Electronic foil preparation device and electronic foil

Abstract

The invention provides an electronic foil preparation device and an electronic foil, relates to the technical field of electronic foil preparation, and aims to solve the technical problems that material foil is oxidized and denatured and the surface of a product is difficult to reach nanoscale granularity in existing electronic foil linkage preparation. The device comprises a crude foil engine, a conveying roller group and post-processing equipment, wherein the crude foil engine and the post-processing equipment are arranged on line; the conveying roller group comprises a plurality of conveying rollers, one or more of the conveying rollers are large-current conductive rollers and are positioned at the section, close to the crude foil machine, of the surface treatment tank, the total current is 200-2000 amperes, and the voltage is 2-20 volts; in the surface treatment tank, the material foil bypasses the conveying rollers to form an arc-shaped path below the liquid level, and inclined anodes are arranged on the two sides. Through the on-line connection of the crude foil engine and the post-processing equipment, the exposure time of the foil is shortened, and the oxidation denaturation of the foil is reduced; the current mutual interference between the crude foil engine and the post-processing equipment is avoided by utilizing the large-current conductive roller, and the preparation effect at two ends is guaranteed; and finally, the electronic foil which is uniform and compact in surface and meets the nanoscale granularity requirement is prepared.

Description

Technical Field

[0001] This disclosure relates to the field of electronic copper foil preparation technology, and in particular to an electronic foil preparation apparatus and an electronic foil. Background Technology

[0002] As a core basic material in the electronic information industry, the surface quality (such as particle size, profile, and roughness) of electronic copper foil directly determines the performance of downstream products. For example, the low profile of copper foil used in high-frequency and high-speed PCBs can reduce signal transmission loss.

[0003] Current electronic copper foil production generally employs a segmented process: after the foil is prepared by electrolytic deposition in the foil-making machine, it must first be wound into rolls and then transferred to separate post-processing equipment for unwinding. This process has two major drawbacks: Oxidation and crystal structure transformation issues: After the copper foil is peeled from the foil-making machine, the winding, transfer, and unwinding time can be as long as 24 hours or more. During this time, the active copper surface undergoes deep oxidation upon contact with air, and the surface crystal structure exhibits irreversible changes (such as abnormal grain growth and grain boundary oxidation). Even after subsequent acid pickling, the original crystal structure cannot be completely restored, resulting in a high surface profile of the finished copper foil (typically ≥1.5 micrometers), with particle diameters and heights at the micrometer level (≥1 micrometer) and uneven distribution, which fails to meet the requirements of high-end applications.

[0004] To overcome the aforementioned problems, existing electronic copper foil manufacturing technologies also include online production of foil-making machines and post-processing equipment to address oxidation and crystal transformation issues during foil production. Traditional post-processing equipment uses multiple electro-treatment tanks for step-by-step electro-treatment, with the electrode configuration typically having the cathode and anode located on opposite surfaces of the foil within the electro-treatment tank – essentially a distributed electrode configuration.

[0005] However, the post-processing equipment still uses the traditional multi-tank step-by-step process, such as combining the roughening tank with the curing tank for multiple cycles, without being optimized for the continuous production characteristics of online production: the traditional process relies on multiple tanks to generate crystal nuclei and inhibit crystal nuclei growth, but the material foil moving speed is relatively slow in online production, and the switching of multiple tanks can easily lead to fluctuations in the electrolytic field, making it difficult to prepare nanoscale uniform grains. Summary of the Invention

[0006] The purpose of this disclosure is to solve the problem of unstable post-processing electrolytic field in existing online electronic foil preparation devices.

[0007] According to a first aspect of this disclosure, an electronic foil manufacturing apparatus is provided, comprising a foil production machine and a post-processing device; the foil production machine and the post-processing device are configured in series, the post-processing device comprising a conveying roller group and a plurality of processing tanks; the end of the foil production machine is connected to the conveying roller group, the conveying roller group being used to sequentially convey the foil produced by the foil production machine through each of the processing tanks to the end of the post-processing device; the conveying roller group comprises a plurality of conveying rollers, wherein one or more of the conveying rollers are conductive rollers, at least one of the conductive rollers is located on the side of any surface treatment tank among the plurality of processing tanks adjacent to the foil production machine, the conductive roller is located outside the surface treatment tank, and the conductive roller is a high-current conductive roller.

[0008] In an exemplary embodiment of this disclosure, based on the foregoing scheme, the total current of the conductive roller is between 200 and 2000 amps.

[0009] In an exemplary embodiment of this disclosure, based on the foregoing scheme, the voltage of the conductive roller is higher than the cathode voltage of the foil-making machine, and the voltage of the conductive roller is between 2 and 20 volts.

[0010] In an exemplary embodiment of this disclosure, based on the foregoing scheme, the surface treatment tank is provided with an anode and a conveying roller. A portion of the roller surface of the conveying roller is submerged below the solution surface of the surface treatment tank. The foil to be treated is conveyed backward around the roller surface of the conveying roller which is submerged below the solution surface. The foil is in an arc shape attached to the roller surface below the solution surface of the surface treatment tank, and the anode is submerged below the solution surface of the surface treatment tank.

