Copper-chromium alloy copper foil based on laser reflectivity, method, circuit board and device

Abstract

According to the copper-chromium alloy copper foil based on the laser reflectivity, the method, the circuit board and the device, the texture structure is etched in the copper-chromium alloy film sheet through the laser etching method before the copper foil coarsening layer is prepared, the copper-chromium alloy copper foil is obtained, the texture structure comprises the multiple main parts, and the multiple main parts are arranged on the copper foil coarsening layer. The trunk parts are connected with each other, the exposed head ends of the trunk parts and the exposed head ends of the branch parts form concave accommodating knots, and the inner diameter of the concave accommodating knots formed at the head ends of the trunk parts is larger than two times of the inner diameter of the trunk parts connected with the concave accommodating knots. The inner diameter of the concave accommodating junction formed at the head end of the branch part is twice larger than that of the branch part connected with the concave accommodating junction, so that the problems that the copper foil is fixed in the printed circuit board to form stress due to the coarsening surface at present, and the printed circuit board is easy to deform after being used for a long time; and the copper foil is easy to generate internal stress while the binding force is relatively poor, so that the copper foil is easy to break when the circuit board is collided, and the product performance is influenced.

Description

Technical Field

[0001] The present application relates to the field of copper foil preparation, and in particular to a copper-chromium alloy copper foil, method, circuit board and device based on laser reflectivity. Background Art

[0002] Copper foil is widely used as a metal material in printed circuit boards. With the development trend of miniaturization of electronic devices, higher requirements are also more clear and specific. The stable fixation of copper foil in the printed circuit board and how to avoid the force formed by the copper foil fixed in the printed circuit board due to the roughened surface, which makes the printed circuit board prone to deformation after long-term use, and the copper foil is prone to internal stress while the bonding force is poor, which makes the copper foil easy to break when the circuit board is collided, affecting the product performance. Therefore, there are deficiencies. Summary of the invention

[0003] The present application provides a copper-chromium alloy copper foil, method, circuit board and device based on laser reflectivity, aiming to solve the problem of stable fixation of copper foil in a printed circuit board and how to avoid the copper foil being fixed in the printed circuit board due to roughened surface to form force, so that the printed circuit board is prone to deformation after long-term use, and the copper foil is prone to generate internal stress while the bonding force is poor, resulting in the copper foil being easily broken when the circuit board is collided, affecting product performance.

[0004] An embodiment of the present application provides a copper-chromium alloy foil, which is used for a circuit board. The circuit board includes a substrate layer, a copper-chromium alloy foil and a circuit structure layer.

[0005] A textured structure is etched in the copper-chromium alloy copper foil, and the textured structure includes multiple main stems and branch stems connecting each main stem, and the exposed head ends of the main stems and the exposed head ends of the branch stems form recessed accommodating knots, and the inner diameter of the recessed accommodating knot formed at the head end of the main stem is larger than twice the inner diameter of the main stem connected thereto, and the inner diameter of the recessed accommodating knot formed at the head end of the branch stem is larger than twice the inner diameter of the branch stem connected thereto.

[0006] In an optional embodiment, the inner diameter of the main body is greater than 6um, and the inner diameter of the branch body is greater than 3um, wherein the inner diameters of the main body and the branch body are the same or different.

[0007] In an optional embodiment, the depth of the recessed accommodating junction is less than 4 um.

[0008] In an optional embodiment, the number of the main body is n, the number of the branch body is m, the area of ​​the copper foil is S, the number of the recessed accommodating junctions is k+m, where k is the number of exposed head ends of the main body, and the length of each branch body is: qS / (k+m), where q is a reference coefficient, and .

[0009] In an optional embodiment, if the area of ​​the copper foil is S, and S is greater than a set threshold, among the multiple recessed accommodating junctions, a connecting portion is formed between two adjacent recessed accommodating junctions by laser etching, and the inner diameter of the connecting portion is the average inner diameter of the main stem or branch stem corresponding to the two connected recessed accommodating junctions.

[0010] In an optional embodiment, if the area of ​​the copper foil is S, and S is greater than a set threshold, among the plurality of recessed accommodating knots, a connecting portion is formed by laser etching between two adjacent recessed accommodating knots, and the inner diameter of the connecting portion is the average inner diameter of the main stem or branch stem corresponding to the two connected recessed accommodating knots, and the number of the plurality of recessed accommodating knots is , where p is an integer greater than or equal to 1, and l is the length of the copper foil.

