CN114603945B

CN114603945B - Metal foil, copper-clad laminate, wiring board, semiconductor, negative electrode material, and battery

Info

Publication number: CN114603945B
Application number: CN202210512371.2A
Authority: CN
Inventors: 苏陟; 曾雪淇; 姚向荣
Original assignee: Guangzhou Fangbang Electronics Co Ltd
Current assignee: Guangzhou Fangbang Electronics Co Ltd
Priority date: 2022-05-12
Filing date: 2022-05-12
Publication date: 2023-03-21
Anticipated expiration: 2042-05-12
Also published as: CN114603945A

Abstract

The invention discloses a metal foil, a copper-clad laminated plate, a circuit board, a semiconductor, a negative electrode material and a battery. The metal foil comprises a coarsening processing surface, and the coarsening processing surface is provided with a plurality of coarsening particles; on the coarsening treatment surface, the maximum outer contour dimension B of each coarsening particle meets the condition that B is more than or equal to 0.5 mu m and less than or equal to 35 mu m; wherein the maximum outline size is the total length of the coarsening particles exposed to the periphery of the surface of the metal foil in a slice obtained in a direction perpendicular to the thickness direction of the metal foil. By adopting the embodiment of the invention, the maximum outer contour size of the coarsening particles of the metal foil is improved, the structure of the metal foil is optimized, the problems of poor adhesion of the metal foil, easy occurrence of foaming, cracking and the like can be effectively solved, the quality of the metal foil is effectively improved, and the reject ratio of products applying the metal foil is reduced.

Description

Metal foil, copper-clad laminate, wiring board, semiconductor, negative electrode material, and battery

Technical Field

The invention relates to the technical field of metal foils, in particular to a metal foil, a copper-clad laminated plate, a circuit board, a semiconductor, a negative electrode material and a battery.

Background

In recent years, with the increasing demand for smaller and higher performance electronic devices, high-density mounting of mounted parts has been advanced, and metal foils are widely used in various electronic technology fields, such as printed wiring boards and battery negative electrode materials.

Taking the application scenario of a printed circuit board as an example, in order to produce good adhesion with a circuit board substrate and reduce the occurrence of foaming, cracking and the like during use, the surface of a conventional metal foil generally needs to be roughened. However, the surface of the metal foil is only subjected to simple roughening treatment, or the height range or width range of the surface roughening particles after roughening is limited, but the influence of the microstructure and size of the roughening particles on the roughness of the metal foil and the degree of stability of the roughening particles themselves is not considered. The rough surface where the micro particles are located is a key structure for obtaining the best adhesion between the metal foil and the substrate, even if the height or the width of the coarsening particles are limited, if the micro form and the size of the coarsening particles on the surface of the roughened metal foil are not proper, in the actual processing production, the roughness of the metal foil is not reasonable, the conditions of poor adhesion, foaming, metal foil fracture and the like in the pressing process are still generated when the metal foil is combined with the substrate, and the quality and the processing efficiency of the circuit board are seriously influenced.

Meanwhile, the roughened layer is subjected to surface treatment such as oxidation resistance and the like according to actual requirements in the follow-up process, if the size of roughened particles of the conducting layer subjected to roughening treatment is too large, the particles are very easy to fall off in a further processing process, the fallen roughened particles such as copper powder, aluminum powder and the like are easily agglomerated on the surface of the roughened layer, the roughness of the roughened surface is increased, the good adhesion between the follow-up process and the substrate is influenced, the processes such as oxidation resistance and the like are influenced, the oxidation resistance process is incomplete, or bubbles exist between the oxidation resistant layer and the roughened surface layer, and the residue of the bubbles further causes the foaming and cracking of the metal foil during the follow-up press-fitting with the substrate; if the surface texture of the coarsened particles is too complex, the roughness of the rough surface is possibly too high, and the transmission loss of high-frequency signals is increased; if the size of the coarsening particles is too small or the surface lines of the coarsening particles are too shallow, the roughness of the rough surface is too low, the effect of enhancing the surface adhesive force required to be adhered with a substrate and the like cannot be achieved, the adhesion is not tight, bubbles are easily generated, the product quality is influenced in the processing of the circuit board, the possibility of falling off or etching occurs in the subsequent processing process of the circuit board, and the reject ratio of the circuit board product is greatly increased.

Currently, there have been few studies on the size and morphology of the roughened particles on the roughened surface of the conductive layer in the microstructure, and problems such as the best adhesion and the large reduction in the incidence of blistering and cracking due to the improvement of the size and morphology of the roughened particles. The method has the advantages that the suitable distribution and shape structure of the coarsening particles are obtained, the falling and powder falling of the coarsening particles on the rough surface are reduced, the subsequent processes such as oxidation resistance are facilitated, meanwhile, the bonding strength of the metal foil and other materials such as a circuit board substrate can be improved, the subsequent processing quality is ensured, and the method is a problem which needs to be solved urgently before technicians in the industry.

Disclosure of Invention

The embodiment of the invention aims to provide a metal foil, a copper-clad laminated board, a circuit board, a semiconductor, a negative electrode material and a battery, which can effectively solve the problems of poor adhesion of the metal foil, easy occurrence of foaming, cracking and the like, effectively improve the quality of the metal foil and reduce the fraction defective of products applying the metal foil by improving the structure of the metal foil.

In order to achieve the above object, an embodiment of the present invention provides a metal foil, including a roughened surface, where the roughened surface has a plurality of roughened particles; on the coarsening treatment surface, the maximum outer contour dimension B of each coarsening particle meets the condition that B is more than or equal to 0.5 mu m and less than or equal to 35 mu m; wherein the maximum outline dimension is a total length of a periphery of the roughened particles exposed on the surface of the metal foil in a slice taken perpendicular to a thickness direction of the metal foil.

As an improvement of the above scheme, on the coarsened surface, the maximum outer contour dimension B of each of the coarsened particles satisfies 0.8 μm ≦ B ≦ 30 μm.

As an improvement of the scheme, on the coarsened surface, the difference F of the maximum outer contour sizes of two adjacent coarsened particles satisfies 0 μm and less than or equal to F and less than or equal to 15.5 μm.

As an improvement of the scheme, on the coarsened surface, the difference F of the maximum outer contour sizes of two adjacent coarsened particles satisfies 2 mu m and less than or equal to F and less than or equal to 12 mu m.