[0011] In an exemplary embodiment of this disclosure, based on the foregoing scheme, the anode includes two anodes, which are symmetrically arranged relative to a plane passing through the axis of the conveying roller and perpendicular to the solution surface, and located on both sides of the plane.

[0012] In an exemplary embodiment of this disclosure, based on the aforementioned scheme, the two anodes are arranged at an angle relative to the solution surface, and the lower ends of the two anodes are offset from the upper ends toward the plane by a predetermined distance, the predetermined distance being 1-10 centimeters.

[0013] In an exemplary embodiment of this disclosure, based on the aforementioned scheme, the conductive roller is made of metal and has an axially penetrating hollow channel inside; the hollow channel is used to circulate a cooling medium to cool the conductive roller and maintain its operating temperature at 20-35°C.

[0014] In an exemplary embodiment of this disclosure, based on the foregoing scheme, the total current of the conductive roller is between 1000 and 1250 amps, and the voltage of the anode closest to the conductive roller is between 7 and 8 volts.

[0015] In an exemplary embodiment of this disclosure, based on the foregoing scheme, the plurality of processing tanks include at least one surface treatment tank, at least one pickling tank, at least one washing tank, and one passivation tank; the pickling tank, washing tank, and passivation tank are sequentially arranged on the side of the surface treatment tank away from the foil production machine along the conveying direction of the foil.

[0016] In another aspect of this disclosure, an electronic foil is provided, which is prepared using an electronic foil preparation apparatus with a front-and-back scheme.

[0017] As can be seen from the above technical solution, this disclosure possesses at least one of the following advantages and positive effects: In this embodiment, the conductive roller facilitates the provision of cathode connection to the surface treatment tank downstream of the process, and the conductive current of this roller is above 200 amps. The conductive roller is located between the foil-making machine and the surface treatment tank, thereby preventing the current in the post-processing equipment from interfering with the current in the foil-making machine, thus ensuring the respective production effects of these two nodes. Attached Figure Description

[0018] The above and other features and advantages of this disclosure will become more apparent from a detailed description of exemplary embodiments thereof with reference to the accompanying drawings.

[0019] Figure 1 This is a schematic diagram of the structure of an electronic foil preparation apparatus according to an embodiment of the present disclosure.

[0020] Figure 2 This is a schematic diagram of another electronic foil preparation apparatus in an embodiment of this disclosure.

[0021] Figure 3 This is a schematic diagram of the surface treatment tank in an embodiment of this disclosure.

[0022] Figure 4 This is a rough electron microscope image of HVLP1 prepared according to the electronic foil preparation apparatus of this embodiment.

[0023] Figure 5 This is a smooth electron microscope image of HVLP1 prepared according to the electronic foil preparation apparatus of this embodiment.

[0024] Figure 6 This is a rough electron microscope image of HVLP2 prepared according to the electronic foil preparation apparatus of this embodiment.

[0025] Figure 7 This is a smooth electron microscope image of HVLP2 prepared according to the electronic foil preparation apparatus of this embodiment.

[0026] Figure 8 This is a rough electron microscope image of HVLP5 prepared according to the electronic foil preparation apparatus of this embodiment.

[0027] Figure 9 This is a smooth electron microscope image of HVLP5 prepared according to the electronic foil preparation apparatus of this embodiment.

[0028] Figure 10 This is a rough electron microscope image of RTF3 prepared according to the electronic foil preparation apparatus of this embodiment.

[0029] Figure 11 This is a smooth electron microscope image of RTF3 prepared according to the electronic foil preparation apparatus of this embodiment.

[0030] Figure 12 This is a rough electron microscope image of RTF4 prepared according to the electronic foil preparation apparatus of this embodiment.

[0031] Figure 13 This is a smooth electron microscope image of RTF4 prepared according to the electronic foil preparation apparatus of this embodiment.

[0032] Figure 14 This is a rough electron microscope image of ERF2 prepared according to the electronic foil preparation apparatus of this embodiment.

[0033] Figure 15 This is a smooth electron microscope image of ERF2 prepared according to the electronic foil preparation apparatus of this embodiment.

[0034] Figure 16 This is a rough electron microscope image of HTE3 prepared according to the electronic foil preparation apparatus of this embodiment.

[0035] Figure 17 This is a smooth electron microscope image of HTE3 prepared according to the electronic foil preparation apparatus of this embodiment.

[0036] The above figures include the following reference numerals: 1. Foil forming machine; 2. Conveying roller assembly; 21. Conductive roller; 22. Conveying roller; 3. Post-processing equipment; 32. Surface treatment tank; 321. First anode; 322. Second anode; 33. Passivation treatment tank; 34. Pickling treatment tank; 4. Foil material. Detailed Implementation

[0037] Exemplary embodiments will now be described more fully with reference to the accompanying drawings. However, these exemplary embodiments can be implemented in many forms and should not be construed as limited to the embodiments set forth herein; rather, they are provided so that this disclosure will be thorough and complete, and will fully convey the concept of the exemplary embodiments to those skilled in the art. The same reference numerals in the drawings denote the same or similar structures, and therefore their detailed description will be omitted.

