A high-strength, high-elasticity beryllium copper foil for 5G base stations and its preparation method

Abstract

This invention proposes a high-strength, high-elasticity beryllium copper foil for 5G base stations and its preparation method. This invention achieves continuous production of large rolls to meet the most advanced high-speed stamping technology, and enables mass production of 0.038mm–0.1mm beryllium copper foil to meet the stringent requirements of miniaturization, high strength, and high precision in fields such as 5G base stations. A segmented heating and cooling heat treatment method ensures that the foil has uniform and fine grains while maintaining high aged hardness. Grinding with hard abrasive rollers ensures a uniform foil surface, providing ample oil storage, lubrication, and heat dissipation surface for high-speed stamping. The use of a large-diameter rolling method solves the problems of lateral wrinkles and precision fluctuations during foil rolling.

Description

Technical Field

[0001] This invention belongs to the field of beryllium copper foil preparation technology, and particularly relates to a high-strength and high-elasticity beryllium copper foil for 5G base stations and its preparation method. Background Technology

[0002] Beryllium copper alloys possess excellent comprehensive properties, making them an indispensable and important industrial material for national economic construction and national defense. Beryllium copper strip and foil are high-value-added products. They are the only copper alloy that combines excellent mechanical, physical, chemical, and corrosion resistance properties. After solution treatment and aging heat treatment, they possess high strength limit, elastic limit, yield limit, and fatigue limit comparable to special steels. They also exhibit high electrical and thermal conductivity, high hardness, wear resistance, and excellent creep resistance.

[0003] With the vigorous promotion and continuous development of 5G technology, higher requirements are being placed on materials, such as high strength, high elasticity, high fatigue resistance, and high conductivity. Beryllium copper alloy, due to its excellent properties, is a key basic material in the construction of 5G base stations and a manufacturing material for core components such as 5G base station chips, antennas, and high-frequency PCBs / copper-clad laminates. Due to the import of materials, costs have increased significantly, leading to a growing demand in the domestic market for the localization of mid-to-high-end beryllium copper foil materials.

[0004] CN114310170A discloses a method for preparing wide beryllium copper strips by reciprocating welding in the additive manufacturing process using wire feeding. This method uses 7-8mm weld overlay blanks to process to 0.05mm, which cannot meet the needs of large-scale mass production and its accuracy is ±0.005mm.

[0005] When the foil thickness is less than 0.1mm, the softening degree of the foil increases significantly. While ensuring the solid solution properties of the material, the degree of material deformation must be considered to severely restrict the implementation of the process. Beryllium copper foil is commonly used in TD01 and TD02 states. These two states offer good formability and machinability, meeting the stringent requirements of complex parts such as 5G shielding covers, springs, and replacement wafers. This necessitates solution treatment before finishing. Under the same heat deformation resistance, thinner pre-finished products are more prone to deformation. With the same thickness, poorer plate shape—i.e., the presence of plate shape defects such as 1 / 4 wave, single-sided wave, or double-sided wave—makes the foil more susceptible to deformation and breakage, preventing complete solution treatment. The challenges include high burrs during the slitting of beryllium copper foil semi-finished and finished products leading to edge warping, low quenching temperatures resulting in low aging performance of finished products, and easy slippage and breakage during the rolling process. These challenges require overcoming the technical bottlenecks in foil production, such as high burrs during edge cutting, wrinkles in high-temperature quenched strips, and easy breakage during cold rolling. Summary of the Invention

[0006] To address the problems of poor rolling sheet shape, severe heat treatment deformation, and low mechanical properties during the processing of beryllium copper foil in existing technologies, this invention proposes a high-strength and high-elasticity beryllium copper foil for 5G base stations and its preparation method.

[0007] The first aspect of this invention discloses a method for preparing high-strength, high-elasticity beryllium copper foil for 5G base stations, the method comprising:

[0008] Step S1: Prepare a beryllium copper foil base material with a thickness of 0.15 mm to 0.25 mm;

[0009] Step S2 involves subjecting the beryllium copper foil base material to at least two sets of continuous solution treatment, rolling, cleaning, and grinding processes, followed by a stretching and straightening process to obtain a finished beryllium copper foil material with a thickness of 0.038 mm to 0.1 mm; wherein,

[0010] When performing at least two sets of continuous solution treatment, rolling, cleaning and grinding processes, if the thickness of the beryllium copper foil base material after the current set of rolling is greater than or equal to 0.1 mm, the solution temperature for the next set of continuous solution treatment shall be increased stepwise from 760℃ to 810℃, and the solution rate shall be 15 to 30 m / min; if the thickness of the beryllium copper foil base material after the current set of rolling is less than 0.1 mm, the solution temperature for the next set of continuous solution treatment shall be decreased, and the solution temperature shall be decreased stepwise from 810℃ to 720℃, and the solution rate shall be 30 to 50 m / min.

