WO2023029908A1

WO2023029908A1 - Composite copper foil structure, preparation method therefor, copper clad laminate, and printed circuit board

Info

Publication number: WO2023029908A1
Application number: PCT/CN2022/111262
Authority: WO
Inventors: 张齐艳; 蔡黎; 高峰
Original assignee: 华为技术有限公司
Priority date: 2021-08-31
Filing date: 2022-08-09
Publication date: 2023-03-09
Also published as: CN113873750A

Abstract

The present application discloses a composite copper foil structure, a preparation method therefor, a copper clad laminate, and a printed circuit board. The composite copper foil structure comprises a copper foil core layer and a shell layer. The copper foil core layer has a first surface and a second surface. The shell layer is located on at least the first surface and the second surface of the copper foil core layer. The shell layer comprises a number N of layers of graphene and a number M of layers of metallic copper. The graphene layers and the metallic copper layers are alternately laminated. A surface of the shell layer close to the copper foil core layer is a graphene layer. A thickness of the copper foil core layer is greater than a thickness of a metallic copper layer in the shell layer. The composite copper foil structure is formed from alternating metallic copper layers and graphene layers. The composite effect of graphene and copper is used to increase the surface electrical conductivity of the composite copper foil structure, thereby providing a composite copper foil structure having high electrical conductivity. Furthermore, since the shell layer composed of graphene layers and metallic copper layers is only disposed on the surface of the core layer, and the core layer still uses copper foil, the cost is relatively low.

Description

复合铜箔结构、其制备方法及覆铜箔层压板和印刷电路板Composite copper foil structure, its preparation method and copper clad laminate and printed circuit board

相关申请的交叉引用Cross References to Related Applications

本申请要求在2021年08月31日提交中国专利局、申请号为202111009822.2、申请名称为“复合铜箔结构、其制备方法及覆铜箔层压板和印刷电路板”的中国专利申请的优先权，其全部内容通过引用结合在本申请中。This application claims the priority of the Chinese patent application submitted to the China Patent Office on August 31, 2021, with the application number 202111009822.2 and the application name "Composite copper foil structure, its preparation method, copper clad laminate and printed circuit board" , the entire contents of which are incorporated in this application by reference.

技术领域technical field

本申请涉及复合铜箔材料技术领域，尤其涉及一种复合铜箔结构、其制备方法及覆铜箔层压板和印刷电路板。The present application relates to the technical field of composite copper foil materials, in particular to a composite copper foil structure, a preparation method thereof, a copper clad laminate and a printed circuit board.

背景技术Background technique

铜箔是电子信息和能源行业的基础材料，被广泛用于集成电路、印刷电路板、电子元件、能量存储设备和航空航天设备，进行信号传输和电气互联。随着5G的发展，信号传输朝着高频高速方向发展，急需降低铜箔的导体损耗以降低PCB传输线路的***损耗；而能源器件向着高能量密度和薄型化、小型化的方向发展，急需提高铜箔的通流能力，并降低铜损和减少焦耳热。这些需求均对铜箔的电导率提出了更高的要求，需要制备出电导率高于100％IACS的高电导率铜箔。当前，商业铜箔的制备方法主要为压延法和电解法，电导率在97％IACS左右，难以满足行业发展对铜箔电导率的需求。Copper foil is a basic material in the electronic information and energy industries, and is widely used in integrated circuits, printed circuit boards, electronic components, energy storage devices, and aerospace equipment for signal transmission and electrical interconnection. With the development of 5G, signal transmission is developing in the direction of high frequency and high speed, and it is urgent to reduce the conductor loss of copper foil to reduce the insertion loss of PCB transmission lines; while energy devices are developing in the direction of high energy density, thinning and miniaturization, there is an urgent need Improve the flow capacity of copper foil, reduce copper loss and reduce Joule heat. These requirements all put forward higher requirements on the electrical conductivity of the copper foil, and it is necessary to prepare a high-conductivity copper foil with an electrical conductivity higher than 100% IACS. At present, the preparation methods of commercial copper foil are mainly calendering method and electrolysis method, and the electrical conductivity is about 97% IACS, which is difficult to meet the needs of the industry development for the electrical conductivity of copper foil.

发明内容Contents of the invention

本申请提供了一种复合铜箔结构、其制备方法及覆铜箔层压板和印刷电路板，用于提供一种高电导率的复合铜箔结构。The present application provides a composite copper foil structure, its preparation method, a copper clad laminate and a printed circuit board, which are used to provide a composite copper foil structure with high electrical conductivity.

第一方面，本申请提供的一种复合铜箔结构，所述复合铜箔结构包括铜箔芯层和壳层，其中，所述铜箔芯层沿厚度方向具有相对的第一表面和第二表面；所述壳层至少位于所述铜箔芯层的所述第一表面和所述第二表面；其中，所述壳层包括：N层石墨烯层和M层金属铜层，所述石墨烯层和所述金属铜层交替叠层设置，且所述壳层中靠近所述铜箔芯层一侧的为所述石墨烯层，N为大于0的整数，M为大于0的整数,且M＝N或M＝N-1；所述铜箔芯层的厚度大于所述壳层中所述金属铜层的厚度。In the first aspect, the present application provides a composite copper foil structure, the composite copper foil structure includes a copper foil core layer and a shell layer, wherein the copper foil core layer has opposite first surfaces and second surfaces along the thickness direction. Surface; the shell layer is located at least on the first surface and the second surface of the copper foil core layer; wherein, the shell layer includes: N layers of graphene layers and M layers of metal copper layers, the graphite The graphene layer and the metal copper layer are alternately stacked, and the graphene layer on the side of the shell layer close to the copper foil core layer is the graphene layer, N is an integer greater than 0, and M is an integer greater than 0, And M=N or M=N-1; the thickness of the copper foil core layer is greater than the thickness of the metal copper layer in the shell layer.

本申请实施例提供的上述复合铜箔结构，由于在铜箔芯层的表面设置有由交替叠层设置的石墨烯层和金属铜层组成的壳层，利用石墨烯和铜的复合效应提升壳层的电导率，从而提升复合铜箔结构的表层电导率，基于导体的趋肤效应，当导体中有交流电或者交变电磁场时，导体内部的电流分布不均匀，电流集中在导体的“皮肤”部分，也就是说电流集中在导体外表的薄层，越靠近导体表面，电流密度越大。因此，通过提高复合铜箔结构的表层电导率(即壳层电导率)就可以实现一种高电导率的复合铜箔结构。并且，由于仅是在芯层的表面设置有由石墨烯层和金属铜层组成的壳层，而芯层还是采用铜箔，相比芯层也采用石墨烯层和金属铜层的复合层，可以降低成本。In the above-mentioned composite copper foil structure provided in the embodiment of the present application, since a shell layer composed of alternately stacked graphene layers and metal copper layers is provided on the surface of the copper foil core layer, the compound effect of graphene and copper is used to improve the shell layer. The conductivity of the layer, thereby improving the surface conductivity of the composite copper foil structure, based on the skin effect of the conductor, when there is an alternating current or an alternating electromagnetic field in the conductor, the current distribution inside the conductor is uneven, and the current is concentrated in the "skin" of the conductor The part, that is to say, the thin layer where the current is concentrated on the outer surface of the conductor, the closer to the surface of the conductor, the greater the current density. Therefore, a high-conductivity composite copper foil structure can be realized by increasing the surface conductivity (ie, shell conductivity) of the composite copper foil structure. And, since the shell layer composed of graphene layer and metal copper layer is only arranged on the surface of the core layer, and the core layer still adopts copper foil, compared with the core layer, the composite layer of graphene layer and metal copper layer is also used, Can reduce costs.

可选的，壳层中的金属铜层可以通过物理气相沉积法或电化学沉积法形成，这样相比直接采用铜箔形成壳层中的金属铜层，壳层中的金属铜层的厚度更薄，从而在壳层厚度一定的情况下降低金属铜层的厚度可以增加壳层中石墨烯层的总层数，从而可以进一步提高壳层的电导率。Optionally, the metallic copper layer in the shell can be formed by physical vapor deposition or electrochemical deposition, so that the thickness of the metallic copper layer in the shell is thinner than directly using copper foil to form the metallic copper layer in the shell. Thin, so that reducing the thickness of the metal copper layer can increase the total number of graphene layers in the shell layer when the thickness of the shell layer is constant, thereby further improving the electrical conductivity of the shell layer.

需要说明的是，在本申请中，壳层至少位于铜箔芯层的第一表面和第二表面，当然，除了第一表面和第二表面，壳层还可以位于铜箔芯层的其它表面，例如位于铜箔芯层的所有表面，在此不作限定。具体可以根据实际应用需求进行设置。It should be noted that in this application, the shell layer is at least located on the first surface and the second surface of the copper foil core layer. Of course, in addition to the first surface and the second surface, the shell layer can also be located on other surfaces of the copper foil core layer. , such as on all surfaces of the copper foil core layer, which is not limited here. Specifically, it may be set according to actual application requirements.

本申请对铜箔芯层的形态不作限定，铜箔芯层的形态包括但不限于为箔片，例如还可以为柱状等，具体可以根据实际应用需求进行设计。例如当应用于PCB中的CCL时，铜箔芯层可以为箔片，当应用于电缆时，铜箔芯层可以为柱状。本申请实施例仅是以铜箔芯层的形态为箔片为例进行示意说明的。The present application does not limit the shape of the copper foil core layer. The shape of the copper foil core layer includes but is not limited to foil, for example, it can also be columnar, etc., which can be designed according to actual application requirements. For example, when applied to CCL in PCB, the copper foil core layer can be a foil, and when applied to a cable, the copper foil core layer can be columnar. The embodiment of the present application is only schematically illustrated by taking the form of the copper foil core layer as a foil as an example.

本申请对壳层中石墨烯层的层数以及金属铜层的层数不作限定，由于石墨烯层与金属铜层是交替设置的，金属铜层的层数可以是与石墨烯层的层数相同，即N＝M，这样壳层最外面的膜层为金属铜层。当然金属铜层的层数也可以比石墨烯层的层数少一层，即N＝M+1，这样壳层最外面的膜层为石墨烯层。The application does not limit the number of layers of the graphene layer in the shell layer and the number of layers of the metal copper layer. Since the graphene layer and the metal copper layer are alternately arranged, the number of layers of the metal copper layer can be the same as the number of layers of the graphene layer. Same, that is, N=M, so the outermost film layer of the shell layer is a metal copper layer. Of course, the number of layers of the metal copper layer can also be one less than that of the graphene layer, that is, N=M+1, so that the outermost film layer of the shell layer is a graphene layer.

示例性的，所述铜箔芯层可以采用商用压延铜箔或电解铜箔形成，在此不作限定。Exemplarily, the copper foil core layer may be formed by using commercial rolled copper foil or electrolytic copper foil, which is not limited herein.

本申请对铜箔芯层厚度的厚度不作限定，可以根据实际应用需求决定，例如以应用于PCB中的CCL为例，铜箔芯层的厚度可以设置为0.5oz～6oz之间，示例性的，铜箔芯层的厚度控制在0.5oz～3oz之间。This application does not limit the thickness of the copper foil core layer, which can be determined according to actual application requirements. For example, taking CCL applied to PCB as an example, the thickness of the copper foil core layer can be set between 0.5oz and 6oz. Exemplary , the thickness of the copper foil core layer is controlled between 0.5oz and 3oz.

可选的，为了提高铜箔芯层与壳层中石墨烯层的界面结合力，可以对铜箔芯层进行单晶化处理，诱导所述铜箔芯层的表面沿(111)晶面择优取向。Optionally, in order to improve the interfacial binding force between the copper foil core layer and the graphene layer in the shell layer, the copper foil core layer can be subjected to single crystallization treatment, and the surface of the copper foil core layer is induced to be preferentially along the (111) crystal plane orientation.

在本申请中，理论上，壳层中石墨烯层的层数在一定范围内，石墨烯层的层数越多，复合铜箔结构的电导率越高，但是当石墨烯层的层数超过该范围时，电导率趋于稳定。考虑到壳层中石墨烯层和金属铜层的层数越多，工艺步骤越多，从而成本越高，在具体实施时，壳层中石墨烯层的层数可以根据成本和电导率进行权衡设计，示例性的，在本申请中，石墨烯层的层数N可以设置为小于或等于100。In this application, theoretically, the number of graphene layers in the shell is within a certain range, the more the number of graphene layers, the higher the conductivity of the composite copper foil structure, but when the number of graphene layers exceeds In this range, the conductivity tends to be stable. Considering that the more layers of graphene layers and metal copper layers in the shell, the more process steps, the higher the cost. In specific implementation, the number of layers of graphene layers in the shell can be weighed according to cost and conductivity Design, for example, in this application, the number N of graphene layers can be set to be less than or equal to 100.

可选地，在本申请中，壳层中石墨烯层的层数可以设置为5层至20层。Optionally, in this application, the number of graphene layers in the shell layer can be set to 5 to 20 layers.

本申请对壳层中石墨烯层的厚度和金属铜层的厚度同样不作限定，具体可以根据实际应用需求进行设计。The present application also does not limit the thickness of the graphene layer and the metal copper layer in the shell layer, which can be specifically designed according to actual application requirements.

