Method for manufacturing metal composite foil and metal composite foil

Abstract

This invention provides a method for manufacturing a metal composite foil and the metal composite foil itself. The manufacturing method includes: first, providing a composite master blank; then, forming multiple hole structures during or after foil rolling of the composite master blank, the hole structures penetrating at least a second metal layer; finally, filling the hole structures with third metal pillars, the conductivity of the third metal pillars being greater than that of the second metal layer, thereby connecting the third metal pillars to the first metal layer. The manufacturing method and metal composite foil provided by this invention, by setting the hole structure and filling the hole structure with third metal pillars to connect the third metal pillars to the first metal layer, and by ensuring that both the first metal layer and the third metal pillars have high conductivity, can improve the conductivity and thermal conductivity of the metal composite foil while reducing costs by using a second metal layer, thus reducing potential safety hazards.

Description

Technical Field

[0001] This invention belongs to the field of composite metal manufacturing technology, and more specifically, relates to a method for manufacturing a metal composite foil and the metal composite foil itself. Background Technology

[0002] Copper-aluminum composite foil is a composite material that combines copper and aluminum through a specific process, possessing both the excellent electrical and thermal conductivity of copper and the advantages of aluminum, such as low density, low cost, and corrosion resistance. Copper-aluminum composite foil is widely used in shielding, electrical conductivity, thermal conductivity, and bonding. Because copper-aluminum composite foil significantly reduces the amount of copper used, it effectively lowers production costs and reduces weight. However, compared to copper foil, its electrical and thermal conductivity are reduced to varying degrees, posing a potential safety hazard in some applications. Summary of the Invention

[0003] The purpose of this invention is to provide a method for manufacturing a metal composite foil and the metal composite foil itself, so as to solve the technical problem that the electrical conductivity and thermal conductivity of copper-aluminum composite foil are relatively low compared to copper foil in the prior art.

[0004] To achieve the above objectives, the technical solution adopted by the present invention is: to provide a method for manufacturing a metal composite foil, comprising the following steps:

[0005] A composite preform is provided, the composite preform comprising a first metal layer and a second metal layer stacked together, wherein the conductivity of the first metal layer is greater than the conductivity of the second metal layer;

[0006] The composite master blank is foil rolled, and multiple hole structures are formed during or after foil rolling, the hole structures at least penetrating the second metal layer;

[0007] A third metal pillar is formed by filling the hole structure, and the conductivity of the third metal pillar is greater than that of the second metal layer.

[0008] Optionally, one end of the hole structure is located on the side of the second metal layer away from the first metal layer, and the other end of the hole structure extends to the connection between the first metal layer and the second metal layer, or the other end of the hole structure extends through the first metal layer.

[0009] Optionally, the first metal layer and the third metal pillar are made of the same material.

[0010] Optionally, the first metal layer and the third metal pillar are both made of one of copper, silver, nickel, and tin, and the second metal layer is made of aluminum.

[0011] Optionally, the step of forming multiple hole structures during or after foil rolling includes forming the hole structures by means of laser or drilling.

[0012] Optionally, the step of filling the hole structure with the third metal pillar includes:

[0013] The third metal pillar is formed by electroplating within the hole structure; or...

[0014] The third metal pillar is deposited within the pore structure.

[0015] Optionally, the step of providing the composite embryo includes:

[0016] The second metallic material is melted and then cooled to a semi-molten state to obtain a semi-molten metal liquid.

[0017] Preheat the first metal material.

[0018] Under vacuum conditions, a semi-molten metal liquid is brought into contact with the surface of the first metal material and continuously cast and rolled to form the second metal layer and the first metal layer, respectively.

[0019] Optionally, the composite preform is cold-rolled before the foil rolling step; and / or,

[0020] After the step of filling the pore structure to form a third metal pillar, the composite preform is subjected to surface smoothing treatment.

[0021] Optionally, between the step of cold rolling the composite preform and the step of foil rolling the composite preform:

[0022] The composite preform was annealed in an inert gas environment.