[0011] According to the method of the first aspect of the present invention, in step S2, a solution treatment is performed using a vertical continuous furnace or a horizontal continuous furnace, and a nitrogen-hydrogen mixed gas is used for protection during the solution treatment process.

[0012] According to the method of the first aspect of the present invention, in step S2, among the multiple sets of continuous solution treatment, rolling, cleaning and grinding processes, the last rolling process is defined as finished product rolling, and the other rolling processes are defined as intermediate rolling; wherein,

[0013] Intermediate rolling uses work rolls with a diameter of 100mm to 180mm to roll the beryllium copper foil base material in 1 to 3 passes. The single pass reduction rate is 2% to 30%, the inlet tension is 1KN to 10KN, the outlet tension is 1KN to 10KN, the rolling speed is 60m / min to 100m / min, the rolling force is 200KN to 300KN, and the bending force is 15KN to 80KN.

[0014] The finished product rolling process uses work rolls with a diameter of 100mm to 180mm to roll the pre-finished beryllium copper foil in 1 to 3 passes. The single pass reduction rate is 2% to 30%, the inlet tension is 1KN to 5KN, the outlet tension is 1KN to 5KN, the rolling speed is 60m / min to 150m / min, the rolling force is 150KN to 300KN, and the bending force is 15KN to 80KN.

[0015] According to the method of the first aspect of the present invention, in step S2, the foil is cleaned using an unfolding cleaning machine that integrates degreasing, pickling, grinding, passivation and drying.

[0016] According to the method of the first aspect of the present invention, the oil content on the surface of the foil after degreasing is less than 5 mg / m². 2 .

[0017] According to the method of the first aspect of the present invention, a brush roller with a Shore hardness of 90 to 95 degrees is used for grinding, the grinding speed is 10 m / min to 50 m / min, and the surface roughness Ra of the foil after grinding is ≤0.12 μm.

[0018] According to the method of the first aspect of the present invention, the brush roller is of the disk type or the radial type.

[0019] According to the method of the first aspect of the present invention, in step S2, the bending straightening process adopts a tension straightening plus multi-roller straightening method, the tension straightening reduction is -1mm to -6mm, the multi-roller straightening reduction per segment is -1mm to -8mm, and both tension control and elongation control are adopted, with the tension control range being 10KN / mm. 2 ~25KN / mm 2 The elongation rate is controlled within the range of 0.1% to 0.3%, and the foil shape after straightening reaches less than 10i.

[0020] The second aspect of this invention discloses a high-strength, high-elasticity beryllium copper foil for 5G base stations, which is prepared by the steps in the preparation method of the high-strength, high-elasticity beryllium copper foil for 5G base stations described in any one of the first aspects of this disclosure.

[0021] According to a second aspect of the present invention, a high-strength, high-elasticity beryllium copper foil for a 5G base station, wherein the chemical composition of the high-strength, high-elasticity beryllium copper foil includes beryllium, nickel, cobalt, iron, and copper; the weight percentages of beryllium, nickel, cobalt, iron, and copper satisfy the following conditions:

[0022] Beryllium, 1.6–2.1%;

[0023] Nickel + Cobalt > 0.2%;

[0024] Nickel + Cobalt + Iron < 0.6%;

[0025] The remainder consists of copper and unavoidable trace impurities;

[0026] The trace impurities include aluminum ≤0.08%, silicon ≤0.08%, and iron ≤0.08%; the total amount of the trace impurities is <0.5%.

[0027] In summary, the solution proposed in this invention has the following technical effects: it enables continuous production of large-roll weights to meet the most advanced high-speed stamping requirements; it enables mass production of 0.038mm to 0.1mm beryllium copper foil to meet the stringent requirements of miniaturization, high strength, and high precision in fields such as 5G base stations; the segmented heating and cooling heat treatment method ensures that the foil has uniform and fine grains while maintaining high aged hardness; the grinding with hard grinding rollers ensures a uniform foil surface, providing a sufficient oil storage, lubrication, and heat dissipation surface for high-speed stamping; and the use of a large-diameter rolling method solves the problems of transverse wrinkles and precision fluctuations during foil rolling. Specifically,

[0028] By employing a solution treatment process involving progressively increasing and decreasing temperatures, coupled with precise control of key parameters such as machine tension, airflow in each zone of the furnace, and temperature in each zone during continuous solution treatment, uniform foil performance and fine grain structure are ensured. Large-diameter rolls overcome lateral wrinkles under varying tensions, and precise control of key parameters such as stable rolling speed achieves a flat foil shape. By controlling the inter-rolling processing rate, the product retains an elongation at break of over 20% even after thickness reduction, providing a strong foundation for straightening. Precise control of stretching and multi-roll straightening ensures the foil achieves a relatively flat shape before continuous solution treatment, enabling it to pass smoothly through the continuous heat treatment furnace. Attached Figure Description

[0029] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0030] Figure 1 This is a flowchart illustrating a method for preparing high-strength, high-elasticity beryllium copper foil for 5G base stations according to an embodiment of the present invention. Detailed Implementation

[0031] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0032] This invention addresses the problems existing in the prior art regarding beryllium copper foil materials, such as poor rolling plate shape, severe heat treatment deformation, low mechanical properties after aging, high internal stress, and severe stamping deformation. It provides a high-strength, high-elasticity beryllium copper foil for 5G base stations and its preparation method, solving problems such as poor rolling plate shape, inability to continuously solution-solidify at high temperatures, and low performance after aging. This meets the application requirements of 5G base stations, micro-diaphragms, and micro-spring sheets, enabling large-roll, mass production of beryllium copper foil materials.