示例性的，在本申请中，壳层中各所述金属铜层的厚度可以控制在0.1μm～40μm之间，具体可以根据金属铜层的制作方法决定，例如金属铜层为压延或电解法制备的铜箔，金属铜层的厚度一般为小于或等于40μm；金属铜层为压延或电解法制备的超薄铜箔，金属铜层的厚度一般为小于或等于10μm；金属铜层为通过PVD法在石墨烯层表面原位沉积的金属铜膜，金属铜层的厚度一般为0.1μm～1μm；金属铜层为电化学沉积法在石墨烯层表面原位沉积的金属铜层，金属铜层的厚度一般为小于或等于3μm。Exemplarily, in this application, the thickness of each metal copper layer in the shell layer can be controlled between 0.1 μm and 40 μm, which can be determined according to the manufacturing method of the metal copper layer, for example, the metal copper layer is rolled or electrolytic. The prepared copper foil, the thickness of the metal copper layer is generally less than or equal to 40 μm; the metal copper layer is an ultra-thin copper foil prepared by calendering or electrolysis, and the thickness of the metal copper layer is generally less than or equal to 10 μm; the metal copper layer is made by PVD The metal copper film deposited in situ on the surface of the graphene layer by the method, the thickness of the metal copper layer is generally 0.1 μm ~ 1 μm; the metal copper layer is the metal copper layer deposited in situ on the surface of the graphene layer by the electrochemical deposition method, the metal copper layer The thickness is generally less than or equal to 3 μm.

可选地，在本申请中，金属铜层的厚度可以控制在0.5μm～6μm之间，进一步地，金属铜层的厚度可以控制在0.1μm～1μm之间，在壳层厚度一定的情况下，通过降低壳层中金属铜层的厚度可以增加壳层中石墨烯层的总层数，从而进一步提升壳层的电导率。Optionally, in this application, the thickness of the metal copper layer can be controlled between 0.5 μm and 6 μm, and further, the thickness of the metal copper layer can be controlled between 0.1 μm and 1 μm, when the thickness of the shell layer is constant , by reducing the thickness of the metal copper layer in the shell, the total number of graphene layers in the shell can be increased, thereby further improving the conductivity of the shell.

本申请中，对壳层中不同金属铜层的厚度不作限定，位于不同层的金属铜层的厚度可以相同，当然也可以不相同。In the present application, the thicknesses of different metal copper layers in the shell layer are not limited, and the thicknesses of metal copper layers located in different layers may be the same or different.

在本申请中，为了提高壳层中石墨烯层和金属铜层的界面结合力，可以对金属铜层进行单晶化处理，诱导所述金属铜层的表面沿(111)晶面择优取向，从而提高该金属铜层与石墨烯层的界面结合力。In the present application, in order to improve the interfacial binding force between the graphene layer and the metallic copper layer in the shell layer, the metallic copper layer can be subjected to single crystallization treatment to induce the preferred orientation of the surface of the metallic copper layer along the (111) crystal plane, Thereby improving the interfacial bonding force between the metal copper layer and the graphene layer.

可选地，本申请的壳层中，所有金属铜层都是经过单晶化处理的，即每一层金属铜层的表面沿(111)晶面择优取向。Optionally, in the shell layer of the present application, all metal copper layers are treated with single crystallization, that is, the surface of each metal copper layer is preferentially oriented along the (111) crystal plane.

示例性的，在本申请中，壳层中各所述石墨烯层的厚度可以设置为1个～10个石墨烯分子层。进一步地，所述石墨烯层的厚度可以设置为1个石墨烯分子层或者2个石墨烯分子层。Exemplarily, in the present application, the thickness of each graphene layer in the shell layer can be set to 1-10 graphene molecular layers. Further, the thickness of the graphene layer can be set to one graphene molecular layer or two graphene molecular layers.

本申请中，对壳层中不同石墨烯层的厚度不作限定，不同的石墨烯层的厚度可以相同，当然也可以不相同。In the present application, the thicknesses of different graphene layers in the shell layer are not limited, and the thicknesses of different graphene layers may be the same or different.

第二方面，本申请提供的一种覆铜箔层压板，包括叠层设置的介质材料和如第一方面或第一方面的各种实施方式所述的复合铜箔结构。In a second aspect, the present application provides a copper-clad laminate, comprising dielectric materials stacked and the composite copper foil structure described in the first aspect or various implementation manners of the first aspect.

第三方面，本申请提供的一种印刷电路板，包括如第二方面所述的覆铜箔层压板，或如第一方面或第一方面的各种实施方式所述的复合铜箔结构。In a third aspect, the present application provides a printed circuit board, comprising the copper clad laminate as described in the second aspect, or the composite copper foil structure as described in the first aspect or various implementation manners of the first aspect.

第四方面，本申请提供的一种复合铜箔结构的制备方法，可以包括：提供铜箔芯层，所述铜箔芯层沿厚度方向具有相对的第一表面和第二表面；至少在所述铜箔芯层的所述第一表面和所述第二表面上形成壳层；其中，所述壳层包括N层石墨烯层和M层金属铜层，且沿所述铜箔芯层指向所述壳层方向，所述石墨烯层和所述金属铜层交替叠层设置，所述壳层中靠近所述铜箔芯层的一面为所述石墨烯层，N为大于0的整数，M为大于0的整数，且M＝N或M＝N-1；所述铜箔芯层的厚度大于所述壳层中所述金属铜层的厚度。In the fourth aspect, the preparation method of a composite copper foil structure provided by the present application may include: providing a copper foil core layer, the copper foil core layer has an opposite first surface and a second surface along the thickness direction; A shell layer is formed on the first surface and the second surface of the copper foil core layer; wherein, the shell layer includes an N-layer graphene layer and an M-layer metal copper layer, and is directed along the copper foil core layer In the direction of the shell layer, the graphene layer and the metal copper layer are alternately laminated, the side of the shell layer close to the copper foil core layer is the graphene layer, N is an integer greater than 0, M is an integer greater than 0, and M=N or M=N-1; the thickness of the copper foil core layer is greater than the thickness of the metal copper layer in the shell layer.

在本申请中，为了提高壳层中石墨烯层和金属铜层的界面结合力，在形成金属铜层后，可以对金属铜层进行单晶化处理后再在金属铜层上形成石墨烯层，其中所述单晶化处理用于诱导所述铜箔芯层的表面沿(111)晶面择优取向。In this application, in order to improve the interfacial binding force between the graphene layer and the metal copper layer in the shell layer, after the metal copper layer is formed, the metal copper layer can be subjected to single crystallization treatment and then the graphene layer can be formed on the metal copper layer , wherein the single crystallization treatment is used to induce the surface of the copper foil core layer to be preferentially oriented along the (111) crystal plane.

本申请对铜箔芯层进行单晶化处理的工艺不作限定，可以为任何公知的方法。In the present application, the single crystallization process of the copper foil core layer is not limited, and may be any known method.

示例性的，在本申请中，可以通过如下方法在所述铜箔芯层的表面上形成所述壳层。Exemplarily, in this application, the shell layer may be formed on the surface of the copper foil core layer by the following method.

第一种方法：the first method:

在所述铜箔芯层表面依次形成交替叠层设置的石墨烯层和金属铜层，直至形成N层所述石墨烯层和M层所述金属铜层。Alternately stacked graphene layers and metal copper layers are sequentially formed on the surface of the copper foil core layer until N layers of the graphene layer and M layers of the metal copper layer are formed.

示例性的，在本申请中，在所述铜箔芯层表面依次形成交替叠层设置的石墨烯层和金属铜层时，至少有一层所述石墨烯层采用薄膜转移法或者化学气相沉积法形成，至少有一层所述金属铜层通过物理气相沉积法或电化学沉积法形成，在此不作限定。Exemplarily, in this application, when alternately stacked graphene layers and metal copper layers are sequentially formed on the surface of the copper foil core layer, at least one layer of the graphene layer is formed by film transfer or chemical vapor deposition. Forming, at least one layer of the metal copper layer is formed by physical vapor deposition or electrochemical deposition, which is not limited herein.

本申请中壳层中的所述金属铜层通过物理气相沉积法或电化学沉积法形成相比直接采用铜箔，可以降低壳层中金属铜层的厚度，在壳层厚度一定的情况下，通过降低壳层中金属铜层的厚度可以增加壳层中石墨烯层的总层数，从而进一步提升壳层的电导率。In the present application, the metal copper layer in the shell layer is formed by physical vapor deposition method or electrochemical deposition method, which can reduce the thickness of the metal copper layer in the shell layer compared with the direct use of copper foil. When the thickness of the shell layer is constant, By reducing the thickness of the metal copper layer in the shell layer, the total number of graphene layers in the shell layer can be increased, thereby further improving the electrical conductivity of the shell layer.

示例性的，在一种可行的实现方式中，壳层中每一所述石墨烯层均采用化学气相沉积法形成，壳层中每一层所述金属铜层均采用物理气相沉积法或电化学沉积法形成。Exemplarily, in a feasible implementation manner, each of the graphene layers in the shell is formed by chemical vapor deposition, and each of the metal copper layers in the shell is formed by physical vapor deposition or electrodeposition. formed by chemical deposition.

或者，在另一种可行的实现方式中，壳层中每一所述石墨烯层均采用薄膜转移法形成，壳层中每一层所述金属铜层均采用物理气相沉积法或电化学沉积法形成。Or, in another feasible implementation, each of the graphene layers in the shell is formed by a thin film transfer method, and each of the metal copper layers in the shell is formed by physical vapor deposition or electrochemical deposition. law formed.

在本申请中，为了提高壳层中石墨烯层和金属铜层的界面结合力，在形成金属铜层后，可以对金属铜层进行单晶化处理后再在金属铜层上形成石墨烯层。In this application, in order to improve the interfacial binding force between the graphene layer and the metal copper layer in the shell layer, after the metal copper layer is formed, the metal copper layer can be subjected to single crystallization treatment and then the graphene layer can be formed on the metal copper layer .

示例性的，在本申请中至少有一层金属铜层是经过单晶化处理的。即在本申请中，在形成第k层金属铜层之后，还可以对所述第k层金属铜层进行单晶化处理，所述单晶化处理用于诱导第k层金属铜层的表面沿(111)晶面择优取向；其中k取大于0且小于或等于M中的至少一个整数。以M＝5为例，例如k取1，在形成第1层金属铜层之后，对所述第1层金属铜层进行单晶化处理，即只有对第1层金属铜层进行了单晶化处理，第2层石墨烯层是形成在经过单晶化处理的第1层金属铜层上的。例如k取1和3，在形成第1层金属铜层之后，对所述第1层金属铜层进行单晶化处理；在形成第3层金属铜层之后，对所述第3层金属铜层进行单晶化处理；即只有第1层金属铜层和第3层金属铜层进行了单晶化处理，第2层石墨烯层是形成在经过单晶化处理的第1层金属铜层上的，第4层石墨烯层是形成在经过单晶化处理的第3层金属铜层上的。Exemplarily, in this application, at least one metal copper layer is subjected to single crystallization treatment. That is, in the present application, after forming the kth layer of metal copper layer, the kth layer of metal copper layer can also be subjected to single crystallization treatment, and the single crystallization treatment is used to induce the surface of the kth layer of metal copper layer Preferred orientation along the (111) crystal plane; wherein k is at least one integer greater than 0 and less than or equal to M. Taking M=5 as an example, for example, k is 1, after the first layer of metal copper layer is formed, the first layer of metal copper layer is subjected to single crystallization treatment, that is, only the first layer of metal copper layer is subjected to single crystallization treatment. The second layer of graphene layer is formed on the first layer of metal copper layer that has undergone single crystallization treatment. For example, k takes 1 and 3, after forming the first layer of metal copper layer, the first layer of metal copper layer is subjected to single crystallization treatment; after forming the third layer of metal copper layer, the third layer of metal copper layer is The layer is subjected to single crystallization treatment; that is, only the first layer of metal copper layer and the third layer of metal copper layer are subjected to single crystallization treatment, and the second layer of graphene is formed on the first layer of metal copper layer that has undergone single crystallization treatment. In the above, the fourth layer of graphene layer is formed on the third layer of metal copper layer that has undergone single crystallization treatment.

第二种方法：The second method:

在所述铜箔芯层的表面形成所述壳层可以包括：在所述铜箔芯层的第一表面和第二表面分别贴合至少一层叠层结构；其中，各所述叠层结构包括金属铜层和位于所述金属铜层表面的石墨烯层。Forming the shell layer on the surface of the copper foil core layer may include: attaching at least one laminated structure to the first surface and the second surface of the copper foil core layer; wherein each laminated structure includes A metal copper layer and a graphene layer located on the surface of the metal copper layer.

示例性的，可以通过热压烧结法在所述铜箔芯层的第一表面和第二表面分别贴合至少一层叠层结构。Exemplarily, at least one laminated structure may be pasted on the first surface and the second surface of the copper foil core layer by hot pressing and sintering.

示例性的，所述叠层结构通过如下方法形成：提供金属铜层；通过薄膜转移法或化学气相沉积法在所述金属铜层的表面形成石墨烯层。Exemplarily, the stacked structure is formed by the following methods: providing a metal copper layer; and forming a graphene layer on the surface of the metal copper layer by a thin film transfer method or a chemical vapor deposition method.

为了提高壳层中石墨烯层和金属铜层的界面结合力，在所述金属铜层的表面形成石墨烯层之前，还可以包括：对所述金属铜层进行单晶化处理。In order to improve the interfacial binding force between the graphene layer and the metal copper layer in the shell layer, before forming the graphene layer on the surface of the metal copper layer, it may further include: performing single crystallization treatment on the metal copper layer.

示例性的，在所述铜箔芯层的表面形成所述壳层，还可以包括：在所述铜箔芯层的第一表面和第二表面分别贴合至少一层叠层结构之前，在所述铜箔芯层的第一表面和/或第二表面上形成石墨烯层。Exemplarily, forming the shell layer on the surface of the copper foil core layer may further include: before attaching at least one laminated structure to the first surface and the second surface of the copper foil core layer, A graphene layer is formed on the first surface and/or the second surface of the copper foil core layer.