As an improvement of the scheme, the ratio of the maximum width to the maximum vertical height of the coarsening particles ranges from 0.2 to 4.

As an improvement of the scheme, the ratio of the maximum width to the maximum vertical height of the coarsening particles ranges from 0.5 to 3.5.

In an improvement of the above aspect, the roughness Rz value of the roughened surface of the metal foil is 2 μm or less.

As an improvement of the above scheme, the metal foil includes a conductive layer, and one surface of the conductive layer is the roughened surface.

As an improvement of the above scheme, the metal foil further includes a carrier layer, and the carrier layer is disposed on a surface of the conductive layer which is not the roughened surface.

As a refinement of the above, the metal foil further comprises a release layer, the release layer being disposed between the carrier layer and the conductive layer.

As a refinement of the above, the carrier layer and/or the release layer is filled with a medium for absorbing heat.

As a refinement of the above solution, the material of the carrier layer includes at least one of the following metal elements: copper, aluminum and zinc, and the thickness of the carrier layer is 5 to 50 mu m.

As an improvement of the scheme, the carrier layer is an organic film, and the thickness of the carrier layer is 10-100 mu m.

In an improvement of the above aspect, the thickness of the release layer is 1 to 8nm.

As a refinement of the above, the metal foil further comprises an adhesive layer disposed between the carrier layer and the release layer.

As an improvement of the above scheme, the metal foil further includes a first oxidation prevention layer, and the first oxidation prevention layer is disposed on a surface of the conductive layer close to the peeling layer.

As an improvement of the above scheme, the metal foil further includes a second oxidation prevention layer, and the second oxidation prevention layer is disposed on a surface of the conductive layer away from the peeling layer.

As a modification of the above aspect, the metal foil further includes a resin layer provided on a surface of the conductive layer remote from the peeling layer.

The embodiment of the invention also provides a copper-clad laminated plate, which comprises the metal foil, and the copper-clad laminated plate is specifically a flexible copper-clad plate or a flexible copper-clad plate.

The embodiment of the invention also provides a circuit board, which comprises a circuit board substrate and the metal foil; and the coarsening surface of the metal foil is pressed with the circuit board substrate.

Embodiments of the present invention also provide a semiconductor material, which includes a metal foil as described in any one of the above.

The embodiment of the invention also provides a negative electrode material applied to a battery, wherein the negative electrode material comprises the metal foil.

The embodiment of the invention also provides a battery, and the negative electrode material of the battery comprises the metal foil.

Compared with the prior art, the metal foil, the copper-clad laminated plate, the circuit board, the semiconductor, the negative electrode material and the battery disclosed by the embodiment of the invention are provided. The metal foil comprises a coarsening processing surface, and the coarsening processing surface is provided with a plurality of coarsening particles; on the coarsened surface, the maximum outer contour dimension B of each coarsened particle satisfies that B is more than or equal to 0.5 mu m and less than or equal to 35 mu m. The embodiment of the invention optimizes the maximum outline dimension of the coarsening particles on the coarsened surface, optimizes the difference of the maximum outline dimensions of the adjacent coarsening particles, the ratio of the maximum width to the maximum height of the coarsening particles and the like according to requirements, and indirectly limits the micro morphology and the size of the coarsening particles, thereby effectively improving the coarsened surface of the metal foil. The metal foil with the roughened surface has reasonable roughness, can effectively improve the adhesion of the metal foil when being applied to the field of circuit boards or when being used as a battery cathode material and being combined with a cathode active material, further reduces the conditions of bubbling, cracking and the like, and does not influence the transmission loss of high-frequency signals in the manufactured circuit boards. Moreover, the coarsening particles with certain outline size are arranged on the coarsening processing surface of the metal foil, so that the flatness uniformity of the surface of the metal foil is increased, and the processing of subsequent fine lines is facilitated. In addition, the arrangement of the multilayer structure of the metal foil is matched, so that the performances of oxidation resistance, moisture resistance, tensile strength, bending resistance, difficulty in breaking, uniformity, compactness and the like of the metal foil are further improved, the quality and the processing efficiency of products applying the metal foil are effectively improved, and the reject ratio of the products applying the metal foil is reduced.

Drawings

FIG. 1 is a schematic structural diagram of a first metal foil according to an embodiment of the present invention;

FIG. 2 is an electron microscope image of a first metal foil provided by an embodiment of the present invention;

FIG. 3 is a schematic diagram of the maximum outer profile dimension of the coarsening particles in the embodiment of the present invention;

FIG. 4 is a schematic diagram of the maximum vertical height and the maximum width of the coarsened particles in the embodiment of the present invention;

FIG. 5 is a schematic structural diagram of a second metal foil provided in an embodiment of the present invention;

FIG. 6 is a schematic structural diagram of a third metal foil provided in an embodiment of the present invention;

FIG. 7 is a schematic structural diagram of a fourth metal foil provided in an embodiment of the present invention;

FIG. 8 is a schematic structural diagram of a fifth metal foil provided in an embodiment of the present invention;

FIG. 9 is a schematic structural diagram of a sixth metal foil provided in an embodiment of the present invention;

FIG. 10 is a schematic structural diagram of a seventh metal foil according to an embodiment of the present invention;

FIG. 11 is a schematic structural diagram of an eighth metal foil according to an embodiment of the present invention;

FIG. 12 is a schematic structural diagram of a ninth metal foil according to an embodiment of the present invention;

FIG. 13 is a schematic structural diagram of a tenth metal foil provided in accordance with an embodiment of the present invention;

FIG. 14 is a schematic structural diagram of an eleventh metal foil according to an embodiment of the present invention;

fig. 15 is a schematic structural diagram of a circuit board according to an embodiment of the present invention;

wherein, 1, roughening the surface; 2. a conductive layer; 3. a carrier layer; 4. a peeling layer; 5. a bonding layer; 6. a first oxidation preventing layer; 7. a second oxidation preventing layer; 8. a resin layer; 11. coarsening the particles; 31. first filler particles; 41. second filler particles; 9. a circuit board substrate.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

In the description of the specification and claims, it is to be understood that the terms "upper", "lower", "left", "right", "front", "back", "top", "bottom", "inner", "outer", and the like, indicate orientations and positional relationships based on those shown in the drawings, are used for convenience in describing embodiments of the present invention, and do not indicate or imply that the referenced devices or components must have a particular orientation, be constructed and operated in a particular orientation, and thus are not to be construed as limiting the embodiments of the present invention.