[0023] The present invention also provides a metal composite foil, which is manufactured using the above-described metal composite foil manufacturing method, comprising a first metal layer and a second metal layer stacked together, wherein the metal composite foil has a hole structure that penetrates at least the second metal layer, and the hole structure is filled with a third metal pillar, wherein the conductivity coefficient of the first metal layer and the conductivity coefficient of the third metal pillar are both greater than the conductivity coefficient of the second metal layer.

[0024] The manufacturing method of the metal composite foil provided by this invention and the beneficial effects of the metal composite foil are as follows: Compared with the prior art, the manufacturing method of the metal composite foil of this invention first provides a composite master blank, and then forms multiple hole structures during or after foil rolling of the composite master blank, the hole structures penetrating at least the second metal layer; finally, a third metal pillar is filled in the hole structure, the conductivity of the third metal pillar is greater than that of the second metal layer, so that the third metal pillar and the first metal layer are connected and conductive. The conductivity of both the first metal layer and the third metal pillar is high, so it is possible to improve the conductivity and thermal conductivity of the metal composite foil while reducing costs by using the second metal layer, and reduce potential risks in use. Attached Figure Description

[0025] To more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0026] Figure 1 A schematic flowchart illustrating the manufacturing method of a metal composite foil provided in an embodiment of the present invention;

[0027] Figure 2 A cross-sectional view of a metal composite foil provided in an embodiment of the present invention;

[0028] Figure 3 This is a front view of a metal composite foil provided in an embodiment of the present invention.

[0029] The following are the labeling elements in the figure:

[0030] 10 - First metal layer; 20 - Second metal layer; 21 - Hole structure; 30 - Third metal pillar. Detailed Implementation

[0031] To make the technical problems to be solved, the technical solutions, and the beneficial effects of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present invention and are not intended to limit the present invention.

[0032] It should be noted that when a component is referred to as being "fixed to" or "set on" another component, it can be directly on or indirectly on that other component. When a component is referred to as being "connected to" another component, it can be directly connected to or indirectly connected to that other component.

[0033] It should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention.

[0034] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0035] Copper-aluminum composite foil is a composite material that combines copper and aluminum through a specific process, possessing both the excellent electrical and thermal conductivity of copper and the advantages of aluminum, such as low density, low cost, and corrosion resistance. Copper-aluminum composite foil is widely used in shielding, electrical conductivity, thermal conductivity, and bonding. Because copper-aluminum composite foil significantly reduces the amount of copper used, it effectively lowers production costs and reduces weight. However, compared to copper foil, its electrical and thermal conductivity are reduced to varying degrees, posing a significant potential hazard in some applications. For example, when copper-aluminum composite foil is used in flexible circuit boards, connectors, and battery materials, high requirements are placed on its electrical and heat dissipation performance. If the aluminum content in the copper-aluminum composite foil is too high, it will lead to a decrease in its electrical and heat dissipation performance, affecting normal use.

[0036] To alleviate or solve the above technical problems, this invention proposes a method for manufacturing a metal composite foil and the metal composite foil. By forming multiple hole structures 21 during or after foil rolling of the composite master blank, and filling the hole structures 21 with third metal pillars 30, the conductivity coefficients of the third metal pillars 30 and the first metal layer 10 are both greater than the conductivity coefficient of the second metal layer 20. In this way, the thermal conductivity and electrical conductivity of the metal composite foil can be increased, and the impact of the decrease in electrical conductivity and thermal conductivity caused by the second metal layer 20 can be reduced.

[0037] The manufacturing method of the metal composite foil provided in the embodiments of the present invention will now be described.

[0038] Please refer to the following: Figures 1 to 3 The manufacturing method of metal composite foil includes the following steps:

[0039] S10: Provide a composite preform, the composite preform including a first metal layer 10 and a second metal layer 20 stacked together, the conductivity of the first metal layer 10 being greater than the conductivity of the second metal layer 20;

[0040] S20: Foil rolling is performed on the composite master blank to form multiple hole structures 21 during or after foil rolling, and the hole structures 21 at least penetrate the second metal layer 20.

[0041] S30: A third metal pillar 30 is filled in the hole structure 21. The conductivity of the third metal pillar 30 is greater than that of the second metal layer 20.