[0038] like Figure 1As shown in the simplified structural diagram, the electronic foil preparation apparatus of this application embodiment mainly includes a foil production machine 1, a conveying roller group 2, and a post-processing device 3. The foil production machine 1 and the post-processing device 3 are configured in series, which can shorten the exposure time of the foil 4 from the foil production stage to the post-processing stage, avoid oxidation and crystallization of the foil 4 surface, and ensure that the initial surface state of the foil 4 meets the requirements of subsequent nanoscale processing. The conveying roller group 2 is partially connected to the rear end of the foil production machine 1 and can convey the foil 4 to the post-processing device 3, that is, it undertakes the continuous conveying function of the foil 4, ensuring that the foil 4 smoothly enters each processing tank of the post-processing device 3. The post-processing device 3 includes the conveying roller group 2 and multiple processing tanks. Each processing tank is arranged sequentially along the conveying direction of the foil 4 to form a complete post-processing process of "surface treatment-pickling-washing-passivation". The surface treatment tank 32 is a functional tank used to realize the construction of nanoscale particles on the surface of the foil 4. The pickling tank, washing tank, and passivation tank respectively undertake the functions of impurity removal, cleaning treatment, and corrosion resistance modification, ensuring that the performance of the finished copper foil meets the standards.

[0039] In this embodiment, after the foil 4 is prepared from the foil-making machine 1, it enters the post-processing equipment 3 via the conveyor roller group 2. The foil 4 is a conductor and electrically connected between the foil-making machine 1 and the post-processing equipment 3, which is equivalent to the foil 4 being sequentially electrically connected to each processing node of this processing equipment. In each processing tank, a cathode conductive roller 21 is configured. The conductive roller 21 is located on the side of one of the surface treatment tanks adjacent to the foil-making machine 1, and is located outside the liquid surface of the surface treatment tank 32. The conductive roller 21 facilitates the provision of cathode connection to the surface treatment tank 32 downstream of the process, and the conductive current of this conductive roller 21 is above 200 amps. The conductive roller 21 is located between the foil-making machine 1 and the surface treatment tank 32 to avoid mutual interference between the current in the post-processing equipment 3 and the current in the foil-making machine 1, thereby ensuring the preparation effect of each of these two nodes.

[0040] On the other hand, the number of conductive rollers 21 is not limited to one; conductive rollers 21 can also be configured in front of other processing tanks equipped with anodes.

[0041] The foil-forming machine 1 in this embodiment can adopt a horizontal electrolysis structure, mainly composed of a cathode roller, an anode, an electrolyte tank, and a stripping roller. The cathode roller is made of titanium, with a diameter of 2.7 meters. Its surface is precision polished to a roughness Ra≤0.2μm. This size and surface precision design ensures that the initial flatness of the foil 4 meets the standard when deposited on the cathode roller surface, avoiding unevenness of the initial surface of the foil 4 due to defects on the cathode roller surface. The cathode roller is driven by a drive system to rotate at a speed of 1.0 rpm, matching a foil-forming speed of 2.5 m / min, ensuring the uniformity of the foil 4 thickness and meeting the HVLP5 requirements of "product thickness 12μm (1 / 3OZ), unit area mass 108±3g / ㎡". The anode and cathode roller are arranged opposite each other in the electrolyte tank to meet the requirements of high-current electrolysis. The electrolyte in the electrolyte tank is a mixture of copper sulfate and sulfuric acid. The electrolyte system, with a copper sulfate concentration of 200 g / L and a sulfuric acid concentration of 80 g / L, is maintained at a temperature of 42 ± 1℃ and a pH value of 1.8 ± 0.1. This electrolyte system ensures stable deposition of copper ions and avoids uneven composition of the foil 4 due to fluctuations in electrolyte concentration or temperature. The cathode current of the foil-making machine 1 is set to 29,600 amps and the cathode voltage to 4.0 V. This parameter combination enables the stable generation of 12 μm thick foil 4. After being peeled off from the cathode roller by the peeling roller, the foil 4 directly enters the conveying roller group 2, eliminating the winding and transfer step in the traditional segmented process. This effectively controls the exposure time of the foil 4 to ≤1.0 minute, which is far lower than the industry-standard interval of more than 24 hours, reducing the risk of oxidation on the surface of the foil 4 from the source.

[0042] The conveyor roller group 2 includes multiple active rollers driven by servo motors and multiple driven rollers. The active rollers and driven rollers are distributed at intervals on each node of the post-processing equipment 3. The servo motors of the active rollers are linked to the foil production speed of the foil production machine 1 through the PLC control system, and the speed is adjusted in real time to ensure synchronization with the foil production speed of 2.5 meters / minute, so as to avoid stretching or wrinkling of the foil 4 during the conveying process. The driven rollers serve as auxiliary support components and are evenly distributed among the active rollers to further ensure the flatness of the foil 4 conveying, laying the foundation for the uniformity of subsequent surface treatment. The conveyor roller group 2 includes a high-current conductive roller 21. This conductive roller 21 is located on the side of the surface treatment tank 32 adjacent to the foil-making machine 1, serving as the electrical inlet for the post-processing stage. It is made of stainless steel, which possesses both good conductivity and resistance to electrolyte corrosion, making it suitable for the electrolyte environment of the post-processing stage and preventing a decline in conductivity due to electrolyte erosion during long-term use. The high-current conductive roller 21 has an axially penetrating hollow channel with a diameter of 3 cm. Deionized water at 32°C flows through the channel as a cooling medium at a flow rate of 8 L / min. This cooling system maintains the operating temperature of the high-current conductive roller 21 at 30±2°C, preventing the heat generated during high-current operation from causing thermal deformation of the foil 4 and ensuring that the foil 4 remains flat when it enters the surface treatment tank 32 while energized. It should be noted that the thickness of the copper foil in the foil-making section is adjustable, ranging from 4 micrometers to 200 micrometers.

