NC cutter for improving bonding performance of PEI material and preparation method and application of NC cutter

Abstract

The invention provides an NC cutter for improving bonding performance of a PEI material and a preparation method and application of the NC cutter, and belongs to the technical field of surface modification of high polymer materials. By adopting the design of reducing the arc of the cutting edge and increasing the elevation angle, the cutting edge of the stress angle cutting edge is sharper, burrs and tool deflection are more effectively inhibited, and a high-precision and high-quality machining surface is realized; meanwhile, the spiral angle of the peripheral cutting edge of the NC cutter is smaller, only one acting point is in contact with the cutting edge in the machining process, the contact points of the cutting edge and the machining face are reduced, and the smoothness and flatness of the surface are improved; by coating the high-hardness DLC coating on the surface of the NC tool, the wear resistance of the tool can be remarkably improved, so that the service life of the tool is prolonged by 4-5 times.

Description

Technical Field

[0001] This invention relates to the field of polymer surface modification technology, and in particular to an NC cutting tool for improving the bonding performance of PEI material, its preparation method and application. Background Technology

[0002] During CNC machining, PEI material is prone to defects such as milling cutter marks, shavings, and burrs, resulting in high surface roughness (typically 70-150 nm). This affects the interface contact amplitude and area during bonding. Furthermore, PEI's surface physical inertness and extremely high strength and rigidity lead to weak interfacial bonding with the substrate, resulting in defects such as bonding delamination, bubbles, and bursting. This results in a bonding yield of less than 60% and a compressive strength of less than 150 kPa, failing to meet the requirements for high-precision medical components. The wear rate of standard machining tools is too high, making mass production costs unacceptable.

[0003] Therefore, how to improve the bonding performance of PEI materials has become a technical problem that urgently needs to be solved in this field. Summary of the Invention

[0004] The purpose of this invention is to provide an NC cutting tool for improving the bonding performance of PEI material, its preparation method and application. The NC cutting tool provided by this invention can significantly improve the surface smoothness and finish of PEI material while ensuring the performance of PEI material itself, thereby improving the molecular bond qualification rate and strength.

[0005] To achieve the above-mentioned objectives, the present invention provides the following technical solution: This invention provides an NC cutting tool for improving the bonding performance of PEI materials. The NC cutting tool is any one or more of a long-neck flat end mill, a long-neck ball end mill, and a long-neck round nose end mill. The cutting edge arc diameter of the NC cutting tool is 7.5~8.5mm. The elevation angle of the NC cutting tool is 7~8°. The helix angle of the NC cutting tool is 36~38°. The cutting edge surface of the NC cutting tool is coated with a DLC coating. The single-side film thickness of the DLC coating is 1.0~1.5μm.

[0006] Preferably, the NC cutting tool is made of fine-grained tungsten steel.

[0007] Preferably, the helix angle of the NC tool is 37.5°.

[0008] Preferably, the hardness of the DLC coating is 2300~2800HV.

[0009] Preferably, the hardness of the DLC coating is 2500 HV.

[0010] Preferably, the coefficient of friction of the DLC coating is 0.05 to 0.1.

[0011] Preferably, the coefficient of friction of the DLC coating is 0.06 to 0.08.

[0012] This invention provides a method for preparing NC cutting tools that improve the bonding performance of PEI materials as described in the above technical solution, comprising the following steps: (1) Prepare a cutting edge at one end of a tungsten steel rod to obtain tungsten steel with a cutting edge; (2) Adjust the helix angle of the outer peripheral cutting edge of the tungsten steel with a cutting edge obtained in step (1) to obtain a milling cutter; (3) The cutting edge surface of the milling cutter obtained in step (2) is coated with a DLC coating to obtain an NC tool that improves the bonding performance of PEI material.

[0013] Preferably, the method for coating the DLC coating in step (3) includes any one of ion beam deposition, sputtering deposition, cathode arc deposition, plasma-enhanced chemical vapor deposition, and hot filament CVD.

[0014] This invention provides the application of the NC cutting tool for improving the bonding performance of PEI material as described in the above technical solution, or the NC cutting tool for improving the bonding performance of PEI material prepared by the preparation method described in the above technical solution, in the PEI material processing process.

