Processing method of high-flatness copper plate

Abstract

The invention provides a high-flatness copper plate machining method which comprises the steps that annealing, leveling and CNC cutting machining are sequentially conducted on a copper plate blank, and the high-flatness copper plate is obtained. Wherein in the CNC cutting machining process, multi-pass cutting is conducted, and the cutting depth of each pass ranges from 0.03 mm to 0.18 mm. The mechanical stress of the copper plate blank is removed through the annealing step, then the annealed copper plate blank becomes smoother through the leveling step, CNC cutting machining is conducted through the multi-pass light cutting strategy, the limited cutting depth is adopted, the residual mechanical stress generated in the machining process can be reduced, and the machining precision is improved. And material deformation caused by too large cutting force is avoided. Therefore, by adopting the processing method disclosed by the invention, the mechanical stress can be effectively reduced, so that the high-flatness copper plate is obtained.

Description

Technical Field

[0001] The invention belongs to the technical field of processing and relates to a processing method of a copper plate with high flatness. Background Art

[0002] In the fields of power equipment and precision instrument manufacturing, copper plates have high flatness requirements. Copper plates are usually used in the windings of large transformers. High-flatness copper plates help to arrange the windings tightly and reduce the gaps caused by uneven surfaces, thereby improving the performance of the transformer. Moreover, in high-frequency transformers, copper plates with good flatness can reduce eddy current losses and improve the efficiency of power conversion. The high-precision copper plate etching process is used to manufacture precision sensors. Sensors have extremely high requirements for dimensional accuracy. High-flatness copper plates provide a good foundation for etching precise sensor structures, which can ensure the accuracy and reliability of sensors.

[0003] Copper has good electrical and thermal conductivity, as well as good ductility and plasticity. During its processing, when the outer dimensions are large and the thickness is thin, that is, when it is processed into a copper plate, special attention should be paid to mechanical stress, which will affect the flatness of the copper plate.

[0004] Therefore, there is an urgent need to provide a processing method that can reduce mechanical stress and thus obtain a copper plate with high flatness. Summary of the invention

[0005] In view of the shortcomings of the prior art, the object of the present invention is to provide a method for processing a copper plate with high flatness. The present invention removes the mechanical stress of the copper plate blank through an annealing step, and then makes the annealed copper plate blank flatter through a leveling step, and then adopts a multi-pass light cutting strategy for CNC (computer numerical control) cutting processing, and limits the depth of each cutting pass to 0.03-0.18mm. The use of the above-mentioned smaller cutting depth can reduce the residual mechanical stress generated during the processing and avoid material deformation due to excessive cutting force. In summary, the processing method of the present invention can effectively reduce mechanical stress, thereby obtaining a copper plate with high flatness.

[0006] To achieve this object, the present invention adopts the following technical solutions:

[0007] The present invention provides a method for processing a high-flatness copper plate, the processing method comprising:

[0008] The copper plate blank is sequentially annealed, leveled and CNC cut to obtain the high-flatness copper plate; wherein, during the CNC cutting process, multiple cutting passes are performed, and the depth of each cutting pass is 0.03-0.18 mm, for example, it can be 0.03 mm, 0.04 mm, 0.05 mm, 0.06 mm, 0.07 mm, 0.08 mm, 0.09 mm, 0.1 mm, 0.11 mm, 0.12 mm, 0.13 mm, 0.14 mm, 0.15 mm, 0.16 mm, 0.17 mm or 0.18 mm, etc., but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0009] It should be noted that the "multiple passes" in the present invention refers to at least two passes. The "high-flatness copper plate" in the present invention refers to a copper plate with a flatness of ≤0.1 mm.

[0010] The present invention removes the mechanical stress of the copper plate blank through the annealing step, and then makes the annealed copper plate blank flatter through the leveling step, and then adopts a multi-pass light cutting strategy for CNC cutting, limiting the depth of each cutting to 0.03-0.18mm. The use of the above-mentioned smaller cutting depth can reduce the residual mechanical stress generated during the processing and avoid material deformation caused by excessive cutting force. In summary, the processing method of the present invention can effectively reduce mechanical stress, thereby obtaining a copper plate with high flatness.