[0033] Please see Figure 1 The first aspect of this invention discloses a method for preparing high-strength, high-elasticity beryllium copper foil for 5G base stations, the method comprising:

[0034] Step S1: Prepare a beryllium copper foil base material with a thickness of 0.15 mm to 0.25 mm;

[0035] In step S1, by adjusting the alloy composition, a beryllium copper foil base material of 0.15-0.25 mm is obtained through smelting, hot rolling, intermediate annealing, continuous solution treatment, intermediate rolling, and finish rolling.

[0036] The alloy consists of beryllium, nickel, cobalt, iron, and copper.

[0037] Step S2 involves subjecting the beryllium copper foil base material to at least two sets of continuous solution treatment, rolling, cleaning, and grinding processes, followed by a stretching and straightening process to obtain a finished beryllium copper foil material with a thickness of 0.038 mm to 0.1 mm; wherein,

[0038] When performing at least two sets of continuous solution treatment, rolling, cleaning and grinding processes, if the thickness of the beryllium copper foil base material after the current set of rolling is greater than or equal to 0.1 mm, the solution temperature for the next set of continuous solution treatment shall be increased stepwise from 760℃ to 810℃, and the solution rate shall be 15 to 30 m / min; if the thickness of the beryllium copper foil base material after the current set of rolling is less than 0.1 mm, the solution temperature for the next set of continuous solution treatment shall be decreased, and the solution temperature shall be decreased stepwise from 810℃ to 720℃, and the solution rate shall be 30 to 50 m / min.

[0039] According to the method of the first aspect of the present invention, in step S2, a solution treatment is performed using a vertical continuous furnace or a horizontal continuous furnace, and a nitrogen-hydrogen mixed gas is used for protection during the solution treatment process.

[0040] According to the method of the first aspect of the present invention, in step S2, among the multiple sets of continuous solution treatment, rolling, cleaning and grinding processes, the last rolling process is defined as finished product rolling, and the other rolling processes are defined as intermediate rolling; wherein,

[0041] Intermediate rolling uses work rolls with a diameter of 100mm to 180mm to roll the beryllium copper foil base material in 1 to 3 passes. The single pass reduction rate is 2% to 30%, the inlet tension is 1KN to 10KN, the outlet tension is 1KN to 10KN, the rolling speed is 60m / min to 100m / min, the rolling force is 200KN to 300KN, and the bending force is 15KN to 80KN.

[0042] The finished product rolling process uses work rolls with a diameter of 100mm to 180mm to roll the pre-finished beryllium copper foil in 1 to 3 passes. The single pass reduction rate is 2% to 30%, the inlet tension is 1KN to 5KN, the outlet tension is 1KN to 5KN, the rolling speed is 60m / min to 150m / min, the rolling force is 150KN to 300KN, and the bending force is 15KN to 80KN.

[0043] According to the method of the first aspect of the present invention, in step S2, the foil is cleaned using an unfolding cleaning machine that integrates degreasing, pickling, grinding, passivation and drying.

[0044] According to the method of the first aspect of the present invention, the oil content on the surface of the foil after degreasing is less than 5 mg / m². 2 .

[0045] According to the method of the first aspect of the present invention, a brush roller with a Shore hardness of 90 to 95 degrees is used for grinding, the grinding speed is 10 m / min to 50 m / min, and the surface roughness Ra of the foil after grinding is ≤0.12 μm.

[0046] According to the method of the first aspect of the present invention, the brush roller is of the disk type or the radial type.

[0047] According to the method of the first aspect of the present invention, in step S2, the bending straightening process adopts a tension straightening plus multi-roller straightening method, the tension straightening reduction is -1mm to -6mm, the multi-roller straightening reduction per segment is -1mm to -8mm, and both tension control and elongation control are adopted, with the tension control range being 10KN / mm. 2 ~25KN / mm 2 The elongation rate is controlled within the range of 0.1% to 0.3%, and the foil shape after straightening reaches less than 10i.

