Processing technology of ultra-thin calendered foil for electronic circuits

Abstract

The present invention aims to disclose a processing process for ultra-thin calendered plain foil for electronic circuits, comprising the following steps: rolling a copper strip with a thickness of 0.15 mm to 0.2 mm through multiple passes to a first plain foil with a thickness of 6 μm to 20 μm; cleaning the first plain foil through two passes of a hydrocarbon degreasing agent solution; drying the cleaned first plain foil; and rolling the dried first plain foil through a wrinkle removal roller, wherein a first diagonal roller surface and a second diagonal roller surface are symmetrically arranged at both ends of the wrinkle removal roller, and the first plain foil is hood annealed to obtain a second plain foil. The beneficial effect is that the first plain foil is rolled after passing through the wrinkle removal roller, wherein the first diagonal roller surface and the second diagonal roller surface are symmetrically arranged at both ends of the wrinkle removal roller, and the middle part of the wrinkle removal roller is a smooth roller, and the wrinkled plain foil is flattened by the surface diagonal grooves of the first diagonal roller surface and the second diagonal roller surface, flattening is achieved while ensuring that most of the width of the ultra-thin calendered plain foil passes through the smooth roller, and the ultra-thin calendered plain foil is rolled up while eliminating wrinkles.

Description

Technical Field

[0001] The present invention relates to the technical field of ultra-thin copper foil processing for new energy, and in particular to a processing technology of ultra-thin calendered copper foil for electronic circuits. Background Art

[0002] Calendered foil is widely used in flexible copper clad laminates (FCCLs), flexible printed circuits (FPCs), 5G and 6G communications, electromagnetic shielding, heat dissipation substrates, graphene film preparation, aerospace, lithium batteries, LEDs, smart cars, drones, wearable electronics, and other industries. Calendered foil, due to its micron-level thickness, is prone to wrinkling during the cleaning and degreasing process after rolling and thinning, resulting in substandard quality of the rolled foil. Furthermore, uneven tension during the cleaning and degreasing process can also lead to wrinkling and even breakage of the foil, seriously affecting cleaning and degreasing efficiency.

[0003] In view of this, there is an urgent need to develop a processing technology for ultra-thin calendered light foil for electronic circuits to overcome the above-mentioned defects. Summary of the Invention

[0004] The purpose of the present invention is to disclose a processing technology for ultra-thin calendered light foil for electronic circuits. The first light foil with a thickness of 6μm-20μm is cleaned and dried with two passes of hydrocarbon degreasing agent solution, and then passed through a wrinkle removal roller and rolled up, so that the ultra-thin calendered light foil can be rolled up without wrinkles.

[0005] To achieve the above-mentioned object of the invention, the present invention provides a process for processing ultra-thin calendered light foil for electronic circuits, comprising the following steps:

[0006] The copper strip with a thickness of 0.15 mm to 0.2 mm is rolled into a first smooth foil with a thickness of 6 μm to 20 μm through multiple passes;

[0007] The first plain foil is cleaned by two passes of a hydrocarbon degreasing agent solution;

[0008] Drying the cleaned first smooth foil;

[0009] The dried first plain foil is rolled up after passing through a wrinkle removal roller, wherein a first diagonal roller surface and a second diagonal roller surface are symmetrically provided at both ends of the wrinkle removal roller;

[0010] The first plain foil is subjected to a mask annealing to obtain a second plain foil.

[0011] Preferably, the multi-pass rolling has 6 to 10 passes.

[0012] Preferably, the heat treatment temperature of the bell annealing is 200° C.-350° C., the temperature is raised for 3 h-6 h, and the temperature is kept for 5 h-12 h; after annealing, the heat treatment is cooled to room temperature with water.

[0013] Preferably, the widths of the first diagonal roller surface and the second diagonal roller surface are 10 mm to 50 mm respectively.

[0014] Preferably, the diagonal lines on the first diagonal roller surface and the second diagonal roller surface are extended and intersected to form a V shape.

[0015] Preferably, the first plain foil is dried by passing through a first row of guide rollers and a second row of guide rollers staggered in the height direction, wherein the number of guide rollers in the first row of guide rollers is one more than the number of guide rollers in the second row of guide rollers;

[0016] The first plain foil is introduced from the first row of guide rollers and shuttles between the first row of guide rollers and the second row of guide rollers, and the substrate is guided out from the first row of guide rollers.