Furthermore, the terms first, second and the like in the description and in the claims, are used for descriptive purposes only to distinguish the same technical features, and are not to be construed as indicating or implying relative importance or implicit indication of the number of technical features indicated, nor is an order or temporal order necessarily described. The terms are interchangeable where appropriate. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature.

Referring to fig. 1 and fig. 2, fig. 1 is a schematic structural diagram of a first metal foil provided in an embodiment of the present invention, and fig. 2 is an electron microscope image of the first metal foil provided in the embodiment of the present invention. The embodiment of the invention provides a metal foil, which comprises a roughened surface 1, wherein the roughened surface 1 is provided with a plurality of roughened particles 11; on the coarsened surface 1, the maximum outer contour dimension B of each coarsened particle 11 satisfies 0.5 μm and B35 μm.

The metal foil can be applied to occasions such as circuit boards, battery negative electrode materials and the like. In order to facilitate the metal foil to be well thermally bonded to the circuit board substrate or the negative electrode active material of the negative electrode material during use, and reduce the occurrence of foaming and cracking, at least one surface of the metal foil is provided with a roughened surface 1, that is, a plurality of roughened particles 11 are arranged on at least one surface of the metal foil, so that the roughened surface is formed.

In particular, the surface of the metal foil subjected to the roughening treatment process is a roughened surface. The coarsening particles refer to projections formed on the corresponding surface of the metal foil subjected to coarsening treatment through a coarsening treatment process.

The shape or size parameter of the coarsening particles on the coarsened surface of the metal foil comprises the following steps: the method for measuring the maximum vertical height, the maximum width and the maximum outer contour dimension is obtained by taking pictures of the section shapes of the surface and the slice by a scanning electron microscope and combining the statistics of measurement, statistics and analysis software. The specific method comprises the following steps:

(1) And (5) preparing a sample. Randomly cutting a sample with a certain size on the whole copper foil product, preparing the sample according to the detection requirement of a scanning electron microscope, observing the section and the surface appearance of the section of the copper foil sample by selecting a proper multiple (generally 2000-10000 times) under the scanning electron microscope, and shooting a topography map.

(2) Repeating the above steps for multiple times to obtain multiple slices and surface topography maps of the same product, and performing statistics and analysis by using statistics and analysis software.

In the embodiment of the present invention, the maximum outer contour dimension B of the roughening particles on the roughening-treated surface 1 is defined, and fig. 3 is a schematic diagram of the maximum outer contour dimension of the roughening particles in the embodiment of the present invention. The maximum outline dimension B is the total length of the roughened particles 11 exposed to the outer periphery of the surface of the metal foil in a slice taken perpendicular to the thickness direction of the metal foil. Since the maximum outline dimension is related to the outline profile of the roughened particle exposed on the surface of the metal foil, it indirectly characterizes the microscopic morphology and size of the roughened particle, if the size (including width and height) of the roughened particle is larger, the maximum outline dimension of the roughened particle is larger; if the microscopic morphology of the coarsened particle is more complicated, for example, the texture level is more abundant, the maximum outline size of the coarsened particle is also larger.

Therefore, the maximum outer contour dimension B of each coarsening particle is set to satisfy the relation that B is more than or equal to 0.5 mu m and less than or equal to 35 mu m on the coarsening surface 1, the micro form and the size of the coarsening particles are indirectly limited, and the coarsening surface of the metal foil is effectively improved. The metal foil with the roughened surface has reasonable roughness, can effectively improve the adhesion of the metal foil when being applied to the field of circuit boards or when being used as a battery cathode material and being combined with a cathode active material, further reduces the conditions of bubbling, cracking and the like, and does not influence the transmission loss of high-frequency signals in the manufactured circuit boards. Moreover, the coarsening particles with certain outline size are arranged on the coarsening processing surface of the metal foil, so that the flatness uniformity of the surface of the metal foil is increased, the processing of subsequent fine lines is facilitated, the quality and the processing efficiency of products using the metal foil are effectively improved, and the reject ratio of the products using the metal foil is reduced.

In a preferred embodiment, the maximum outer contour dimension B of each of the roughened particles on the roughened surface satisfies 0.8 μm B30 μm.

By adopting the technical means of the embodiment of the invention, the size and the form of the coarsening particles 11 can be further optimized, so that the size and the form of the coarsening particles are more reasonable, the width and the height range of the coarsening particles are indirectly determined, the roughness of the surface of the metal foil can be more reasonable, the bonding property of the metal foil and other materials such as a circuit board substrate is well improved, the coarsening particles can stably grow or attach to the surface of a conducting layer of the metal foil and are not easy to fall off or fall off, the subsequent finishing quality such as a circuit processing process is improved, and the phenomena of foaming, cracking and the like of the metal foil during lamination are further reduced. Moreover, the coarsened surface of the coarsened particles with a certain outer contour size limited by the invention is adopted, so that the evenness of the surface of the metal foil is increased, and the processing of a fine circuit is facilitated.

In a preferred embodiment, the difference F between the maximum outer contour sizes of two adjacent coarsened particles on the coarsened surface satisfies 0 μm ≦ F ≦ 15.5 μm.

In a more preferred embodiment, the difference F between the maximum outer contour dimensions of two adjacent roughened particles on the roughened surface satisfies 2 μm or less and F or less and 12 μm or less.

In the embodiment of the present invention, for the first coarsening particles and the second coarsening particles which are adjacently arranged, the maximum outer profile sizes thereof are B1 and B2, respectively, and then the difference F = | B1-B2|. The range of the difference F is between 0 and 15.5 mu m, and preferably between 2 and 12 mu m.

By adopting the technical means of the embodiment of the invention, on the basis of limiting the maximum outer contour dimension of the coarsening particles 11, the difference value of the maximum outer contour dimension of the adjacent coarsening particles 11 is further optimized, so that the size and form difference of two adjacent coarsening particles is smaller, the poor flatness uniformity of the whole coarsened surface caused by the large size and form difference of the adjacent coarsening particles is avoided, the condition of unbalanced adhesion due to the non-uniform local roughness on the coarsened surface is effectively avoided, the distribution uniformity of the coarsening particles is improved, the rationality of the overall roughness of the coarsened surface is ensured, the good adhesion of the whole coarsened surface is ensured, and the occurrence of the conditions of foaming, cracking and the like of the metal foil is further reduced.