[0011] Preferably, the annealing temperature is 580-620°C, for example, 580°C, 590°C, 600°C, 610°C or 620°C, etc., but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0012] The present invention performs annealing within a limited temperature range, which can effectively remove the mechanical stress of the copper plate blank. If the annealing temperature is too low or too high, it is difficult to achieve the above effect.

[0013] Preferably, after the annealing, the copper slab is taken out and cooled naturally, and then the leveling is performed.

[0014] It should be noted that the natural cooling refers to cooling at room temperature in air.

[0015] Preferably, the natural cooling time is 110-140 min, for example, it can be 110 min, 115 min, 120 min, 125 min, 130 min, 135 min or 140 min, etc., but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0016] The present invention limits the cooling method and cooling time to ensure that the stress removal of the copper slab is maximized. If the natural cooling time is too short, it is difficult to achieve the above effect.

[0017] Preferably, the flatness of the leveling is ≤1 mm, for example, it can be 0.05 mm, 0.1 mm, 0.2 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm or 1 mm, etc., but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0018] Preferably, the fixture used in the CNC cutting process includes a vacuum suction cup for fixing the copper plate blank.

[0019] The fixture of the present invention uses a vacuum suction cup to evenly distribute the force on the product, thereby avoiding deformation of the workpiece due to excessive local stress.

[0020] Preferably, multiple flipping processes are performed during the CNC cutting process.

[0021] It should be noted that the multiple times refers to at least 2 times, for example, it can be 2 times, 3 times, 5 times, 8 times, 10 times or 20 times.

[0022] In the present invention, repeated flipping processing is used to maximize the uniform distribution of force on the material.

[0023] Furthermore, during CNC cutting, the tool path is rationally planned to minimize idle travel time and tool load variation on the workpiece to reduce stress concentration.

[0024] Preferably, during the CNC cutting process, a water-based coolant is sprayed on the cutting area for cooling.

[0025] It should be noted that the cutting area is where the tool contacts the copper plate blank.

[0026] Copper has good thermal conductivity. During the processing, the friction between the tool and the copper material generates heat which is absorbed by the material and causes deformation of the material, affecting the flatness.

[0027] To solve the above problems, the present invention uses water-based coolant for cooling during the machining process to reduce tool wear and control machining temperature. It also ensures that the coolant is evenly sprayed on the cutting area. The coolant plays a lubricating role and can reduce the heat generated by the friction between the tool and the workpiece, thereby avoiding deformation of the workpiece.

[0028] Preferably, the CNC cutting process includes roughing and finishing performed sequentially; during the roughing process, the cutting depth of each pass is 0.12-0.18 mm, for example, it can be 0.12 mm, 0.13 mm, 0.14 mm, 0.15 mm, 0.16 mm, 0.17 mm or 0.18 mm, etc.; during the finishing process, the cutting depth of each pass is 0.03-0.08 mm, for example, it can be 0.03 mm, 0.04 mm, 0.05 mm, 0.06 mm, 0.07 mm or 0.08 mm, etc., but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0029] During the rough machining process of the present invention, if the cutting depth of each pass is too small, the cutting process will take a long time; if the cutting depth of each pass is too large, residual mechanical stress may be generated during the machining process, and the material may be deformed due to excessive cutting force, thereby affecting the flatness of the copper plate.

[0030] During the finishing process of the present invention, if the cutting depth of each pass is too small, the time required for cutting processing will be too long; if the cutting depth of each pass is too large, residual mechanical stress may be generated during the processing, and the material may be deformed due to excessive cutting force, thereby affecting the flatness of the copper plate.

[0031] Preferably, the tool is a carbide tool or a tool with a diamond coating.

[0032] The present invention adopts a carbide tool or a tool with a diamond coating, which is suitable for copper material processing and can improve the durability of the tool.

[0033] Preferably, the rake angle of the tool used in the CNC cutting process is 5°-10°, for example, it can be 5°, 6°, 7°, 8°, 9° or 10°, and the back angle is 15°-20°, for example, it can be 15°, 16°, 17°, 18°, 19° or 20°, but it is not limited to the listed values, and other unlisted values ​​within this numerical range are also applicable.