[0043] The post-processing equipment 3 includes a surface treatment tank 32 as its core function, specifically configured as follows: The tank contains one conveying roller 22 and two anodes, namely, a first anode 321 and a second anode 322. The conveying roller 22 can be an active roller with a diameter of 350mm, and two-thirds of its surface is immersed in the electrolyte. The foil 4 is conveyed backwards around the surface of the conveying roller below the electrolyte surface, forming an arc shape attached to the surface of the conveying roller 22 below the liquid surface, with an arc path radius of 10cm. This arc design extends the contact time between the foil 4 and the electrolyte, while also providing space for the formation of a gradual electrolytic field. The first anode 321 and the second anode 322 can be constructed using zinc plates or titanium metal grid structures. Titanium metal grids not only possess excellent conductivity and resistance to electrolyte corrosion, but their grid structure also promotes uniform electrolyte flow, avoiding surface treatment differences caused by uneven local electrolyte concentration. The first anode 321 and the second anode 322 are symmetrically arranged on both sides of the conveying roller 22, i.e., opposite to each other after the conveying roller. The roller 21 is symmetrically arranged on the plane perpendicular to the solution surface along its axis and at a 65° angle to the solution surface, i.e., at a 25° angle relative to the plane perpendicular to the solution surface along the axis of the conveying roller 21. The lower end is offset 8 cm relative to the upper end towards the center of the surface treatment tank 32. This tilt and offset design makes the distance between different points on the arc path of the foil 4 and the first anode 321 and the second anode 322 gradually distributed (the closest distance is 2 cm and the farthest distance is 5 cm), thereby forming a gradual electrolytic field from 25 A / dm² (the inlet end of the foil 4) to 5 A / dm² (the outlet end of the foil 4), providing a stable electrolytic environment for the "roughening-curing" composite alternating treatment of the foil 4 surface. The electrolyte in the surface treatment tank 32 is a mixture of copper sulfate and sulfuric acid with concentrations of 160 g / L and 90 g / L, respectively, and the temperature is controlled at 38 ± 1 °C. These electrolyte parameters ensure that copper ions are stably deposited in the gradual electrolytic field to form nano-sized particles.

[0044] Specifically, such as Figure 3 As shown, the electrolytic reaction zone of the foil 4 to be surface-treated in the electrolyte in the surface treatment tank 32 is roughly divided into three segments. Segment A is the section on the feed side where the first anode 321 is close to and roughly parallel to the foil 4. Segment B is the area where the foil 4 does not correspond to either the first anode 321 or the second anode 322. Segment C is the section on the discharge side where the foil 4 is close to and roughly parallel to the second anode 322. Among these, segment A has the highest current density, thus undergoing a roughening (generating crystal nuclei) reaction, while segment B undergoes a solidification (inhibiting crystal nuclei growth) reaction. The current density in segment C is lower than that in segment A but higher than that in segment B, resulting in a "roughening-solidification" composite alternating treatment on the surface of the foil 4. Furthermore, in segment B, the foil 4 forms a continuously gradually changing distance distribution with the inclined anode along an arc-shaped path, corresponding to a current density that gradually changes from 25 A / dm² to 5 A / dm².

[0045] In the above embodiments, without the potential isolation of the high-current conductive roller (voltage higher than 3.5V of the foil forming machine), the current fluctuation of the foil forming machine will cause the current density gradient of the gradual electrolytic field to shift from 25-5A / dm² to 20-8A / dm², and the agglomeration rate of nanoparticles will increase from ≤5% to ≥20%. Without the gradual electrolytic field, the high-current conductive roller can only improve the processing efficiency (2.5m / min), but the particle size will increase from 50-200nm to 300-500nm, which cannot meet the high-end requirements.

[0046] The pickling solution in pickling tank 34 is a sulfuric acid solution with a concentration of 60 g / L and a temperature of 30°C. The foil 4 is treated in the tank for 15 seconds to remove any trace oxide layer and electrolyte impurities that may remain on the surface of the foil 4, thus preventing impurities from affecting the uniformity of the subsequent nanoscale particles. The passivation solution in passivation tank 33 is a chromate solution with a concentration of 12 g / L, a pH value of 3.5, and a temperature of 30°C. The foil 4 is treated for 30 seconds to form an 8 nm thick chromate passivation film on the surface of the foil 4, meeting the potential requirements of high-end copper foil for corrosion resistance (neutral salt spray test ≥96 hours).