In a preferred embodiment, the ratio of the maximum width to the maximum vertical height of the coarsening particles is in a range of 0.2 to 4.

In a more preferred embodiment, the ratio of the maximum width to the maximum vertical height of the coarsened particles is in a range of 0.5 to 3.5.

Specifically, referring to fig. 4, it is a schematic diagram of the maximum vertical height and the maximum width of the coarsening particles in the embodiment of the present invention. The maximum vertical height H refers to a vertical distance between the highest point of the coarsened particle and the root thereof. The maximum width W refers to a maximum value of the width or diameter of the coarsened particles. Assuming that the maximum width of a certain coarsening particle is W1 and the maximum vertical height is H1, the ratio α = W1/H1 of the maximum width to the maximum vertical height. The range of the ratio alpha is 0.2 to 4, preferably 0.5 to 3.5.

In the embodiment of the invention, besides optimizing the difference value between the maximum outer contour dimension of the coarsening particles and the maximum outer contour dimension of the adjacent coarsening particles, the ratio of the maximum width to the maximum vertical height of the coarsening particles is optimized, the size ranges of the maximum width and the maximum vertical height of the same coarsening particle are indirectly limited, the micro form of the coarsening particles is further limited, the overlarge difference of the form structures of different coarsening particles on the coarsening processing surface is effectively avoided, the leveling uniformity and the reasonability of the overall roughness of the coarsening processing surface are avoided being influenced, the good adhesion and foaming performance of the metal foil are further improved, and the phenomena of metal foil, cracking, wrinkling and the like during pressing are reduced.

It should be noted that the shapes of the coarsening particles 11 in fig. 1 to 4 are merely exemplary, and the coarsening particles 11 may be in other shapes such as clusters, ice-hanging shapes, stalactites, and dendrites due to differences in process means and parameters. In addition, the roughened particles 11 in the embodiments of the present invention are not limited to the shapes shown in the drawings and described above, and any roughened particles 11 having a function of providing a surface roughness of the metal foil are within the scope of the present invention. Also, in a specific implementation, a material layer of the metal foil may be formed first, and then the coarsening particles 11 may be formed on the material layer through another process. Of course, the material layer of the metal foil and the roughening particles 11 may also be an integral structure formed by a one-step molding process. The material of the roughening particles 11 may be the same as or different from the material of the metal foil, and is not limited herein.

In a preferred embodiment, the roughness Rz value of the roughened surface of the metal foil is 2 μm or less.

By adopting the technical means of the embodiment of the invention, the maximum outer contour size of the coarsening particles 11 is optimized, so that the roughness of the coarsened surface is less than or equal to 2 microns, a certain roughness required by good peel strength can be ensured, the roughness is controlled in an optimal range, the roughness is not too large or too small or the fluctuation is not too obvious, the problems of foaming, wrinkling and the like in the hot pressing process of the metal foil application process are avoided, the problems of signal transmission loss and fine circuit etching caused by too high roughness are also avoided, the peel strength caused by too low roughness is not enough, and the defect rate of the circuit board product is improved because the circuit board cannot be stably pressed on a substrate.

As a preferred embodiment, refer to fig. 5, which is a schematic structural diagram of a second metal foil provided in an embodiment of the present invention. The metal foil comprises a conductive layer 2, and one surface of the conductive layer 2 is the roughened surface 1.

In the embodiment of the present invention, the main structure of the metal foil includes the conductive layer 2, in practical applications, for example, in the field of circuit boards, the conductive layer 2 is thermally pressed and bonded with a substrate of the circuit board, for example, in the field of batteries, the metal foil is used as a negative electrode material of the battery, and the conductive layer 2 is thermally pressed and bonded with a negative electrode active material in the negative electrode material. One surface of the conductive layer 2 for bonding with a substrate of a circuit board or a material such as a negative electrode active material is provided as the roughened surface 1, so that the adhesiveness of the conductive layer 2 is increased, and the occurrence of foaming, wrinkling, cracking and the like during bonding is reduced.

The conductive layer 2 is made of a metal having high conductivity and low resistivity. The conductive layer 2 comprises a single metal conductive layer and/or an alloy conductive layer; the single metal conducting layer is made of any one of copper, aluminum, zinc, nickel, silver and gold, the alloy conducting layer is made of any two or more of copper, aluminum, zinc, nickel, silver and gold, or any two or more of copper, aluminum, zinc, nickel, silver and gold and other materials in a mixed mode.

In a specific implementation process, the conductive layer 2 of the metal foil may be formed first, and then the coarsening particles 11 may be formed on the conductive layer 2 through another process. Of course, the conductive layer 2 of the metal foil and the roughening particles 11 may also be an integral structure formed by a one-step molding process. The material of the roughening particles 11 may be the same as or partially the same as or different from the material of the conductive layer 2, and is not limited herein.

As a preferred implementation manner, refer to fig. 6, which is a schematic structural diagram of a third metal foil provided in an embodiment of the present invention. The metal foil comprises a conductive layer 2 and a carrier layer 3, wherein the carrier layer 3 is arranged on one surface, which is not the roughened surface 1, of the conductive layer 2.

In the embodiment of the invention, the metal foil is of a multilayer structure and comprises a conductive layer 2 and a carrier layer 3 which are sequentially stacked, wherein one surface of the conductive layer 2 is a roughened surface 1, and the other surface is provided with the carrier layer 3.

The carrier layer 3 may be used to carry and protect the conductive layer 2, so that the conductive layer 2 is not damaged by external contact or collision, and after the metal foil and the circuit board are pressed at high temperature, the carrier layer 3 needs to be peeled off.

The carrier layer 3 is made of a metallic material or a non-metallic material. The metal material comprises at least one of metal elements such as copper, aluminum, zinc and the like; the non-metallic material includes an organic thin film, etc. Since the carrier layer 3 mainly plays a role of carrying, a certain thickness is required, when the carrier layer 3 is a material having a metal element such as copper, aluminum or zinc, the thickness of the carrier layer is preferably 5-50 μm, more preferably 8-35 μm, such as 8 μm, 10 μm, 12 μm, 15 μm, 18 μm, 20 μm, 25 μm, 30 μm, 35 μm, etc., when the carrier layer is a non-metal material such as an organic film, the thickness of the carrier layer is preferably 10-100 μm, such as 10 μm, 15 μm, 18 μm, 20 μm, 25 μm, 30 μm, 40 μm, 50 μm, 60 μm, 70 μm, 80 μm, 90 μm, 100 μm, etc., and the specific thickness of the carrier layer 3 can be set according to the actual use requirements, which will not be described in detail herein.