[0034] The present invention selects a tool geometry suitable for finishing, such as a smaller rake angle and a larger back angle, to reduce cutting force.

[0035] Preferably, during the rough machining process, the rotation speed of the tool is 4000-6000rpm, for example, it can be 4000rpm, 4100rpm, 4200rpm, 4500rpm, 4800rpm, 5000rpm, 5200rpm, 5500rpm, 5800rpm or 6000rpm, etc., and the feed speed is 2000-3000mm / min, for example, it can be 2000mm / min, 2100mm / min, 2200mm / min, 2300mm / min, 2400mm / min, 2500mm / min, 2600mm / min, 2700mm / min, 2800mm / min, 2900mm / min or 3000mm / min, but it is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0036] Preferably, during the finishing process, the rotation speed of the tool is 4000-6000rpm, for example, it can be 4000rpm, 4100rpm, 4200rpm, 4500rpm, 4800rpm, 5000rpm, 5200rpm, 5500rpm, 5800rpm or 6000rpm, etc., and the feed speed is 2000-3000mm / min, for example, it can be 2000mm / min, 2100mm / min, 2200mm / min, 2300mm / min, 2400mm / min, 2500mm / min, 2600mm / min, 2700mm / min, 2800mm / min, 2900mm / min or 3000mm / min, but it is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0037] In view of the good ductility of copper, the tool rotation speed set in the present invention is relatively high, approximately in the range of 4000-6000 rpm.

[0038] The present invention sets the feed speed to be approximately in the range of 2000-3000 mm / min, which ensures the processing efficiency and avoids the degradation of the surface quality caused by too fast feeding. The feed speed is appropriately reduced during fine processing.

[0039] The present invention selects a CNC machine tool with high precision and high stability to perform CNC cutting processing to ensure the positioning accuracy and repeated positioning accuracy of the machine tool.

[0040] The numerical range described in the present invention not only includes the point values ​​listed above, but also includes any point values ​​between the above numerical ranges that are not listed. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the range.

[0041] Compared with the prior art, the present invention has the following beneficial effects:

[0042] The present invention removes the mechanical stress of the copper plate blank through the annealing step, and then makes the annealed copper plate blank flatter through the leveling step, and then adopts a multi-pass light cutting strategy for CNC cutting, limiting the depth of each cutting to 0.03-0.18mm. The use of the above-mentioned smaller cutting depth can reduce the residual mechanical stress generated during the processing and avoid material deformation caused by excessive cutting force. In summary, the processing method of the present invention can effectively reduce mechanical stress, thereby obtaining a copper plate with high flatness. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 Optical photographs of the vacuum chuck used in Examples 1-3 of the present invention.

[0044] Figure 2 This is an optical photograph of the high-flatness copper plate provided in Example 1 of the present invention. DETAILED DESCRIPTION

[0045] The technical scheme of the present invention is further described below by specific implementation methods. For ease of understanding the present invention, the present invention lists the following embodiments. Those skilled in the art should understand that the embodiments are only to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0046] The technical solution of the present invention is further illustrated below through specific implementation methods.

[0047] The room temperature described in the following examples refers to 25°C.

[0048] Example 1

[0049] This embodiment provides a method for processing a high-flatness copper plate, comprising the following steps:

[0050] (1) The copper sheet blank is annealed at 600° C. After the annealing is completed, the copper sheet blank is taken out and naturally cooled at room temperature in air for 120 minutes, and then flattened by a shaping machine to obtain a flattened copper sheet blank with a flatness of ≤1 mm.

[0051] (2) A vacuum suction cup is used to fix the flattened copper sheet blank, wherein the vacuum suction cup has a structure such as Figure 1As shown, CNC cutting is then performed. The tool material used in CNC cutting is cemented carbide, the front angle is 10°, and the back angle is 20°. The CNC cutting includes roughing and finishing. During the roughing process, multiple cutting passes are performed, the depth of each cutting pass is 0.15mm, the tool rotation speed is 4000rpm, and the feed speed is 2500mm / min; during the finishing process, multiple cutting passes are performed, the depth of each cutting pass is 0.05mm, the tool rotation speed is 5000rpm, and the feed speed is 2000mm / min. During the entire process of CNC cutting, multiple flipping processes are performed, and water-based coolant is sprayed on the cutting area for cooling. After the CNC cutting process is completed, a high-flatness copper plate is obtained, as shown Figure 2 shown.

