectively protect the functional layer 300 (such as copper foil) from the influence of oxidation, and has good bonding, and is suitable for use in the fields of electronics, communications, and aerospace. Polyimide has excellent high temperature resistance as the material of the anti-oxidation layer 102. Polyimide materials can still maintain stable chemical and physical properties at high temperatures, and can withstand temperatures of up to 400 degrees Celsius or more. Therefore, using polyimide as the material of the anti-oxidation layer 102 can not only protect the functional layer 300 (such as copper foil) from the influence of oxidation, but also maintain stable performance under high temperature environment, and is suitable for application fields that require high temperature resistance environment.

[0033] In addition, the material of the organic layer can also be any one of nitrogen-containing organic compounds, sulfur-containing organic compounds and hydroxy acids. Nitrogen-containing organic compounds include the following types: ketoxime compounds, transition metal chelators, organic amine compounds and nitrogen heterocyclic compounds; ketoxime compounds, such as phenyl oxime, o-nitrobenzene oxime, etc., can form complexes with the surface of metal oxides, thereby slowing down the oxidation rate of metals; transition metal chelators, such as nitrosopropanedione, etc., can form stable coordination complexes with metals, which can effectively prevent the oxidation reaction of metals; organic amine compounds, such as aniline, diethylamine, etc., can react with the surface of metal oxides to form amine copper complexes, thereby playing an antioxidant role; nitrogen heterocyclic compounds, such as pyridine, imidazole, etc., have strong coordination ability and can form stable complexes with metals, thereby slowing down the oxidation rate of metals. Of course, in addition to the nitrogen-containing organic compounds mentioned above, it can also be other nitrogen-containing organic compounds with antioxidant ability in the prior art, and this embodiment will not be described in detail here. Sulfur-containing organic compounds, such as mercaptoethanol, mercaptopropanol, etc., can react with the surface of metal oxides to form relatively stable complexes, thereby slowing down the oxidation rate of metals. Types of sulfur-containing organic compounds include disulfide compounds and thiothioether compounds; disulfide compounds, such as ethylene disulfide, propylene disulfide, etc., can form complexes with metal surfaces and have certain antioxidant capacity; thiothioether compounds, such as thiophenyl ether, thioethyl ether, etc., can react chemically with metals to slow down the oxidation process of metals. Of course, in addition to the above-mentioned sulfur-containing organic compounds, other sulfur-containing organic compounds with antioxidant capacity in the prior art can also be used, and this embodiment will not be described in detail here. Hydroxylic acids can form stable complexes with metal ions by chelating metal ions, thereby slowing down the oxidation rate of metals and having certain antioxidant capacity.

[0034] Furthermore, it is worth noting that the thermal expansion coefficient determines the deformation behavior of the material when heated. If the thermal expansion coefficient is too large, the degree of elongation or contraction of the material when the temperature changes will be more serious, which can easily lead to material deformation, cracking or fatigue fracture. Therefore, this embodiment limits the thermal expansion coefficient of the anti-oxidation layer 102 to 12ppm / ℃~32ppm / ℃, for example, it can be 12ppm / ℃, 14ppm / ℃, 17ppm / ℃, 20ppm / ℃, 23ppm / ℃, 25ppm / ℃, 28ppm / ℃, 32ppm / ℃, etc. This embodiment does not make specific limitations here, so as to ensure that the thermal expansion coefficient of the anti-oxidation layer 102 is not too large, thereby avoiding deformation, cracking or fatigue fracture of the anti-oxidation layer 102 during high-temperature pressing.

[0035] As a preferred solution, the non-metallic layer 103 further includes a conductive filler member, the conductive filler member is disposed in the organic layer, and the conductive filler member is a nano-scale oxide.

[0036] Specifically, in this embodiment, conductive fillers are added to the non-metallic layer 103. The conductive fillers are specifically nano-scale oxides, such as nano-titanium dioxide, nano-silicon dioxide, nano-zinc oxide, nano-aluminum oxide, nano-zirconium oxide, nano-cerium oxide, nano-iron oxide, etc. The addition of conductive fillers can improve the heat resistance, conductivity and mechanical properties of the non-metallic layer 103.

[0037] As a preferred solution, the thickness of the anti-oxidation layer 102 is 1 nm to 900 nm.