[0011] In an optional embodiment, if qS / (k+m) is greater than a set threshold and the length of the connecting portion is higher than the average length of the connecting portion, a secondary recessed accommodating junction is formed on the corresponding connecting portion, and the inner diameter of the secondary recessed accommodating junction is the same as or different from the inner diameter of the recessed accommodating junction.

[0012] The present application also provides a method for preparing the copper-chromium alloy copper foil as described above, comprising: A copper-chromium alloy thin film sheet is obtained by electrolysis; Etching the texture structure in the copper-chromium alloy thin film by a laser etching method to obtain a copper-chromium alloy copper foil; The surface of the copper-chromium alloy copper foil on which the texture structure is etched is roughened.

[0013] An embodiment of the present application further provides a circuit board, including a circuit board body and at least one electronic component configured on the circuit board body, the circuit board body including a first circuit board layer and a second circuit board layer, and the copper-chromium alloy copper foil as described above is combined between the first circuit board layer and the second circuit board layer.

[0014] An embodiment of the present application further provides a circuit device, including a housing and the circuit board as described above, wherein the circuit board is placed inside the housing.

[0015] Beneficial Effects It can be seen from the above technical scheme that the present application provides a copper-chromium alloy copper foil, method, circuit board and device based on laser reflectivity. Before preparing the copper foil roughening layer, the present application first etches a texture structure in the copper-chromium alloy thin film by a laser etching method to obtain a copper-chromium alloy copper foil. The texture structure includes a plurality of main stems and branch stems connecting each main stem. The exposed head ends of the main stems and the exposed head ends of the branch stems form recessed accommodating junctions. The inner diameter of the recessed accommodating junction formed at the head end of the main stem is greater than twice the inner diameter of the main stem connected thereto, and the inner diameter of the recessed accommodating junction formed at the head end of the branch stem is greater than twice the inner diameter of the branch stem connected thereto. In this way, the main stem, the branch stem and the recessed accommodating junction cooperate to form a special buffer structure. When bonding with the insulating layer of the printed circuit board, the insulating layer can be dispersedly entered into the buffer structure after being squeezed, so that the copper foil will not be deformed when bonding with the insulating layer. Through points (recessed accommodating junctions) and lines (main stems and branches) The buffer combination of the recessed point (recessed accommodating node) and the insulating layer (main stem and branch stem) can not only form a buffer in a more dispersed manner, but also has a stable positioning function, so that there will be no displacement between the copper foil and the insulating layer during the use of the circuit board. Furthermore, the present application can solve the problem that the copper foil is fixed in the printed circuit board due to the roughened surface, which makes the printed circuit board easy to deform after long-term use, and the copper foil is easy to generate internal stress while the bonding force is poor, which makes the copper foil easy to break when the circuit board is collided, affecting the product performance. A dispersed buffer structure is formed before roughening. After roughening, the roughened protrusions combine with the insulating layer to "squeeze" the insulating layer, so that the extruded insulating layer can enter the texture structure of the present application. The extruded part of the insulating layer will not form a large force on the main structure of the copper foil, and the buffer combination with recessed points (recessed accommodating nodes) and lines (main stem and branch stem) itself can absorb part of the stress influence, so it can avoid the problem that the copper foil is easy to generate internal stress, which makes the copper foil easy to break when the circuit board is collided. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0017] Figure 1 It is a schematic diagram of the preparation method of the copper-chromium alloy copper foil in the embodiment of the present application.

[0018] Figure 2 It is one of the structural schematic diagrams of the copper-chromium alloy copper foil in the embodiment of the present application.

[0019] Figure 3 This is the second structural schematic diagram of the copper-chromium alloy copper foil in the embodiment of the present application. DETAILED DESCRIPTION

[0020] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0021] In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined. It should be noted that the anilox roller, manufacturing method and tempered glass of the tempered glass disclosed in the present application can be used in the field of display technology, and can also be used in any field except the field of display technology. The application field of the anilox roller, manufacturing method and tempered glass of the tempered glass disclosed in the present application is not limited.