[0052] Example 2

[0053] This embodiment provides a method for processing a high-flatness copper plate, comprising the following steps:

[0054] (1) The copper slab was annealed at 580° C. After the annealing was completed, the copper slab was taken out and naturally cooled at room temperature in air for 110 min, and then leveled by a shaping machine to obtain a leveled copper slab with a flatness of ≤1 mm.

[0055] (2) A vacuum suction cup is used to fix the flattened copper sheet blank, wherein the vacuum suction cup has a structure such as Figure 1 As shown, CNC cutting is then performed. The tool material used in CNC cutting is cemented carbide, the front angle is 10°, and the back angle is 20°. The CNC cutting includes roughing and finishing. During the roughing process, multiple cutting passes are performed, the depth of each cutting pass is 0.15mm, the tool speed is 4000rpm, and the feed speed is 2500mm / min; during the finishing process, multiple cutting passes are performed, the depth of each cutting pass is 0.05mm, the tool speed is 5000rpm, and the feed speed is 2000mm / min. During the whole process of CNC cutting, multiple flipping processes are performed, and water-based coolant is sprayed on the cutting area for cooling. After the CNC cutting process is completed, a high-flatness copper plate is obtained.

[0056] Example 3

[0057] This embodiment provides a method for processing a high-flatness copper plate, comprising the following steps:

[0058] (1) The copper sheet blank is annealed at 620° C. After the annealing is completed, the copper sheet blank is taken out and naturally cooled at room temperature in air for 130 minutes, and then flattened by a shaping machine to obtain a flattened copper sheet blank with a flatness of ≤1 mm.

[0059] (2) A vacuum suction cup is used to fix the flattened copper sheet blank, wherein the vacuum suction cup has a structure such as Figure 1 As shown, CNC cutting is then performed. The tool material used in CNC cutting is cemented carbide, the front angle is 10°, and the back angle is 20°. The CNC cutting includes roughing and finishing. During the roughing process, multiple cutting passes are performed, the depth of each cutting pass is 0.15mm, the tool speed is 4000rpm, and the feed speed is 2500mm / min; during the finishing process, multiple cutting passes are performed, the depth of each cutting pass is 0.05mm, the tool speed is 5000rpm, and the feed speed is 2000mm / min. During the whole process of CNC cutting, multiple flipping processes are performed, and water-based coolant is sprayed on the cutting area for cooling. After the CNC cutting process is completed, a high-flatness copper plate is obtained.

[0060] As can be seen from Examples 1-3, the present invention can remove the mechanical stress of the copper sheet blank through the annealing step, and then make the annealed copper sheet blank flatter through the leveling step, and then adopt the strategy of multi-pass light cutting for CNC cutting, and adopt a smaller cutting depth to reduce the residual mechanical stress generated during the processing, and avoid material deformation due to excessive cutting force. At the same time, the present invention uses a water-based coolant for cooling during the processing to reduce tool wear and control the processing temperature. And ensure that the coolant is evenly sprayed on the cutting area, the coolant plays a lubricating role, and can reduce the heat generated by the friction between the tool and the workpiece, thereby avoiding deformation of the workpiece. In summary, the processing method of the present invention can effectively reduce mechanical stress and reduce thermal deformation, thereby obtaining a copper plate with high flatness.

[0061] Example 4

[0062] The difference between this embodiment and embodiment 1 is that during the rough machining process, the cutting depth of each pass is 0.1 mm.

[0063] The remaining parameters remain the same as those in Example 1.

[0064] It can be seen from Example 1 and Example 4 that if the cutting depth of each pass during rough machining is too small, the time required for the cutting process will be too long.

[0065] Example 5

[0066] The difference between this embodiment and embodiment 1 is that during the finishing process, the depth of each cutting pass is 0.1 mm.

[0067] The remaining parameters remain the same as those in Example 1.