[0047] In one embodiment, the "first anode 321 and second anode 322 of titanium metal grid" in the surface treatment tank 32 can be replaced with "titanium metal mesh anode (mesh size 0.5×0.5mm, wire diameter 0.2mm)", while maintaining a 25° tilt angle and an 8cm lower offset. The mesh structure of the titanium mesh improves the electrolyte flow efficiency by 30%, and the electrolyte concentration fluctuation in the surface treatment tank 32 is reduced from ±5% to ±2%. Because the electrolyte flow is more uniform, the current density gradient can be optimized to 20-3A / dm² (originally 25-5A / dm²), while still maintaining the gradual change characteristics.

[0048] The uniformity of particles on the foil surface is improved. The measured roughness Rz of the treated side of RTF4 copper foil is 1.33-1.40μm (better than the original titanium grid's 1.33-1.45μm). It is suitable for products with high requirements for electrolyte uniformity (such as ERF buried resistive copper foil). When treating WW-E-50, the temperature coefficient of resistance (TCR) can be reduced from 60ppm / ℃ to 55ppm / ℃, and the thermal stability is better.

[0049] Example 1: HVLP high frequency high speed ultra-low profile copper foil (copper foil thickness adjustable, 4-200 micrometers).

[0050] 1. Product models that can be manufactured: HVLP1: Suitable for substrate-like SLP / IC packaging, high-end consumer electronics and 5G communication, with a side roughness Rz≤2.0μm.

[0051] HVLP2: Suitable for IC packaging and high-speed digital circuits (HSD), handling side roughness Rz≤1.5μm.

[0052] HVLP3: Suitable for IC packaging and high-speed digital circuits, handling side roughness Rz≤1.0μm.

[0053] HVLP4: Suitable for IC packaging and high-speed digital circuits, handling side roughness Rz≤0.8μm.

[0054] HVLP5: Suitable for IC packaging and high-speed digital circuits, handling side roughness Rz≤0.5μm.

[0055] 2. Preparation instructions: Foil production parameter adjustment: According to the thickness requirements of each model, foil production machine 1 prepares 12μm (1 / 3OZ), 18μm (1 / 2OZ), and 35μm (1OZ) foils 4, with the cathode current maintained at 29600A, and the electrolyte concentration of copper sulfate at 200g / L and sulfuric acid at 80g / L.

[0056] High-current conductive roller parameters: HVLP1-HVLP3 use conductive roller 21 with a current of 1000 amps and a voltage of 7.0 volts; HVLP4-HVLP5 use a current of 1250 amps and a voltage of 7.5 volts (higher than the cathode voltage of the foil-making machine by 3.5 volts) to ensure a stable electrolytic field.

[0057] Surface treatment tank parameters: HVLP1-HVLP2: The first anode 321 and the second anode 322 are tilted at an angle of 20°, with the lower end offset by 5 cm. The current density gradient is 18-5 A / dm², and the electrolyte is copper sulfate 160 g / L and sulfuric acid 90 g / L.

[0058] HVLP3-HVLP4: Anode tilt angle 22°, lower end offset 6 cm, current density gradient 15-5 A / dm², electrolyte additive (concentration 3 g / L).

[0059] HVLP5: Anode tilt angle 25°, lower end offset 8 cm, current density gradient 25-5 A / dm², electrolyte additive concentration 5 g / L, to enhance the generation of nano-sized particles.

[0060] Post-processing: pickling time 15 seconds, water washing time 20 seconds, passivation time 30 seconds. For HVLP4-HVLP5, an additional precision water washing (resistivity ≥20MΩ・cm) is added to avoid impurities affecting surface roughness.

[0061] 3. Technical effects: HVLP1: Measured surface roughness Rz of the treated side is 1.66-1.87 μm, and that of the untreated side is 1.3-1.5 μm, both meeting the requirements of ≤2.0 μm / ≤1.5 μm. Figure 4 , Figure 5As shown, SEM inspection (5.00KX) shows that the surface particles are uniform, without agglomeration, and the grains are dense, which meets the signal transmission requirements of 5G communication equipment.

[0062] HVLP2: The measured surface roughness Rz of the treated side is 1.41-1.49 μm, and that of the untreated side is 1.2-1.4 μm, both meeting the requirement of ≤1.5 μm. (See attached image) Figure 6 , Figure 7 As shown; tensile strength ≥300MPa (RT), ≥190MPa (180℃), elongation ≥11% (RT), matching the processing requirements of IC packaging substrate.

[0063] HVLP5: Measured surface roughness Rz of the treated side is 0.4-0.5 μm, while that of the untreated side is 1.2-1.4 μm, fully meeting the requirement of ≤0.5 μm; SEM inspection ( Figure 8 , Figure 9 The surface particle size is 50-180 nm, and the distribution density is ≥1×10⁻⁶. 6 Each piece per square millimeter shows no signs of oxidation.

[0064] Example 2: RTF reverse copper foil (RTF1-RTF4).

[0065] 1. Product Model: RTF1: Suitable for high-density interconnect (HDI) boards and automotive electronics, handling side roughness Rz≤3.0μm.

[0066] RTF2: Suitable for HDI and automotive electronics, with a side roughness Rz≤2.3μm.

[0067] RTF3: Suitable for HDI and automotive electronics, with a side roughness Rz≤2.1μm.

[0068] RTF4 (WW-R-LR): Suitable for HDI and automotive electronics, for processing side roughness Rz≤1.9μm.