当然，在具体实施时，也可以将第一种方法和第二种进行结合，在此不作限定。以N＝M＝4为例，例如可以先在所述铜箔芯层的表面上形成第一层石墨烯层，接着在第一层石墨烯层上形成第一层金属铜层，然后再在第一层金属铜层上贴合3层叠层结构。Certainly, during specific implementation, the first method and the second method may also be combined, which is not limited here. Taking N=M=4 as an example, for example, the first layer of graphene layer can be formed on the surface of the copper foil core layer, and then the first layer of metal copper layer is formed on the first layer of graphene layer, and then A 3-layer laminated structure is pasted on the first metal copper layer.

需要说明的是，在本申请中，可以同时在所述铜箔芯层的不同表面形成所述壳层，例如同时在所述铜箔芯层的第一表面和第二表面形成所述壳层；当然也可以在所述铜箔芯层不同的表面上依次形成所述壳层，例如先在所述铜箔芯层的第一表面形成所述壳层，然后再在所述铜箔芯层的第二表面形成所述壳层。It should be noted that, in this application, the shell layers can be formed on different surfaces of the copper foil core layer at the same time, for example, the shell layers can be formed on the first surface and the second surface of the copper foil core layer at the same time. ; Of course, the shell layer can also be formed sequentially on different surfaces of the copper foil core layer, for example, the shell layer is first formed on the first surface of the copper foil core layer, and then the shell layer is formed on the copper foil core layer The second surface of the form the shell.

上述第二方面至第四方面中任一方面可以达到的技术效果可以参照上述第一方面中任一可能设计可以达到的技术效果说明，这里不再重复赘述。The technical effects that can be achieved by any one of the above-mentioned second to fourth aspects can be described with reference to the technical effects that can be achieved by any possible design in the above-mentioned first aspect, and will not be repeated here.

附图说明Description of drawings

图1为本申请实施例提供的一种复合铜箔结构的结构示意图；FIG. 1 is a schematic structural view of a composite copper foil structure provided in an embodiment of the present application;

图2为本申请实施例提供的另一种复合铜箔结构的结构示意图；Fig. 2 is a structural schematic diagram of another composite copper foil structure provided by the embodiment of the present application;

图3为本申请实施例提供的复合铜箔结构的一种制备方法的流程示意图；Fig. 3 is a schematic flow chart of a preparation method of a composite copper foil structure provided in an embodiment of the present application;

图4为本申请实施例提供的复合铜箔结构的另一种制备方法的流程示意图；Fig. 4 is a schematic flow chart of another preparation method of the composite copper foil structure provided by the embodiment of the present application;

图5为本申请实施例提供的复合铜箔结构的另一种制备方法的流程示意图；Fig. 5 is a schematic flow diagram of another preparation method of the composite copper foil structure provided by the embodiment of the present application;

图6为采用本申请一种实施例提供的制备方法制备复合铜箔结构的示意图；Fig. 6 is a schematic diagram of a composite copper foil structure prepared by a preparation method provided by an embodiment of the present application;

图7为采用本申请另一实施例提供的制备方法制备复合铜箔结构的示意图；Fig. 7 is a schematic diagram of a composite copper foil structure prepared by a preparation method provided by another embodiment of the present application;

图8为采用本申请另一实施例提供的制备方法制备复合铜箔结构的示意图；Fig. 8 is a schematic diagram of a composite copper foil structure prepared by a preparation method provided by another embodiment of the present application;

图9为采用本申请另一实施例提供的制备方法制备复合铜箔结构的示意图；Fig. 9 is a schematic diagram of a composite copper foil structure prepared by a preparation method provided by another embodiment of the present application;

图10为采用本申请另一实施例提供的制备方法制备复合铜箔结构的示意图；Fig. 10 is a schematic diagram of preparing a composite copper foil structure using a preparation method provided by another embodiment of the present application;

图11为本申请实施例提供的复合铜箔结构的另一种制备方法的流程示意图；Fig. 11 is a schematic flow diagram of another preparation method of the composite copper foil structure provided in the embodiment of the present application;

图12为本申请一种实施例中复合铜箔结构的制备过程的结构示意图；Fig. 12 is a structural schematic diagram of the preparation process of the composite copper foil structure in an embodiment of the present application;

图13为本申请实施例提供的复合铜箔结构的另一种制备方法的流程示意图；Fig. 13 is a schematic flow diagram of another preparation method of the composite copper foil structure provided in the embodiment of the present application;

图14为本申请另一实施例中复合铜箔结构的制备过程的结构示意图；Fig. 14 is a structural schematic diagram of the preparation process of the composite copper foil structure in another embodiment of the present application;

图15为本申请实施例提供的复合铜箔结构的另一种制备方法的流程示意图；Fig. 15 is a schematic flow chart of another preparation method of the composite copper foil structure provided in the embodiment of the present application;

图16为本申请又一实施例中复合铜箔结构的制备过程的结构示意图；Fig. 16 is a structural schematic diagram of the preparation process of the composite copper foil structure in another embodiment of the present application;

图17为本申请实施例提供的一种覆铜箔层压板的结构示意图。FIG. 17 is a schematic structural diagram of a copper-clad laminate provided in an embodiment of the present application.

具体实施方式Detailed ways

为了使本申请的目的、技术方案和优点更加清楚，下面将结合附图对本申请作进一步地详细描述。In order to make the purpose, technical solution and advantages of the application clearer, the application will be further described in detail below in conjunction with the accompanying drawings.

应注意的是，在本说明书中，相似的标号和字母在下面的附图中表示类似项，因此，一旦某一项在一个附图中被定义，则在随后的附图中不需要对其进行进一步定义和解释。It should be noted that in this specification, similar numerals and letters denote similar items in the following drawings, therefore, once an item is defined in one drawing, it does not need to be identified in subsequent drawings. for further definition and explanation.

在本申请的描述中，需要说明的是，术语“中”、“上”、“下”、“左”、“右”、“竖直”、“水平”、“内”、“外”等指示的方位或位置关系为基于附图所示的方位或位置关系，仅是为了便于描述本申请和简化描述，而不是指示或暗示所指的装置或元件必须具有特定的方位、以特定的方位构造和操作，因此不能理解为对本申请的限制。本申请中所描述的表达位置与方向的词，均是以附图为例进行的说明，但根据需要也可以做出改变，所做改变均包含在本发明保护范围内。本申请的附图仅用于示意相对位置关系不代表真实比例。此外，术语“第一”、“第二”仅用于描述目的，而不能理解为指示或暗示相对重要性。In the description of this application, it should be noted that the terms "middle", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" etc. The indicated orientation or positional relationship is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the referred device or element must have a specific orientation, use a specific orientation construction and operation, therefore should not be construed as limiting the application. The words expressing position and direction described in this application are all described by taking the accompanying drawings as an example, but changes can also be made according to needs, and all changes are included in the protection scope of the present invention. The drawings in this application are only used to illustrate the relative positional relationship and do not represent the true scale. In addition, the terms "first" and "second" are used for descriptive purposes only, and should not be understood as indicating or implying relative importance.

在本申请的描述中，需要说明的是，除非另有明确的规定和限定，术语“安装”、“相连”、“连接”应做广义理解，例如，可以是固定连接，也可以是可拆卸连接，或一体地连接；可以是机械连接，也可以是电连接；可以是直接相连，也可以通过中间媒介间接相连，可以是两个元件内部的连通。对于本领域的普通技术人员而言，可以具体情况理解上述术语在本申请中的具体含义。In the description of this application, it should be noted that unless otherwise specified and limited, the terms "installation", "connection", and "connection" should be understood in a broad sense, for example, it can be a fixed connection or a detachable connection. Connected, or integrally connected; it can be mechanically connected or electrically connected; it can be directly connected or indirectly connected through an intermediary, and it can be the internal communication of two components. Those of ordinary skill in the art can understand the specific meanings of the above terms in this application in specific situations.

以下，对本申请实施例中的部分用语进行解释说明，以便于本领域技术人员理解。In the following, some terms used in the embodiments of the present application are explained, so as to facilitate the understanding of those skilled in the art.

化学气相沉积(Chemical Vapor Deposition，CVD)：是一种用来产生纯度高、性能好的固态材料的化学技术。半导体产业使用此技术来成长薄膜。典型的CVD工艺是将晶圆(基底)暴露在一种或多种不同的前趋物下，在基底表面发生化学反应或/及化学分解来产生欲沉积的薄膜。反应过程中通常也会伴随地产生不同的副产品，但大多会随着气流被带走，而不会留在反应腔(reaction chamber)中。Chemical Vapor Deposition (CVD): A chemical technique used to produce solid materials with high purity and good performance. The semiconductor industry uses this technique to grow thin films. In a typical CVD process, the wafer (substrate) is exposed to one or more different precursors, and a chemical reaction or/and chemical decomposition occurs on the surface of the substrate to produce a film to be deposited. Different by-products are usually produced during the reaction, but most of them will be taken away with the airflow instead of staying in the reaction chamber.

物理气相沉积(Physical Vapor Deposition，PVD)：在真空条件下，采用物理方法，将材料源——固体或液体表面气化成气态原子、分子或部分电离成离子，并通过低压气体(或等离子体)过程，在基体表面沉积具有某种特殊功能的薄膜的技术。物理气相沉积的主要方法有，真空蒸镀、溅射镀膜、电弧等离子体镀、离子镀膜，及分子束外延等。发展到目前，物理气相沉积技术不仅可沉积金属膜、合金膜、还可以沉积化合物、陶瓷、半导体、聚合物膜等。Physical vapor deposition (Physical Vapor Deposition, PVD): Under vacuum conditions, using physical methods, the material source—solid or liquid surface is vaporized into gaseous atoms, molecules or parts ionized into ions, and passed through low-pressure gas (or plasma) Process, the technology of depositing a thin film with a certain special function on the surface of the substrate. The main methods of physical vapor deposition are vacuum evaporation, sputtering coating, arc plasma plating, ion coating, and molecular beam epitaxy. Developed to the present, physical vapor deposition technology can not only deposit metal films, alloy films, but also deposit compounds, ceramics, semiconductors, polymer films, etc.

电化学沉积(Electrochemical Deposition)：是指在外电场作用下电流通过电解质溶液中正负离子的迁移并在电极上发生得失电子的氧化还原反应而形成镀层的技术。在阴极产生金属离子的还原而获得金属镀层，称为电镀。在阳极发生阳极金属的氧化而形成合用的氧化膜，称为金属的电化学氧化，简称金属的电氧化。Electrochemical Deposition (Electrochemical Deposition): refers to the technology of forming a coating through the migration of positive and negative ions in the electrolyte solution under the action of an external electric field and the redox reaction of gaining and losing electrons on the electrode. The reduction of metal ions at the cathode to obtain a metal coating is called electroplating. Oxidation of the anode metal occurs at the anode to form a suitable oxide film, which is called electrochemical oxidation of metal, or electro-oxidation of metal for short.

薄膜转移法：将薄膜从一个衬底分离并转移到另外一个衬底(目标衬底)上。Thin film transfer method: The thin film is separated from one substrate and transferred to another substrate (target substrate).

为了方便理解本申请实施例提供的复合铜箔结构，首先说明一下其应用场景，该复合铜箔结构被广泛用于集成电路、印刷电路板(Printed Circuit Board，PCB)、电子元件、能量存储设备和航空航天设备，进行信号传输和电气互联。以PCB为例，PCB是通过对覆铜箔层压板(Copper Clad Laminate，CCL)有选择地进行加工、蚀刻、钻孔及镀铜等工序而制成的具有不同导电图形的印制电路。CCL作为PCB制造中的基板材料，对PCB主要起互连导通、绝缘和支撑的作用，对电路中信号的传输速度、能量损失和特性阻抗等有很大的影响，因此，PCB的性能、品质、制造中的加工性、制造水平、制造成本以及长期的可靠性及稳定性在很大程度上取决于CCL。其中，CCL简称覆铜板，是将电子玻纤布或其它增强性材料浸以树脂，然后在其一面或双面覆以铜箔并经热压而制成的一种板状材料。In order to facilitate the understanding of the composite copper foil structure provided by the embodiment of the present application, its application scenario is first explained. The composite copper foil structure is widely used in integrated circuits, printed circuit boards (Printed Circuit Board, PCB), electronic components, and energy storage devices. And aerospace equipment, signal transmission and electrical interconnection. Taking PCB as an example, PCB is a printed circuit with different conductive patterns made by selectively processing, etching, drilling and copper plating on Copper Clad Laminate (CCL). As the substrate material in PCB manufacturing, CCL mainly plays the role of interconnection, insulation and support for PCB, and has a great influence on the transmission speed, energy loss and characteristic impedance of signals in the circuit. Therefore, the performance of PCB, Quality, processability in manufacturing, manufacturing level, manufacturing cost, and long-term reliability and stability largely depend on CCL. Among them, CCL is referred to as copper clad laminate, which is a plate material made by impregnating electronic glass fiber cloth or other reinforcing materials with resin, and then covering one or both sides with copper foil and hot pressing.

随着信号传输朝着高频高速方向发展，急需降低PCB中导体损耗以降低传输线的***损耗；能源器件向着高能量密度和薄型化、小型化的方向发展，急需提高铜箔的通流能力、同时降低铜损和减少焦耳热。这些需求均对铜箔的电导率提出了更高的要求，需要制备出电导率高于100％IACS的高电导率铜箔。当前，商业铜箔的制备方法主要为压延法和电解法，电导率在97％IACS左右，难以满足行业发展对铜箔电导率的需求。With the development of signal transmission in the direction of high frequency and high speed, it is urgent to reduce the conductor loss in PCB to reduce the insertion loss of transmission line; energy devices are developing in the direction of high energy density, thinning and miniaturization, and there is an urgent need to improve the flow capacity of copper foil, At the same time reduce copper loss and reduce Joule heating. These requirements all put forward higher requirements on the electrical conductivity of the copper foil, and it is necessary to prepare a high-conductivity copper foil with an electrical conductivity higher than 100% IACS. At present, the preparation methods of commercial copper foil are mainly calendering method and electrolysis method, and the electrical conductivity is about 97% IACS, which is difficult to meet the needs of the industry development for the electrical conductivity of copper foil.