[0038] It is worth noting that the thickness of the anti-oxidation layer 102 affects its performance. Generally speaking, when the thickness of the anti-oxidation layer 102 is small, its anti-oxidation performance is poor, so that it cannot effectively prevent the outer surface of the metal foil carrier 100 from being polluted by moisture, dust and other objects in the air and causing oxidation reaction; when the thickness of the anti-oxidation layer 102 is large, although its anti-oxidation performance is relatively good, it will cause the mechanical properties such as adhesion to decrease, resulting in cracks and shedding of the anti-oxidation layer 102, and the anti-oxidation layer 102 is too thick, which will increase the production cost. Therefore, in this embodiment, By limiting the thickness of the anti-oxidation layer 102 to 1nm to 900nm, for example, the thickness of the anti-oxidation layer 102 is 1nm, 13nm, 70nm, 130nm, 180nm, 250nm, 350nm, 500nm, 650nm, 750nm, 900nm, etc., which is not specifically limited in this embodiment, it is ensured that the anti-oxidation layer 102 has good anti-oxidation properties while not causing a decrease in mechanical properties due to excessive thickness, avoiding cracks and falling off, and ensuring the normal storage and use of the peelable metal foil.

[0039] Furthermore, the thickness of the support layer 101 is 15 μm to 50 μm.

[0040] It is worth noting that since the support layer 101 is used to provide support strength for the functional layer 300 and play a bearing role, it needs to have a certain thickness to play a stable supporting role. In this embodiment, the thickness of the support layer 101 is set to 15μm to 50μm. For example, the thickness of the support layer 101 is 15μm, 18μm, 24μm, 37μm, 48μm, 50μm, etc. This embodiment is not specifically limited here, so that the support layer 101 is not too thin, ensuring that its thickness is sufficient as the support layer 101 to provide support strength for the strippable metal foil, and facilitating the production and manufacturing of the metal foil carrier 100, because a too thin support layer 101 is easy to adhere to the surface of the conveying roller, resulting in more wrinkles, fine lines and other defects. At the same time, it is not too thick to avoid the volume and weight of the strippable metal foil being too large. In addition, within the thickness range of 15μm to 50μm, the automatic or manual stripping efficiency under different processes can be met, and the peeling strength is stable.

[0041] As a preferred solution, the anti-oxidation layer 102 further includes a conductive support mesh, the conductive support mesh is disposed in the organic layer, and the conductive filler is electrically connected to the conductive support mesh.

[0042] Specifically, in this embodiment, a conductive support mesh is disposed in the organic layer, and the conductive support mesh is electrically connected to the conductive filler, so that the metal foil carrier 100 can be conductive as a whole, meeting the requirements of ETS application and coreless process.

[0043] See also Figure 2 As a preferred embodiment, the anti-oxidation layer 102 further includes an inorganic metal layer 104, and the inorganic metal layer 104 is connected to a side of the organic layer facing away from the first surface.

[0044] Specifically, the material of the inorganic metal layer 104 includes at least one of metals such as nickel, copper, chromium, zinc and / or an alloy including at least one of them. By setting the inorganic metal layer 104 in the anti-oxidation layer 102, after the functional layer 300 is pressed, the anti-oxidation effect can be further improved after some wet processes.

[0045] As a preferred solution, the inorganic metal layer 104 is electrically connected to the conductive support network.

[0046] Specifically, the present embodiment electrically connects the inorganic metal layer 104 to the conductive support network in the organic layer, which can, on the one hand, further improve the conductivity of the metal foil carrier 100; on the other hand, if the bonding force between the inorganic metal layer 104 and the non-metallic layer 103 is small, the inorganic metal layer 104 and the non-metallic layer 103 are easily delaminated during the stripping process of the metal foil carrier 100, resulting in low reliability of the metal foil carrier 100. Therefore, the bonding force between the inorganic metal layer 104 and the non-metallic layer 103 can be improved through electrical connection to avoid delamination during the stripping process.

[0047] As a preferred solution, the thickness ratio of the non-metal layer 103 to the inorganic metal layer 104 is 4:1 to 50:1.

[0048] Specifically, since the non-metallic layer 103 includes a conductive filler and a conductive support mesh, the present embodiment limits the thickness ratio of the non-metallic layer 103 to the inorganic metal layer 104 to 4:1 to 50:1, such as 4:1, 10:1, 16:1, 22:1, 28:1, 34:1, 40:1, 47:1, 50:1, etc., thereby increasing the proportion of the non-metallic layer 103, so that the metal foil carrier 100 has better conductive effect and oxidation resistance. In addition, if the proportion of the inorganic metal layer 104 is too high, it is difficult to separate impurities after melting during the recycling process of the metal foil carrier 100, resulting in more impurities when the metal ions are recycled, reducing the recycling quality of the metal and causing serious waste of resources. Therefore, increasing the proportion of the non-metallic layer 103 helps to reduce impurities when the metal ions are recycled after the metal foil carrier 100 is stripped.

[0049] As a preferred solution, the anti-oxidation layer 102 is formed on the first surface of the support layer 101 by any one of a chemical solution method, a vacuum deposition method, a heat treatment method, an electrochemical treatment method and a surface modification method.