[0022] The present application provides a method for preparing a copper-chromium alloy copper foil, wherein the copper-chromium alloy copper foil is used for a circuit board, wherein the circuit board comprises a substrate layer, a copper-chromium alloy copper foil and a circuit structure layer, such as Figure 1 As shown, the copper-chromium alloy copper foil comprises: S1: obtaining a copper-chromium alloy thin film by electrolysis; S2: etching a texture structure in the copper-chromium alloy thin film by a laser etching method to obtain a copper-chromium alloy copper foil, wherein the texture structure includes a plurality of main stems and branch stems connected to each main stem, the exposed head ends of the main stems and the exposed head ends of the branch stems form a recessed accommodating junction, the inner diameter of the recessed accommodating junction formed at the head end of the main stem is greater than twice the inner diameter of the main stem connected thereto, and the inner diameter of the recessed accommodating junction formed at the head end of the branch stem is greater than twice the inner diameter of the branch stem connected thereto; S3: performing a roughening treatment on the surface of the copper-chromium alloy copper foil on which the texture structure is etched.

[0023] The present application provides a method for preparing a copper-chromium alloy copper foil. Before preparing a roughened layer of the copper foil, the present application first etches a texture structure in the copper-chromium alloy thin film by a laser etching method to obtain a copper-chromium alloy copper foil. The texture structure includes a plurality of main stems and branch stems connecting each main stem. The exposed head ends of the main stems and the exposed head ends of the branch stems form recessed accommodating junctions. The inner diameter of the recessed accommodating junction formed at the head end of the main stem is larger than twice the inner diameter of the main stem connected thereto, and the inner diameter of the recessed accommodating junction formed at the head end of the branch stem is larger than twice the inner diameter of the branch stem connected thereto. In this way, the main stem, the branch stem and the recessed accommodating junction cooperate to form a special buffer structure. When the main stem, the branch stem and the recessed accommodating junction are joined together, the insulating layer can be dispersedly entered into the buffer structure after being squeezed, so that the copper foil will not be deformed when joined with the insulating layer. Through the buffer combination of points (recessed accommodating junctions) and lines (main stems and branch stems), not only The buffer is formed in a more dispersed manner, and the recessed accommodating node also has a stable positioning function, so that there will be no displacement between the copper foil and the insulating layer during the use of the circuit board. Furthermore, the present application can solve the problem that the copper foil is fixed in the printed circuit board due to the roughened surface, which forms a force, so that the printed circuit board is easily deformed after long-term use, and the copper foil is prone to generate internal stress while the bonding force is poor, which causes the copper foil to easily break when the circuit board is collided, affecting the product performance. A dispersed buffer structure is formed before roughening. After roughening, the roughened protrusions combine with the insulating layer to "squeeze open" the insulating layer, so that the extruded insulating layer can enter the texture structure of the present application. The extruded part of the insulating layer will not form a large force on the main structure of the copper foil, and the buffer combination with recessed points (recessed accommodating nodes) and lines (main stem and branch stem) itself can absorb part of the stress influence, thereby avoiding the problem that the copper foil is prone to generate internal stress, which causes the copper foil to easily break when the circuit board is collided.

[0024] Specifically, in an optional embodiment, the step of obtaining the copper-chromium alloy thin film by electrolysis includes: A solution containing copper sulfate and chromium sulfate is electrolyzed in an electrolytic cell, wherein the electrolytic cell uses an insoluble material as an anode, and the electrolytic cell uses a cathode roller whose bottom is immersed in the copper sulfate and chromium sulfate electrolyte and rotates at a constant speed as a cathode, and the copper and chromium in the solution are deposited on the surface of the cathode roller to form a copper-chromium alloy film.

[0025] Specifically, this embodiment describes a method of 4 ) and chromium sulfate (SnSO 4 ) in a mixed electrolyte, and the specific parameters and steps for depositing a copper-chromium alloy film by electrolysis on an anode made of an insoluble material and a rotating cathode roller.

[0026] First, prepare the equipment: Electrolytic cell: Made of corrosion-resistant stainless steel, with an insulating layer coated inside to prevent current short circuit.

[0027] Anode: A square anode made of an insoluble material (such as platinum or titanium) with an area of ​​120 cm².

[0028] Cathode: A roller made of stainless steel or other corrosion-resistant materials, with a diameter of 10 cm and a length of 30 cm.

[0029] Then proceed with the electrolyte configuration: Solution ratio: copper sulfate solution: 0.5 M, chromium sulfate solution: 0.2 M.

[0030] After mixing, ensure that the pH of the solution is maintained between 2-3 to improve deposition uniformity.