基于此，本申请提供了一种高电导率的复合铜箔结构，该复合铜箔结构在高频信号(例如在信号频率大于1MHZ)场合尤为适用。为了便于理解本申请技术方案，下面将结合附图和具体实施方式对本申请所提供的高电导率的复合铜箔结构进行具体说明。Based on this, the present application provides a high-conductivity composite copper foil structure, which is especially suitable for high-frequency signal (for example, signal frequency greater than 1MHZ). In order to facilitate the understanding of the technical solution of the present application, the composite copper foil structure with high electrical conductivity provided by the present application will be specifically described below in conjunction with the drawings and specific embodiments.

参见图1和图2，图1为本申请实施例提供的一种复合铜箔结构的结构示意图，图2为本申请实施例提供的另一种复合铜箔结构的结构示意图。所述复合铜箔结构10包括铜箔芯层11和壳层12，其中，所述铜箔芯层11沿厚度方向X具有相对的第一表面和第二表面；所述壳层12至少位于所述铜箔芯层11的所述第一表面和所述第二表面；其中，所述壳层12包括：N层石墨烯层：1211～121N和M层金属铜层1221～122M，所述石墨烯层121n(n为1～N的任意整数)和所述金属铜层122m(m为1～M的任意整数)沿X方向交替叠层设置，且所述壳层12中靠近所述铜箔芯层11的一面的为所述石墨烯层121_n，N为大于0的整数，M为大于0的整数,且M＝N或M＝N-1，所述铜箔芯层11的厚度大于所述壳层12中所述金属铜层122n的厚度。例如图1中以N等于4，M等于4为例进行示意，且所述壳层12中靠近所述铜箔芯层11一侧的为第一层石墨烯层1211，在所述壳层12中，且沿所述铜箔芯层11指向所述壳层12方向，依次为第一层石墨烯层1211、第一层金属铜层1221、第二层石墨烯层1212、第二层金属铜层1222、第三层石墨烯层1213、第三层金属铜层1223、第四层石墨烯层1214和第四层金属铜层1224。图2中以N等于4，M等于3为例进行示意，且所述壳层12中靠近所述铜箔芯层11一侧的为第一层石墨烯层1211，在所述壳层12中，且沿所述铜箔芯层11指向所述壳层12方向，依次为第一层石墨烯层1211、第一层金属铜层1221、第二层石墨烯层1212、第二层金属铜层1222、第三层石墨烯层1213、第三层金属铜层1223和第四层石墨烯层1214。Referring to Fig. 1 and Fig. 2, Fig. 1 is a schematic structural diagram of a composite copper foil structure provided in the embodiment of the present application, and Fig. 2 is a schematic structural diagram of another composite copper foil structure provided in the embodiment of the present application. The composite copper foil structure 10 includes a copper foil core layer 11 and a shell layer 12, wherein the copper foil core layer 11 has opposite first and second surfaces along the thickness direction X; The first surface and the second surface of the copper foil core layer 11; wherein, the shell layer 12 includes: N layers of graphene layers: 1211 ~ 121N and M layers of metal copper layers 1221 ~ 122M, the graphite Alkene layers 121n (n is any integer from 1 to N) and the metal copper layer 122m (m is any integer from 1 to M) are alternately stacked along the X direction, and the shell layer 12 is close to the copper foil One side of the core layer 11 is the graphene layer 121_n, N is an integer greater than 0, M is an integer greater than 0, and M=N or M=N-1, the thickness of the copper foil core layer 11 is greater than the The thickness of the metal copper layer 122n in the shell layer 12. For example, in Fig. 1, N is equal to 4, M is equal to 4 as an example, and the first graphene layer 1211 is on the side of the shell layer 12 close to the copper foil core layer 11, and in the shell layer 12 , and along the copper foil core layer 11 pointing to the direction of the shell layer 12, followed by the first layer of graphene layer 1211, the first layer of metal copper layer 1221, the second layer of graphene layer 1212, the second layer of metal copper layer layer 1222 , a third layer of graphene layer 1213 , a third layer of metallic copper layer 1223 , a fourth layer of graphene layer 1214 and a fourth layer of metallic copper layer 1224 . In Fig. 2, N is equal to 4 and M is equal to 3 as an example, and the first layer of graphene layer 1211 is the first layer of graphene layer 1211 in the shell layer 12 near the copper foil core layer 11, and in the shell layer 12 , and along the copper foil core layer 11 pointing to the direction of the shell layer 12, followed by the first layer of graphene layer 1211, the first layer of metal copper layer 1221, the second layer of graphene layer 1212, the second layer of metal copper layer 1222 , the third graphene layer 1213 , the third metal copper layer 1223 and the fourth graphene layer 1214 .

基于导体的趋肤效应，当导体中有交流电或者交变电磁场时，导体内部的电流分布不均匀，电流集中在导体的“皮肤”部分，也就是说电流集中在导体外表的薄层，越靠近导体表面，电流密度越大。因此，本申请实施例提供的上述复合铜箔结构，在铜箔芯层的表面设置有由交替叠层设置的石墨烯层和金属铜层组成的壳层，利用石墨烯和铜的复合效应来提升复合铜箔结构的表层电导率，从而可以提供一种高电导率的复合铜箔结构。并且，由于仅是在芯层的表面设置有由石墨烯层和金属铜层组成的壳层，而芯层还是采用铜箔，相比芯层同样也采用石墨烯层和金属铜层的复合层，可以降低成本。Based on the skin effect of the conductor, when there is alternating current or alternating electromagnetic field in the conductor, the current distribution inside the conductor is uneven, and the current is concentrated in the "skin" part of the conductor, that is to say, the current is concentrated in the thin layer on the outside of the conductor. The higher the current density is at the surface of the conductor. Therefore, the above-mentioned composite copper foil structure provided by the embodiment of the present application is provided with a shell layer composed of alternately stacked graphene layers and metal copper layers on the surface of the copper foil core layer, and utilizes the composite effect of graphene and copper to Improve the surface conductivity of the composite copper foil structure, thereby providing a composite copper foil structure with high conductivity. And, since the shell layer composed of graphene layer and metal copper layer is only arranged on the surface of the core layer, and the core layer still adopts copper foil, compared with the core layer, the composite layer of graphene layer and metal copper layer is also used. , can reduce costs.

可选的，壳层中的金属铜层可以通过PVD法或电化学沉积法形成，这样相比直接采用铜箔形成壳层中的金属铜层，壳层中的金属铜层的厚度更薄，从而在壳层厚度一定的情况下降低金属铜层的厚度可以增加壳层中石墨烯层的总层数，从而可以进一步提高壳层的电导率。Optionally, the metal copper layer in the shell layer can be formed by PVD method or electrochemical deposition method, so that compared with directly using copper foil to form the metal copper layer in the shell layer, the thickness of the metal copper layer in the shell layer is thinner, Therefore, reducing the thickness of the metal copper layer can increase the total number of graphene layers in the shell layer when the thickness of the shell layer is constant, thereby further improving the electrical conductivity of the shell layer.

本申请对铜箔芯层的形态不作限定，铜箔芯层的形态包括但不限于为箔片，例如还可以为柱状等，具体可以根据实际应用需求进行设计。例如当应用于PCB中的CCL时，铜箔芯层可以为箔片，当应用于电缆时，铜箔芯层可以为柱状。本申请实施例仅是以铜箔芯层的形态为板状为例进行示意说明的。The present application does not limit the shape of the copper foil core layer. The shape of the copper foil core layer includes but is not limited to foil, for example, it can also be columnar, etc., which can be designed according to actual application requirements. For example, when applied to CCL in PCB, the copper foil core layer can be a foil, and when applied to a cable, the copper foil core layer can be columnar. The embodiment of the present application is only schematically illustrated by taking the shape of the copper foil core layer as a plate as an example.

在本申请中，1oz是指重量1oz的铜均匀平铺在1平方英尺(ft ²)的面积上所达到的厚度。它是用单位面积的重量来表示铜箔的平均厚度，用公式来表示，即1oz＝28.35g/ft ²，1ft ²＝0.09290304m ²，1oz约为0.035mm。 In this application, 1 oz refers to the thickness achieved by uniformly spreading copper weighing 1 oz over an area of 1 square foot (ft ² ). It uses the weight per unit area to represent the average thickness of copper foil, which is expressed by the formula, that is, 1oz=28.35g/ft ² , 1ft ² =0.09290304m ² , and 1oz is about 0.035mm.

可选的，为了提高铜箔芯层与壳层中石墨烯层的界面结合力，可以对铜箔芯层进行单晶化处理，所述单晶化处理用于诱导所述铜箔芯层的表面沿(111)晶面择优取向。Optionally, in order to improve the interface binding force between the copper foil core layer and the graphene layer in the shell layer, the copper foil core layer can be subjected to single crystallization treatment, and the single crystallization treatment is used to induce the copper foil core layer The surface is preferentially oriented along the (111) crystal plane.

示例性的，在本申请中，壳层中各所述金属铜层的厚度可以控制在0.1μm～40μm之间，具体可以根据金属铜层的制作方法决定，例如金属铜层为压延或电解法制备的铜箔，金属铜层的厚度一般为小于或等于40μm；金属铜层为压延或电解法制备的超薄铜箔，金属铜层的厚度一般为小于或等于10μm；金属铜层为通过PVD法在石墨烯层表面原位沉积的金属铜膜，金属铜层的厚度一般为0.1μm～1μm；金属铜层为电化学沉积法在石墨烯层表面原位沉积的金属铜层，金属铜层的厚度一般为小于或等于3μm。由PVD法或电化学沉积法形成的金属铜层的厚度明显要小于由铜箔形成的金属铜层的厚度。Exemplarily, in this application, the thickness of each metal copper layer in the shell layer can be controlled between 0.1 μm and 40 μm, which can be determined according to the manufacturing method of the metal copper layer, for example, the metal copper layer is rolled or electrolytic. The prepared copper foil, the thickness of the metal copper layer is generally less than or equal to 40 μm; the metal copper layer is an ultra-thin copper foil prepared by calendering or electrolysis, and the thickness of the metal copper layer is generally less than or equal to 10 μm; the metal copper layer is made by PVD The metal copper film deposited in situ on the surface of the graphene layer by the method, the thickness of the metal copper layer is generally 0.1 μm ~ 1 μm; the metal copper layer is the metal copper layer deposited in situ on the surface of the graphene layer by the electrochemical deposition method, the metal copper layer The thickness is generally less than or equal to 3 μm. The thickness of the metal copper layer formed by PVD method or electrochemical deposition method is obviously smaller than that of the metal copper layer formed by copper foil.

本申请中，对壳层中不同金属铜层的厚度不作限定，位于不同层的金属铜层的厚度可以相同，当然也可以不相同。In the present application, there is no limitation on the thicknesses of the different metal copper layers in the shell layer, and the thicknesses of the metal copper layers in different layers may be the same or different.

在本申请中，为了提高壳层中石墨烯层和金属铜层的界面结合力，可以对金属铜层进行单晶化处理，以诱导所述金属铜层的表面沿(111)晶面择优取向，从而提高该金属铜层与石墨烯层的界面结合力。当然，在本申请中，也可以对金属层不进行单晶化处理，在此不作限定。In the present application, in order to improve the interfacial binding force between the graphene layer and the metal copper layer in the shell layer, the metal copper layer can be subjected to single crystallization treatment to induce the surface of the metal copper layer to be preferentially oriented along the (111) crystal plane , thereby improving the interfacial bonding force between the metal copper layer and the graphene layer. Of course, in the present application, the metal layer may not be subjected to single crystallization treatment, which is not limited here.

示例性的，为了提高壳层中石墨烯层和金属铜层的界面结合力，本申请的壳层中，至少有一层金属铜层是经过单晶化处理的。Exemplarily, in order to improve the interfacial bonding force between the graphene layer and the metal copper layer in the shell layer, in the shell layer of the present application, at least one metal copper layer is subjected to single crystallization treatment.

可选地，本申请的壳层中，所有金属铜层都是经过单晶化处理的，以诱导每一层金属铜层的表面沿(111)晶面择优取向。Optionally, in the shell layer of the present application, all metallic copper layers are treated with single crystallization, so as to induce the surface of each metallic copper layer to be preferentially oriented along the (111) crystal plane.

示例性的，在本申请中，壳层中各所述石墨烯层的厚度可以设置为1～10个层石墨烯分子层。进一步地，所述石墨烯层的厚度可以设置为1个石墨烯分子层或者2个石墨烯分子层。Exemplarily, in the present application, the thickness of each graphene layer in the shell layer can be set to 1-10 graphene molecular layers. Further, the thickness of the graphene layer can be set to one graphene molecular layer or two graphene molecular layers.

本申请实施例还提供了上述复合铜箔结构的制备方法，如图3所示，所述制备方法可以包括以下步骤：The embodiment of the present application also provides a preparation method of the above composite copper foil structure, as shown in Figure 3, the preparation method may include the following steps:

步骤S101、提供铜箔芯层，所述铜箔芯层沿厚度方向具有相对的第一表面和第二表面。Step S101 , providing a copper foil core layer, the copper foil core layer has a first surface and a second surface opposite to each other along the thickness direction.

步骤S102、至少在所述铜箔芯层的所述第一表面和所述第二表面上形成壳层。Step S102, forming a shell layer on at least the first surface and the second surface of the copper foil core layer.