[0042] The first metal layer 10 and the second metal layer 20 are respectively made of a first metal material and a second metal material. The composite preform has a sheet-like structure, with the first metal layer 10 on one side and the second metal layer 20 on the other side. The junction of the first metal layer 10 and the second metal layer 20 is the interface of the composite preform. The conductivity of the first metal layer 10 is the same as the conductivity of the first metal material, and the conductivity of the second metal layer 20 is the same as the conductivity of the second metal material.

[0043] The hole structure 21 at least penetrates the second metal layer 20, meaning that the hole structure 21 penetrates at least along the thickness direction of the second metal layer 20. One end of the hole structure 21 is exposed on the side of the second metal layer 20 away from the first metal layer 10, and the other end of the hole structure 21 extends at least to the interface of the composite preform. In this way, when the third metal pillar 30 is filled, the third metal pillar 30 will come into contact with and conduct electricity to the first metal layer 10, thereby enhancing the thermal conductivity and electrical conductivity of the composite preform.

[0044] The third metal pillar 30 is made of a third metal material, and its electrical conductivity is the same as that of the third metal material. The electrical conductivity of both the first metal layer 10 and the third metal pillar 30 is greater than that of the third metal material. Since the electrical conductivity and thermal conductivity of a metal material are positively correlated, the thermal conductivity of both the first metal layer 10 and the third metal pillar 30 is also greater than that of the third metal material. By creating a hole structure 21 and filling it with the third metal pillar 30, the third metal pillar 30 and the first metal layer 10 can be made to contact and conduct electricity, thus improving the electrical and thermal conductivity of the composite preform.

[0045] The manufacturing method of the metal composite foil in the above embodiments first provides a composite master blank, and then forms a plurality of hole structures 21 during or after foil rolling of the composite master blank. The hole structures 21 penetrate at least the second metal layer 20. Finally, a third metal pillar 30 is filled in the hole structure 21. The conductivity of the third metal pillar 30 is greater than that of the second metal layer 20, so that the third metal pillar 30 and the first metal layer 10 are connected and conductive. The conductivity of both the first metal layer 10 and the third metal pillar 30 is high. Therefore, the conductivity and thermal conductivity of the metal composite foil can be improved while reducing costs by using the second metal layer 20, and potential safety hazards can be reduced.

[0046] In some embodiments of the present invention, please refer to Figure 2 and Figure 3 One end of the hole structure 21 is located on the side of the second metal layer 20 away from the first metal layer 10, and the other end of the hole structure 21 extends to the junction of the first metal layer 10 and the second metal layer 20, or the other end of the hole structure 21 extends through the first metal layer 10. This embodiment includes two technical solutions: First, the hole structure 21 penetrates only the second metal layer 20, with one end of the hole structure 21 located on the side of the second metal layer 20 away from the first metal layer 10, and the other end extending to the interface (the connection between the first metal layer 10 and the second metal layer 20), and the length of the hole structure 21 is equal to the thickness of the second metal layer 20; Second, the hole structure 21 penetrates both the first metal layer 10 and the second metal layer 20. Understandably, the hole structure 21 penetrates the composite preform, with one end of the hole structure 21 located on the side of the second metal layer 20 away from the first metal layer 10, and the other end extending to the side of the first metal layer 10 away from the second metal layer 20, and the length of the hole structure 21 is equal to the sum of the thicknesses of the first metal layer 10 and the second metal layer 20.

[0047] One end of the hole structure 21 is located on the side of the second metal layer 20 away from the first metal layer 10, and the other end of the hole structure 21 extends through the second metal layer 20, or through the second metal layer 20 and the first metal layer 10. After the third metal pillar 30 fills the hole structure 21, the first metal layer 10 and the third metal pillar 30 can contact each other to form a conductive point, thereby improving the electrical and thermal conductivity.

[0048] In other embodiments, one end of the hole structure 21 is located on the side of the second metal layer 20 away from the first metal layer 10, and the other end of the hole structure 21 extends into the interior of the first metal layer 10, but does not penetrate the first metal layer 10. In this embodiment, the length of the hole structure 21 is greater than the thickness of the second metal layer 20, but less than the sum of the thicknesses of the first metal layer 10 and the second metal layer 20. When the third metal post 30 is located within the hole structure 21, one end of the third metal post 30 is recessed into the first metal layer 10 and makes contact with and conducts with the first metal layer 10.