[0031] Then set the electrolysis parameters: Current density: Set to 5 mA / cm² to ensure uniform coating over a large area.

[0032] Electrolysis time: 6 hours, the time can be adjusted according to the required film thickness.

[0033] Temperature control: Keep the electrolyte temperature at 25±2°C to stabilize the chemical reaction rate.

[0034] Stirring speed: The electrolyte was stirred at a constant speed of 300 rpm by a pump to improve ion mobility.

[0035] Finally, the electrolysis process is carried out: First, turn off the power supply to ensure that there is no short circuit between the anode and cathode, and then fill the electrolytic cell with the mixed electrolyte. Then turn on the cathode roller and rotate it at a constant speed (set to 1 rpm) to form a uniform flow layer on the cathode surface to promote uniform deposition. Finally, turn on the power supply to pass the current through the electrolytic cell to start the electrolysis reaction.

[0036] It should be noted that after the electrolysis is completed, the power supply is turned off, the roller is taken out, gently washed with deionized water to remove the residual electrolyte, and dried using a hot air dryer with the temperature set to 60°C for 30 minutes to obtain the electrolyzed copper foil film.

[0037] It should be noted that the electrolysis process of the present application can adopt an existing electrolysis process, and the present application does not impose any limitation on this.

[0038] It should be noted that in the specific process, the present applicant has found through research that copper-chromium alloy has a relatively low laser utilization rate due to its high laser reflectivity. At the same time, copper-chromium alloy has high thermal stability. Therefore, when the laser output power is increased, it can be etched to form a smaller texture structure. Therefore, by combining the characteristics of the material, the combination of the main stem, branch stem and recessed accommodating junction of the present application is studied.

[0039] The copper-chromium alloy copper foil prepared by the above process of this application has a chromium content of 0.5-1.2%, a high purity of copper-chromium alloy, high thermal conductivity, high mechanical strength and wear resistance, a tensile strength of 295MPa, an elongation of not less than 6%, and a thermal conductivity of 290 W / (m℃); hardness: ≥490HB (Brinell hardness); its mass resistivity is not greater than 0.183Ω·g / ㎡, which is not elaborated in this application.

[0040] The embodiment of the present application further provides a copper-chromium alloy copper foil. Specifically, the copper-chromium alloy copper foil is used for a circuit board. The circuit board includes a substrate layer, a copper-chromium alloy copper foil and a circuit structure layer. A textured structure is etched in the copper-chromium alloy copper foil. The textured structure includes a plurality of main stems and branch stems connecting each main stem. The exposed head ends of the main stems and the exposed head ends of the branch stems form recessed accommodating junctions. The inner diameter of the recessed accommodating junction formed at the head end of the main stem is larger than twice the inner diameter of the main stem connected thereto, and the inner diameter of the recessed accommodating junction formed at the head end of the branch stem is larger than twice the inner diameter of the branch stem connected thereto.

[0041] Combine the following Figure 2 and Figure 3 , the above-mentioned texture structure of this application is described in detail.

[0042] The texture structure includes multiple main trunks 11 and branch trunks 12 connecting each main trunk 11, and the exposed head ends of the main trunks 11 and the exposed head ends of the branch trunks 12 form a recessed accommodating knot 13, and the inner diameter of the recessed accommodating knot 13 is larger than twice the inner diameter of the main trunk 11 or the branch trunk 12 connected thereto.

[0043] Specifically, Figure 2 As shown, the present application includes multiple different starting points extending in the form of trunks and branches, thereby gradually distributing on the entire copper foil. Figure 2 and Figure 3 The example is only an example for the purpose of explanation. In actual situations, the texture structure may be more complex in form and structure, which will not be elaborated in this application.

[0044] In an optional embodiment, the inner diameter of the main body 11 is greater than 6um, and the inner diameter of the branch body 12 is greater than 3um, wherein the inner diameters of the main body 11 and the branch body 12 are the same or different. In this way, the inner diameters of the main body 11 and the branch body 12 have a preferred size range, which is conducive to providing a more suitable replacement space.

[0045] It should be noted that the recessed accommodating junction 13 of the present application further plays a role in positioning and fixing. When the insulating layer is combined, the position of the insulating layer and the layer structure of the present application can be further limited by the structure, so that misalignment is not easily formed.

[0046] In an optional embodiment, the depth of the recessed accommodating junction 13 is less than 4 um. In this way, the depth of the recess is within a reasonable range, thereby controlling the depth within 4 um and preventing the copper foil from being more easily broken due to excessive depth.