其中，所述壳层包括N层石墨烯层和M层金属铜层，所述石墨烯层和所述金属铜层交替叠层设置，所述壳层中靠近所述铜箔芯层一侧为所述石墨烯层，N为大于0的整数，M为大于0的整数，所述铜箔芯层的厚度大于所述壳层中所述金属铜层的厚度。Wherein, the shell layer includes N layers of graphene layers and M layers of metal copper layers, the graphene layers and the metal copper layers are alternately laminated, and the side of the shell layer close to the copper foil core layer is In the graphene layer, N is an integer greater than 0, M is an integer greater than 0, and the thickness of the copper foil core layer is greater than the thickness of the metal copper layer in the shell layer.

为了提高铜箔芯层与壳层的界面结合力，参加图4，在步骤S101和S102之间，还可以包括步骤S103：对所述铜箔芯层进行单晶化处理，所述单晶化处理用于诱导铜箔芯层的表面沿(111)晶面择优取向。In order to improve the interfacial bonding force between the copper foil core layer and the shell layer, referring to Fig. 4, between steps S101 and S102, step S103 may also be included: performing single crystallization treatment on the copper foil core layer, the single crystallization The treatment is used to induce a preferred orientation of the surface of the copper foil core layer along the (111) crystal plane.

具体地，在本申请中，可以通过如下方法在所述铜箔芯层的表面上形成所述壳层。Specifically, in the present application, the shell layer may be formed on the surface of the copper foil core layer by the following method.

第一种方法：the first method:

在所述铜箔芯层表面依次形成交替叠层设置的石墨烯层和金属铜层，直至形成N层所述石墨烯层和M层所述金属铜层。即壳层是在所述铜箔芯层表面逐层形成的，以壳层中包括3层石墨烯层和3层金属铜层为例，参见图5，在所述铜箔芯层的表面上形成所述壳层是可以包括以下步骤：Alternately stacked graphene layers and metal copper layers are sequentially formed on the surface of the copper foil core layer until N layers of the graphene layer and M layers of the metal copper layer are formed. That is to say, the shell layer is formed layer by layer on the surface of the copper foil core layer, and the shell layer includes 3 layers of graphene layers and 3 layers of metal copper layers as an example, referring to Fig. 5, on the surface of the copper foil core layer Forming the shell may include the following steps:

步骤S201、在所述铜箔芯层的表面上形成第一层石墨烯层；Step S201, forming a first graphene layer on the surface of the copper foil core layer;

步骤S202、在第一层石墨烯层上形成第一层金属铜层；Step S202, forming a first metal copper layer on the first graphene layer;

步骤S203、在第一层金属铜层上形成第二层石墨烯层；Step S203, forming a second graphene layer on the first metal copper layer;

步骤S204、在第二层石墨烯层上形成第二层金属铜层；Step S204, forming a second metal copper layer on the second graphene layer;

步骤S205、在第二层金属铜层上形成第三层石墨烯层；Step S205, forming a third graphene layer on the second metal copper layer;

步骤S206、在第三层石墨烯层上形成第三层金属铜层。Step S206, forming a third metal copper layer on the third graphene layer.

本申请中壳层中的所述金属铜层通过物理气相沉积法或电化学沉积法形成相比直接采用铜箔，可以降低壳层中金属铜层的厚度，在壳层厚度一定的情况下，通过降低壳层中金属铜层的厚度可以增加壳层中石墨烯层的总层数，从而可以进一步提升壳层的电导率。In the present application, the metal copper layer in the shell layer is formed by physical vapor deposition method or electrochemical deposition method, which can reduce the thickness of the metal copper layer in the shell layer compared with the direct use of copper foil. When the thickness of the shell layer is constant, By reducing the thickness of the metal copper layer in the shell layer, the total number of graphene layers in the shell layer can be increased, thereby further improving the electrical conductivity of the shell layer.

示例性的，在本申请中至少有一层金属铜层是经过单晶化处理的。即在本申请中，在形成第k层金属铜层之后，还可以对所述第k层金属铜层进行单晶化处理，所述单晶化处理用于诱导第k层金属铜层的表面沿(111)晶面择优取向；其中k取大于0且小于或等于M中的至少一个整数。以M＝5为例，例如k取1，在形成第1层金属铜层之后，对所述第1层金属铜层进行单晶化处理，即只有对第1层金属铜层进行了单晶化处理，第2层石墨烯层是形成在经过单晶化处理的第1层金属铜层上的。例如k取1和3，在形成第1层金属铜层之后，对所述第1层金属铜层进行单晶化处理；在形成第3层金属铜层之后，对所述第3层金属铜层进行单晶化处理；即只有第1层金属铜层和第3层金属铜层进行了单晶化处理，第2层石墨烯层是形成在经过单晶化处理的第1层金属铜层上的，第4层石墨烯层是形成在经过单晶化处理的第3层金属铜层上的。Exemplarily, in this application, at least one metal copper layer is subjected to single crystallization treatment. That is, in the present application, after forming the kth layer of metal copper layer, the kth layer of metal copper layer can also be subjected to single crystallization treatment, and the single crystallization treatment is used to induce the surface of the kth layer of metal copper layer Preferred orientation along the (111) crystal plane; wherein k is at least one integer greater than 0 and less than or equal to M. Taking M=5 as an example, for example, k is 1, and after forming the first layer of metal copper layer, the first layer of metal copper layer is subjected to single crystallization treatment, that is, only the first layer of metal copper layer is subjected to single crystallization treatment. The second layer of graphene layer is formed on the first layer of metal copper layer that has undergone single crystallization treatment. For example, k takes 1 and 3, after forming the first layer of metal copper layer, the first layer of metal copper layer is subjected to single crystallization treatment; after forming the third layer of metal copper layer, the third layer of metal copper layer is The layer is subjected to single-crystallization treatment; that is, only the first layer of metal copper layer and the third layer of metal copper layer are subjected to single-crystallization treatment, and the second layer of graphene is formed on the first layer of metal copper layer that has undergone single-crystallization treatment. In the above, the fourth layer of graphene layer is formed on the third layer of metal copper layer that has undergone single crystallization treatment.

可选地，在本申请中每一层金属铜层都是经过单晶化处理的，从而提高壳层中每一层石墨烯层和与其相邻的金属铜层的界面结合力。Optionally, in the present application, each layer of metal copper layer is treated with single crystallization, so as to improve the interfacial bonding force between each graphene layer in the shell layer and its adjacent metal copper layer.

第二种方法：The second method:

如图6和图7所示，在所述铜箔芯层11的表面形成所述壳层12，可以包括：在所述铜箔芯层11的第一表面和第二表面分别贴合至少一层叠层结构01；其中，各所述叠层结构01包括金属铜层122和位于所述金属铜层122表面的石墨烯层121。As shown in Figures 6 and 7, forming the shell layer 12 on the surface of the copper foil core layer 11 may include: attaching at least one layer to the first surface and the second surface of the copper foil core layer 11 respectively Laminated structure 01; wherein, each of the laminated structures 01 includes a metal copper layer 122 and a graphene layer 121 located on the surface of the metal copper layer 122 .

参考图6，可以先通过薄膜转移法在所述金属铜层122的一侧表面上形成石墨烯层121，从而形成叠层结构01。然后在所述铜箔芯层11的第一表面和第二表面分别贴合至少一层叠层结构01形成复合铜箔结构。在形成的复合铜箔结构中，叠层结构01中的石墨烯层121可以位于靠近铜箔芯层11一侧，金属铜层122可以位于远离铜箔芯层11一侧。Referring to FIG. 6 , a graphene layer 121 can be formed on one side surface of the metal copper layer 122 by thin film transfer method, so as to form a laminated structure 01 . Then at least one laminated structure 01 is pasted on the first surface and the second surface of the copper foil core layer 11 to form a composite copper foil structure. In the formed composite copper foil structure, the graphene layer 121 in the laminated structure 01 may be located on the side close to the copper foil core layer 11 , and the metal copper layer 122 may be located on the side away from the copper foil core layer 11 .

参考图7，可以先通过化学气相沉积法可以在所述金属铜层122的所有表面形成石墨烯层121，从而形成叠层结构01。然后在所述铜箔芯层11的第一表面和第二表面分别贴合至少一层叠层结构01形成复合铜箔结构。在形成的复合铜箔结构中，任意相邻两层金属铜层122m之间的石墨烯层121n是由两层叠层结构01中的两层石墨烯层121形成的。Referring to FIG. 7 , a graphene layer 121 can be formed on all surfaces of the metal copper layer 122 by chemical vapor deposition, thereby forming a stacked structure 01 . Then at least one laminated structure 01 is pasted on the first surface and the second surface of the copper foil core layer 11 to form a composite copper foil structure. In the formed composite copper foil structure, the graphene layer 121n between any two adjacent metal copper layers 122m is formed by the two graphene layers 121 in the two-layer laminate structure 01 .

为了提高壳层中石墨烯层和金属铜层的界面结合力，在所述金属铜层的表面形成石墨烯层之前，还可以包括：对所述金属铜层进行单晶化处理，所述单晶化处理用于诱导所述金属铜层的表面沿(111)晶面择优取向。In order to improve the interfacial binding force between the graphene layer and the metal copper layer in the shell layer, before forming the graphene layer on the surface of the metal copper layer, it may also include: performing single crystallization treatment on the metal copper layer, the single The crystallization treatment is used to induce the surface of the metal copper layer to be preferentially oriented along the (111) crystal plane.

示例性的，如图8至图10所示，在所述铜箔芯层11的表面形成所述壳层12，还可以包括：在所述铜箔芯层11的第一表面和第二表面分别贴合至少一层叠层结构01之前，在所述铜箔芯层11的第一表面和/或第二表面上形成石墨烯层121。其中，图8至图10均是以在所述铜箔芯层11的第一表面和第二表面上均形成石墨烯层121为例进行示意。Exemplarily, as shown in FIGS. 8 to 10 , forming the shell layer 12 on the surface of the copper foil core layer 11 may also include: forming the shell layer 12 on the first surface and the second surface of the copper foil core layer 11 Before laminating at least one laminated structure 01 , a graphene layer 121 is formed on the first surface and/or the second surface of the copper foil core layer 11 . Wherein, FIGS. 8 to 10 all take graphene layers 121 formed on both the first surface and the second surface of the copper foil core layer 11 as an example to illustrate.

示例性的，在形成的复合铜箔结构中，对于叠层结构01中石墨烯层121是通过薄膜转移法形成在所述金属铜层122的一侧表面上的情况：如图8所示，叠层结构01中的石墨烯层121可以位于靠近铜箔芯层11一侧，金属铜层122可以位于远离铜箔芯层11一侧；或者，如图9所示，叠层结构01中的石墨烯层121可以位于远离铜箔芯层11一侧，金属铜层122可以位于靠近铜箔芯层11一侧。Exemplarily, in the formed composite copper foil structure, for the case where the graphene layer 121 in the laminated structure 01 is formed on one side surface of the metal copper layer 122 by a thin film transfer method: as shown in FIG. 8 , The graphene layer 121 in the laminated structure 01 can be located near the copper foil core layer 11 side, and the metal copper layer 122 can be located away from the copper foil core layer 11 side; or, as shown in Figure 9, the laminated structure 01 in The graphene layer 121 may be located on a side away from the copper foil core layer 11 , and the metal copper layer 122 may be located on a side close to the copper foil core layer 11 .

示例性的，在形成的复合铜箔结构中，对于叠层结构01中石墨烯层121是通过化学气相沉积法形成在所述金属铜层122的所有表面上的情况，形成的复合铜箔结构如图10所示，位于第一层金属铜层1221与铜箔芯层11之间的第一层石墨烯层1211是由第一层叠层结构01中的石墨烯层121和形成在铜箔芯层11表面的石墨烯层121形成的。Exemplarily, in the formed composite copper foil structure, for the case where the graphene layer 121 in the laminated structure 01 is formed on all surfaces of the metal copper layer 122 by chemical vapor deposition, the formed composite copper foil structure As shown in Figure 10, the first graphene layer 1211 between the first metal copper layer 1221 and the copper foil core layer 11 is formed by the graphene layer 121 in the first laminated structure 01 and the copper foil core layer 1211. The graphene layer 121 on the surface of the layer 11 is formed.

下面结合具体实施例，对本申请进行详细说明。需要说明的是，本实施例中是为了更好的解释本申请，但不限制本申请。The present application will be described in detail below in combination with specific embodiments. It should be noted that this embodiment is for better explaining the present application, but not limiting the present application.

实施例一、Embodiment one,

该实施例采用层叠生长法(原位生长石墨烯层+原位生长金属铜层)制备复合铜箔结构，如图11所示，结合图12，具体可以包括以下步骤：In this embodiment, a laminated growth method (in-situ growth of graphene layer + in-situ growth of metal copper layer) is used to prepare a composite copper foil structure, as shown in Figure 11, in combination with Figure 12, the following steps may be specifically included:

步骤S401、对铜箔芯层进行单晶化处理，制备出具有较大单晶畴区Cu(111)的铜箔芯层，形成如图12中(a)所示的结构。Step S401 , performing single crystallization treatment on the copper foil core layer to prepare a copper foil core layer with a relatively large single crystal domain region Cu(111), forming a structure as shown in (a) in FIG. 12 .

其中Cu(111)晶面高度取向为铜箔芯层的厚度方向。The Cu(111) crystal plane is highly oriented in the thickness direction of the copper foil core layer.