[0015] This invention provides an NC cutting tool for improving the bonding performance of PEI materials. The NC cutting tool is any one or more of a long-neck flat-end mill, a long-neck ball end mill, and a long-neck round nose end mill. The cutting edge radius of the NC cutting tool is 7.5~8.5mm; the elevation angle of the NC cutting tool is 7~8°; the helix angle of the NC cutting tool is 36~38°; and the cutting edge surface of the NC cutting tool is coated with a DLC coating. The single-sided film thickness of the DLC coating is 1.0~1.5μm. This invention, by adopting a reduced cutting edge radius and a larger elevation angle design, makes the cutting edge sharper at the force angle, more effectively suppressing burrs and tool skew, achieving high-precision and high-quality machined surfaces. Simultaneously, the smaller helix angle of the outer peripheral cutting edge of the NC cutting tool results in only one contact point during machining, reducing the contact points between the cutting edge and the machined surface, and increasing surface smoothness and flatness. By coating the surface of the NC cutting tool with a high-hardness DLC coating, the wear resistance of the tool can be significantly improved, thereby increasing its service life by 4~5 times. The results of the embodiments show that the NC tool provided by the present invention can process up to the 18th PEI material, with a total processing time of 31 hours and 30 minutes. In contrast, conventional tools, due to high wear, must stop processing after the 4th material, with a total processing time of 7 hours. This demonstrates that the NC tool provided by the present invention has a longer service life. Furthermore, the surface roughness of the PEI material processed using the provided NC tool is reduced to below 55 nm, while the flatness is maintained at 100%. 2Within a range of mm ± 0.015 mm, the bonding shear strength of PEI material is increased to over 15 MPa, and the bonding yield reaches over 90%, solving the bonding defect problem of traditional processes. Attached Figure Description

[0016] Figure 1 This is a photograph of a long-neck flat-bottom end mill used in NC machining. Figure 2 This is a schematic diagram of the structure when the NC tool is a long-neck flat-bottom end mill; Figure 3 This is a photograph of a long-neck ball end mill used in NC machining. Figure 4 This is a schematic diagram of the structure when the NC cutting tool is a long-neck ball end mill; Figure 5 This is a photograph of a long-neck round nose end mill when the NC cutting tool is a long-neck round nose end mill. Figure 6 This is a schematic diagram of the structure when the NC tool is a long-neck round nose end mill; Figure 7 A comparison diagram of the cutting edge structure of the NC cutting tool obtained in Example 1 and Comparative Example 1; Figure 8 A schematic diagram of the contact structure during machining using the NC tool provided in Example 1; Figure 9 A schematic diagram of the contact structure during machining using the NC tool provided in Comparative Example 1; Figure 10 A comparison chart of the service life of NC cutting tools provided in Example 1 and Comparative Example 1; Figure 11 This is a photograph of a flat PEI material after it has been machined using the NC tool provided in Example 1. Figure 12 This is a photograph of the actual product after the columnar PEI material has been machined using the NC tool provided in Example 1. Detailed Implementation

[0017] This invention provides an NC cutting tool for improving the bonding performance of PEI materials. The NC cutting tool is any one or more of a long-neck flat end mill, a long-neck ball end mill, and a long-neck round nose end mill. The cutting edge arc diameter of the NC cutting tool is 7.5~8.5mm. The elevation angle of the NC cutting tool is 7~8°. The helix angle of the NC cutting tool is 36~38°. The cutting edge surface of the NC cutting tool is coated with a DLC coating. The single-side film thickness of the DLC coating is 1.0~1.5μm.

[0018] In this invention, the NC cutting tool is preferably made of finely milled tungsten steel, more preferably Japanese Daijet tungsten steel JC8050. By using finely milled tungsten steel rods of the above-mentioned material as the main material, this invention enables the NC cutting tool to possess both chipping resistance and wear resistance, making it suitable for various machining scenarios such as sidewall cutting and plane cutting.

[0019] In this invention, when the NC cutting tool is a long-neck flat end mill, a long-neck ball end mill, or a long-neck round nose end mill, the parameters and physical diagrams of the long-neck flat end mill, long-neck ball end mill, and long-neck round nose end mill are shown in Table 1 and... Figures 1-6 As shown: Table 1. Parameters of long-neck flat end mills, long-neck ball end mills, and long-neck round nose end mills

[0020] From Table 1 and Figures 1-6 It can be seen that by controlling the parameters of the NC tool, the present invention can further improve the machining efficiency of the tool, thereby improving the surface finish and flatness of the machined PEI material.

[0021] In this invention, the cutting edge radius of the NC tool is 7.5~8.5mm, preferably 8mm; the elevation angle of the NC tool is 7~8°, preferably 7.5°. By adopting a design that reduces the cutting edge radius and increases the elevation angle, this invention makes the cutting edge sharper at the force angle, more effectively suppressing burrs and tool skew, and achieving high-precision and high-quality machined surfaces.