The carrier layer 3 is separated from the conductive layer 2 in a strippable or non-strippable manner. When the carrier layer 3 is removed in a non-peeling removal manner, such as: laser etching, chemical etching, grinding, plasma removal, and the like. When the carrier layer 3 is removed by peeling, the peeling means is, for example: manually peeled off and removed directly, or peeled off with the aid of a mechanical device.

Preferably, referring to fig. 7, a schematic structural diagram of a fourth metal foil provided in an embodiment of the present invention is shown. The metal foil comprises a conductive layer 2 and a carrier layer 3, and further comprises a peeling layer 4, wherein the peeling layer 4 is arranged between the carrier layer 3 and the conductive layer 2. That is, the metal foil includes a carrier layer 3, a peeling layer 4, and a conductive layer 2, which are sequentially stacked, and a surface of the conductive layer 2 away from the peeling layer 4 is the roughened surface 1.

In the embodiment of the present invention, when the carrier layer 3 is removed by peeling, the peeling is: the removal is effected by peeling off the release layer 4, i.e. the separation of the carrier layer 3 from the conductive layer 2 is achieved by peeling off the release layer 4.

Simultaneously, because the existence of peel off layer, can block the metal migration between conducting layer 2 and the carrier layer 3, moreover, peel off layer 4 can cover or fill the surface of carrier layer 3 unevenness, makes conducting layer 2 that forms in another surface of peel off layer 4 more level and more smooth, even and compact, has reduced the emergence of pinhole, and then is favorable to the preparation of follow-up circuit.

Preferably, the peeling layer 4 is made of a metallic material or a non-metallic material. The metal material comprises any one or more of molybdenum, titanium and niobium; the non-metallic material comprises silicon, graphite, organic polymer materials and the like. When the release layer is a non-metallic material, the form may be a release layer. The release layer comprises a silicon-free release agent release layer, a silicone oil release layer or a nitrogen release layer. The release layer may be formed by coating and drying a release agent, and in one embodiment, the release agent may include HDPE (high density polyethylene) and PMA (propylene glycol methyl ether acetate) solvent, and the like. When the two release agents are used, the mass ratio of HDPE to PMA is preferably (1-5) to 7. In another embodiment, the release agent may include a fluorine release agent and a solvent; wherein, the volume ratio of the fluorine release agent to the solvent is preferably (5-30) to 1. It is understood that the above solvent is not particularly limited, and a release agent solvent, such as butanone, which is conventional in the art, may be used, and does not limit the present invention.

Preferably, the size of the release layer 4 is 1 to 8nm, such as 1nm, 1.5nm, 2nm, 2.5nm, 3nm, 4nm, 6nm, and 8nm, and of course, the specific thickness of the release layer 4 may be set according to the actual use requirement, which is not described herein in further detail.

By adopting the structural arrangement of the stripping layer in the embodiment of the invention, the proper adhesive strength can be ensured, and meanwhile, a certain adhesive capacity is also kept, so that the metal foil cannot be delaminated in the hot pressing process.

Preferably, when the metal foil includes the carrier layer 3, the peeling layer 4, and the conductive layer 2, the method of preparing the metal foil includes:

(1) Preparing a carrier layer 3;

(2) Forming a peeling layer 4 on one side of the carrier layer 3;

(3) The conductive layer 2 is formed on the side of the release layer 4 remote from the carrier layer 3.

In a preferred embodiment, the carrier layer 3 and/or the release layer 4 are filled with a medium for absorbing heat in the metal foil. By adding the medium for absorbing heat, when the metal foil is hot-pressed on a circuit board substrate or used as a negative electrode material of a new energy battery and is hot-pressed and bonded with a negative electrode active material, the medium for absorbing heat can absorb heat, the heat of the bonding surface of the conductive layer 2 is reduced, and the occurrence of foaming, wrinkling, cracking and the like during metal foil bonding is further reduced.

Preferably, the medium for absorbing heat is filler particles.

Fig. 8 to 10 are schematic structural views of fifth to seventh metal foils according to an embodiment of the present invention. In the metal foil, the filler particles are filled in three ways: one is that only the carrier layer 3 is filled with first filler particles 31, as can be seen in particular in fig. 8; secondly, only the peeling layer 4 is filled with second filler particles 41, which can be seen in fig. 9; thirdly, the carrier layer 3 is filled with first filler particles 31, and the peeling layer 4 is filled with second filler particles 41, as can be seen in fig. 10.

It is to be understood that the shapes of the filler particles in fig. 8 to 10 are merely exemplary, and the filler particles may also have other shapes such as cluster, ice, stalactite, dendritic, and the like, due to differences in process means and parameters. The medium for absorbing heat in the embodiment of the present invention is not limited to the filler particles, and is not limited to the illustrated shape and the above-described shape, and any medium having a heat absorbing function and filled in the support layer or the release layer is within the scope of the present invention.

As a preferred implementation manner, refer to fig. 11, which is a schematic structural diagram of an eighth metal foil provided in an embodiment of the present invention. The metal foil comprises a conductive layer 2, a carrier layer 3, a peeling layer 4 and an adhesive layer 5, wherein the adhesive layer 5 is arranged between the carrier layer 3 and the peeling layer 4. That is, the metal foil includes a carrier layer 3, an adhesive layer 5, a peeling layer 4, and a conductive layer 2, which are sequentially stacked, and a surface of the conductive layer 2 remote from the peeling layer 4 is the roughened surface 1.

In the embodiment of the invention, the bonding layer 5 is additionally arranged between the carrier layer 3 and the peeling layer 4, so that the bonding force between the carrier layer 3 and the peeling layer 4 is improved, the carrier layer 3 and the peeling layer 4 are not separated during peeling, the peeling force is increased, and the peeling effect can be effectively improved. Meanwhile, due to the existence of the bonding layer 5 and the stripping layer 4, the uneven surface of the carrier layer 3 can be covered, so that the conducting layer 2 formed on the other surface of the stripping layer 4 is smoother, uniform and compact, the occurrence of pinholes is reduced, and the manufacture of subsequent circuits is facilitated.