[0048] According to the method of the first aspect of the present invention, in step S2, the chemical composition of the finished beryllium copper foil includes beryllium, nickel, cobalt, iron, and copper; the weight percentages of beryllium, nickel, cobalt, iron, and copper satisfy the following conditions:

[0049] Beryllium, 1.6–2.1%;

[0050] Nickel + Cobalt > 0.2%;

[0051] Nickel + Cobalt + Iron < 0.6%;

[0052] The remainder consists of copper and unavoidable trace impurities;

[0053] The trace impurities include aluminum ≤0.08%, silicon ≤0.08%, and iron ≤0.08%; the total amount of the trace impurities is <0.5%.

[0054] The second aspect of this invention discloses a high-strength, high-elasticity beryllium copper foil for 5G base stations, which is prepared using the steps in the preparation method of the high-strength, high-elasticity beryllium copper foil for 5G base stations described in any one of the first aspects of this disclosure. The beryllium copper foil has a thickness of 0.038 mm to 0.1 mm, with a thickness accuracy of ±0.003 mm.

[0055] The chemical composition of the high-strength, high-elasticity beryllium copper foil includes beryllium, nickel, cobalt, iron, and copper. The weight percentages of beryllium, nickel, cobalt, iron, and copper satisfy the following condition:

[0056] Beryllium, 1.6–2.1%;

[0057] Nickel + Cobalt > 0.2%;

[0058] Nickel + Cobalt + Iron < 0.6%;

[0059] The remainder consists of copper and unavoidable trace impurities;

[0060] The trace impurities include aluminum ≤0.08%, silicon ≤0.08%, and iron ≤0.08%; the total amount of the trace impurities is <0.5%.

[0061] The implementation steps of this method will be explained in detail below with several examples.

[0062] The alloy composition of the beryllium copper foil in the following embodiments is shown in the table below:

[0063]

[0064] Example 1: 0.038mm foil

[0065] (1) Adjust the alloy composition according to Table 1, and obtain 0.15mm beryllium copper foil base material through smelting, hot rolling, intermediate annealing, continuous solution treatment, intermediate rolling and finish rolling;

[0066] (2) Continuous solution treatment of beryllium copper foil base material: Solution treatment is carried out by vertical continuous quenching furnace. Under the protection of nitrogen and hydrogen gas, the temperature of the quenching furnace is maintained at 760℃, the strip speed is maintained at 15m / min, the cooling method is gas cooling, and the cooling intensity is 300℃ / min.

[0067] (3) Intermediate rolling is performed by rolling the beryllium copper foil base material in three passes using work rolls with a roll diameter of 170mm.

[0068] The first pass has a reduction rate of 30%, an inlet tension of 6 kN, an outlet tension of 7 kN, a rolling speed of 100 m / min, a rolling force of 240–260 kN, and a bending force of 40–50 kN.

[0069] The second pass has a reduction rate of 20%, an inlet tension of 6 kN, an outlet tension of 7 kN, a rolling speed of 90 m / min, a rolling force of 200–240 kN, and a bending force of 40–50 kN.

[0070] The third pass has a reduction rate of 10%, an inlet tension of 5KN, an outlet tension of 6KN, a rolling speed of 90m / min, a rolling force of 200-260KN, and a bending force of 40-50KN.

[0071] (4) Beryllium copper foil cleaning and grinding: The foil is cleaned using an unfolded cleaning machine that integrates degreasing, pickling, grinding, passivation and drying. After degreasing, the oil content on the foil surface is 3.5 mg / m2. It is then ground using a Shore A 95 degree radial brush roller at a grinding speed of 30 m / min. The surface roughness of the foil after grinding is Ra 0.14 m.

[0072] (5) Continuous solution treatment of beryllium copper foil: Solution treatment is carried out in a vertical continuous quenching furnace. Under the protection of nitrogen and hydrogen gas, the temperature of the quenching furnace is maintained at 740℃, the strip speed is maintained at 35m / min, and the cooling method is gas cooling.

[0073] (6) Finished product rolling: The beryllium copper foil base material is rolled in 3 passes using work rolls with a roll diameter of 180mm.

[0074] The first pass has a reduction rate of 30%, an inlet tension of 4KN, an outlet tension of 5KN, a rolling speed of 100m / min, a rolling force of 240~260KN, and a bending force of 40~50KN.

[0075] The second pass has a reduction rate of 20%, an inlet tension of 3KN, an outlet tension of 4KN, a rolling speed of 100m / min, a rolling force of 220-240KN, and a bending force of 40-50KN.

[0076] The third pass has a reduction rate of 10%, an inlet tension of 3KN, an outlet tension of 4KN, a rolling speed of 100m / min, a rolling force of 230-240KN, and a bending force of 40-50KN.

[0077] (7) The foil was cleaned using an unfolded cleaning machine that integrates degreasing, pickling, grinding, passivation and drying. After degreasing, the oil content on the foil surface was 3 mg / m2. It was then ground using a radial brush roller with a Shore hardness of A92 degrees at a grinding speed of 40 m / min. The surface roughness of the foil after grinding was Ra0.1 μm.