[0047] In an optional embodiment, the number of the main body 11 is n, the number of the branch body 12 is m, the area of ​​the copper foil is S, the number of the recessed accommodating knots 13 is k+m, where k is the number of exposed head ends of the main body 11, and the length of each branch body 12 is: qS / (k+m), where q is a reference coefficient, and q= / (m + n). In this embodiment, the length of each branch portion 12 can be obtained by calculating the length model of the branch portion 12. Meanwhile, the main portion 11 is generally arranged in a uniform manner throughout the copper foil. Therefore, there is no need to determine the length range of the main portion 11 as long as it can meet the arrangement requirements.

[0048] In the length model of the branch 12 in this embodiment, the reference coefficient , the more branches 12 there are, the smaller q is. Correspondingly, since the length model of the branch stem 12 is qS / (k+m), it can be seen that the length of the branch stem 12 is positively correlated with q and negatively correlated with m, the shorter the length of the corresponding branch stem 12 is. Through this model, the relative relationship between the length of the branch stem 12 and the number of the branch stems 12 can be reasonably limited, thereby ensuring that the copper foil has a certain uniform dispersion and improving the overall performance of the copper foil.

[0049] In an optional embodiment, if the area of ​​the copper foil is S, and S is greater than a set threshold, a connecting portion 14 is formed between two adjacent recessed accommodating nodes 13 among the multiple recessed accommodating nodes 13 by laser etching, and the inner diameter of the connecting portion 14 is the average inner diameter of the main body 11 or branch body 12 corresponding to the two connected recessed accommodating nodes 13. In this embodiment, when S is greater than the set threshold, it means that the copper foil area is large. At this time, the distance between the two recessed accommodating nodes 13 may be too far. Then, by setting the connecting portion 14, the recessed accommodating nodes 13 with a relatively long distance are connected, thereby improving the uniformity of local dispersion and avoiding the problem of uneven force caused by local uneven dispersion when subsequently bonding with the insulating layer. Furthermore, the inner diameter of the connecting portion 14 is the average inner diameter of the main body 11 or branch body 12 corresponding to the two connected recessed accommodating nodes 13, thereby avoiding the influence of anisotropy differences caused by the additional addition of the connecting portion 14.

[0050] In an optional embodiment, if the area of ​​the copper foil is S, and S is greater than a set threshold, among the plurality of recessed accommodating nodes 13, a connecting portion 14 is formed by laser etching between two adjacent recessed accommodating nodes 13, and the inner diameter of the connecting portion 14 is the average inner diameter of the main body 11 or the branch body 12 correspondingly connected to the two connected recessed accommodating nodes 13, and the number of the plurality of recessed accommodating nodes 13 is , where p is an integer greater than or equal to 1. In this embodiment, by configuring the number of recessed accommodating knots 13 with the connecting portion 14, the number of recessed accommodating knots 13 is positively correlated with the length of the branch portion 12, and negatively correlated with the overall area, and S / 2lp is equivalent to proportionally reducing the width of the copper foil to the same order of magnitude as the branch portion 12, and then calculating the multiple difference in combination with the length of the branch portion 12, combined with the introduction of the P coefficient, the number of recessed accommodating knots 13 determined in this way is within a more reasonable range, and will not lead to a higher overall density.

[0051] In an optional embodiment, if qS / (k+m) is greater than a set threshold value and the length of the connecting portion 14 is longer than the average connecting portion length, a secondary recessed accommodating knot 13 is formed on the corresponding connecting portion, and the inner diameter of the secondary recessed accommodating knot 13 is the same as or different from the inner diameter of the recessed accommodating knot 13. In this embodiment, if the length of the connecting portion 14 is longer than the average connecting portion length, the secondary recessed accommodating knot 13 can be further added to improve the local uniformity, which is not described in detail in this application.

[0052] In an optional embodiment, it also includes: The surface of the copper-chromium alloy copper foil 1 after the roughening treatment and on which the texture structure is etched is passivated.

[0053] In an optional embodiment, the step of roughening the surface of the copper-chromium alloy foil on one side of which the texture structure is etched comprises: Rough protrusions are formed on one side surface of the texture structure by electrolyzing a diluted copper sulfate solution.