[0022] In this invention, the helix angle of the NC cutting tool is 36~38°. As one embodiment of this invention, the helix angle of the NC cutting tool can be 36°, 36.5°, 37°, 37.5°, or 38°. By controlling the helix angle of the NC cutting tool, compared to the strong helix angle of 45° for conventional tools, this invention has a smaller helix angle on the outer periphery of the cutting edge. During machining, there is only one point of contact between the cutting edge and the machined surface, reducing the number of contact points between the cutting edge and the machined surface, and increasing the surface finish and flatness.

[0023] In this invention, the single-side film thickness of the DLC coating is 1.0~1.5μm; the hardness of the DLC coating is preferably 2300~2800HV; and the coefficient of friction of the DLC coating is preferably 0.05~0.1. As one embodiment of this invention, the single-side film thickness of the DLC coating can be 1.0μm, 1.1μm, 1.2μm, 1.3μm, 1.4μm, or 1.5μm; the hardness of the DLC coating can be 2300HV, 2400HV, 2500HV, 2600HV, 2700HV, or 2800HV; and the coefficient of friction of the DLC coating can be 0.05, 0.06, 0.07, 0.08, 0.09, or 0.1. This invention, by coating the surface of NC cutting tools with a high-hardness DLC coating, can significantly improve the wear resistance of the tools, thereby increasing their service life by 4~5 times.

[0024] This invention employs a design that reduces the radius of the cutting edge and increases the elevation angle, resulting in a sharper cutting edge at the force angle. This effectively suppresses burrs and tool skew, achieving high-precision and high-quality machined surfaces. Simultaneously, the outer peripheral helix angle of the NC tool is smaller, meaning there is only one point of contact between the cutting edge and the machined surface during machining. This reduces the number of contact points between the cutting edge and the machined surface, increasing surface smoothness and flatness. Furthermore, by coating the NC tool surface with a high-hardness DLC coating, the tool's wear resistance can be significantly improved, thereby increasing its service life by 4-5 times.

[0025] The NC cutting tool provided by this invention can work well with NC precision machine tools, significantly improving the surface smoothness and gloss of PEI material while ensuring its inherent properties, thereby increasing the molecular bond qualification rate and strength of PEI material.

[0026] This invention provides a method for preparing NC cutting tools that improve the bonding performance of PEI materials as described in the above technical solution, comprising the following steps: (1) Prepare a cutting edge at one end of a tungsten steel rod to obtain tungsten steel with a cutting edge; (2) Adjust the helix angle of the outer peripheral cutting edge of the tungsten steel with a cutting edge obtained in step (1) to obtain a milling cutter; (3) A DLC coating is applied to the cutting edge surface of the milling cutter obtained in step (2) to obtain an NC tool that improves the bonding performance of PEI material.

[0027] The present invention prepares a cutting edge at one end of tungsten steel to obtain tungsten steel with a cutting edge.

[0028] In this invention, the tungsten carbide rod is preferably made of Japanese Daijet tungsten carbide JC8050. By using this material as the main material for particle size analysis, the NC cutting tool can possess both chipping resistance and wear resistance, making it suitable for various machining scenarios such as sidewall cutting and planar cutting.

[0029] The present invention does not impose any special limitations on the shape of the tungsten carbide rod. It can be determined based on the technical common sense of those skilled in the art, and can be conventionally selected according to the size of the required NC tool.

[0030] In this invention, the preferred method for preparing the cutting edge is to fix the tail of a tungsten carbide rod and then groove the cutting edge portion of the tungsten carbide rod to form the cutting edge. In this invention, the material used for grooving is preferably a tungsten carbide rod. This invention does not impose any special limitations on the specific operation of grooving; it can be determined based on the technical knowledge of those skilled in the art. By employing the above method, this invention can obtain a cutting edge with a suitable arc and elevation angle at one end of a tungsten carbide rod.

[0031] After obtaining tungsten steel with a cutting edge, the present invention adjusts the helix angle of the outer peripheral cutting edge of the tungsten steel with a cutting edge to obtain a milling cutter.

[0032] This invention does not impose any specific limitations on the adjustment operations; adjustments can be made using methods well-known to those skilled in the art, as long as the helix angle of the outer peripheral cutting edge meets the requirements. This invention employs conventional cutting tools and machining methods, increasing the cutting force angle and contact area of ​​the tool, and testing with increments of 0.5° under the same conditions, continuing until an interference fit of 11° is achieved. By adjusting the helix angle of the tungsten carbide outer peripheral cutting edge, in testing, the NC tool's elevation angle was 7.5° and the helix angle was 37.5°, achieving the best results in terms of cutting speed and surface finish.

[0033] After obtaining the milling cutter, the present invention coats the cutting edge surface of the milling cutter with a DLC coating to obtain an NC tool that improves the bonding performance of PEI material.