Preferably, the bonding layer may be a metallic bonding layer or a non-metallic bonding layer. When a metal bonding layer; the metal bonding layer is made of any one or more of copper, zinc, nickel, iron and manganese; or the metal bonding layer is made of one of copper or zinc and one of nickel, iron and manganese. When the non-metal adhesive layer is used, the material is at least one selected from polystyrene, vinyl acetate, polyester, polyethylene, polyamide, rubber or acrylate thermoplastic resin, phenolic, epoxy, thermoplastic polyimide, urethane, melamine or alkyd thermosetting resin, BT resin and ABF resin.

Preferably, when the metal foil includes the carrier layer 3, the adhesive layer 5, the peeling layer 4, and the conductive layer 2, the metal foil is prepared by a method including:

(1) Preparing a carrier layer 3;

(2) Forming an adhesive layer 5 on one side of the carrier layer 3;

(3) Forming a release layer 4 on the side of the adhesive layer 5 facing away from the carrier layer 3;

(4) The conductive layer 2 is formed on the surface of the release layer 4 remote from the adhesive layer 5.

As a preferred implementation manner, refer to fig. 12, which is a schematic structural diagram of a ninth metal foil provided in an embodiment of the present invention. The metal foil comprises a conductive layer 2, a carrier layer 3, a stripping layer 4 and a first anti-oxidation layer 6, wherein the first anti-oxidation layer 6 is arranged on one surface, close to the stripping layer 4, of the conductive layer 2. That is, the metal foil includes a carrier layer 3, a peeling layer 4, a first oxidation preventing layer 6, and a conductive layer 2, which are sequentially stacked, and a surface of the conductive layer 2 away from the peeling layer 4 is the roughened surface 1.

In the embodiment of the invention, the first anti-oxidation layer 6 is arranged between the stripping layer 4 and the conducting layer 2, so that the oxidation resistance of the conducting layer 2 can be improved, an oxidation film generated by oxidation of the conducting layer is prevented, the electric conduction and heat conduction effects are influenced, the number of pinholes on the surface of the metal foil is reduced, and the conducting integrity of an etched circuit after the metal foil is subsequently bonded on a circuit board substrate is ensured. Further, since the adhesion between the first oxidation preventing layer 6 and the peeling layer 4 is weak, the peeling effect can be improved.

Optionally, the first oxidation preventing layer is made of at least one of metals such as nickel, copper, chromium, zinc, and/or an alloy including at least one of them. Illustratively, the first oxidation preventing layer 6 is formed on the surface of the conductive layer 2 by a process including electroless plating, electroless micro-plating, and the like.

As a preferred embodiment, refer to fig. 13, which is a schematic structural diagram of a tenth metal foil according to an embodiment of the present invention. The metal foil comprises a conductive layer 2, a carrier layer 3, a stripping layer 4, a first anti-oxidation layer 6 and a second anti-oxidation layer 7, wherein the second anti-oxidation layer 7 is arranged on one surface, far away from the stripping layer 4, of the conductive layer 2. That is, the metal foil includes a carrier layer 3, a peeling layer 4, a first oxidation prevention layer 6, a conductive layer 2, and a second oxidation prevention layer 7, which are sequentially stacked, and a surface of the conductive layer 2 remote from the peeling layer 4 is the roughened surface 1.

In the embodiment of the invention, the second oxidation resistant layer 7 is additionally arranged on the roughened surface 1 of the conductive layer 2, so that the oxidation resistance of the bonding surface of the conductive layer 2 and the circuit board substrate can be effectively protected, and the bonding performance of the conductive layer 2 and the substrate can be synergistically improved by selecting a proper material. In addition, the second oxidation preventing layer 7 is formed on the roughened surface 1 of the conductive layer 2, and the roughened particles 11 on the roughened surface 1 satisfy the following conditions: the maximum outer contour dimension B of each coarsening particle satisfies 0.5 mu m-B-35 mu m, preferably 0.8 mu m-B-30 mu m, and the difference F between the maximum outer contour dimensions of adjacent coarsening particles and the ratio of the maximum width to the maximum vertical height of the coarsening particle are defined, so that the second oxidation resistant layer 7 is formed without causing the coarsening particles 11 to fall off and agglomerate on the coarsening surface, the surface irregularity of the coarsening surface is increased, the subsequent good adhesion with the substrate is influenced, the implementation of the oxidation resistant process is not influenced, the oxidation resistant process is not thorough, or bubbles exist between the oxidation resistant layer and the coarsening surface layer, and the residue of the bubbles further causes the foaming and cracking of the metal foil during the subsequent lamination with the substrate.

Optionally, the second oxidation preventing layer is made of at least one of metals such as nickel, copper, chromium, zinc, and/or an alloy including at least one of them. Illustratively, the second oxidation preventing layer 7 is formed on the roughened surface 1 of the conductive layer 2 by a process including electroless plating, electroless micro-plating, or the like.

As a preferred implementation manner, refer to fig. 14, which is a schematic structural diagram of an eleventh metal foil provided in the embodiment of the present invention. The metal foil comprises a conductive layer 2, a carrier layer 3, a peeling layer 4 and a resin layer 8, wherein the resin layer 8 is arranged on one surface of the conductive layer 2 far away from the peeling layer 4. That is, the metal foil includes a carrier layer 3, a peeling layer 4, a conductive layer 2, and a resin layer 8, which are sequentially stacked, and a surface of the conductive layer 2 remote from the peeling layer 4 is the roughened surface 1.

In the embodiment of the invention, the resin layer 8 is additionally arranged on the roughened surface 1 of the conductive layer 2, namely, the resin layer 8 is arranged on the surface of the conductive layer 2 bonded with the circuit board substrate, so that the functions of oxidation resistance, moisture resistance, water resistance and the like can be achieved, and the bonding performance with the substrate can be improved.

The resin layer 8 is made of at least one of thermoplastic resin, thermosetting resin, BT resin and ABF value, wherein the thermoplastic resin comprises polystyrene, vinyl acetate, polyester, polyethylene, polyamide, rubber or acrylic thermoplastic resin; the thermosetting resin comprises phenolic, epoxy, thermoplastic polyimide, carbamate, melamine or alkyd thermosetting resin.

It should be noted that the structure of the metal foil provided in the embodiment of the present invention is not limited to the multilayer structure of the above embodiment, and in practical applications, other material layers and additional structures may be added according to requirements, which do not limit the present invention.