[0054] In addition, further, the present application also provides a circuit board, including a circuit board body and at least one electronic component configured on the circuit board body, the circuit board body includes a first circuit board layer and a second circuit board layer, and the copper-chromium alloy copper foil as described above is combined between the first circuit board layer and the second circuit board layer.

[0055] In addition, further, the present application also provides a circuit device, including a housing and the circuit board as described above, wherein the circuit board is placed inside the housing.

[0056] The circuit device of the present application may be a terminal device, an electronic device, etc., and the present application does not impose any limitation on this.

[0057] It should be noted that the copper-chromium alloy copper foil embodiments and manufacturing method embodiments provided in the embodiments of the present invention can be referenced to each other, and the embodiments of the present application are not limited to this. Any technician familiar with the technical field can easily think of changes within the technical scope disclosed in the present application, and they should be included in the protection scope of the present application. Therefore, they will not be repeated. The above is only an optional embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present application should be included in the protection scope of the present application.

Claims

1. A copper-chromium alloy copper foil, characterized in that: The copper-chromium alloy copper foil is used for a circuit board, and the circuit board comprises a substrate layer, a copper-chromium alloy copper foil and a circuit structure layer; A textured structure is etched in the copper-chromium alloy copper foil, and the textured structure includes multiple main stems and branch stems connecting each main stem, and the exposed head ends of the main stems and the exposed head ends of the branch stems form recessed accommodating knots, and the inner diameter of the recessed accommodating knot formed at the head end of the main stem is larger than twice the inner diameter of the main stem connected thereto, and the inner diameter of the recessed accommodating knot formed at the head end of the branch stem is larger than twice the inner diameter of the branch stem connected thereto.

2. The copper-chromium alloy copper foil according to claim 1, characterized in that: The inner diameter of the main body is greater than 6um, and the inner diameter of the branch body is greater than 3um, wherein the inner diameters of the main body and the branch body are the same or different.

3. The copper-chromium alloy copper foil according to claim 1, characterized in that: The depth of the recessed accommodating junction is less than 4 um.

4. The copper-chromium alloy copper foil according to claim 1, characterized in that: The number of the main body is n, the number of the branch body is m, the area of ​​the copper foil is S, the number of the recessed accommodating junctions is k+m, where k is the number of exposed head ends of the main body, and the length of each branch body is: qS / (k+m), where q is a reference coefficient, and .

5. The copper-chromium alloy copper foil according to claim 1, characterized in that: If the area of ​​the copper foil is S, and S is greater than a set threshold, among the multiple recessed accommodating junctions, a connecting portion is formed between two adjacent recessed accommodating junctions by laser etching, and the inner diameter of the connecting portion is the average inner diameter of the main stem or branch stem corresponding to the two connected recessed accommodating junctions.

6. The copper-chromium alloy copper foil according to claim 4, characterized in that: If the area of ​​the copper foil is S, and S is greater than a set threshold, among the plurality of recessed accommodating nodes, a connecting portion is formed between two adjacent recessed accommodating nodes by laser etching, and the inner diameter of the connecting portion is the average inner diameter of the main stem or branch stem corresponding to the two connected recessed accommodating nodes, and the number of the plurality of recessed accommodating nodes is , where p is an integer greater than or equal to 1, and l is the length of the copper foil.

7. The copper-chromium alloy copper foil according to claim 6, characterized in that: If qS / (k+m) is greater than a set threshold and the length of the connecting portion is higher than the average length of the connecting portion, a secondary recessed accommodating junction is formed on the corresponding connecting portion, and the inner diameter of the secondary recessed accommodating junction is the same as or different from the inner diameter of the recessed accommodating junction.

8. A method for preparing the copper-chromium alloy copper foil as claimed in claim 1, characterized in that: include: A copper-chromium alloy thin film sheet is obtained by electrolysis; Etching the texture structure in the copper-chromium alloy thin film by a laser etching method to obtain a copper-chromium alloy copper foil; The surface of the copper-chromium alloy copper foil on which the texture structure is etched is roughened.

9. A circuit board, characterized in that: It comprises a circuit board body and at least one electronic component arranged on the circuit board body, wherein the circuit board body comprises a first circuit board layer and a second circuit board layer, and the copper-chromium alloy copper foil as claimed in any one of claims 1 to 7 is combined between the first circuit board layer and the second circuit board layer.

10. A circuit device, characterized in that: It comprises a housing and the circuit board as claimed in claim 9, wherein the circuit board is placed inside the housing.

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