[0069] 2. Preparation instructions: Foil production parameter adjustment: Foil production machine 1 prepares 12μm, 18μm, and 35μm foils 4, with copper sulfate concentration of 190g / L and sulfuric acid concentration of 75g / L in the electrolyte, and temperature of 41±1℃, to improve the toughness of foil 4.

[0070] High-current conductive roller parameters: RTF1-RTF2 use conductive roller 21 with a current of 1100 amps and a voltage of 7.2 volts; RTF3-RTF4 use a current of 1200 amps and a voltage of 7.4 volts to ensure fine surface treatment.

[0071] Surface treatment tank parameters: RTF1-RTF2: The first anode 321 and the second anode 322 are tilted at an angle of 18°, with the lower end offset by 5 cm. The current density gradient is 22-8 A / dm², and an etching optimizer (concentration 2 g / L) is added to the electrolyte.

[0072] RTF3-RTF4: Anode tilt angle 20°, lower end offset 7 cm, current density gradient 20-6 A / dm², electrolyte etching optimizer concentration 3 g / L, to improve etching accuracy.

[0073] Post-processing: Pickling time is 18 seconds to enhance the removal of surface impurities; passivation treatment uses a composite passivation solution (chromate + silane) for 35 seconds to improve peel strength; RTF3-RTF4 adds a tension calibration process, with tension controlled at 60N to ensure surface flatness after flipping.

[0074] 3. Technical effects: RTF3: Measured surface roughness Rz of the treated side is 1.68-1.93 μm, and that of the untreated side is 3.5-4.0 μm, which meets the specifications in the brochure: ≤2.1 μm / ≤4.0 μm. Figure 10 , Figure 11 As shown; peel strength (PPO substrate) ≥2.0lb / in, etching accuracy deviation ≤0.02mm, meeting the fine circuit processing requirements of HDI board.

[0075] RTF4: Measured surface roughness Rz of the treated side is 1.33-1.45 μm, and that of the untreated side is 3.0-3.8 μm, both meeting the requirements of ≤1.9 μm / ≤3.0 μm; SEM inspection ( Figure 12 , Figure 13 The surface exhibits uniform particle distribution, no burrs, and corrosion resistance (neutral salt spray test) ≥72 hours, making it suitable for the harsh environment of automotive electronics.

[0076] Example 3: HTE high temperature and high elongation copper foil.

[0077] 1. Product Model: WW-H-HR: Suitable for RF and microwave printed circuit boards and base station infrastructure, handling side roughness Rz ≥ 4.0 μm. WW-H-MR: Suitable for IC substrates and HDI / SLP, mobile communication devices, with side roughness of 4.0>Rz>2.0μm.

[0078] 2. Preparation instructions: Foil production parameter adjustment: Foil production machine 1 prepares 12μm, 18μm, and 35μm foils 4, the cathode current is adjusted to 30000 amps, a high temperature stabilizer (concentration 4g / L) is added to the electrolyte, the temperature is 43±1℃, and the high temperature ductility of foil 4 is improved.

[0079] High-current conductive roller parameters: The conductive roller 21 has a current of 1250 amps and a voltage of 7.5 volts to ensure stable temperature (30±2℃) under high current.

[0080] Surface treatment tank parameters: WW-H-HR: The first anode 321 and the second anode 322 are tilted at an angle of 15°, with the lower end offset by 5 cm. The current density gradient is 28-10 A / dm², and a roughening and strengthening agent (concentration 3 g / L) is added to the electrolyte.

[0081] WW-H-MR: Anode tilt angle 17°, lower end offset 6 cm, current density gradient 25-8 A / dm², roughening and reinforcing agent concentration 2 g / L, balancing roughness and ductility.

[0082] Post-processing: Pickling time 20 seconds to remove surface oxide layer; Curing treatment tank (added between surface treatment tank and pickling tank) current density 10A / dm², treatment time 10 seconds to enhance grain stability; Passivation treatment time 40 seconds to improve high temperature oxidation resistance.

[0083] 3. Technical effects: WW-H-MR: Measured surface roughness Rz of the treated side is 2.5-3.0μm, and that of the untreated side is 1.3-1.5μm, meeting the specification of 4.0>Rz>2.0μm / ≤1.5μm; tensile strength ≥300MPa (RT), ≥190MPa (180℃), elongation ≥8% (RT), ≥12.5% ​​(180℃), meeting the requirements for high-temperature lamination processing of IC substrates; SEM inspection (… Figure 16-17 The surface particles are dense with no grain boundary oxidation. After being placed at high temperature (180℃) for 2 hours, the elongation decreases by ≤5%, indicating excellent antioxidant properties.

[0084] Example 4: ERF buried copper foil.

[0085] 1. Product Model: WW-E-50: Suitable for consumer electronics and aerospace, with a standard resistance of 50Ω.

[0086] WW-E-50+: Suitable for consumer electronics and aerospace, with a standard resistance of 63Ω.

[0087] WW-E-25: Suitable for consumer electronics and aerospace, with a standard resistance of 25Ω.

[0088] WW-E-10: Suitable for consumer electronics and aerospace, with a standard resistance of 10Ω.