[0017] Preferably, the first row of guide rollers includes a first upper guide roller, a second upper guide roller, a third upper guide roller and a fourth upper guide roller; the second row of guide rollers includes a first lower guide roller, a second lower guide roller and a third lower guide roller.

[0018] Preferably, the first row of guide rollers and the second row of guide rollers are both active rollers.

[0019] Preferably, the pulling tension of the first smooth foil during cleaning, drying and winding is 200N-500N.

[0020] Preferably, the line speed of the first smooth foil during cleaning is 30 m / min-60 m / min.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] The first smooth foil is rolled up after passing through the wrinkle-removing roller. The first diagonal roller surface and the second diagonal roller surface are symmetrically arranged at both ends of the wrinkle-removing roller, and the middle part of the wrinkle-removing roller is a smooth roller. The wrinkled film is flattened by the surface diagonal lines of the first diagonal roller surface and the second diagonal roller surface. The ultra-thin calendered smooth foil of most widths is flattened while passing through the smooth roller, and the ultra-thin calendered smooth foil can be rolled up without wrinkles. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a process flow chart of the ultra-thin calendered light foil processing of the present invention.

[0024] Figure 2 Schematic diagram of the wrinkle removal roller of the present invention.

[0025] Figure 3 This is a schematic diagram of the cleaning and drying production line for the ultra-thin calendered light foil of the present invention.

[0026] Among them, 1. Cleaning tank; 11. Active roller; 2. First row of guide rollers; 21. First upper guide roller; 22. Second upper guide roller; 23. Third upper guide roller; 24. Fourth upper guide roller; 3. Second row of guide rollers; 31. First lower guide roller; 32. Second lower guide roller; 33. Third lower guide roller; 4. First tension sensor; 5. Second tension sensor; 6. Wrinkle removal roller; 61. First twill roller surface; 62. Second twill roller surface; 7. Twill; 8. First smooth foil; 9. Drying chamber; 10. Pinhole inspection. DETAILED DESCRIPTION

[0027] The present invention is described in detail below with reference to the various embodiments shown in the accompanying drawings, but it should be noted that these embodiments are not limitations of the present invention, and any equivalent transformations or substitutions in functions, methods, or structures made by ordinary technicians in this field based on these embodiments are all within the scope of protection of the present invention.

[0028] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thick", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like to indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operate in a specific direction, and therefore should not be understood as limiting the present invention.

[0029] Example 1

[0030] See also Figures 1 to 3 This embodiment provides a process for processing ultra-thin calendered light foil for electronic circuits, comprising the following steps:

[0031] Step S1: rolling a copper strip with a thickness of 0.15mm-0.2mm into a first plain foil with a thickness of 6μm-20μm through multiple passes; specifically, the rolling passes of the multiple passes are 6-10 times, and the thickness of the first plain foil after rolling is 6μm-20μm, preferably 8μm and 12μm.

[0032] Step S2: See Figure 3The first plain foil is cleaned by two passes of hydrocarbon degreasing agent solution. Specifically, the surface of the first plain foil obtained by rolling will be attached with grease and other impurities, and needs to be cleaned. The surface is cleaned with a hydrocarbon degreasing agent solution with low corrosiveness, and is cleaned by two passes of hydrocarbon degreasing agent solution in succession. The first cleaning removes most of the grease and impurities, and the second cleaning further removes the grease and impurities. Three horizontally arranged active rollers 11 are set in each cleaning tank 1. The linear speeds of these active rollers 11 are equal, and the roller spacing between adjacent active rollers 11 is 50cm-80cm; the linear speed of the first plain foil during cleaning is 30m / min-60m / min, preferably 50m / min. The linear speed of the active roller 11 is consistent with the linear speed of the first plain foil, so that the friction force on the first plain foil during the cleaning process is minimized, thereby preventing the first plain foil from deformation or even breakage.