[0078] (8) Stretch straightening: Stretch straightening combined with multi-roller straightening is adopted. The stretch straightening reduction is -3.5mm, and the multi-roller straightening reduction per section is -4.2mm. Tension control range: 15KN / mm2. Elongation control range: 0.15%. The straightened plate shape reaches less than 10i.

[0079] (9) Finished product slitting: Finished products are slitting according to customer requirements.

[0080] Example 2: 0.06mm foil

[0081] (1) Adjust the alloy composition according to Table 1, and obtain a 0.16mm beryllium copper foil base material by smelting, hot rolling, intermediate annealing, continuous solution treatment, intermediate rolling and finish rolling.

[0082] (2) Continuous solution treatment of beryllium copper foil base material: Solution treatment is carried out in a vertical continuous quenching furnace. Under the protection of nitrogen and hydrogen gas, the temperature of the quenching furnace is maintained at 790℃, the strip speed is maintained at 14m / min, the cooling method is gas cooling, and the cooling intensity is 300℃ / min.

[0083] (3) Intermediate rolling is performed by rolling the beryllium copper foil base material in three passes using work rolls with a roll diameter of 160mm.

[0084] The first pass has a reduction rate of 30%, an inlet tension of 6 kN, an outlet tension of 7 kN, a rolling speed of 100 m / min, a rolling force of 220–240 kN, and a bending force of 50–60 kN.

[0085] The second pass has a reduction rate of 18%, an inlet tension of 5KN, an outlet tension of 6KN, a rolling speed of 80m / min, a rolling force of 230-250KN, and a bending force of 40-50KN.

[0086] The third pass has a reduction rate of 2%, an inlet tension of 5KN, an outlet tension of 6KN, a rolling speed of 80m / min, a rolling force of 100-120KN, and a bending force of 20-30KN.

[0087] (4) Beryllium copper foil cleaning and grinding: The foil is cleaned using an unfolded cleaning machine that integrates degreasing, pickling, grinding, passivation and drying. After degreasing, the oil content on the foil surface is 3mg / m2. It is then ground using a radial brush roller with a Shore hardness of A92 degrees at a grinding speed of 50m / min. The surface roughness of the foil after grinding is Ra0.11m.

[0088] (5) Continuous solution treatment of beryllium copper foil: Solution treatment is carried out in a vertical continuous quenching furnace. Under the protection of nitrogen and hydrogen gas, the temperature of the quenching furnace is maintained at 770℃, the strip speed is maintained at 40m / min, and the cooling method is gas cooling.

[0089] (6) Finished product rolling: The beryllium copper foil base material is rolled in two passes using work rolls with a roll diameter of 180mm.

[0090] The first pass has a reduction rate of 30%, an inlet tension of 4KN, an outlet tension of 5KN, a rolling speed of 100m / min, a rolling force of 240-260KN, and a bending force of 60-70KN.

[0091] The second pass has a reduction rate of 4%, an inlet tension of 3KN, an outlet tension of 4KN, a rolling speed of 100m / min, a rolling force of 200-220KN, and a bending force of 40-50KN.

[0092] (7) The foil was cleaned using an unfolded cleaning machine that integrates degreasing, pickling, grinding, passivation and drying. After degreasing, the oil content on the foil surface was 3 mg / m2. It was then ground using a radial brush roller with a Shore hardness of A92 degrees at a grinding speed of 50 m / min. The surface roughness of the foil after grinding was Ra0.1 μm.

[0093] (8) Stretch straightening: Stretch straightening combined with multi-roller straightening is adopted. The stretch straightening reduction is -3mm, and the multi-roller straightening reduction per section is -3.5mm. Tension control range: 18KN / mm2. Elongation control range: 0.1%. The straightened plate shape reaches less than 10i.

[0094] (9) Finished product slitting: Finished products are slitting according to customer requirements.

[0095] Example 3: 0.05mm foil

[0096] (1) Adjust the alloy composition according to Table 1, and obtain 0.12mm beryllium copper foil base material through smelting, hot rolling, intermediate annealing, continuous solution treatment, intermediate rolling and finish rolling;

[0097] (2) Continuous solution treatment of beryllium copper foil base material: Solution treatment is carried out by vertical continuous quenching furnace. Under the protection of nitrogen and hydrogen gas, the temperature of the quenching furnace is maintained at 800℃, the foil blank speed is maintained at 30m / min, the cooling method is gas cooling, and the cooling intensity is 300℃ / min.

[0098] (3) Intermediate rolling is performed by rolling the beryllium copper foil base material in three passes using work rolls with a roll diameter of 160mm.

[0099] 1) The first pass has a reduction rate of 30%, an inlet tension of 6KN, an outlet tension of 7KN, a rolling speed of 100m / min, a rolling force of 220~240KN, and a bending force of 50~60KN.

[0100] 2) The second pass has a reduction rate of 20%, an inlet tension of 5KN, an outlet tension of 6KN, a rolling speed of 100m / min, a rolling force of 230~250KN, and a bending force of 40~50KN.