[0050] Specifically, the chemical solution method is to use a specific chemical solution, such as a chemical bath, dipping or spraying method, to apply a solution containing an antioxidant or a coating on the surface of the support layer 101 to form an anti-oxidation layer 102. The vacuum deposition method is to use physical or chemical deposition technology, such as physical vapor deposition (PVD) or chemical vapor deposition (CVD), to deposit an anti-oxidation layer 102 on the surface of the support layer 101. Commonly used materials include silicon nitride, zinc oxide, etc. The heat treatment method is to perform heat treatment at high temperature to cause an oxidation reaction on the surface of the support layer 101 to form a dense oxide layer. This method is often used for red copper foil. The electrochemical treatment method is to use an electrochemical method to form an anti-oxidation layer 102 on the surface of the support layer 101. For example, a metal oxide layer or other anti-oxidation layer 102 is formed on the surface of the support layer 101 by anodizing or electrodeposition in an electrolyte. The surface modification method is to achieve the anti-oxidation effect by chemically modifying the surface of the support layer 101 or spraying a modified layer, for example, spraying of modified nanomaterials, self-assembly of organic amine molecules, etc. Preferably, the anti-oxidation layer 102 in this embodiment is formed on the surface of any side of the support layer 101 by physical vapor deposition.

[0051] As a preferred solution, the material of the support layer 101 includes at least one of copper, aluminum, magnesium, titanium, lead, zinc, silver, nickel, cadmium, iron, chromium, cobalt, and gold and / or an alloy of at least one of them. Taking the peelable copper foil as an example, the material of the support layer 101 in this embodiment is preferably copper, which has low cost and is convenient to produce on the same production line, thereby improving the production efficiency of the product.

[0052] See also Figure 2 , Figure 2 It is a schematic diagram of the structure of a peelable metal foil in an embodiment of the utility model. The second aspect of the embodiment of the utility model provides a peelable metal foil, wherein the peelable metal foil comprises a functional layer 300, a peeling layer 200 and a metal foil carrier 100 as described in any embodiment of the first aspect, wherein the functional layer 300 is connected to the second surface of the support layer 101 in the metal foil carrier 100 through the peeling layer 200.

[0053] It is worth noting that the functional layer 300 plays a conductive role. In this embodiment, the functional layer 300 is preferably a thin copper layer. Of course, the material of the functional layer 300 may also include at least one of copper, aluminum, zinc, nickel, and silver metal elements. This embodiment will not be described in detail here. Preferably, the thickness of the thin copper layer in this embodiment is 1 to 5 μm, for example, 1 μm, 1.6 μm, 2.3 μm, 3.5 μm, 4 μm, 5 μm, etc. This embodiment is not specifically limited here.

[0054] In practical applications, for example, when the functional layer 300 is used in the field of circuit boards, the functional layer 300 is heat-pressed and bonded to the substrate of the circuit board. For example, when it is used in the field of electronic material production, the copper functional layer 300 is combined with a composite material to make a copper-clad laminate, a flexible copper-clad laminate, or as a raw material for the production of adhesive-coated copper foil. For example, when it is used in the field of batteries, the copper functional layer 300 is used as the negative electrode material (negative electrode current collector) of the battery, and it is heat-pressed and bonded to the negative electrode active material in the negative electrode material. The aluminum functional layer 300 is used as the positive electrode material (positive electrode current collector) of the battery.

[0055] The function of the peeling layer 200 is to separate the metal foil carrier 100 from the functional layer 300 by peeling; at the same time, due to the existence of the peeling layer 200, the metal migration between the functional layer 300 and the metal foil carrier 100 can be blocked, and the peeling layer 200 can cover or fill the uneven surface of the metal foil carrier 100, so that the functional layer 300 formed on the other surface of the peeling layer 200 is smoother, more uniform and denser, reducing the occurrence of pinholes, which is beneficial to the subsequent circuit production.

[0056] The material of the peeling layer 200: including metals, such as any one or more materials of copper, nickel, silicon, molybdenum, graphite, titanium and niobium, and may also contain a certain amount of copper; or, non-metals, such as organic polymer materials, or silicon-free release agent release layer, silicone oil release layer or nitrogen release layer, and the release layer can be formed by coating and drying the release agent. The release agent may include HDPE (high-density polyethylene) and PMA (propylene glycol methyl ether acetate) solvents, etc.; when the above two release agents are used, the mass ratio of HDPE:PMA is preferably (1-5):7. In other embodiments, the release agent may include a fluorine release agent and a solvent; wherein the volume ratio of the fluorine release agent:solvent is preferably (5-30):1; there is no special restriction on the types of the above solvents, and conventional release agent solvents in the art may be selected, such as butanone, which does not constitute a limitation on the present utility model.