[0034] In this invention, the method for coating DLC ​​coating preferably includes any one of ion beam deposition, sputtering deposition, cathode arc deposition, plasma-enhanced chemical vapor deposition, and hot filament CVD.

[0035] In this invention, when the method for coating the DLC coating is ion beam deposition, the preferred operation of the ion beam deposition is: placing a milling cutter into a vacuum chamber and then evacuating the chamber to a vacuum level <10. -6 Pa is applied, followed by the activation of an ion source to generate a carbon ion beam. Single-valence carbon ions are selected using a mass analysis magnetic field. Finally, the carbon ions are accelerated under an electric field and bombard the cutting edge surface of the milling cutter, depositing a DLC coating. In this invention, the deposition temperature is preferably 20~300℃; the deposition time is preferably 1~60min; the energy of the carbon ion beam is preferably 100~1000eV; and the deposition bias voltage is preferably -100~-1000V. By controlling the deposition parameters, this invention enables the DLC coating to achieve the required thickness and performance.

[0036] In this invention, when the method for coating the DLC coating is sputter deposition, the preferred operation of the sputter deposition is as follows: a graphite target is installed in a sputtering device, a milling cutter is placed opposite the graphite target, an inert gas is introduced to a pressure of 1-10 Pa, then an radio frequency power supply is applied to generate plasma. The plasma bombards the graphite target under the action of an electric field, causing carbon atoms to be sputtered out. The sputtered carbon atoms are deposited on the cutting edge surface of the milling cutter, forming a DLC coating. In this invention, the inert gas is preferably argon. In this invention, the deposition temperature is preferably 20-300℃; the deposition time is preferably 1-60 min; and the deposition bias voltage is preferably -100 to -1000 V. This invention does not impose special limitations on parameters such as radio frequency power, gas flow rate, and sputtering time during sputter deposition; these parameters are determined based on the technical knowledge of those skilled in the art, as long as the thickness and performance of the DLC coating meet the requirements.

[0037] In this invention, when the method for coating the DLC coating is cathodic arc deposition, the preferred operation of the cathodic arc deposition is as follows: a carbon target is installed in the equipment, a milling cutter is placed below the carbon target, an electric arc is ignited, and the arc discharge is maintained by a power source, causing the carbon target to evaporate and ionize. Then, a magnetic filtering channel is used between the vacuum arc and the substrate to filter out large neutral particles and some ions, allowing single-component carbon ions to deposit on the cutting edge surface of the milling cutter, forming the DLC coating. In this invention, the deposition temperature is preferably 20~300℃; the deposition pressure is preferably <10℃. -6 Pa; the deposition time is preferably 1~60 min; the deposition bias voltage is preferably -100~-1000V. This invention does not impose special limitations on parameters such as magnetic field strength and bias voltage during cathode arc deposition; these can be determined based on the technical knowledge of those skilled in the art, as long as the thickness and performance of the DLC coating meet the requirements.

[0038] In this invention, when the method for coating the DLC coating is plasma-enhanced chemical vapor deposition (PECVD), the preferred operation of PECVD is as follows: a milling cutter is placed in the PECVD reaction chamber, a vacuum is drawn to 0.1~10 Pa, and then a mixed gas is introduced. Plasma is excited by a radio frequency or microwave power supply, causing the mixed gas to decompose and generate carbon-containing groups and hydrogen atoms. The carbon-containing groups are adsorbed on the cutting edge surface of the milling cutter, while the hydrogen atoms adsorb onto the sp(s) in the DLC coating. 2 Carbon components are etched to adjust sp. 3 / sp 2The proportions are used to deposit a DLC coating. In this invention, the mixed gas includes a carbon-containing gas and hydrogen; the carbon-containing gas is preferably any one or more of methane, acetylene, and propane; the volume ratio of the carbon-containing gas to hydrogen is preferably 1:(1~10); the carbon-containing groups are preferably any one or more of CH3, CH2, and C2; the excitation power of the radio frequency or microwave power supply is preferably 100~1000W, more preferably 500~600W; the deposition time is preferably 1~60min; and the deposition bias voltage is preferably -100~-1000V. This invention does not impose special limitations on parameters such as gas flow rate, power, temperature, and deposition time during plasma-enhanced chemical vapor deposition. These parameters are determined based on the technical knowledge of those skilled in the art, as long as they enable the thickness and performance of the DLC coating to meet the requirements.