[0101] 3) The third pass has a reduction rate of 10%, an inlet tension of 3KN, an outlet tension of 4KN, a rolling speed of 80m / min, a rolling force of 200~220KN, and a bending force of 20~30KN.

[0102] (4) Beryllium copper foil cleaning and grinding: The foil is cleaned using an unfolded cleaning machine that integrates degreasing, pickling, grinding, passivation and drying. After degreasing, the oil content on the foil surface is 3mg / m2. It is then ground using a radial brush roller with a Shore hardness of A93 at a grinding speed of 50m / min. The surface roughness of the foil after grinding is Ra0.11m.

[0103] (5) Continuous solution treatment of beryllium copper foil: Solution treatment is carried out in a vertical continuous quenching furnace. Under the protection of nitrogen and hydrogen gas, the temperature of the quenching furnace is maintained at 730℃, the strip speed is maintained at 30m / min, and the cooling method is gas cooling.

[0104] (6) Finished product rolling: The beryllium copper foil base material is rolled in one pass using work rolls with a roll diameter of 180mm.

[0105] 1) The first pass has a reduction rate of 20%, an inlet tension of 4KN, an outlet tension of 5KN, a rolling speed of 100m / min, a rolling force of 240~260KN, and a bending force of 50~60KN;

[0106] (7) The foil was cleaned using an unfolded cleaning machine that integrates degreasing, pickling, grinding, passivation and drying. After degreasing, the oil content on the foil surface was 3 mg / m2. It was then ground using a radial brush roller with a Shore hardness of A92 degrees at a grinding speed of 50 m / min. The surface roughness of the foil after grinding was Ra0.1 μm.

[0107] (8) Stretch straightening: Stretch straightening combined with multi-roller straightening is adopted. The stretch straightening reduction is -3.5mm, and the multi-roller straightening reduction per section is -4.5mm. Tension control range: 14KN / mm2. Elongation control range: 0.16%. The straightened plate shape reaches less than 10i.

[0108] (9) Finished product slitting: Finished products are slitting according to customer requirements.

[0109] Example 4: 0.08mm foil

[0110] (1) Adjust the alloy composition according to Table 1, and obtain 0.2 mm beryllium copper foil base material by smelting, hot rolling, intermediate annealing, continuous solution treatment, intermediate rolling and finish rolling.

[0111] (2) Continuous solution treatment of beryllium copper foil base material: Solution treatment is carried out in a vertical continuous quenching furnace. Under the protection of nitrogen and hydrogen gas, the temperature of the quenching furnace is maintained at 780℃, the strip speed is maintained at 28m / min, and the cooling method is gas cooling.

[0112] (3) Intermediate rolling is performed by rolling the beryllium copper foil base material in two passes using work rolls with a roll diameter of 170mm.

[0113] 1) The first pass has a reduction rate of 30%, an inlet tension of 6KN, an outlet tension of 7KN, a rolling speed of 100m / min, a rolling force of 230~250KN, and a bending force of 40~50KN.

[0114] 2) The second pass has a reduction rate of 17%, an inlet tension of 5KN, an outlet tension of 6KN, a rolling speed of 100m / min, a rolling force of 200~220KN, and a bending force of 30~40KN.

[0115] (4) Beryllium copper foil cleaning and grinding: The foil is cleaned using an unfolded cleaning machine that integrates degreasing, pickling, grinding, passivation and drying. After degreasing, the oil content on the foil surface is 3mg / m2. It is then ground using a radial brush roller with a Shore hardness of A91 at a grinding speed of 30m / min. The surface roughness of the foil after grinding is Ra0.14m.

[0116] (5) Continuous solution treatment of beryllium copper foil: Solution treatment is carried out in a vertical continuous quenching furnace. Under the protection of nitrogen and hydrogen gas, the temperature of the quenching furnace is maintained at 800℃, the strip speed is maintained at 28m / min, and the cooling method is gas cooling.

[0117] (6) Finished product rolling: The beryllium copper foil base material is rolled in 3 passes using work rolls with a roll diameter of 180mm.

[0118] The first pass has a reduction rate of 25%, an inlet tension of 6KN, an outlet tension of 7KN, a rolling speed of 100m / min, a rolling force of 250-280KN, and a bending force of 50-60KN.

[0119] The second pass has a reduction rate of 14%, an inlet tension of 6KN, an outlet tension of 7KN, a rolling speed of 100m / min, a rolling force of 240-260KN, and a bending force of 40-50KN.

[0120] (7) The foil was cleaned using an unfolded cleaning machine that integrates degreasing, pickling, grinding, passivation and drying. After degreasing, the oil content on the foil surface was 3 mg / m2. It was then ground using a radial brush roller with a Shore hardness of A91 at a grinding speed of 35 m / min. The surface roughness of the foil after grinding was Ra0.12 μm.