[0057] Preferably, the thickness of the peeling layer 200 in this embodiment is 20 nm to 900 nm, for example, 20 nm, 45 nm, 125 nm, 245 nm, 500 nm, 675 nm, 800 nm, 900 nm, etc., which is not specifically limited in this embodiment. In addition, the peeling layer 200 in this embodiment can be processed on the metal foil carrier 100 by sputtering, evaporation, etc.

[0058] In a specific implementation process, the metal foil carrier 100 is separated from the functional layer 300 in a peelable removal manner or a non-peeling removal manner. When the metal foil carrier 100 is removed in a non-peeling removal manner, the non-peeling manner may be, for example, laser etching, chemical etching, grinding, plasma removal, etc. When the metal foil carrier 100 is removed by peeling, the peeling manner may be, for example, direct removal by manual peeling, or peeling with the aid of mechanical equipment. In this embodiment, an anti-oxidation layer 102 is provided in the metal foil carrier 100, and the anti-oxidation layer 102 includes a non-metallic layer 103. Since the melting point and boiling point of the non-metallic layer 103 are greatly different from those of the metal layer, during the recycling process after the metal foil carrier 100 is peeled off, it is easy to separate impurities after melting, which helps to improve the recycling efficiency and reduce resource waste. At the same time, the provision of the anti-oxidation layer 102 makes the outer surface of the metal foil carrier 100 not easily contaminated by moisture, dust and other objects in the air, and can maintain a relatively dry and clean surface state. At the same time, it is not easily oxidized, which can ensure the normal storage and use of the peelable metal foil.

[0059] A third aspect of an embodiment of the utility model provides a circuit board, wherein the circuit board comprises the peelable metal foil as described in the first aspect.

[0060] The metal foil carrier 100, the peelable metal foil and the circuit board provided by the embodiment of the utility model have the following beneficial effects:

[0061] (1) The anti-oxidation layer 102 is provided in the metal foil carrier 100, so that the outer surface of the metal foil carrier 100 is not easily contaminated by moisture, dust and other objects in the air, and can maintain a relatively dry and clean surface state. At the same time, it is not easily oxidized, which can ensure the normal storage and use of the peelable metal foil.

[0062] (2) An anti-oxidation layer 102 is provided in the metal foil carrier 100, and the anti-oxidation layer 102 includes a non-metallic layer 103. Since the melting point and boiling point of the non-metallic layer 103 are greatly different from those of the metal layer, it is easy to melt and separate impurities during the recycling process after the metal foil carrier 100 is peeled off, which helps to improve the recycling efficiency and reduce resource waste.

[0063] The above is a preferred embodiment of the present invention. It should be pointed out that a person skilled in the art can make several improvements and modifications without departing from the principle of the present invention. These improvements and modifications are also considered to be within the protection scope of the present invention.

Claims

1. A metal foil carrier, characterized in that: The metal foil carrier includes a support layer and an anti-oxidation layer. The support layer has a first surface and a second surface on two opposite sides. The anti-oxidation layer is arranged on the first surface. The second surface is used to connect the functional layer. The anti-oxidation layer includes a non-metallic layer.

2. The metal foil carrier according to claim 1, characterized in that The non-metal layer includes an organic layer, the organic layer is disposed on the first surface, and the thermal expansion coefficient of the anti-oxidation layer is 12 ppm / ° C. to 32 ppm / ° C.

3. The metal foil carrier according to claim 2, characterized in that The non-metal layer further includes a conductive filler, which is disposed in the organic layer and is a nano-scale oxide.

4. The metal foil carrier according to claim 2, characterized in that The thickness of the anti-oxidation layer is 1 nm to 900 nm; and / or, The thickness of the support layer is 15 μm to 50 μm.

5. The metal foil carrier according to claim 3, characterized in that: The anti-oxidation layer further comprises a conductive support mesh, wherein the conductive support mesh is arranged in the organic layer, and the conductive filler is electrically connected to the conductive support mesh.

6. The metal foil carrier according to claim 5, characterized in that The anti-oxidation layer further includes an inorganic metal layer, and the inorganic metal layer is connected to a side of the organic layer facing away from the first surface.

7. The metal foil carrier according to claim 6, characterized in that The inorganic metal layer is electrically connected to the conductive support network.

8. The metal foil carrier according to claim 7, characterized in that The thickness ratio of the non-metal layer to the inorganic metal layer is 4:1 to 50:

1.

9. A peelable metal foil, characterized in that: The strippable metal foil comprises a functional layer, a stripping layer and the metal foil carrier according to any one of claims 1 to 8, wherein the functional layer is connected to the second surface of the supporting layer in the metal foil carrier through the stripping layer.

10. A circuit board, characterized in that: The circuit board comprises the peelable metal foil as claimed in claim 9.

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