[0089] 2. Preparation instructions: Foil production parameter adjustment: Foil production machine 1 prepares 18μm foil 4, nickel-cobalt composite salt (concentration 5g / L) is added to the electrolyte, cathode current is 29800 A, temperature is 42±1℃, and the basis for resistance regulation is established.

[0090] High-current conductive roller parameters: The conductive roller 21 is used with a current of 1250 amps and a voltage of 7.5 volts to ensure uniformity of resistive layer deposition.

[0091] Surface treatment tank parameters: First anode 321 and second anode 322 tilt angle 20°, lower end offset 8 cm, current density gradient 18-6A / dm², electrolyte with added resistance control additive (concentration 4-8g / L, adjusted according to resistance requirements: 8g / L for WW-E-10, 4g / L for WW-E-50).

[0092] Post-treatment process: pickling time is 15 seconds to remove surface impurities; water washing adopts three-stage water washing (resistivity ≥10MΩ・cm, 15MΩ・cm, 20MΩ・cm respectively) to avoid electrolyte residue affecting resistance stability; passivation treatment uses chromium-free passivation solution, treatment time is 30 seconds to improve thermal stability.

[0093] 3. Technical effects: WW-E-50: Measured sheet resistance is 50.2Ω, with a sheet resistance fluctuation of ≤3.2%, meeting the 50Ω / ≤5% specification; Temperature coefficient of resistance (TCR) is 58ppm / ℃, capacitance (5Hz) is 0.9pF, and inductance (5Hz) is 0.5nH, meeting the impedance matching requirements of high-frequency circuits; SEM testing ( Figure 14-15 The resistive layer exhibits uniform particle size and no agglomeration. After 100 thermal cycles (25°-125°C), the sheet resistance fluctuation is ≤4%, demonstrating excellent thermal stability. The surface roughness of the treated side is Rz 5.2-5.8μm, while that of the untreated side is Rz 1.5-1.7μm. The peel strength (PTFE substrate) is ≥11lb / in, making it suitable for the harsh environments of aerospace equipment.

[0094] Other variations of the embodiments in this application: The "post-processing equipment 3" (including high-current conductive roller 21, surface treatment tank 32, pickling / washing / passivation tank) in the embodiments of this application is not connected to the foil production machine 1; the foil 4 comes from an external foil production machine (not the foil production machine 1 of this application), and after being wound up, it is transferred to the unwinding station of the post-processing equipment 3. After unwinding, it first passes through the high-current conductive roller 21 and then enters each processing tank.

[0095] High-current conductive roller 21 parameters: total current 1000-1250A, voltage 6-7.5V (no need to match the cathode voltage of a specific foil production machine, only needs to be 0.5-1V higher than the initial potential of the foil after unwinding), cooling medium is 32℃ deionized water, flow rate 6-8L / min.

[0096] Parameters of surface treatment tank 32: the tilt angle of the first anode 321 and the second anode 322 is 20-25°, the lower end is offset by 5-8cm, the current density gradient is 15-25A / dm²→5A / dm², and the electrolyte is copper sulfate 150-180g / L + sulfuric acid 80-100g / L.

[0097] Foil exposure control: After the foil is wound up by the external foil forming machine, the time for transferring it to the subsequent processing equipment is controlled to 2-4 hours (shorter than the traditional 24 hours). With the electrical optimization of the high-current conductive roller, the impact of oxidation can still be reduced.

[0098] The surface oxidation rate of the foil is controlled at ≤5% (lower than ≥30% of the traditional segmented process), and the surface particle size can reach 100-300nm (although slightly higher than 50-200nm of the online mode, it still meets the needs of mid-to-high-end copper foil, such as RTF1-RTF2).

[0099] Suitable for small and medium-scale production scenarios (no need for a foil production machine), it can process externally purchased foil rolls, reducing initial equipment investment.

[0100] The preparation apparatus of this embodiment is adapted for the preparation of shielding copper foil, blackened copper foil, and aluminum foil.

[0101] In this application, the core design of the electronic foil preparation apparatus (such as online configuration, gradient electrolytic field, modular processing tank, high-current conductive roller, etc.) is universal and not limited to only the HVLP, RTF, HTE, ERF and other electronic copper foil types mentioned above. Based on the preparation logic of different functional electronic copper foils in the existing embodiments (such as achieving specific surface performance modification of the foil by adjusting the electrolytic parameters of the surface treatment tank, the electrolyte system or the post-processing process), those skilled in the art can obviously infer that this apparatus can also be used to prepare shielding copper foil, blackened copper foil and aluminum foil.

[0102] For shielding copper foil, the core requirement is to form a modified layer (such as a nickel-cobalt alloy layer, a conductive oxide layer, etc.) with electromagnetic shielding function on the foil surface. This is consistent with the idea in this patent of controlling the deposition of particles on the foil surface through a gradual electrolytic field to achieve specific surface properties (such as low profile and high density). By simply referring to the existing electronic copper foil preparation logic and adjusting the electrolyte composition (such as adding an alloy ion source) and electrolytic parameters (such as current density gradient and voltage) in the surface treatment tank, the continuous preparation of shielding copper foil can be completed by utilizing the online delivery and stable electrolytic field of the device, without the need for innovative modifications to the core structure of the device.