[0039] In this invention, when the method for coating the DLC coating is hot-wire CVD, the preferred operation of the hot-wire CVD is as follows: a heating filament is installed in the reaction chamber, a milling cutter is placed near the filament, a carbon-containing gas is introduced, and then the filament is heated to decompose the carbon-containing gas to produce carbon atoms. The carbon atoms are deposited on the cutting surface of the milling cutter to form a DLC coating. In this invention, the carbon-containing gas is preferably any one or more of methane, acetylene, and propane; the heating temperature is preferably 1500~2000℃; the deposition pressure is preferably 1~10 Pa; the deposition time is preferably 1~60 min; and the deposition bias voltage is preferably -100~-1000V. This invention does not impose special limitations on parameters such as gas flow rate and deposition time during hot-wire CVD; these parameters are determined based on the technical knowledge of those skilled in the art, as long as the thickness and performance of the DLC coating meet the requirements.

[0040] The preparation method provided by this invention is simple and does not require significant adjustments to existing preparation processes. Only minor adjustments to some tool parameters are needed to obtain NC tools that can improve the bonding performance of PEI materials. This avoids environmental pollution caused by the use of chemical substances, shortens the maximum NC process time, is suitable for industrial mass production, reduces production costs, and is conducive to large-scale industrial promotion.

[0041] The present invention also provides the application of the NC cutting tool for improving the bonding performance of PEI material as described in the above technical solution or the NC cutting tool for improving the bonding performance of PEI material prepared by the preparation method described in the above technical solution in the PEI material processing process.

[0042] The present invention does not impose any special limitations on the specific operation of the application, and can be applied in a manner known to those skilled in the art.

[0043] In this invention, when the PEI material is planar PEI material, the processing is preferably roughing and finishing.

[0044] In this invention, the NC cutting tools used for roughing are preferably long-neck ball end mills and long-neck flat end mills.

[0045] In this invention, the parameters for rough machining of the top and bottom surfaces of the PEI material preferably include: spindle speed 9000~11000 r / min, feed rate 2100~2300 mm / min, depth of cut ap×ae of 0.18×0.12 mm, allowance 0.07~0.08 mm, and machining time 25~30 min. More preferably, the parameters are: spindle speed 10000 r / min, feed rate 2200 mm / min, depth of cut ap×ae of 0.18×0.12 mm, allowance 0.08 mm, and machining time 27 min.

[0046] In this invention, the parameters for rough machining of the side surface of PEI material preferably include: spindle speed 9000~11000 r / min, feed rate 1700~2000 mm / min, depth of cut ap×ae of 0.3×0.1 mm, allowance 0.09~0.11 mm, and machining time 15~20 min. More preferably, the parameters are: spindle speed 10000 r / min, feed rate 1800 mm / min, depth of cut ap×ae of 0.3×0.1 mm, allowance 0.1 mm, and machining time 18 min.

[0047] In this invention, the NC cutting tools used for finishing are preferably long-neck ball end mills, long-neck flat end mills, and long-neck round nose end mills.

[0048] In this invention, the parameters for finishing the PEI material preferably include: spindle speed 16000~20000 r / min, feed rate 2800~3200 mm / min, depth of cut ap×ae of 0.1×0.05 mm, allowance 0 mm, and machining time 40~60 min. More preferably, the parameters are: spindle speed 18000 r / min, feed rate 3000 mm / min, depth of cut ap×ae of 0.1×0.05 mm, allowance 0 mm, and machining time 50 min.

[0049] In this invention, the preferred parameters for finishing the side surface of PEI material include: spindle speed 16000~20000 r / min, feed rate 1000~1400 mm / min, depth of cut ap×ae of 0.08×0.05 mm, allowance 0 mm, and machining time 30~50 min. More preferably, the parameters are: spindle speed 18000 r / min, feed rate 1200 mm / min, depth of cut ap×ae of 0.08×0.05 mm, allowance 0 mm, and machining time 40 min.

[0050] In this invention, the parameters for finishing the bottom surface of PEI material preferably include: spindle speed 16000~20000 r / min, feed rate 400~600 mm / min, depth of cut ap×ae of 0.05×0.05 mm, allowance 0 mm, and machining time 10~15 min. More preferably, the parameters are: spindle speed 18000 r / min, feed rate 500 mm / min, depth of cut ap×ae of 0.05×0.05 mm, allowance 0 mm, and machining time 13 min.

[0051] In this invention, when the PEI material is a raised PEI material, the processing is preferably roughing, intermediate processing and finishing.

[0052] In this invention, the NC cutting tool used for roughing is preferably a long-neck ball end mill.

[0053] In this invention, the parameters for rough machining of PEI material preferably include: spindle speed 7000~10000 r / min, feed rate 2400~2600 mm / min, depth of cut ap×ae of 0.18×0.12 mm, allowance 0.07~0.08 mm, and machining time 15~25 min. More preferably, the parameters are: spindle speed 8000 r / min, feed rate 2500 mm / min, depth of cut ap×ae of 0.18×0.12 mm, allowance 0.08 mm, and machining time 20 min.