[0121] (8) Stretch straightening: Stretch straightening combined with multi-roller straightening is adopted. The stretch straightening reduction is -4mm, and the multi-roller straightening reduction per section is -3mm. Tension control range: 20KN / mm2. Elongation control range: 0.2%. The straightened plate shape reaches less than 10i.

[0122] (9) Finished product slitting: Finished products are slitting according to customer requirements.

[0123] Example 5: 0.1mm foil

[0124] (1) Adjust the alloy composition according to Table 1, and obtain a 0.25mm beryllium copper foil base material through smelting, hot rolling, intermediate annealing, continuous solution treatment, intermediate rolling and finish rolling;

[0125] (2) Continuous solution treatment of beryllium copper foil base material: Solution treatment is carried out in a vertical continuous quenching furnace. Under the protection of nitrogen and hydrogen gas, the temperature of the quenching furnace is maintained at 800℃, the strip speed is maintained at 28m / min, and the cooling method is gas cooling.

[0126] (3) Intermediate rolling is performed by rolling the beryllium copper foil base material in three passes using work rolls with a roll diameter of 170mm.

[0127] The first pass has a reduction rate of 30%, an inlet tension of 6 kN, an outlet tension of 7 kN, a rolling speed of 100 m / min, a rolling force of 230–250 kN, and a bending force of 40–50 kN.

[0128] The second pass has a reduction rate of 20%, an inlet tension of 5KN, an outlet tension of 6KN, a rolling speed of 100m / min, a rolling force of 200-220KN, and a bending force of 30-40KN.

[0129] The third pass has a reduction rate of 10%, an inlet tension of 5KN, an outlet tension of 6KN, a rolling speed of 80m / min, a rolling force of 150-180KN, and a bending force of 20-30KN.

[0130] (4) Beryllium copper foil cleaning and grinding: The foil is cleaned using an unfolded cleaning machine that integrates degreasing, pickling, grinding, passivation and drying. After degreasing, the oil content on the foil surface is 3.2 mg / m2. It is then ground using a radial brush roller with a Shore hardness of A91 at a grinding speed of 25 m / min. The surface roughness of the foil after grinding is Ra0.13 m.

[0131] (5) Continuous solution treatment of beryllium copper foil: Solution treatment is carried out in a vertical continuous quenching furnace. Under the protection of nitrogen and hydrogen gas, the temperature of the quenching furnace is maintained at 810℃, the strip speed is maintained at 28m / min, and the cooling method is gas cooling.

[0132] (6) Finished product rolling: The beryllium copper foil base material is rolled in one pass using work rolls with a roll diameter of 180mm.

[0133] The first pass has a reduction rate of 20%, an inlet tension of 6KN, an outlet tension of 7KN, a rolling speed of 100m / min, a rolling force of 220-240KN, and a bending force of 50-60KN.

[0134] (7) The foil was cleaned using an unfolded cleaning machine that integrates degreasing, pickling, grinding, passivation and drying. After degreasing, the oil content on the foil surface was 3 mg / m2. It was then ground using a radial brush roller with a Shore hardness of A91 at a grinding speed of 35 m / min. The surface roughness of the foil after grinding was Ra0.11 μm.

[0135] (8) Stretch straightening: Stretch straightening combined with multi-roller straightening is adopted. The stretch straightening reduction is -4mm, and the multi-roller straightening reduction per section is -4mm. Tension control range: 25KN / mm2. Elongation control range: 0.25%. The straightened plate shape reaches less than 10i.

[0136] (9) Finished product slitting: Finished products are slitting according to customer requirements.

[0137] The mechanical properties of the product in the example are shown in the table below.

[0138] hardness Tensile strength (MPa) Yield strength (MPa) elongation % Example 1 238 870 820 9.2 Example 2 245 862 810 8 Example 3 200 630 580 15 Example 4 230 780 720 8 Example 5 195 680 620 16

[0139] In summary, the solution proposed in this invention has the following technical effects: it enables continuous production of large-roll weights to meet the most advanced high-speed stamping requirements; it enables mass production of 0.038mm to 0.1mm beryllium copper foil to meet the stringent requirements of miniaturization, high strength, and high precision in fields such as 5G base stations; the segmented heating and cooling heat treatment method ensures that the foil has uniform and fine grains while maintaining high aged hardness; the grinding with hard grinding rollers ensures a uniform foil surface, providing a sufficient oil storage, lubrication, and heat dissipation surface for high-speed stamping; and the use of a large-diameter rolling method solves the problems of transverse wrinkles and precision fluctuations during foil rolling. Specifically,

[0140] By employing a solution treatment process involving progressively increasing and decreasing temperatures, coupled with precise control of key parameters such as machine tension, airflow in each zone of the furnace, and temperature in each zone during continuous solution treatment, uniform foil performance and fine grain structure are ensured. Large-diameter rolls overcome lateral wrinkles under varying tensions, and precise control of key parameters such as stable rolling speed achieves a flat foil shape. By controlling the inter-rolling processing rate, the product retains an elongation at break of over 20% even after thickness reduction, providing a strong foundation for straightening. Precise control of stretching and multi-roll straightening ensures the foil achieves a relatively flat shape before continuous solution treatment, enabling it to pass smoothly through the continuous heat treatment furnace.