示例性的，可以将商用铜箔(0.5oz)裁剪成20cm*20cm幅宽，放置在耐温石英载具上，然后将整个装置放入化学气相沉积管式炉；通入惰性气体氩(纯度为99.99％)，流量为 300sccm以上，去除化学气相沉积管式炉内的残留氧；然后通入氢气(纯度为99.99％)至1个大气压(1×10 ⁵pa)；然后将化学气相沉积管式炉的炉内的温度升温至800℃～1100℃，同时通入氢气，氢气流量控制在2sccm～500sccm，对铜箔芯层进行退火，退火时间为0.5小时～3小时；之后缓慢降温至室温得到较大单晶畴区Cu(111)的铜箔芯层。 Exemplarily, the commercial copper foil (0.5oz) can be cut into 20cm*20cm width, placed on the temperature-resistant quartz carrier, and then the whole device is put into a chemical vapor deposition tube furnace; the inert gas argon (purity 99.99%), the flow ^rate is more than 300sccm, remove the residual oxygen in the chemical vapor deposition tube furnace; The temperature in the furnace is raised to 800 ℃ ~ 1100 ℃, and hydrogen gas is introduced at the same time. The flow rate of hydrogen gas is controlled at 2 sccm ~ 500 sccm, and the copper foil core layer is annealed. The annealing time is 0.5 hours to 3 hours; then slowly cool down to room temperature A copper foil core layer of Cu(111) in the larger single crystal domain region is obtained.

步骤S402、采用CVD法在铜箔芯层11表面上原位生长石墨烯层1211，形成如图12中(b)所示的结构。Step S402 , growing a graphene layer 1211 in situ on the surface of the copper foil core layer 11 by CVD to form a structure as shown in (b) in FIG. 12 .

本申请对采用CVD法生长石墨烯层的工艺不作限定，可以为任何公知的方法。The application does not limit the process of growing the graphene layer by the CVD method, which may be any known method.

示例性的，退火结束后，开始通入甲烷(CH ₄)和惰性气体的混合气体，混合气体中CH ₄含量为200ppm～20000ppm，混合气体流量为0.2sccm～50sccm，同时调节H ₂流量为0.2sccm～50sccm，惰性气体流量保持不变，压力维持1个大气压，生长时间为10min～20h，在铜箔芯层表面覆盖生长出石墨烯层。 Exemplarily, after the annealing is completed, a mixed gas of methane (CH ₄ ) and an inert gas is introduced, the content of CH ₄ in the mixed gas is 200 ppm-20000 ppm, the flow rate of the mixed gas is 0.2 sccm-50 sccm, and the H ₂ flow rate is adjusted to 0.2 sccm～50sccm, the flow rate of the inert gas remains unchanged, the pressure is maintained at 1 atmosphere, the growth time is 10min～20h, and the graphene layer is grown on the surface of the copper foil core layer.

步骤S403、采用PVD法或电化学沉积法在石墨烯层1211表面原位生长金属铜层1221，形成如图12中(c)所示的结构。Step S403, using PVD method or electrochemical deposition method to in-situ grow metal copper layer 1221 on the surface of graphene layer 1211 to form a structure as shown in (c) in FIG. 12 .

本申请对采用PVD法生长金属铜层的工艺不作限定，可以为任何公知的方法。PVD法一般包括真空蒸镀、溅射镀膜、电弧等离子体镀、离子镀膜，及分子束外延等方法。The present application does not limit the process of growing the metal copper layer by PVD method, which may be any known method. PVD methods generally include methods such as vacuum evaporation, sputtering coating, arc plasma plating, ion coating, and molecular beam epitaxy.

示例性的，可以采用磁控溅射法先后在第一表面侧石墨烯层上和第二表面侧石墨烯层上溅射金属铜层，在具体实施时，采用高纯铜靶材(99.99％)，高真空溅射，在石墨烯层表面溅射金属铜层。磁控溅射的条件为：溅射压力4*10 ^-4Pa，功率为500W。金属铜层的厚度可以为500nm。 Exemplarily, the metal copper layer can be sputtered successively on the graphene layer on the first surface side and on the graphene layer on the second surface side by using the magnetron sputtering method. In specific implementation, a high-purity copper target (99.99% ), high vacuum sputtering, sputtering metal copper layer on the surface of graphene layer. The conditions of magnetron sputtering are: sputtering pressure 4*10 ^-4 Pa, power 500W. The thickness of the metallic copper layer may be 500nm.

申请对采用电化学沉积法生长金属铜层的工艺不作限定，可以为任何公知的方法。The application does not limit the process of growing the metal copper layer by the electrochemical deposition method, which may be any known method.

示例性的，将表面覆有石墨烯层的铜箔芯层放置在电镀槽的阴极，阳极可以采用磷铜板，电镀所需电流密度和电镀时间根据金属铜层厚度控制。一种实施例中，镀铜所用的电镀液的配方可以为：300g/L CuSO ₄·5H ₂O，50g/L H ₂SO ₄，10g/L葡萄糖，电流密度可为3A/dm ²，温度可为25℃。经过一段时间的电镀后，铜箔芯层表面的石墨烯层上会覆盖一层1μm厚左右的金属铜层，关闭直流电源，将阴极板从镀液中取出，用乙醇对阴极板进行清洁，并用氮气将表面吹干，完成一层金属铜层的电镀，石墨烯层被完全被包裹在金属铜层中。 Exemplarily, the copper foil core layer covered with a graphene layer is placed on the cathode of the electroplating tank, the anode can be a phosphor copper plate, and the current density and electroplating time required for electroplating are controlled according to the thickness of the metal copper layer. In one embodiment, the formula of the electroplating solution used for copper plating can be: 300g/L CuSO ₄ ·5H ₂ O, 50g/L H ₂ SO ₄ , 10g/L glucose, the current density can be 3A/dm ² , and the temperature can be is 25°C. After a period of electroplating, the graphene layer on the surface of the copper foil core layer will be covered with a metal copper layer with a thickness of about 1 μm. Turn off the DC power supply, take the cathode plate out of the plating solution, and clean the cathode plate with ethanol. And dry the surface with nitrogen to complete the electroplating of a metal copper layer, and the graphene layer is completely wrapped in the metal copper layer.

可选地，在步骤S403之后，还可以执行步骤S404：对金属铜层进行退火以进行单晶化处理。Optionally, after step S403, step S404 may also be performed: annealing the metal copper layer to perform single crystallization treatment.

本申请对对金属铜层进行单晶化处理的工艺不作限定，可以为任何公知的方法。The present application does not limit the process of performing single crystallization treatment on the metal copper layer, which may be any known method.

示例性的，可以将已经制备的复合膜层(金属铜层/石墨烯层/铜箔芯层)进行退火：将复合膜层放置在耐温石英载具上，然后将整个装置放入化学气相沉积设备中；通入惰性气体氩(纯度为99.99％)，流量为300sccm以上，去除设备内的残留氧；然后通入氢气(纯度为99.99％)至1个大气压(1×10 ⁵pa)；然后30分钟将设备内加热炉内的温度升温至500℃时，通入H ₂，H ₂流量为2sccm～500sccm,保温30分钟，然后30分钟内由500℃升温到1000℃进行二次保温30分钟，之后再自然降温到室温。 Exemplarily, the prepared composite film layer (metal copper layer/graphene layer/copper foil core layer) can be annealed: the composite film layer is placed on a temperature-resistant quartz carrier, and then the entire device is put into a chemical vapor phase In the deposition equipment; feed inert gas argon (purity: 99.99%) with a flow rate of 300 sccm or more to remove residual oxygen in the equipment; then feed hydrogen (purity: 99.99%) to 1 atmosphere (1×10 ⁵ pa); Then, when the temperature in the heating furnace in the equipment is raised to 500°C in 30 minutes, H ₂ is introduced, and the flow rate of H ₂ is 2sccm to 500sccm. minutes, and then cooled down to room temperature naturally.

之后重复步骤S402、S403和S404N次，形成如图12中(d)所示的复合铜箔结构。Afterwards, steps S402, S403 and S404 are repeated N times to form a composite copper foil structure as shown in (d) of FIG. 12 .

示例性的，当步骤S403采用磁控溅射法溅射金属铜层时，可以重复步骤S402、S403和S404三十次左右，从而可以获得1oz厚度左右的复合铜箔结构。Exemplarily, when the metal copper layer is sputtered by magnetron sputtering in step S403, steps S402, S403 and S404 may be repeated about 30 times, so as to obtain a composite copper foil structure with a thickness of about 1 oz.

示例性的，当步骤S403采用电化学沉积法生长金属铜层时，可以重复步骤S402、S403 和S404十七次左右，从而可以获得1oz厚度左右的复合铜箔结构。Exemplarily, when the electrochemical deposition method is used to grow the metal copper layer in step S403, steps S402, S403 and S404 may be repeated about seventeen times, so as to obtain a composite copper foil structure with a thickness of about 1 oz.

需要说明的是，在该实施例中，步骤S401和步骤S404并不是必须执行的，可执行，也可以不执行，在此不作限定。It should be noted that, in this embodiment, step S401 and step S404 are not necessarily executed, and may or may not be executed, which is not limited herein.

在该实施例一中，采用PVD法或电化学沉积法形成壳层中的金属铜层，可以降低壳层中金属铜层的厚度，在壳层厚度一定的情况下，通过降低壳层中金属铜层的厚度可以增加壳层中石墨烯层的总层数，从而进一步提升壳层的电导率。In this embodiment one, the metal copper layer in the shell layer is formed by PVD method or electrochemical deposition method, which can reduce the thickness of the metal copper layer in the shell layer. The thickness of the copper layer can increase the total number of graphene layers in the shell, thereby further improving the conductivity of the shell.

实施例二、Embodiment two,

该实施例采用层叠形成法(薄膜转移法形成石墨烯层+原位生长金属铜层)制备复合铜箔结构，如图13所示，结合图14，具体可以包括以下步骤：In this embodiment, a composite copper foil structure is prepared by lamination method (film transfer method to form a graphene layer + in-situ growth metal copper layer), as shown in Figure 13, in combination with Figure 14, the following steps can be specifically included:

步骤S501、对铜箔芯层进行单晶化处理，制备出具有较大单晶畴区Cu(111)的铜箔芯层，形成如图14中(a)所示的结构。Step S501 , performing single crystallization treatment on the copper foil core layer to prepare a copper foil core layer with a large single crystal domain region Cu(111), forming a structure as shown in (a) in FIG. 14 .

示例性的，可以将商用铜箔(0.5oz)裁剪成20cm*20cm幅宽，放置在耐温石英载具上，然后将整个装置放入化学气相沉积管式炉；通入惰性气体氩(纯度为99.99％)，流量为300sccm以上，去除化学气相沉积管式炉内的残留氧；然后通入氢气(纯度为99.99％)至1个大气压(1×10 ⁵pa)；然后将化学气相沉积管式炉的炉内的温度升温至800℃～1100℃，同时通入氢气，氢气流量控制在2sccm～500sccm，对铜箔芯层进行退火，退火时间为0.5小时～3小时；之后缓慢降温至室温得到较大单晶畴区Cu(111)的铜箔芯层。 Exemplarily, the commercial copper foil (0.5oz) can be cut into 20cm*20cm width, placed on the temperature-resistant quartz carrier, and then the whole device is put into a chemical vapor deposition tube furnace; the inert gas argon (purity 99.99%), the flow rate is more than 300sccm ^, remove the residual oxygen in the chemical vapor deposition tube furnace; The temperature in the furnace is raised to 800 ℃ ~ 1100 ℃, and hydrogen gas is introduced at the same time. The flow rate of hydrogen gas is controlled at 2 sccm ~ 500 sccm, and the copper foil core layer is annealed. The annealing time is 0.5 hours to 3 hours; then slowly cool down to room temperature A copper foil core layer of Cu(111) in the larger single crystal domain region is obtained.

步骤S502、采用薄膜转移法先后在铜箔芯层11的第一表面和第二表面铺一层石墨烯层1211，形成如图14中(b)所示的结构。Step S502 , successively laying a layer of graphene layer 1211 on the first surface and the second surface of the copper foil core layer 11 by film transfer method to form a structure as shown in (b) in FIG. 14 .

本实施例采用薄膜转移法制备石墨烯层的工艺不作限定，可以为任何公知的方法。示例性的，可以将形成在衬底上的石墨烯层从衬底剥离转移贴合在铜箔芯层的第一表面和第二表面上，衬底可以为铜箔衬底、蓝宝石衬底等，在此不作限定。In this embodiment, the process of preparing the graphene layer by the film transfer method is not limited, and may be any known method. Exemplarily, the graphene layer formed on the substrate can be peeled off from the substrate and bonded on the first surface and the second surface of the copper foil core layer, and the substrate can be a copper foil substrate, a sapphire substrate, etc. , is not limited here.

可选地，在铺石墨烯层之前可以在铜箔芯层的表面均匀滴上乙醇，待乙醇完全挥发之后，石墨烯层便可紧密结合在铜箔芯层的表面。Optionally, ethanol can be evenly dripped on the surface of the copper foil core layer before laying the graphene layer. After the ethanol is completely volatilized, the graphene layer can be tightly bonded to the surface of the copper foil core layer.

步骤S503、采用电化学沉积法在石墨烯层1211表面原位生长金属铜层1221，形成如图14中(c)所示的结构。Step S503 , growing a metal copper layer 1221 in situ on the surface of the graphene layer 1211 by electrochemical deposition to form a structure as shown in (c) of FIG. 14 .

示例性的，将表面覆有石墨烯层的铜箔芯层放置在电镀槽的阴极，电镀所需电流密度和电镀时间根据金属铜层厚度控制。一种实施例中，镀铜所用的电镀液的配方可以为：300g/L CuSO ₄·5H ₂O，50g/L H ₂SO ₄，10g/L葡萄糖，电流密度可为3A/dm ²，温度可为25℃。经过一段时间的电镀后，铜箔芯层表面的石墨烯层上会覆盖一层1μm厚左右的金属铜层，关闭直流电源，将阴极板从镀液中取出，用乙醇对阴极板进行清洁，并用氮气将表面吹干，完成一层金属铜层的电镀，石墨烯层被完全被包裹在金属铜层中。 Exemplarily, the copper foil core layer covered with a graphene layer is placed on the cathode of the electroplating tank, and the current density and electroplating time required for electroplating are controlled according to the thickness of the metal copper layer. In one embodiment, the formula of the electroplating solution used for copper plating can be: 300g/L CuSO ₄ ·5H ₂ O, 50g/L H ₂ SO ₄ , 10g/L glucose, the current density can be 3A/dm ² , and the temperature can be is 25°C. After a period of electroplating, the graphene layer on the surface of the copper foil core layer will be covered with a metal copper layer with a thickness of about 1 μm. Turn off the DC power supply, take the cathode plate out of the plating solution, and clean the cathode plate with ethanol. And dry the surface with nitrogen to complete the electroplating of a metal copper layer, and the graphene layer is completely wrapped in the metal copper layer.