[0068] It can be seen from Examples 1 and 5 that if the cutting depth of each pass during finishing is too large, residual mechanical stress may be generated during the machining process, and excessive cutting force may cause material deformation, thereby affecting the flatness of the copper plate.

[0069] Example 6

[0070] The difference between this embodiment and embodiment 1 is that the annealing temperature is 550°C.

[0071] The remaining parameters remain the same as those in Example 1.

[0072] Example 7

[0073] The difference between this embodiment and embodiment 1 is that the annealing temperature is 650°C.

[0074] The remaining parameters remain the same as those in Example 1.

[0075] It can be seen from Example 1 and Examples 6-7 that if the annealing temperature is too low or too high, it is difficult to fully remove the mechanical stress of the copper plate blank, thereby affecting the flatness of the final copper plate.

[0076] Example 8

[0077] The difference between this embodiment and embodiment 1 is that the natural cooling time is 100 minutes.

[0078] The remaining parameters remain the same as those in Example 1.

[0079] Example 9

[0080] The difference between this embodiment and embodiment 1 is that the natural cooling time is 150 minutes.

[0081] The remaining parameters remain the same as those in Example 1.

[0082] It can be seen from Examples 1 and 6-7 that if the natural cooling time is too short, it is difficult to fully remove the mechanical stress of the copper plate blank, thereby affecting the flatness of the final copper plate. If the natural cooling time is too long, the overall processing time is extended.

[0083] Comparative Example 1

[0084] The difference between this embodiment and embodiment 1 is that during the rough machining process, the cutting depth of each pass is 0.2 mm.

[0085] The remaining parameters remain the same as those in Example 1.

[0086] It can be seen from Example 1 and Comparative Example 1 that if the cutting depth of each pass during rough machining is too large, residual mechanical stress may be generated during the machining process, and the material may be deformed due to excessive cutting force, thereby affecting the flatness of the copper plate.

[0087] Comparative Example 2

[0088] The difference between this embodiment and embodiment 1 is that during the finishing process, the cutting depth of each pass is 0.01 mm.

[0089] The remaining parameters remain the same as those in Example 1.

[0090] It can be seen from Example 1 and Comparative Example 2 that if the cutting depth of each pass during fine machining is too small, the time required for the cutting process will be too long.

[0091] The above description is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention are within the protection scope and disclosure scope of the present invention.

Claims

1. A method for processing a high-flatness copper plate, characterized in that: The processing method comprises: The copper plate blank is subjected to annealing, leveling and CNC cutting in sequence to obtain the high-flatness copper plate; In the process of CNC cutting, multiple cutting passes are performed, and the depth of each cutting pass is 0.03-0.18 mm.

2. The processing method according to claim 1, characterized in that: The annealing temperature is 580-620°C.

3. The processing method according to claim 1 or 2, characterized in that: After the annealing, the copper slab is taken out and cooled naturally, and then the leveling is performed; Preferably, the natural cooling time is 110-140 minutes; Preferably, the flatness of the leveling is ≤1 mm.

4. The processing method according to any one of claims 1 to 3, characterized in that: The fixture used in the CNC cutting process includes a vacuum suction cup for fixing the copper plate blank.

5. The processing method according to any one of claims 1 to 4, characterized in that: During the CNC cutting process, multiple flipping processes are performed.

6. The processing method according to any one of claims 1 to 5, characterized in that: During the CNC cutting process, a water-based coolant is sprayed on the cutting area for cooling.

7. The processing method according to any one of claims 1 to 6, characterized in that: The CNC cutting process includes roughing and finishing performed sequentially; During the rough machining process, the cutting depth of each pass is 0.12-0.18 mm; During the finishing process, the cutting depth of each pass is 0.03-0.08 mm.

8. The processing method according to claim 7, characterized in that: The front angle of the tool used in the CNC cutting process is 5°-10°, and the back angle is 15°-20°.

9. The processing method according to claim 8, characterized in that: During the rough machining process, the tool rotation speed is 4000-6000rpm and the feed speed is 2000-3000mm / min.

10. The processing method according to claim 8 or 9, characterized in that: During the finishing process, the tool speed is 4000-6000rpm and the feed speed is 2000-3000mm / min.

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