[0049] In some embodiments, the shape and size of the cross-section of the hole structure 21 are not limited, and can be a circular, elliptical, square, or other similar structure. Correspondingly, the cross-sectional shape of the third metal column 30 is the same as the cross-sectional shape of the hole structure 21.

[0050] In some embodiments, the hole structure 21 may be a structure with a uniform cross-section or a structure with a gradually changing cross-section. For example, the hole structure 21 may be a cylindrical hole or a hemispherical hole, etc.

[0051] In some embodiments, the cross-sectional dimension of the third metal column 30 is equal to or slightly smaller than the dimension of the hole structure 21.

[0052] In some embodiments, the number of hole structures 21 is multiple, and they are arranged along a rectangular array or a circular array.

[0053] In some embodiments of the present invention, please refer to Figure 2 and Figure 3 The first metal layer 10 and the third metal pillar 30 are made of the same material, and they are in contact with each other and conduct electricity. When the first metal layer 10 and the third metal pillar 30 are made of the same material, the metal composite foil only includes two materials, which has a simple composition and more stable performance. The contact surfaces of the first metal layer 10 and the third metal pillar 30 are more likely to form a stable connection.

[0054] In some embodiments, the first metal layer 10 and the third metal pillar 30 are both made of one of copper, silver, nickel, and tin, and the second metal layer 20 is made of aluminum. For example, the first metal layer 10 and the third metal pillar 30 are both made of copper, or the first metal layer 10 and the third metal pillar 30 are both made of silver. The thermal conductivity of copper, silver, nickel, and tin is greater than that of aluminum.

[0055] In other embodiments, the first metal layer 10 and the third metal pillar 30 are made of different materials. For example, the first metal layer 10 is made of copper and the third metal pillar 30 is made of silver; or, the first metal layer 10 is made of copper and the third metal pillar 30 is made of nickel. In this embodiment, it is sufficient that the conductivity of both the first metal layer 10 and the third metal pillar 30 is greater than that of the second metal layer 20.

[0056] In some embodiments of the present invention, please refer to Figure 1 The step of forming multiple hole structures 21 during or after foil rolling includes forming the hole structures 21 by laser or drilling. In step S20, the hole structures 21 are formed by laser or drilling.

[0057] Specifically, when forming the hole structure 21 by laser cutting, a laser or similar device is generally used to achieve laser cutting. When forming the hole structure 21 by laser cutting, the edges of the hole structure 21 are smoother, and different shapes of hole structures 21 can be selected according to requirements. The cutting effect of laser cutting is better.

[0058] When forming the hole structure 21 by drilling, the cutting is generally achieved by rotating the drill bit. Therefore, the hole structure 21 formed by drilling is generally a circular hole structure. The processing cost is relatively low when forming the hole structure 21 by drilling.

[0059] In some embodiments, forming multiple hole structures 21 during foil rolling can be understood as punching holes in the composite master blank while it is being fed to the foil rolling mill using a foil rolling mill.

[0060] In some embodiments, forming multiple hole structures 21 after foil rolling can be understood as forming a foil structure after foil rolling, and then punching holes in the foil structure after foil rolling.

[0061] Foil rolling is a special cold rolling process mainly used to produce foil materials with a thickness between 0.0015 and 0.012 mm. The foil rolling process is generally carried out using a foil rolling mill.

[0062] In some embodiments, the thickness of the composite metal foil formed after foil rolling is 0.0015 to 0.012 mm.

[0063] In some embodiments of the present invention, please refer to Figure 1 The step of filling the hole structure 21 with the third metal pillar 30 includes:

[0064] A third metal pillar 30 is formed by electroplating within the hole structure 21; or...

[0065] A third metal pillar 30 is deposited within the pore structure 21.

[0066] Step S30 can be implemented in two different ways. In the first way, a third metal material is electroplated inside the hole structure 21. After the third metal material fills the hole structure 21, a third metal pillar 30 is formed. In this way, the third metal pillar 30 fills the hole structure 21, so the size of the third metal pillar 30 and the hole structure 21 are perfectly matched, and the connection between the third metal pillar 30 and the first metal layer 10 is more stable. In the second way, a third metal material is deposited inside the hole structure 21. After the third metal material fills the hole structure 21, a third metal pillar 30 is formed. In this way, the third metal pillar 30 fills the hole structure 21, so the size of the third metal pillar 30 and the hole structure 21 are perfectly matched, and the connection between the third metal pillar 30 and the first metal layer 10 is more stable.