In addition, the metal foil provided by the embodiment of the invention can also be applied to a copper-clad laminated board, such as an RCC (resin-coated copper sheet) scene, which is mainly used for a high-density circuit, and in the case, the roughened surface of the metal foil is far away from the side of the copper foil coated with resin. The metal foil provided by the embodiment of the invention can also be applied to an FCCL (flexible copper clad laminate) scene, at the moment, the metal foil is positioned on one side or two sides of the resin, and one side of the coarsened surface is the side far away from the resin.

The strength properties of the common metal foil and the metal foil of the structure of the embodiment of the present invention were respectively tested by specific examples, in which,

a represents a metal foil of the structure of the embodiment of the present invention, including metal foils A1, A2, and A3.

The maximum outer contour dimension B of each coarsening particle on the coarsened surface of the metal foil A1 is in the range of 0.5-32 μm. On the roughened surface of the metal foil A2, the maximum outer contour dimension B of each roughened particle ranges from 1.2 to 17 μm. On the roughened surface of the metal foil A3, the maximum outer contour dimension B of each roughened particle is in the range of 13 to 35 μm.

B represents a normal metal foil, and the maximum outline dimension B of each coarsening particle on the rough processing surface of the normal metal foil is tested to be less than 0.5 mu m.

By testing the peel strength of the metal foil with the structure of the embodiment of the invention and the peel strength of the common metal foil after different conditions of the same hot pressing, tin bleaching and process solution treatment, the data are shown in table 1:

TABLE 1

Peel strength (N/cm)	High temperature lamination	Tin bleaching	Process solution
				Metal foil A1	8.6	7.9	6.7
Metal foil A2	9.2	8.5	7.6
				Metal foil A3	10.3	9.0	8.5
Common metal foil B	5.1	——	——

Wherein: the "-" symbol represents that the sample had delaminated and failed to test for loss of peel strength data.

The peel strength test operation under the above three treatment modes is as follows:

and (3) high-temperature pressing peel strength test operation:

(1) Laminating in a stacking mode of copper foil/PP sheet/hard board, wherein the size of the PP sheet is 200mm multiplied by 250mm, and the laminating parameters of a pressure transmission machine are as follows: 200 ℃ (above) 2h 28kg/cm2;

(2) Electroplating and thickening to 35 mu m, baking after electroplating, wherein baking parameters are as follows: 60min at 100 ℃;

(3) Scribing a test sample strip with the width of 5mm by using a cutter;

(4) Adhering the hard board surface to a roller of a peeling strength tester, peeling thin copper with the length of about 2cmc, and clamping the thin copper on a chuck;

(5) The film was vertically stretched upward, and the peel strength data after stabilization was recorded and the average value was calculated and recorded as F (N/cm).

And (3) peeling strength testing operation of the tin bleaching process:

(2) Electroplating and thickening to 35 mu m, baking before and after electroplating, wherein baking parameters are as follows: 60min at 100 ℃;

(3) Float tin in the solder bath at 288 ℃ for 10sec 3 times;

(4) Scribing a test sample strip with the width of 5mm by using a cutter;

(5) Adhering the hard board surface to a roller of a peeling strength tester, peeling about 2cm of thin copper, and clamping the copper on a chuck;

(6) The sheet was stretched vertically upward, and the peel strength data after stabilization was recorded and the average value was calculated.

The test operation of the process solution was carried out according to the PCP standard method, the operating method being as follows:

(3) Soaking the sample in dichloromethane at 23 + -2 deg.C for 75 + -5 sec, taking out, and drying at 125 + -5 deg.C for 15 + -5 min;

(4) Soaking in 10g/L sodium hydroxide solution at 90 + -5 deg.C for 5 + -1 min, taking out, and rinsing in 50-55 deg.C hot water for 5 + -1 min;

(5) Soaking in mixed solution containing 10g/L sulfuric acid (specific gravity 1.836) and 30g/L boric acid at 60 + -5 deg.C for 30 + -5 min, taking out, washing with hot water at 55 + -5 deg.C for 5 + -1 min, and drying at 125 + -5 deg.C for 30 + -5 min;

(6) Soaking in 220 + -5 deg.C hot oil tank for 40 + -5 sec, and soaking in 23 + -2 deg.C isopropanol for 75 + -5 sec to remove hot oil;

(7) Airing the sample in the air, and scribing a test sample strip with the width of 5mm by using an art designer;

(8) Adhering the hard board surface to a roller of a peeling strength tester, peeling about 2cm of thin copper, and clamping the copper on a chuck;

(9) And (5) vertically stretching upwards, recording the peel strength data after stabilization, and calculating the average value.

It can be seen that the peel strength of the metal foil with the structure of the invention is higher than that of the common metal foil, which shows that the metal foil with the structure of the invention has higher bonding strength and better adhesion with the substrate. After the subsequent tin bleaching and processing solution treatment, the metal foil still has good peel strength and excellent bonding performance with a substrate, but the common metal foil has low peel strength, and the subsequent tin bleaching and processing solution treatment process has complete self-separation and can not test the peel strength.

The embodiment of the invention provides a metal foil, which optimizes the maximum outline size of the coarsening particles on the coarsened surface, optimizes the difference value of the maximum outline sizes of the adjacent coarsening particles, the ratio of the maximum width to the maximum height of the coarsening particles and the like according to requirements, and indirectly limits the microscopic morphology and the size of the coarsening particles, thereby effectively improving the coarsened surface of the metal foil. The metal foil with the roughened surface has reasonable roughness, can effectively improve the adhesion of the metal foil when being applied to the field of circuit boards or when being used as a battery cathode material and being combined with a cathode active material, further reduces the conditions of bubbling, cracking and the like, and does not influence the transmission loss of high-frequency signals in the manufactured circuit boards. Moreover, the coarsening particles with certain outline size are arranged on the coarsening processing surface of the metal foil, so that the flatness uniformity of the surface of the metal foil is increased, and the processing of subsequent fine lines is facilitated. And moreover, the arrangement of the multilayer structure of the metal foil is matched, so that the performances of oxidation resistance, moisture resistance, tensile strength, bending resistance, difficulty in breaking, uniformity, compactness and the like of the metal foil are further improved, the quality and the processing efficiency of a product applying the metal foil are effectively improved, and the reject ratio of the product applying the metal foil is reduced.

Example two

The embodiment of the invention also provides a copper-clad laminated plate, which can be a flexible copper-clad plate, also called flexible copper-clad plate, wherein the flexible copper-clad plate comprises the metal foil in any embodiment.