[0054] In this invention, the NC cutting tool used for the machining process is preferably a long-neck flat-bottom milling cutter.

[0055] In this invention, the preferred parameters for machining PEI material include: spindle speed 10000~14000 r / min, feed rate 1400~1800 mm / min, depth of cut ap×ae of 0.12×0.08 mm, allowance 0.02~0.04 mm, and machining time 30~50 min. More preferably, the preferred parameters are: spindle speed 12000 r / min, feed rate 1600 mm / min, depth of cut ap×ae of 0.12×0.08 mm, allowance 0.03 mm, and machining time 40 min.

[0056] In this invention, the NC tool used for finishing the plane of PEI material is preferably a long-neck round nose end mill; the parameters for finishing the plane of PEI material preferably include: spindle speed 20000~26000 r / min, feed rate 2600~3000 mm / min, depth of cut ap×ae is 0.1×0.05 mm, allowance 0 mm, and machining time 40~60 min, preferably: spindle speed 24000 r / min, feed rate 2800 mm / min, depth of cut ap×ae is 0.1×0.05 mm, allowance 0 mm, and machining time 50 min.

[0057] In this invention, the NC tool used for finishing the side of PEI material is preferably a long-neck flat-bottom end mill; the parameters for finishing the side of PEI material preferably include: spindle speed 18000~22000 r / min, feed rate 800~1200 mm / min, depth of cut ap×ae is 0.03×0.03 mm, allowance 0 mm, and machining time 40~50 min, preferably: spindle speed 20000 r / min, feed rate 1000 mm / min, depth of cut ap×ae is 0.03×0.03 mm, allowance 0 mm, and machining time 45 min.

[0058] In this invention, the NC tool used for finishing the bottom surface of the PEI material is preferably a long-neck round nose end mill; the parameters for finishing the bottom surface of the PEI material preferably include: spindle speed 22000~26000 r / min, feed rate 400~600 mm / min, depth of cut ap×ae is 0.03×0.03 mm, allowance 0 mm, and machining time 15~20 min, preferably: spindle speed 24000 r / min, feed rate 500 mm / min, depth of cut ap×ae is 0.03×0.03 mm, allowance 0 mm, and machining time 17 min.

[0059] The technical solutions of this invention will be clearly and completely described below with reference to the embodiments thereof. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0060] Example 1 A non-conductive dicing (NC) tool for improving the bonding performance of PEI materials, wherein the NC tool is a long-neck flat-bottom end mill; the material of the NC tool is Japanese DIEJ tungsten steel JC8050; the cutting edge radius diameter of the NC tool is 8mm; the elevation angle of the NC tool is 7.5°; the helix angle of the NC tool is 37.5°; the cutting edge surface of the NC tool is coated with a DLC coating; the single-sided film thickness of the DLC coating is 1.5μm; the hardness of the DLC coating is 2500HV; and the coefficient of friction of the DLC coating is 0.08; denoted as DHR237. The method for preparing the NC cutting tool that improves the bonding performance of PEI material comprises the following steps: (1) Fix the tail of the tungsten steel rod, and then use the tungsten steel rod to slot the cutting edge of the tungsten steel rod to form a cutting edge, thus obtaining tungsten steel with a cutting edge; (2) Adjust the helix angle of the outer peripheral cutting edge of the tungsten steel with a cutting edge obtained in step (1) to obtain a milling cutter; (3) A DLC coating is applied to the cutting edge surface of the milling cutter obtained in step (2) to obtain an NC tool that improves the bonding performance of PEI material; The method for applying the DLC coating is sputter deposition. Specifically, a graphite target is installed in a sputtering device, and a milling cutter is placed opposite the graphite target. Inert gas is then introduced until the pressure reaches 10 Pa. Next, an RF power supply is applied to generate plasma. Under the influence of an electric field, the plasma bombards the graphite target, causing carbon atoms to sputter out. The sputtered carbon atoms are deposited on the cutting edge surface of the milling cutter, forming the DLC coating. The inert gas is argon. The deposition temperature is 150°C, the deposition time is 10 minutes, and the deposition bias voltage is -100V.