[0067] Electroplating is a process that uses the principle of electrolysis to deposit a thin layer of another metal or alloy onto the surface of certain metals. It is a process that uses electrolysis to attach a metal film to the surface of metal or other material parts. Deposition is a chemical technology that mainly uses one or more gaseous compounds or elements containing thin film elements to chemically react on the surface of a substrate to form a thin film.

[0068] In some embodiments of the present invention, please refer to Figure 1 The steps for providing a composite embryo include:

[0069] The second metallic material is melted and then cooled to a semi-molten state to obtain a semi-molten metal liquid.

[0070] Preheat the first metal material.

[0071] Under vacuum conditions, a semi-molten metal liquid is brought into contact with the surface of a first metal material and continuously cast and rolled to form a second metal layer 20 and a first metal layer 10, respectively.

[0072] In step S10, the composite preform includes a first metal layer 10 and a second metal layer 20 stacked together. That is, after the above steps, a first metal layer 10 and a second metal layer 20 are formed stacked together. The first metal material is sheet-like, and after preheating, it is easier to combine with the semi-molten metal, ensuring a more stable bonding surface between the first and second metal materials. Under vacuum conditions, the semi-molten metal is brought into contact with the surface of the first metal material, and the process is carried out under vacuum conditions, which can prevent oxidation of the first and second metal materials and ensure the electrical conductivity of the composite preform. Continuous casting and rolling refers to the process of rolling and deforming the molten metal while it is continuously casting and solidifying. Specifically, in this embodiment, liquid metal is directly poured onto the first metal material located in the roll gap, so that the first and second metal materials are continuously rolled and formed. The first metal material forms the first metal layer 10 after continuous casting and rolling, and the second metal material forms the second metal layer 20 after continuous casting and rolling.

[0073] In some embodiments of the present invention, please refer to Figure 1 Before the foil rolling step, the composite preform is cold-rolled; and / or,

[0074] After the step of filling the hole structure 21 to form the third metal pillar 30, the composite preform is subjected to surface smoothing treatment.

[0075] Understandably, the composite preform needs to be cold-rolled before step S20. Cold rolling before step S20 reduces the thickness of the composite preform, facilitating foil rolling. After step S30, the surface of the composite preform is smoothed to make the surface at the location of the third metal pillar 30 smooth, ensuring that any position on the surface of the metal composite foil is smooth.

[0076] Cold rolling is typically carried out at room temperature and is used to roll metal sheets through a rolling mill. The purpose of rolling is to reduce the thickness of the metal sheet while improving its surface quality, dimensional accuracy, and mechanical properties.

[0077] In some embodiments of the present invention, please refer to Figure 1 Between the cold rolling step of the composite preform and the foil rolling step of the composite preform:

[0078] The composite preform was annealed in an inert gas environment.

[0079] Inert gases are colorless and odorless monatomic gases at room temperature and pressure, and are unlikely to undergo chemical reactions. Because these gases essentially do not react with other elements, they are called inert gases. In an inert gas environment, the composite preform is chemically stable and will not react with oxygen or other elements. Annealing is a metal heat treatment process that involves slowly heating the metal to a certain temperature, holding it for a sufficient time, and then cooling it at an appropriate rate. Annealing the composite preform can eliminate internal stress, improve the material's plasticity and toughness, and optimize the interface layer between the first metal layer 10 and the second metal layer 20.

[0080] Annealing can eliminate internal stress in the composite preform, improving its plasticity and toughness. Foil rolling can further reduce the thickness of the composite preform, forming a metal composite foil.

[0081] In some embodiments, the inert gas environment may be a helium environment, an argon environment, a neon environment, etc.

[0082] In some embodiments of the present invention, the method for manufacturing metal composite foil includes the following steps:

[0083] The second metallic material is melted and then cooled to a semi-molten state to obtain a semi-molten metal liquid.