[0103] For blackened copper foil, the key lies in forming a uniform black oxide layer or composite layer on the surface of the copper foil through chemical or electrolytic methods to enhance its adhesion to the resin. The modular process of "surface treatment-pickling-washing-passivation" in the post-processing equipment of this patent has the adjustment space to adapt to different surface modification requirements. Referring to the post-processing logic of existing electronic foils, it is only necessary to replace the electrolyte in the surface treatment tank with a system suitable for the blackening reaction (such as alkaline oxidation solution) and fine-tune conventional parameters such as processing time and temperature to achieve the preparation of blackened copper foil. This adaptation method is a conventional application extension that can be directly conceived by those skilled in the art based on existing experience.

[0104] For aluminum foil (such as electrolytic aluminum foil commonly used in the electronics industry, pharmaceutical aluminum foil, etc.), the core framework of this device (continuously conveying roller group, adjustable electrolytic / chemical treatment tank, and potential isolation design of high-current conductive roller) is essentially a general platform for "continuous foil preparation + surface functional modification". Referring to the existing electronic copper foil preparation logic, only by changing the raw material system of the foil production machine (such as using aluminum electrolyte instead of copper electrolyte), adjusting the chemical reagents of the treatment tank (such as adapting to aluminum passivation solution and etching solution), and adapting the conveying roller group to conventional materials (such as selecting aluminum corrosion resistant metal materials) according to the material characteristics of aluminum foil, the device can be used for continuous preparation and post-processing of aluminum foil. The entire adaptation process does not need to break through the core design concept of the original device, which is an obvious application expansion.

[0105] In summary, the core design of the device in this application does not limit the type of foil or the surface function. Based on the preparation logic of different electronic copper foils in the existing embodiments, those skilled in the art can directly infer its compatibility with shielding copper foil, blackened copper foil and aluminum foil without creative labor.

[0106] It should be understood that this disclosure is not limited to the detailed structure and arrangement of the components presented herein. This disclosure is capable of other embodiments and can be implemented and performed in various ways. The foregoing variations and modifications fall within the scope of this disclosure. It should be understood that this disclosure, and the defined disclosure, extends to all alternative combinations of two or more individual features mentioned or apparent in the text and / or drawings. All these different combinations constitute multiple alternative aspects of this disclosure. The embodiments described in this disclosure illustrate the best known mode for implementing this disclosure and will enable those skilled in the art to utilize this disclosure.

Claims

1. An electronic foil preparation apparatus, characterized in that, Including foil making machines and post-processing equipment; The foil-making machine and the post-processing equipment are configured to be connected in series. The post-processing equipment includes the conveying roller group and multiple processing tanks. The end of the foil-making machine is connected to the conveying roller group, which is used to convey the foil produced by the foil-making machine through each of the processing tanks to the end of the post-processing equipment. The conveying roller group includes multiple conveying rollers, one or more of which are conductive rollers. At least one of the conductive rollers is located on the side of any of the surface treatment tanks in the plurality of processing tanks adjacent to the foil production machine. The conductive roller is located outside the surface treatment tank and is a high-current conductive roller.

2. The electronic foil preparation apparatus according to claim 1, characterized in that, The total current of the conductive roller is between 200 and 2000 amps.

3. The electronic foil preparation apparatus according to claim 1, characterized in that, The voltage of the conductive roller is higher than the cathode voltage of the foil-making machine, and the voltage of the conductive roller is between 2 and 20 volts.

4. The electronic foil preparation apparatus according to claim 1, characterized in that, The surface treatment tank is equipped with an anode and a conveying roller. Part of the roller surface of the conveying roller is submerged below the solution surface of the surface treatment tank. The foil to be treated is conveyed backward around the roller surface of the conveying roller that is submerged in the solution. The foil is in an arc shape attached to the roller surface below the liquid surface of the surface treatment tank, and the anode is immersed in the solution surface of the surface treatment tank.

5. The electronic foil preparation apparatus according to claim 4, characterized in that, The anode includes two anodes, which are symmetrically arranged on opposite sides of a plane passing through the axis of the conveying roller and perpendicular to the solution surface.

6. The electronic foil preparation apparatus according to claim 5, characterized in that, The two anodes are arranged at an angle relative to the solution surface, and the lower ends of the two anodes are offset from the upper ends of the plane by a predetermined distance, the predetermined distance being 1-10 cm.

7. The electronic foil preparation apparatus according to claim 1, characterized in that, The conductive roller is made of metal and has an axially penetrating hollow channel inside. The hollow channel is used to circulate cooling medium to cool the conductive roller and maintain its operating temperature at 20-35℃.

8. The electronic foil preparation apparatus according to claim 1, characterized in that, The total current of the conductive roller is between 1000 and 1250 amps, and the voltage of the anode closest to the conductive roller is between 7 and 8 volts.

9. The electronic foil preparation apparatus according to claim 1, characterized in that, The plurality of processing tanks include at least one surface treatment tank, at least one pickling tank, at least one water washing tank, and at least one passivation tank; The pickling tank, washing tank, and passivation tank are sequentially arranged on the side of the surface treatment tank away from the foil production machine along the conveying direction of the foil.

10. An electronic foil, characterized in that, Prepared by the electronic foil preparation apparatus according to any one of claims 1 to 9.

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