[0061] Example 2 A non-conductive dicing (NC) tool for improving the bonding performance of PEI materials, wherein the NC tool is a long-neck ball end mill; the material of the NC tool is Japanese DIEJ tungsten steel JC8050; the cutting edge radius diameter of the NC tool is 8mm; the elevation angle of the NC tool is 7.5°; the helix angle of the NC tool is 37.5°; the cutting edge surface of the NC tool is coated with a DLC coating; the single-sided film thickness of the DLC coating is 1.5μm, the hardness of the DLC coating is 2500HV, and the coefficient of friction of the DLC coating is 0.08; denoted as DRH230R; The method for preparing the NC cutting tool that improves the bonding performance of PEI material comprises the following steps: (1) Fix the tail of the tungsten steel rod, and then use the tungsten steel rod to slot the cutting edge of the tungsten steel rod to form a cutting edge, thus obtaining tungsten steel with a cutting edge; (2) Adjust the helix angle of the outer peripheral cutting edge of the tungsten steel with a cutting edge obtained in step (1) to obtain a milling cutter; (3) A DLC coating is applied to the cutting edge surface of the milling cutter obtained in step (2) to obtain an NC tool that improves the bonding performance of PEI material; The method for applying the DLC coating is sputter deposition. Specifically, a graphite target is installed in a sputtering device, and a milling cutter is placed opposite the graphite target. Inert gas is then introduced until the pressure reaches 10 Pa. Next, an RF power supply is applied to generate plasma. Under the influence of an electric field, the plasma bombards the graphite target, causing carbon atoms to sputter out. The sputtered carbon atoms are deposited on the cutting edge surface of the milling cutter, forming the DLC coating. The inert gas is argon. The deposition temperature is 150°C, the deposition time is 10 minutes, and the deposition bias voltage is -100V.

[0062] Example 3 A non-conductive machining (NC) tool for improving the bonding performance of PEI materials, wherein the NC tool is a long-neck round nose end mill; the material of the NC tool is Japanese DIEJ tungsten steel JC8050; the cutting edge radius diameter of the NC tool is 8mm; the elevation angle of the NC tool is 7.5°; the helix angle of the NC tool is 37.5°; the cutting edge surface of the NC tool is coated with a DLC coating; the single-sided film thickness of the DLC coating is 1.5μm, the hardness of the DLC coating is 2500HV, and the coefficient of friction of the DLC coating is 0.08; denoted as DHR237R; The method for preparing the NC cutting tool that improves the bonding performance of PEI material comprises the following steps: (1) Fix the tail of the tungsten steel rod, and then use the tungsten steel rod to slot the cutting edge of the tungsten steel rod to form a cutting edge, thus obtaining tungsten steel with a cutting edge; (2) Adjust the helix angle of the outer peripheral cutting edge of the tungsten steel with a cutting edge obtained in step (1) to obtain a milling cutter; (3) A DLC coating is applied to the cutting edge surface of the milling cutter obtained in step (2) to obtain an NC tool that improves the bonding performance of PEI material; The method for applying the DLC coating is sputter deposition. Specifically, a graphite target is installed in a sputtering device, and a milling cutter is placed opposite the graphite target. Inert gas is then introduced until the pressure reaches 10 Pa. Next, an RF power supply is applied to generate plasma. Under the influence of an electric field, the plasma bombards the graphite target, causing carbon atoms to sputter out. The sputtered carbon atoms are deposited on the cutting edge surface of the milling cutter, forming the DLC coating. The inert gas is argon. The deposition temperature is 150°C, the deposition time is 10 minutes, and the deposition bias voltage is -100V.

[0063] Comparative Example 1 An NC cutting tool, wherein the NC cutting tool is a long-neck flat-end mill; the material of the NC cutting tool is Japanese Daijie tungsten steel JC8050; the cutting edge radius diameter of the NC cutting tool is 8mm; the elevation angle of the NC cutting tool is 7.5°; and the helix angle of the NC cutting tool is 45°. The preparation method of the NC cutting tool is the same as in Example 1.

[0064] The comparison (middle) of the cutting edge structure of the NC cutting tool obtained in Example 1 (left) and Comparative Example 1 (right) is shown in the figure. Figure 7 As shown. By Figure 7 It can be seen that the NC cutting tool obtained by the present invention has a sharper cutting edge by adopting a design that reduces the radius of the cutting edge and increases the elevation angle.

[0065] Using the NC cutting tools provided in Example 1 and Comparative Example 1, when machining to a depth of 2D (the diameter of the tungsten carbide), the contact structure between the NC cutting tool and the product to be machined is shown in the diagram below. Figure 8 and Figure 9 As shown. By Figure 8 and Figure 9 It can be seen that the NC tool provided in Embodiment 1 of the present invention has one contact point with the product to be processed, while the NC tool provided in Comparative Example 1 has two contact points with the product to be processed.

[0066] The service life of the NC cutting tools provided in Example 1 and Comparative Example 1 was tested. The test method was as follows: the surface of PEI material was machined using the NC cutting tool. The initial dimensions of the PEI material were 60mm × 44.5mm × 32mm, the machining depth was 12mm, and commercially available cutting fluid was used for cooling during the machining process. Then, the machining time, the number of parts machined, and the burr height and surface roughness of the PEI material surface after machining were calculated. The results are shown in Table 2 and... Figure 10 As shown: Table 2 shows the burr height and surface roughness of the machined surface when the NC cutting tools provided in Example 1 and Comparative Example 1 machine PEI material.