可选地，在步骤S503之后，还可以执行步骤S504：对金属铜层进行退火以进行单晶化处理。Optionally, after step S503, step S504 may also be performed: annealing the metal copper layer to perform single crystallization treatment.

示例性的，可以将已经制备的复合膜层(金属铜层/石墨烯层/铜箔芯层)进行退火：将复合膜层放置在耐温石英载具上，然后将整个装置放入化学气相沉积设备中；通入惰性气体氩(纯度为99.99％)，流量为300sccm以上，去除设备内的残留氧；然后通入氢气(纯度为99.99％)至1个大气压(1×10 ⁵pa)；然后30分钟将设备内加热炉内的温度升温至500℃时，通入H ₂，H ₂流量为2sccm～500sccm,保温30分钟，然后30分钟内由500℃升温到1000℃进行二次保温30分钟，之后再自然降温到室温。 Exemplarily, the prepared composite film layer (metal copper layer/graphene layer/copper foil core layer) can be annealed: place the composite film layer on a temperature-resistant quartz carrier, and then put the entire device into a chemical vapor phase In the deposition equipment; feed inert gas argon (purity: 99.99%) with a flow rate of 300 sccm or more to remove residual oxygen in the equipment; then feed hydrogen (purity: 99.99%) to 1 atmosphere (1×10 ⁵ pa); Then, when the temperature in the heating furnace in the equipment is raised to 500°C in 30 minutes, H ₂ is introduced, and the flow rate of H ₂ is 2sccm to 500sccm. minutes, and then cooled down to room temperature naturally.

之后重复步骤S502、S503和S504N次，形成如图14中(d)所示的复合铜箔结构。Afterwards, steps S502, S503 and S504 are repeated N times to form a composite copper foil structure as shown in (d) of FIG. 14 .

示例性的，可以重复步骤S502、S503和S504三十四次左右，从而可以获得3oz厚度左右的复合铜箔结构。Exemplarily, steps S502, S503 and S504 may be repeated about thirty-four times, so as to obtain a composite copper foil structure with a thickness of about 3 oz.

可选地，当采用薄膜转移法在金属铜层上形成石墨烯层时，在铺石墨烯层之前可以在金属铜层的表面均匀滴上乙醇，待乙醇完全挥发之后，石墨烯层便可紧密结合在金属铜层的表面。Optionally, when the film transfer method is used to form a graphene layer on the metal copper layer, ethanol can be evenly dripped on the surface of the metal copper layer before the graphene layer is spread. After the ethanol is completely volatilized, the graphene layer can be compacted. Bonded to the surface of the metal copper layer.

需要说明的是，在该实施例中，步骤S501和步骤S504并不是必须执行的，可执行，也可以不执行，在此不作限定。It should be noted that, in this embodiment, step S501 and step S504 are not necessarily executed, and may or may not be executed, which is not limited herein.

在该实施例二中，采用电化学沉积法形成壳层中的金属铜层，可以降低壳层中金属铜层的厚度，在壳层厚度一定的情况下，通过降低壳层中金属铜层的厚度可以增加壳层中石墨烯层的总层数，从而进一步提升壳层的电导率。In this embodiment two, the metal copper layer in the shell layer is formed by electrochemical deposition, which can reduce the thickness of the metal copper layer in the shell layer. The thickness can increase the total number of graphene layers in the shell, thereby further improving the conductivity of the shell.

实施例三、Embodiment three,

该实施例采用热压烧结法制备复合铜箔结构，如图15所示，结合图16，具体可以包括以下步骤：This embodiment adopts the hot pressing sintering method to prepare the composite copper foil structure, as shown in Figure 15, combined with Figure 16, it may specifically include the following steps:

步骤S601、对铜箔芯层和叠层结构中的金属铜层进行单晶化处理。Step S601 , performing single crystallization treatment on the copper foil core layer and the metal copper layer in the laminated structure.

本申请对铜箔芯层和金属铜层进行单晶化处理的工艺不作限定，可以为任何公知的方法。In the present application, the single crystallization process of the copper foil core layer and the metal copper layer is not limited, and may be any known method.

示例性的，可以将1oz厚的商用铜箔裁剪成20cm*20cm幅宽形成铜箔芯层，将6μm厚的商用铜箔裁剪成20cm*20cm幅宽形成金属铜层，然后将铜箔芯层和金属铜层放置在耐温石英载具上，然后将整个装置放入化学气相沉积管式炉；通入惰性气体氩(纯度为99.99％)，流量为300sccm以上，去除化学气相沉积管式炉内的残留氧；然后通入氢气(纯度为99.99％)至1个大气压(1×10 ⁵pa)；然后将化学气相沉积管式炉的炉内的温度升温至800℃～1100℃，同时通入氢气，氢气流量控制在2sccm～500sccm，对铜箔芯层进行退火，退火时间为0.5小时～3小时；之后缓慢降温至室温得到较大单晶畴区Cu(111)的铜箔芯层。 Exemplarily, a 1oz thick commercial copper foil can be cut into a width of 20cm*20cm to form a copper foil core layer, a 6μm thick commercial copper foil can be cut into a width of 20cm*20cm to form a metal copper layer, and then the copper foil core layer and the metal copper layer are placed on the temperature-resistant quartz carrier, and then the whole device is put into a chemical vapor deposition tube furnace; the inert gas argon (purity is 99.99%) is introduced, and the flow rate is more than 300 sccm, and the chemical vapor deposition tube furnace is removed. the residual oxygen inside; then pass hydrogen (purity is 99.99%) to 1 atmosphere (1×10 ⁵ pa); Inject hydrogen, the hydrogen flow rate is controlled at 2sccm-500sccm, anneal the copper foil core layer, the annealing time is 0.5 hours to 3 hours; then slowly cool down to room temperature to obtain a copper foil core layer of Cu(111) with a large single crystal domain region.

可选地，还可以采用CVD法在铜箔芯层11表面生长石墨烯层121，形成如图16(a)所示的结构。Optionally, a graphene layer 121 can also be grown on the surface of the copper foil core layer 11 by CVD to form a structure as shown in FIG. 16( a ).

步骤S602、制备叠层结构。Step S602, preparing a laminated structure.

在具体实施时，可以采用CVD法在金属铜层122上下表面原位生长石墨烯层121形成如图16中(b)所示的叠层结构01。In a specific implementation, the graphene layer 121 can be grown in situ on the upper and lower surfaces of the metal copper layer 122 by CVD method to form the laminated structure 01 as shown in (b) of FIG. 16 .

示例性的，采用CVD法原位生长石墨烯层可以包括：退火结束后，开始通入甲烷(CH ₄)和惰性气体的混合气体，混合气体中CH ₄含量为200ppm～20000ppm，混合气体流量为0.2sccm～50sccm，同时调节H ₂流量为0.2sccm～50sccm，惰性气体流量保持不变，压力维持1个大气压，生长时间为10min～20h，在铜箔芯层表面覆盖生长出石墨烯层。 Exemplarily, the in-situ growth of the graphene layer by the CVD method may include: after the annealing is completed, start feeding a mixed gas of methane (CH ₄ ) and an inert gas, the content of CH ₄ in the mixed gas is 200ppm-20000ppm, and the flow rate of the mixed gas is 0.2sccm~50sccm, while adjusting the _H2 flow rate to 0.2sccm~50sccm, keeping the inert gas flow rate unchanged, maintaining the pressure at 1 atmosphere, and growing for 10min~20h, the graphene layer is covered and grown on the surface of the copper foil core layer.

可选地，在金属铜层表面采用CVD法原位生长石墨烯层与在铜箔芯层表面生长石墨烯层可以同时进行。Optionally, the in-situ growth of the graphene layer on the surface of the metal copper layer and the growth of the graphene layer on the surface of the copper foil core layer can be performed simultaneously.

步骤S603、在铜箔芯层11的第一表面侧和第二表面侧分别层叠至少一层叠层结构01，形成如图16中(c)所示的结构。Step S603, laminating at least one laminated structure 01 on the first surface side and the second surface side of the copper foil core layer 11 respectively to form a structure as shown in (c) of FIG. 16 .

步骤S604、对层叠好的铜箔芯层11和叠层结构01进行热压烧结，形成如图16中(d)所示的复合铜箔结构。Step S604 , hot pressing and sintering the laminated copper foil core layer 11 and laminated structure 01 to form a composite copper foil structure as shown in (d) of FIG. 16 .

需要说明的是，热压烧结可以包括在惰性气体保护下的热压烧结、微波烧结、放电等离子体烧结等中的任一种，在此不作限制。It should be noted that the hot press sintering may include any one of hot press sintering under the protection of inert gas, microwave sintering, spark plasma sintering, etc., which is not limited here.

示例性的，可以将一片1oz厚的包覆有石墨烯层的铜箔芯层和12层叠层结构进行层叠，然后在700℃～1100℃，压力50MPa～200MPa的条件下进行热压烧结，热压烧结时间为10钟～120分钟，从而可以获得3oz厚度左右的复合铜箔结构。热压烧结可以使各膜层之间进行致密化结合，同时使铜箔基体的晶粒进一步取向，提高铜箔单晶化程度和Cu(111)晶面的择优取向，以提高铜箔与石墨烯的界面结合力，从而有利于电子掺杂效应的实现，提高复合铜箔结构的电导率。Exemplarily, a 1oz-thick copper foil core layer coated with a graphene layer and a 12-layer laminated structure can be stacked, and then hot-pressed and sintered at 700°C to 1100°C and a pressure of 50MPa to 200MPa. The pressing and sintering time is 10 minutes to 120 minutes, so that a composite copper foil structure with a thickness of about 3 oz can be obtained. Hot pressing and sintering can make the dense bonding between the various film layers, and at the same time make the grains of the copper foil substrate further oriented, improve the degree of single crystallization of the copper foil and the preferred orientation of the Cu(111) crystal plane, so as to improve the copper foil and graphite. The interfacial binding force of ene is beneficial to the realization of the electronic doping effect and the electrical conductivity of the composite copper foil structure is improved.

由于本申请实施例提供的复合铜箔结构的电导率较高，因此该复合铜箔结构可以应用于具有低损耗特性的高频高速领域和具有低铜损、大通流特性的功率电子领域的覆铜箔层压板和印刷电路板。Due to the high electrical conductivity of the composite copper foil structure provided by the embodiment of the present application, the composite copper foil structure can be applied to the high-frequency high-speed field with low loss characteristics and the cladding in the power electronics field with low copper loss and large flow characteristics. Copper clad laminates and printed circuit boards.

当前行业的高端板材损耗(M8:0.7dB@in@28GHz)难以支撑高速链路基于PCB连接演进，迫切需要低损耗板材大幅突破；当前主流材料下，介质损耗的占比已经较小，铜损耗主导了总损耗。而通过降低铜箔粗糙度来降低铜损耗的技术路径将要逼近物理极限，因此需要提高铜箔电导率来降低铜损耗。对于能源功率电子平面磁架构，PCB绕组铜损耗导致焦耳热大量聚集，严重制约了MOS管的工作效率，因此也需要通过提高绕组铜的电导率来降低热量来源。基于此，本申请实施例提供的复合铜箔结构可以应用于高速(例如112G)PCB架构和功率电子平面磁架构。The current industry's high-end board loss (M8:0.7dB@in@28GHz) is difficult to support the evolution of high-speed links based on PCB connections, and there is an urgent need for a breakthrough in low-loss boards; under the current mainstream materials, the proportion of dielectric loss is already small, and copper loss dominates the total loss. The technical path to reduce copper loss by reducing the roughness of copper foil will approach the physical limit, so it is necessary to increase the conductivity of copper foil to reduce copper loss. For the planar magnetic structure of energy power electronics, the copper loss of PCB windings leads to a large amount of Joule heat accumulation, which seriously restricts the working efficiency of MOS tubes. Therefore, it is also necessary to reduce the heat source by increasing the conductivity of winding copper. Based on this, the composite copper foil structure provided by the embodiment of the present application can be applied to high-speed (for example, 112G) PCB architecture and power electronic planar magnetic architecture.

此外，本申请实施例提供的复合铜箔结构还可以应用于引线框架、连接器、法兰、散热器等场景，在此不作限定。In addition, the composite copper foil structure provided in the embodiments of the present application can also be applied to scenarios such as lead frames, connectors, flanges, and heat sinks, which are not limited here.

相应地，参见图17，本申请还提供了一种覆铜箔层压板，该覆铜箔层压板可以包括叠层设置的介质材料20和本申请实施例提供的上述任一种复合铜箔结构10。在具体实施时，如图17所示，复合铜箔结构10可以位于介质材料20的两侧，当然也可以仅位于介质材料的其中一侧，在此不作限定。由于该覆铜箔层压板解决问题的原理与前述一种复合铜箔结构相似，因此该覆铜箔层压板的实施可以参见前述复合铜箔结构的实施，重复之处不再赘述。Correspondingly, referring to FIG. 17 , the present application also provides a copper-clad laminate, which may include stacked dielectric materials 20 and any of the above-mentioned composite copper foil structures provided in the embodiments of the present application 10. In a specific implementation, as shown in FIG. 17 , the composite copper foil structure 10 may be located on both sides of the dielectric material 20 , and of course may only be located on one side of the dielectric material, which is not limited here. Since the principle of solving the problem of the copper-clad laminate is similar to that of the aforementioned composite copper foil structure, the implementation of the copper-clad laminate can refer to the implementation of the aforementioned composite copper foil structure, and the repetition will not be repeated.