[0033] Step S3: Drying the cleaned first foil. Specifically, the moisture and residual hydrocarbon degreasing agent on the surface of the cleaned first foil are removed by heating and drying. To improve the drying efficiency, the first foil is passed up and down through a plurality of rollers in a nearly vertical direction, so that the first foil is dried within a limited drying length and the drying area is reduced. The specific technical solution is as follows. The running direction of the first foil is shown in FIG. Figure 3 In the direction of the arrow shown, the first plain foil is dried by the first row of guide rollers 2 and the second row of guide rollers 3 staggered along the height direction. The first row of guide rollers 2 is arranged at the upper part of the drying chamber 9, and the second row of guide rollers 3 is arranged at the lower part of the drying chamber 9 to maximize the use of the height space of the drying chamber 9. The number of guide rollers in the first row of guide rollers 2 is one more than the number of guide rollers in the second row of guide rollers 3. The first plain foil is introduced from the first row of guide rollers 2 and shuttles between the first row of guide rollers 2 and the second row of guide rollers 3. The substrate is led out from the first row of guide rollers 3. The first row of guide rollers 2 includes a first upper guide roller 21, a second upper guide roller 22, and a third upper guide roller 3. The first guide roller 23 and the fourth upper guide roller 24; the second row of guide rollers 3 include the first lower guide roller 31, the second lower guide roller 32 and the third lower guide roller 33; the first light foil shuttles through the first upper guide roller 21, the first lower guide roller 31, the second upper guide roller 22, the second lower guide roller 32, the third upper guide roller 23, the third lower guide roller 33 and the fourth upper guide roller 24 in sequence, and leaves the drying chamber 9 through the fourth upper guide roller 24; in order to ensure that the friction force on the first light foil is minimized and prevent the first light foil from being stretched, deformed or even broken, the first row of guide rollers 2 and the second row of guide rollers 3 are both active rollers, and their linear speeds are consistent with the linear speed of the active roller 11.

[0034] For further explanation, see Figure 3To reduce stretching and wrinkling of the first foil during the cleaning process, the traction tension of the first foil during cleaning, drying, and winding is 200N-500N, preferably 300N. A first tension sensor 4 is installed at the entrance of the two hydrocarbon degreasing solution channels, and a second tension sensor 5 is installed at the exit of the drying chamber 9. The traction tension of the first foil is maintained constant through real-time control of the first and second tension sensors 4 and 5. The tension difference signal obtained by the first and second tension sensors 4 and 5 is transmitted to a servo motor, which controls the first and second rows of guide rollers 2 and 3. By synchronously accelerating or decelerating the linear speeds of the first and second rows of guide rollers 2 and 3, the friction force on the first foil is increased or decreased, thereby changing the traction force on the first foil and maintaining a constant linear speed throughout the cleaning process.

[0035] Step S4: The dried first smooth foil is rolled up after passing through a wrinkle removal roller 6. A first diagonal roller surface 61 and a second diagonal roller surface 62 are symmetrically provided at both ends of the wrinkle removal roller 6. Specifically, the middle portion of the wrinkle removal roller 6 is a smooth roller, while the two ends are provided with a first diagonal roller surface 61 and a second diagonal roller surface 62. The diagonal roller surfaces apply friction in the flattening direction to the two ends of the first smooth foil, thereby flattening the first smooth foil. To reduce marks on the surface of the first smooth foil caused by the friction between the first diagonal roller surface 61 and the second diagonal roller surface 62, the widths of the first diagonal roller surface and the second diagonal roller surface are 10 mm to 50 mm, preferably 30 mm. The edge width of the first smooth foil affected by the diagonal roller surfaces within this width range is the portion that needs to be cut off during subsequent trimming, and no additional loss of the first smooth foil is caused.

[0036] To further illustrate the working principle of the wrinkle removal roller 6, the diagonal lines 7 on the first diagonal roller surface 61 and the second diagonal roller surface 62 are extended and intersected to form a V-shape. During the rotation of the wrinkle removal roller 6, the friction between the rotating diagonal lines 7 and the first smooth foil causes the first smooth foil to stretch in the flattening direction. Since the middle part of the wrinkle removal roller 6 is a smooth roller, the two ends of the first smooth foil are stretched by the friction force of the diagonal lines 7, thereby achieving flattening without affecting the middle surface of the first smooth foil.

[0037] Step S5: The first plain foil is subjected to hood annealing to obtain a second plain foil. Specifically, in order to eliminate the stress of the first plain foil after rolling and improve the toughness of the first plain foil, the foil is annealed in a hood furnace with high annealing efficiency and small footprint. The heat treatment temperature of the hood annealing is 200°C-350°C, the temperature is raised for 3h-6h, and the temperature is kept for 5h-12h. After annealing, the foil is water-cooled to room temperature to obtain the second plain foil.