[0067] Combine Table 2 and Figure 10 It can be seen that the NC tool provided in Embodiment 1 of the present invention can process up to the 18th PEI material, with a total processing time of 31 hours and 30 minutes. However, the tool provided in Comparative Example 1 suffers from severe wear and damage, and must be stopped after processing the 4th material. Otherwise, the burr height and surface roughness of the processed PEI material will increase significantly, failing to meet the technical requirements. The total processing time is 7 hours. This indicates that the NC tool provided by the present invention has a longer service life. At the same time, the NC tool's processing process is stable, and good processing accuracy and surface finish can be obtained.

[0068] Application Example 1 The planar PEI material was machined using the NC cutting tools provided in Examples 1-3. The machining process included roughing and finishing. Specific process parameters are shown in Table 3, and the results are as follows: Figure 11 As shown: Table 3 shows the process parameters for machining planar PEI material using the NC tools provided in Examples 1-3.

[0069] Application Example 2 The NC cutting tools provided in Examples 1-3 were used to machine the raised PEI material. The machining process included roughing, intermediate machining, and finishing. Specific process parameters are shown in Table 4, and the results are as follows: Figure 12 As shown: Table 4 shows the process parameters for machining raised PEI material using the NC cutting tools provided in Examples 1-3.

[0070] Depend on Figure 11 and Figure 12 It can be seen that the NC cutting tool provided by the present invention has a high degree of flatness and smoothness after processing PEI material.

[0071] right Figure 11 and Figure 12 The surface roughness of the PEI material after processing, including the flat surfaces and cylindrical side surfaces, was tested. The surface roughness of the PEI material was reduced to below 55 nm, and the flatness was guaranteed to be within 100%. 2 Within a range of mm ± 0.015 mm, the bonding shear strength of PEI material is increased to over 15 MPa, and the bonding yield reaches over 90%, solving the bonding defect problem of traditional processes.

[0072] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. An NC cutting tool for improving the bonding performance of PEI materials, wherein the NC cutting tool is any one or more of a long-neck flat end mill, a long-neck ball end mill, and a long-neck round nose end mill; the cutting edge arc diameter of the NC cutting tool is 7.5~8.5mm; the elevation angle of the NC cutting tool is 7~8°; the helix angle of the NC cutting tool is 36~38°; the cutting edge surface of the NC cutting tool is coated with a DLC coating; and the single-side film thickness of the DLC coating is 1.0~1.5μm.

2. The NC cutting tool for improving the bonding performance of PEI material according to claim 1, characterized in that, The NC cutting tool is made of fine-grained tungsten steel.

3. The NC cutting tool for improving the bonding performance of PEI material according to claim 1, characterized in that, The helix angle of the NC tool is 37.5°.

4. The NC cutting tool for improving the bonding performance of PEI material according to claim 1, characterized in that, The hardness of the DLC coating is 2300~2800HV.

5. The NC cutting tool for improving the bonding performance of PEI material according to claim 4, characterized in that, The hardness of the DLC coating is 2500 HV.

6. The NC cutting tool for improving the bonding performance of PEI material according to claim 1, characterized in that, The coefficient of friction of the DLC coating is 0.05~0.

1.

7. The NC cutting tool for improving the bonding performance of PEI material according to claim 6, characterized in that, The coefficient of friction of the DLC coating is 0.06~0.

08.

8. The method for preparing the NC cutting tool for improving the bonding performance of PEI material according to any one of claims 1 to 7, characterized in that, Includes the following steps: (1) Prepare a cutting edge at one end of a tungsten steel rod to obtain tungsten steel with a cutting edge; (2) Adjust the helix angle of the outer peripheral cutting edge of the tungsten steel with a cutting edge obtained in step (1) to obtain a milling cutter; (3) A DLC coating is applied to the cutting edge surface of the milling cutter obtained in step (2) to obtain an NC tool that improves the bonding performance of PEI material.

9. The preparation method according to claim 8, characterized in that, The method for coating the DLC coating in step (3) includes any one of ion beam deposition, sputtering deposition, cathode arc deposition, plasma-enhanced chemical vapor deposition, and hot filament CVD.

10. The application of the NC cutting tool for improving the bonding performance of PEI material as described in any one of claims 1 to 7, or the NC cutting tool for improving the bonding performance of PEI material prepared by the preparation method described in claim 8 or 9, in the PEI material machining process.

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