在具体实施时，可以利用公知的方法对复合铜箔结构进行表面粗化后，搭配介质材料，通过公知的热压方法制备成CCL，在此不作限定。During specific implementation, the surface of the composite copper foil structure can be roughened by using known methods, and a dielectric material can be used to prepare a CCL by using a known hot pressing method, which is not limited here.

需要说明的是，应用于覆铜箔层压板的复合铜箔结构中，壳层的最外层可以为金属铜层。It should be noted that, in the composite copper foil structure applied to the copper clad laminate, the outermost layer of the shell layer may be a metallic copper layer.

相应地，本申请还提供了一种印刷电路板，包括本申请实施例提供的覆铜箔层压板或者本申请实施例提供的复合铜箔结构。由于该印刷电路板解决问题的原理与前述一种复合铜箔结构相似，因此该印刷电路板的实施可以参见前述复合铜箔结构的实施，重复之处不再赘述。Correspondingly, the present application also provides a printed circuit board, including the copper clad laminate provided in the embodiment of the present application or the composite copper foil structure provided in the embodiment of the present application. Since the problem-solving principle of the printed circuit board is similar to that of the above-mentioned composite copper foil structure, the implementation of the printed circuit board can refer to the implementation of the aforementioned composite copper foil structure, and the repetition will not be repeated.

在具体实施时，可以通过加工、蚀刻、钻孔及镀铜等工序，制成具有不同导电图形的印制电路。In practice, printed circuits with different conductive patterns can be made through processes such as processing, etching, drilling, and copper plating.

综上，本申请将石墨烯层与金属铜层进行层叠制备的壳层，可以获得较高的电导率，可以降低铜损，在电子电路、集成电路等电子信息行业具有重要的应用前景。另外，本申请采用铜箔芯层和壳层的结构设计，不仅可以提高复合铜箔结构的电导率，还能赋予复合铜箔结构大的通流能力，降低复合铜箔结构的制备成本，在高频电源PCB领域具有重要的应用。另外，使用该复合铜箔结构制备的PCB可以显著降低铜损、提高通流和导热能力，在高速、功率电子等领域有重要的应用。In summary, the shell layer prepared by laminating the graphene layer and the metal copper layer in this application can obtain higher electrical conductivity and reduce copper loss, and has important application prospects in electronic information industries such as electronic circuits and integrated circuits. In addition, this application adopts the structural design of the copper foil core layer and shell layer, which can not only improve the electrical conductivity of the composite copper foil structure, but also endow the composite copper foil structure with a large flow capacity, reducing the preparation cost of the composite copper foil structure. The field of high-frequency power supply PCB has important applications. In addition, the PCB prepared by using the composite copper foil structure can significantly reduce copper loss, improve flow and thermal conductivity, and has important applications in high-speed, power electronics and other fields.

显然，本领域的技术人员可以对本申请进行各种改动和变型而不脱离本申请的精神和范围。这样，倘若本申请的这些修改和变型属于本申请权利要求及其等同技术的范围之内，则本申请也意图包含这些改动和变型在内。Obviously, those skilled in the art can make various changes and modifications to the application without departing from the spirit and scope of the application. In this way, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalent technologies, the present application is also intended to include these modifications and variations.

Claims

一种复合铜箔结构，其特征在于，包括：A composite copper foil structure, characterized in that it comprises:

铜箔芯层，所述铜箔芯层沿厚度方向具有相对的第一表面和第二表面；a copper foil core layer having opposite first and second surfaces along the thickness direction;

壳层，所述壳层至少位于所述铜箔芯层的所述第一表面和所述第二表面；a shell layer, the shell layer is located at least on the first surface and the second surface of the copper foil core layer;

其中，所述壳层包括N层石墨烯层和M层金属铜层，所述石墨烯层和所述金属铜层交替叠层设置，所述壳层中靠近所述铜箔芯层的一面为所述石墨烯层，N为大于0的整数，M为大于0的整数，且M＝N或M＝N-1；Wherein, the shell layer includes N layers of graphene layers and M layers of metal copper layers, the graphene layers and the metal copper layers are alternately stacked, and the side of the shell layer close to the copper foil core layer is In the graphene layer, N is an integer greater than 0, M is an integer greater than 0, and M=N or M=N-1;

所述铜箔芯层的厚度大于所述壳层中所述金属铜层的厚度。The thickness of the copper foil core layer is greater than the thickness of the metal copper layer in the shell layer.
如权利要求1所述的复合铜箔结构，其特征在于，所述铜箔芯层是经过单晶化处理后的，所述单晶化处理用于诱导所述铜箔芯层的表面沿(111)晶面择优取向。The composite copper foil structure according to claim 1, wherein the core layer of copper foil is processed through single crystallization, and the single crystallization treatment is used to induce the surface edge of the core layer of copper foil ( 111) Preferred orientation of crystal planes.
如权利要求1或2所述的复合铜箔结构，其特征在于，所述M层金属铜层中至少有一层所述金属铜层是单晶化处理后的，所述单晶化处理用于诱导所述金属铜层的表面沿(111)晶面择优取向。The composite copper foil structure according to claim 1 or 2, wherein at least one layer of the metal copper layer in the M layers of metal copper layer is after single crystallization treatment, and the single crystallization treatment is used for The surface of the metallic copper layer is induced to be preferentially oriented along the (111) crystal plane.
如权利要求1-3任一项所述的复合铜箔结构，其特征在于，所述铜箔芯层的厚度为0.5oz～6oz。The composite copper foil structure according to any one of claims 1-3, characterized in that the thickness of the copper foil core layer is 0.5oz˜6oz.
如权利要求1-4任一项所述的复合铜箔结构，其特征在于，所述M层金属铜层中，每一层所述金属铜层的厚度为0.1μm～40μm。The composite copper foil structure according to any one of claims 1-4, characterized in that, among the M layers of metal copper layers, the thickness of each metal copper layer is 0.1 μm˜40 μm.
如权利要求1-5任一项所述的复合铜箔结构，其特征在于，所述N层石墨烯层中，每一层所述石墨烯层厚度为1～10层石墨烯分子层。The composite copper foil structure according to any one of claims 1-5, characterized in that, among the N graphene layers, the thickness of each graphene layer is 1-10 graphene molecular layers.
如权利要求1-6任一项所述的复合铜箔结构，其特征在于，所述壳层中的所述金属铜层通过物理气相沉积法或电化学沉积法形成。The composite copper foil structure according to any one of claims 1-6, characterized in that, the metal copper layer in the shell layer is formed by physical vapor deposition or electrochemical deposition.
一种覆铜箔层压板，其特征在于，包括叠层设置的介质材料和如权利要求1-7任一项所述的复合铜箔结构。A copper-clad laminate, characterized in that it comprises a laminated dielectric material and the composite copper foil structure according to any one of claims 1-7.
一种印刷电路板，其特征在于，包括如权利要求8所述的覆铜箔层压板，或如权利要求1-7任一项所述的复合铜箔结构。A printed circuit board, characterized by comprising the copper clad laminate according to claim 8, or the composite copper foil structure according to any one of claims 1-7.
一种复合铜箔结构的制备方法，其特征在于，包括：A method for preparing a composite copper foil structure, characterized in that it comprises:

提供铜箔芯层，所述铜箔芯层沿厚度方向具有相对的第一表面和第二表面；providing a copper foil core layer having opposing first and second surfaces along a thickness direction;

至少在所述铜箔芯层的所述第一表面和所述第二表面上形成壳层；forming a shell layer on at least the first surface and the second surface of the copper foil core layer;

其中，所述壳层包括N层石墨烯层和M层金属铜层，所述石墨烯层和所述金属铜层交替叠层设置，所述壳层中靠近所述铜箔芯层一侧为所述石墨烯层，N为大于0的整数， M为大于0的整数，且M＝N或M＝N-1；所述铜箔芯层的厚度大于所述壳层中所述金属铜层的厚度。Wherein, the shell layer includes N layers of graphene layers and M layers of metal copper layers, the graphene layers and the metal copper layers are alternately laminated, and the side of the shell layer close to the copper foil core layer is In the graphene layer, N is an integer greater than 0, M is an integer greater than 0, and M=N or M=N-1; the thickness of the copper foil core layer is greater than that of the metal copper layer in the shell layer thickness of.
如权利要求10所述的制备方法，其特征在于，在所述铜箔芯层的表面上形成所述壳层之前还包括：对所述铜箔芯层进行单晶化处理，所述单晶化处理用于诱导所述铜箔芯层的表面沿(111)晶面择优取向。The preparation method according to claim 10, characterized in that, before forming the shell layer on the surface of the copper foil core layer, it also includes: performing single crystallization treatment on the copper foil core layer, the single crystal The chemical treatment is used to induce the surface of the copper foil core layer to be preferentially oriented along the (111) crystal plane.
如权利要求10或11所述的制备方法，其特征在于，在所述铜箔芯层的表面上形成所述壳层，包括：The preparation method according to claim 10 or 11, wherein forming the shell layer on the surface of the copper foil core layer comprises:

在所述铜箔芯层表面依次形成交替叠层设置的石墨烯层和金属铜层，直至形成N层所述石墨烯层和M层所述金属铜层。Alternately stacked graphene layers and metal copper layers are sequentially formed on the surface of the copper foil core layer until N layers of the graphene layer and M layers of the metal copper layer are formed.
如权利要求12所述的制备方法，其特征在于，在所述铜箔芯层表面依次形成交替叠层设置的石墨烯层和金属铜层时，至少有一层所述石墨烯层采用薄膜转移法或者化学气相沉积法形成。The preparation method according to claim 12, characterized in that, when alternately laminated graphene layers and metal copper layers are sequentially formed on the surface of the copper foil core layer, at least one layer of the graphene layer adopts a film transfer method Or formed by chemical vapor deposition.
如权利要求12所述的制备方法，其特征在于，在所述铜箔芯层表面依次形成交替叠层设置的石墨烯层和金属铜层时，至少有一层所述金属铜层通过物理气相沉积法或电化学沉积法形成。The preparation method according to claim 12, characterized in that, when alternately stacked graphene layers and metal copper layers are sequentially formed on the surface of the copper foil core layer, at least one layer of the metal copper layer is deposited by physical vapor deposition method or electrochemical deposition method.
如权利要求12-14任一项所述的制备方法，其特征在于，在所述铜箔芯层表面依次形成交替叠层设置的石墨烯层和金属铜层时，还包括：在形成第k层金属铜层后对所述第k层金属铜层进行单晶化处理，所述单晶化处理用于诱导所述金属铜层的表面沿(111)晶面择优取向；其中k取大于0且小于或等于M中的至少一个整数。The preparation method according to any one of claims 12-14, characterized in that, when successively forming alternately laminated graphene layers and metallic copper layers on the surface of the copper foil core layer, further comprising: forming the kth After layering the metal copper layer, the k-th layer of metal copper layer is subjected to single crystallization treatment, and the single crystallization treatment is used to induce the surface of the metal copper layer to be preferentially oriented along the (111) crystal plane; wherein k is greater than 0 And less than or equal to at least one integer in M.
如权利要求10或11所述的制备方法，其特征在于，在所述铜箔芯层的表面形成所述壳层，包括：The preparation method according to claim 10 or 11, wherein forming the shell layer on the surface of the copper foil core layer comprises:

在所述铜箔芯层的第一表面和第二表面分别贴合至少一层叠层结构；其中，各所述叠层结构包括金属铜层和位于所述金属铜层表面的石墨烯层。At least one laminated structure is pasted on the first surface and the second surface of the copper foil core layer respectively; wherein each laminated structure includes a metal copper layer and a graphene layer located on the surface of the metal copper layer.
如权利要求16所述的制备方法，其特征在于，在所述铜箔芯层的表面形成所述壳层，还包括：The preparation method according to claim 16, wherein forming the shell layer on the surface of the copper foil core layer further comprises:

在所述铜箔芯层的第一表面和第二表面分别贴合至少一层叠层结构之前，在所述铜箔芯层的第一表面和/或第二表面上形成石墨烯层。A graphene layer is formed on the first surface and/or the second surface of the copper foil core layer before the first surface and the second surface of the copper foil core layer are bonded with at least one laminated structure respectively.
如权利要求16或17所述的制备方法，其特征在于，所述叠层结构通过如下方法形成：The preparation method according to claim 16 or 17, wherein the laminated structure is formed by the following method:

提供金属铜层；Provide a metallic copper layer;

通过薄膜转移法或化学气相沉积法在所述金属铜层的表面形成石墨烯层。A graphene layer is formed on the surface of the metal copper layer by a film transfer method or a chemical vapor deposition method.
如权利要求18所述的制备方法，其特征在于，在所述金属铜层的表面形成石墨烯层之前，还包括：preparation method as claimed in claim 18, is characterized in that, before forming graphene layer on the surface of described metallic copper layer, also comprises:

对所述金属铜层进行单晶化处理,所述单晶化处理用于诱导所述金属铜层的表面沿(111)晶面择优取向。The single crystallization treatment is performed on the metal copper layer, and the single crystallization treatment is used to induce the surface of the metal copper layer to be preferentially oriented along the (111) crystal plane.
如权利要求16-19任一项所述的制备方法，其特征在于，在所述铜箔芯层的第一表面和第二表面分别贴合至少一层叠层结构，包括：The preparation method according to any one of claims 16-19, wherein at least one laminated structure is pasted on the first surface and the second surface of the copper foil core layer, including:

通过热压烧结法在所述铜箔芯层的第一表面和第二表面分别贴合至少一层叠层结构。At least one laminated structure is pasted on the first surface and the second surface of the copper foil core layer by a hot pressing sintering method.