[0038] See also Figure 3The cleaning and drying process of the first light foil is as follows: after rolling and annealing, the first light foil is coiled. The rolled first light foil 8 passes through several guide rollers and enters two cleaning tanks 1 in succession. The cleaning tank 1 contains a hydrocarbon degreasing agent solution. After cleaning, it enters the drying chamber 9. The drying chamber 9 has a first row of guide rollers 2 and a second row of guide rollers 3 staggered along the height direction to maximize the height space of the drying chamber 9; after drying, a pinhole inspection is carried out. After the pinhole inspection, the first light foil passes through the wrinkle removal roller 6 and is then rolled up, so that the first light foil is flattened for rolling. The cleaned first light foil can be used in flexible copper clad laminates (FCCL), flexible circuit boards (FPC), 5G communications, 6G communications, electromagnetic shielding, heat dissipation substrates, graphene film preparation, aerospace, lithium batteries, LEDs, smart cars, drones, wearable electronic products and other industries.

[0039] The technical effects of this embodiment are as follows: the first plain foil is cleaned, dried and rolled up under a constant tension of 200N-500N, which can effectively reduce the wrinkling of the first plain foil. At the same time, the first plain foil is rolled up after passing through the wrinkle-removing roller. The first diagonal roller surface and the second diagonal roller surface are symmetrically arranged at both ends of the wrinkle-removing roller, and the middle part of the wrinkle-removing roller is a smooth roller. The wrinkled film is flattened by the surface diagonal lines of the first diagonal roller surface and the second diagonal roller surface. The ultra-thin calendered plain foil of most widths is flattened while passing through the smooth roller, and the ultra-thin calendered plain foil can be rolled up without wrinkles.

Claims

1. The processing technology of ultra-thin calendered light foil for electronic circuits is characterized by: The following steps are involved: The copper strip with a thickness of 0.15 mm to 0.2 mm is rolled into a first plain foil with a thickness of 8 μm to 20 μm through multiple passes; The first plain foil is cleaned by two passes of hydrocarbon degreasing solution, and three horizontally arranged active rollers are provided in each cleaning tank; The cleaned first plain foil is dried by passing through a first row of guide rollers and a second row of guide rollers staggered in the height direction. The first row of guide rollers has one more guide roller than the second row of guide rollers. The first plain foil is introduced from the first row of guide rollers and shuttles between the first and second rows of guide rollers. The substrate is then discharged from the first row of guide rollers. The first plain foil passes up and down through several rollers in a nearly vertical direction. The first and second rows of guide rollers are active rollers. A first tension sensor is provided at the entrance of the two hydrocarbon degreasing agent solutions, and a second tension sensor is provided at the exit of the drying chamber. The tension difference signal obtained by the first tension sensor and the second tension sensor is transmitted to a servo motor, which controls the acceleration or deceleration of the linear speed of the first row of guide rollers and the second row of guide rollers to increase or decrease the friction force on the first plain foil, so that the linear speed of the first plain foil is maintained constant throughout the cleaning process. The linear speed of the first row of guide rollers, the second row of guide rollers, and the driving roller are kept consistent. The dried first plain foil is rolled up after passing through a wrinkle removal roller, wherein a first diagonal roller surface and a second diagonal roller surface are symmetrically provided at both ends of the wrinkle removal roller; The first plain foil is subjected to a mask annealing to obtain a second plain foil.

2. The process for processing ultra-thin calendered light foil for electronic circuits according to claim 1, characterized in that: The multi-pass rolling process has a rolling pass number of 6 to 10.

3. The process for processing ultra-thin calendered light foil for electronic circuits according to claim 1, characterized in that: The heat treatment temperature of the bell-type annealing is 200° C.-350° C., the temperature is raised for 3 h-6 h, and the temperature is kept for 5 h-12 h; after annealing, the heat is cooled to room temperature with water.

4. The process for processing ultra-thin calendered light foil for electronic circuits according to claim 1, characterized in that: The widths of the first diagonal roller surface and the second diagonal roller surface are respectively 10 mm to 50 mm.

5. The process for processing ultra-thin calendered light foil for electronic circuits according to claim 2, characterized in that: The diagonal lines on the first diagonal roller surface and the second diagonal roller surface are extended and intersected to form a V shape.

6. The process for processing ultra-thin calendered light foil for electronic circuits according to claim 1, characterized in that: The first row of guide rollers includes a first upper guide roller, a second upper guide roller, a third upper guide roller and a fourth upper guide roller; the second row of guide rollers includes a first lower guide roller, a second lower guide roller and a third lower guide roller.

7. The process for processing ultra-thin calendered light foil for electronic circuits according to claim 1, characterized in that: The pulling tension of the first smooth foil during cleaning, drying and winding is 200N-500N.

8. The process for processing ultra-thin calendered light foil for electronic circuits according to claim 1, characterized in that: The line speed of the first smooth foil during cleaning is 30 m / min-60 m / min.

Images