[0084] Preheat the first metal material.

[0085] Under vacuum conditions, a semi-molten metal liquid is brought into contact with the surface of the first metal material and continuously cast and rolled to form the second metal layer 20 and the first metal layer 10, respectively, thus forming a composite master blank. The conductivity of the first metal layer 10 is greater than that of the second metal layer 20.

[0086] The composite blank is cold rolled, the composite master blank is annealed in an inert gas environment, and then the composite master blank is foil rolled, forming a plurality of hole structures 21 during or after foil rolling, the hole structures 21 at least penetrating the second metal layer 20.

[0087] A third metal pillar 30 is filled into the hole structure 21 and then cold-rolled. The conductivity of the third metal pillar 30 is greater than that of the second metal layer 20.

[0088] The composite embryo is surface-smoothed.

[0089] Please see Figure 2 and Figure 3 The present invention also provides a metal composite foil, which includes a first metal layer 10 and a second metal layer 20 stacked together. The metal composite foil has a hole structure 21 that penetrates at least the second metal layer 20. The hole structure 21 is filled with a third metal pillar 30. The conductivity coefficient of the first metal layer 10 and the conductivity coefficient of the third metal pillar 30 are both greater than the conductivity coefficient of the second metal layer 20.

[0090] The first metal layer 10 and the second metal layer 20 are made of a first metal material and a second metal material, respectively, and the junction of the first metal layer 10 and the second metal layer 20 is the interface of the composite preform. The conductivity of the first metal layer 10 is the same as the conductivity of the first metal material, the conductivity of the second metal layer 20 is the same as the conductivity of the second metal material, and the third metal pillar 30 is made of a third metal material, the conductivity of the third metal pillar 30 is the same as the conductivity of the third metal material.

[0091] The metal composite foil provided by the present invention has a hole structure 21 that penetrates at least the second metal layer 20, and a third metal pillar 30 is filled in the hole structure 21. The conductivity of the third metal pillar 30 is greater than that of the second metal layer 20, so that the third metal pillar 30 and the first metal layer 10 are connected and conductive. Since the conductivity of both the first metal layer 10 and the third metal pillar 30 is high, it is possible to improve the conductivity and thermal conductivity of the metal composite foil while reducing costs by using the second metal layer 20, and reduce potential safety hazards.

[0092] In some embodiments, one end of the hole structure 21 is formed on the side of the second metal layer 20 away from the first metal layer 10, and the other end of the hole structure 21 extends to the junction of the first metal layer 10 and the second metal layer 20, or the other end of the hole structure 21 extends through the first metal layer 10. This embodiment includes two technical solutions: First, the hole structure 21 penetrates only the second metal layer 20, with one end of the hole structure 21 located on the side of the second metal layer 20 away from the first metal layer 10, and the other end extending to the interface (the connection between the first metal layer 10 and the second metal layer 20), and the length of the hole structure 21 is equal to the thickness of the second metal layer 20; Second, the hole structure 21 penetrates both the first metal layer 10 and the second metal layer 20. Understandably, the hole structure 21 penetrates the composite preform, with one end of the hole structure 21 located on the side of the second metal layer 20 away from the first metal layer 10, and the other end extending to the side of the first metal layer 10 away from the second metal layer 20, and the length of the hole structure 21 is equal to the sum of the thicknesses of the first metal layer 10 and the second metal layer 20.

[0093] One end of the hole structure 21 is located on the side of the second metal layer 20 away from the first metal layer 10, and the other end of the hole structure 21 extends through the second metal layer 20, or through the second metal layer 20 and the first metal layer 10. After the third metal pillar 30 fills the hole structure 21, the first metal layer 10 and the third metal pillar 30 can contact each other to form a conductive point, thereby improving the electrical and thermal conductivity.

[0094] In other embodiments, one end of the hole structure 21 is located on the side of the second metal layer 20 away from the first metal layer 10, and the other end of the hole structure 21 extends into the interior of the first metal layer 10, but does not penetrate the first metal layer 10. In this embodiment, the length of the hole structure 21 is greater than the thickness of the second metal layer 20, but less than the sum of the thicknesses of the first metal layer 10 and the second metal layer 20. When the third metal post 30 is located within the hole structure 21, one end of the third metal post 30 is recessed into the first metal layer 10 and makes contact with and conducts with the first metal layer 10.