[0141] Please note that the technical features of the above embodiments can be combined arbitrarily. For the sake of brevity, not all possible combinations of the technical features in the above embodiments have been described. However, as long as the combination of these technical features does not contradict each other, it should be considered within the scope of this specification. The above embodiments only illustrate several implementation methods of this application, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the invention patent. It should be pointed out that for those skilled in the art, several modifications and improvements can be made without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A method for preparing high-strength and high-elasticity beryllium copper foil for 5G base stations, characterized by, The method comprises: Step S1, preparing a beryllium copper foil base material with a thickness of 0.15mm to 0.25mm; Step S2, obtaining a beryllium copper foil product with a thickness of 0.038mm to 0.1mm through a bending and straightening process after at least two groups of continuous solid solution, rolling, cleaning and grinding processes on the beryllium copper foil base material; wherein, When the thickness of the beryllium copper foil base material after rolling of the current group is greater than or equal to 0.1mm, the solid solution temperature of the next group of continuous solid solution is gradually increased from 760℃ to 810℃, and the solid solution speed is 15-30m / min; if the thickness of the beryllium copper foil base material after rolling of the current group is less than 0.1mm, the solid solution temperature of the next group of continuous solid solution is reduced; the solid solution temperature is gradually reduced from 810℃ to 720℃, and the solid solution speed is 30-50m / min; In the step S2, the last rolling process in the multiple groups of continuous solid solution, rolling, cleaning and grinding processes is defined as the product rolling, and the other rolling processes are defined as the intermediate rolling; wherein, The intermediate rolling adopts a 1-pass to 3-pass rolling on the beryllium copper foil base material by using a working roll with a roll diameter of 100mm to 180mm, a single-pass reduction rate of 2% to 30%, an entry side tension of 1KN to 10KN, an exit side tension of 1KN to 10KN, a rolling speed of 60m / min to 100m / min, a rolling force of 200KN to 300KN, and a bending roll force of 15KN to 80KN; The product rolling adopts a 1-pass to 3-pass rolling on the pre-product beryllium copper foil by using a working roll with a roll diameter of 100mm to 180mm, a single-pass reduction rate of 2% to 30%, an entry side tension of 1KN to 5KN, an exit side tension of 1KN to 5KN, a rolling speed of 60m / min to 150m / min, a rolling force of 150KN to 300KN, and a bending roll force of 15KN to 80KN; The high-strength and high-elasticity beryllium copper foil comprises beryllium, nickel, cobalt, iron and copper; the weight percentages of the beryllium, nickel, cobalt, iron and copper satisfy the following conditions: Beryllium, 1.6-2.1%; Nickel+cobalt>0.2%; Nickel+cobalt+iron<0.6%; The rest is copper and unavoidable trace impurities; The trace impurities include aluminum≤0.08%, silicon≤0.08%, and iron≤0.08%; and the total amount of the trace impurities is <0.5%.

2. The production method according to claim 1, characterized by, In the step S2, a vertical continuous furnace or a horizontal continuous furnace is used for solid solution treatment, and nitrogen-hydrogen mixed gas is used for protection during the solid solution process.

3. The preparation method according to claim 1, characterized in that, In the step S2, a development type cleaning line integrating degreasing, pickling, grinding, passivation and drying is used for cleaning the foil.

4. The production method according to claim 3, characterized by, The surface oil content of the foil after degreasing is less than 5 mg / m 2 .

5. The preparation method according to claim 1, characterized in that, A brush roll with Shore hardness A of 90 degrees to 95 degrees is used for grinding, and the grinding speed is 10m / min to 50m / min; and the surface roughness Ra of the foil after grinding is ≤0.12μm.

6. The preparation method according to claim 5, characterized in that, The brush roll is of a disc type or a radial type.

7. The preparation method according to claim 1, characterized in that, In the step S2, the stretch-bend-straightening process adopts a stretch-straightening plus multi-roller straightening mode, the stretch-straightening reduction is-1mm~ -6mm, the multi-roller straightening reduction of each section is-1mm~ -8mm, and two modes of tension control and elongation control are adopted, the tension control range is 10KN / mm 2 ~25KN / mm 2 , the elongation control range is 0.1%~0.3%, and the foil shape after straightening is less than 10i.

8. A high-strength high-elasticity beryllium copper foil for a 5G base station, characterized by comprising, The high-strength and high-elasticity beryllium copper foil for a 5G base station is prepared by using the steps in the preparation method of the high-strength and high-elasticity beryllium copper foil for a 5G base station according to any one of claims 1 to 7.

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