It should be noted that, the structure of the metal foil may refer to the structure of the metal foil described in any of the above embodiments, and details are not described herein again.

The structure of the flexible copper clad laminate comprises: a metal foil layer, a glue layer, a metal foil layer, or, comprising: metal foil layer, glue film. The material of the glue layer can be Polyimide (PI), thermoplastic Polyimide (TPI), resin and the like.

Compared with the prior art, the application of the metal foil as the flexible copper clad plate material has the following advantages: through improving the structure of the coarsening treatment surface of the metal foil, due to the existence of coarsening particles on the surface and the reasonable arrangement and proportion of the structure, the polyimide layer and the metal foil layer can be combined more tightly, the performance of the product in the subsequent specific use process is more stable and reliable, and the transmission loss of high-frequency signals is less. Meanwhile, the adhesion of the metal foil in combination with PI or TPI can be effectively improved, the conditions of foaming, wrinkling, cracking and the like are further reduced, the quality and the processing efficiency of the circuit board are improved, and the reject ratio of products is reduced.

EXAMPLE III

Fig. 15 is a schematic structural diagram of a circuit board according to an embodiment of the present invention. The embodiment of the invention provides a circuit board, which comprises a circuit board substrate 9 and a metal foil as described in any one of the embodiments; the roughened surface 1 of the metal foil is pressed with the circuit board substrate 9.

It should be noted that, the structure of the metal foil may refer to the structure of the metal foil described in any of the above embodiments, and details are not described herein.

By adopting the technical means of the embodiment of the invention, the structure of the roughened surface of the metal foil is improved, the method is suitable for manufacturing high-frequency and high-density circuit boards, the adhesiveness of the metal foil when the metal foil is combined with a circuit board substrate can be effectively improved, the conditions of bubbling, wrinkling, cracking and the like are further reduced, the quality and the processing efficiency of the circuit board are improved, and the reject ratio of the circuit board is reduced.

Example four

The embodiment of the invention also provides a semiconductor material, which comprises the metal foil in any one of the above embodiments.

By adopting the technical means of the embodiment of the invention, the application of the metal foil as the semiconductor material improves the structure of the roughened surface of the metal foil, is suitable for manufacturing semiconductor devices and integrated circuits, can effectively improve the adhesiveness of the metal foil, further reduces the conditions of bubbling, wrinkling, cracking and the like, improves the quality and the processing efficiency of the semiconductor devices and the integrated circuits, and reduces the fraction defective of the semiconductor devices and the integrated circuits.

EXAMPLE five

Compared with the prior art, the application of the metal foil as the negative electrode carrier or current collector of the battery has the following advantages: the structure of the roughened surface of the metal foil is improved, the adhesion of the metal foil serving as a negative electrode material and a negative electrode active material is improved, the negative electrode active material of the battery can be tightly combined with the metal foil, the negative electrode active material is not easy to fall off from the surface of the metal foil during use, and the metal foil material is not easy to crack or deform under strong impact or during charging and discharging of the battery.

The embodiment of the invention also provides a battery, and the negative electrode material of the battery comprises the metal foil in any embodiment.

Compared with the prior art, the application of the metal foil as the negative electrode carrier or current collector of the battery has the following advantages: the structure of the roughened surface of the metal foil is improved, the roughened surface can be suitable for new energy batteries, such as lithium batteries and sodium ion batteries, and can be used as a negative current collector and a carrier material.

While the foregoing is directed to the preferred embodiment of the present invention, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention.

Claims

1. The metal foil is characterized by comprising a roughened surface, wherein the roughened surface is provided with a plurality of roughened particles; on the coarsened surface, the maximum outer contour dimension B of each coarsened particle meets the condition that B is more than or equal to 0.5 mu m and less than or equal to 35 mu m; wherein the maximum outline dimension is a total length of the outer periphery of the roughened particles exposed on the surface of the metal foil in a slice taken perpendicular to a thickness direction of the metal foil; and the ratio range of the maximum width of the coarsening particles to the maximum vertical height is 0.2-4; on the coarsened surface, the difference F between the maximum outer contour sizes of two adjacent coarsened particles satisfies that F is more than or equal to 0 μm and less than or equal to 15.5 μm.

2. The metal foil according to claim 1, wherein on the roughened surface, a maximum outer contour dimension B of each of the roughened particles satisfies 0.8 μm B30 μm.

3. The metal foil according to claim 1 or 2, wherein the roughened surface of the metal foil has a roughness Rz value of 2 μm or less.

4. The metal foil according to claim 1 or 2, wherein the metal foil comprises a conductive layer, and one surface of the conductive layer is the roughened surface.

5. The metal foil of claim 4 further comprising a carrier layer disposed on a side of the conductive layer that is not the roughened surface.

6. The metal foil of claim 5, further comprising a release layer disposed between the carrier layer and the conductive layer.

7. A metal foil as claimed in claim 5, wherein the material of the carrier layer comprises at least one of the following metal elements: copper, aluminum and zinc, wherein the thickness of the carrier layer is 5-50 mu m; or the material of the carrier layer is an organic film, and the thickness of the carrier layer is 10-100 mu m.

8. The metal foil of claim 6, wherein the release layer has a thickness of 1 to 8nm.

9. The metal foil of claim 6, further comprising an adhesive layer disposed between the carrier layer and the release layer.

10. The metal foil as claimed in claim 6, further comprising a first oxidation preventing layer and/or a second oxidation preventing layer, wherein the first oxidation preventing layer is provided on a surface of the conductive layer close to the peeling layer, and the second oxidation preventing layer is provided on a surface of the conductive layer away from the peeling layer.

11. The metal foil of claim 6, further comprising a resin layer disposed on a side of the conductive layer remote from the release layer.

12. A copper-clad laminate comprising the metal foil as recited in any one of claims 1 to 11.

13. A circuit board comprising a circuit board substrate and the metal foil according to any one of claims 1 to 11; and the coarsening surface of the metal foil is pressed with the circuit board substrate.

14. A semiconductor material, characterized in that it comprises a metal foil according to any one of claims 1 to 11.

15. A negative electrode material for a battery, wherein the negative electrode material comprises the metal foil according to any one of claims 1 to 11.

16. A battery, characterized in that the negative electrode material of the battery comprises the metal foil according to any one of claims 1 to 11.