[0095] In some embodiments of the present invention, please refer to Figure 2 and Figure 3 The first metal layer 10 and the third metal pillar 30 are made of the same material, and they are in contact with each other and conduct electricity. When the first metal layer 10 and the third metal pillar 30 are made of the same material, the metal composite foil only includes two materials, which has a simple composition and more stable performance. The contact surfaces of the first metal layer 10 and the third metal pillar 30 are more likely to form a stable connection.

[0096] In some embodiments, the first metal layer 10 and the third metal pillar 30 are both made of one of copper, silver, nickel, and tin, and the second metal layer 20 is made of aluminum. For example, the first metal layer 10 and the third metal pillar 30 are both made of copper, or the first metal layer 10 and the third metal pillar 30 are both made of silver. The thermal conductivity of copper, silver, nickel, and tin is greater than that of aluminum.

[0097] In other embodiments, the first metal layer 10 and the third metal pillar 30 are made of different materials. For example, the first metal layer 10 is made of copper and the third metal pillar 30 is made of silver; or, the first metal layer 10 is made of copper and the third metal pillar 30 is made of nickel. In this embodiment, it is sufficient that the conductivity of both the first metal layer 10 and the third metal pillar 30 is greater than that of the second metal layer 20.

[0098] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for manufacturing a metal composite foil, characterized in that, Includes the following steps: A composite preform is provided, the composite preform comprising a first metal layer and a second metal layer stacked together, wherein the conductivity of the first metal layer is greater than the conductivity of the second metal layer; The composite master blank is foil rolled, and multiple hole structures are formed during or after foil rolling, the hole structures at least penetrating the second metal layer; A third metal pillar is formed by filling the hole structure, and the conductivity of the third metal pillar is greater than that of the second metal layer.

2. The method for manufacturing metal composite foil as described in claim 1, characterized in that, One end of the hole structure is located on the side of the second metal layer away from the first metal layer, and the other end of the hole structure extends to the connection between the first metal layer and the second metal layer, or the other end of the hole structure extends through the first metal layer.

3. The method for manufacturing metal composite foil as described in claim 1, characterized in that, The first metal layer and the third metal pillar are made of the same material.

4. The method for manufacturing metal composite foil as described in claim 3, characterized in that, The first metal layer and the third metal pillar are both made of one of copper, silver, nickel, and tin, and the second metal layer is made of aluminum.

5. The method for manufacturing metal composite foil as described in claim 1, characterized in that, The steps of forming multiple hole structures during or after foil rolling include: forming the hole structures by means of laser or drilling.

6. The method for manufacturing metal composite foil as described in claim 1, characterized in that, The step of filling the hole structure with the third metal pillar includes: The third metal pillar is formed by electroplating within the hole structure; or... The third metal pillar is deposited within the pore structure.

7. The method for manufacturing metal composite foil as described in claim 1, characterized in that, The steps of providing the composite embryo include: The second metallic material is melted and then cooled to a semi-molten state to obtain a semi-molten metal liquid. Preheat the first metal material. Under vacuum conditions, a semi-molten metal liquid is brought into contact with the surface of the first metal material and continuously cast and rolled to form the second metal layer and the first metal layer, respectively.

8. The method for manufacturing a metal composite foil according to any one of claims 1-7, characterized in that, Prior to the foil rolling step, the composite master blank is cold-rolled; and / or, After the step of filling the pore structure to form a third metal pillar, the composite preform is subjected to surface smoothing treatment.

9. The method for manufacturing the metal composite foil as described in claim 8, characterized in that, Between the step of cold rolling the composite preform and the step of foil rolling the composite preform: The composite preform was annealed in an inert gas environment.

10. A metal composite foil, manufactured using the method for manufacturing the metal composite foil according to any one of claims 1-9, characterized in that: The metal composite foil includes a first metal layer and a second metal layer stacked together. The metal composite foil has a hole structure that penetrates at least the second metal layer. The hole structure is filled with a third metal pillar. The conductivity of the first metal layer and the conductivity of the third metal pillar are both greater than the conductivity of the second metal layer.

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