PCB drill bit for PCB processing

Abstract

The utility model discloses a PCB drill needle for PCB processing, including drill needle body, the center of inside drill needle body is provided with hard alloy base material, and the surface of drill needle body outside hard alloy base material is sequentially provided with drill bit section, variable pitch helical section, drill hole section, polishing section and connecting section, the drill bit section includes the drill needle head of integral molding with hard alloy base material, and the both sides of drill needle head are provided with high -strength cutting edge, the tail end of drill needle head is connected with variable pitch helical section, the variable pitch helical section is gradually changed state of first small then big, and the hard alloy base material outside variable pitch helical section and drill hole section all spiral setting has main blade and vice blade. The utility model main blade adopts the design of variable rake angle, makes the front end big rake angle can effectively reduce the cutting resistance, is suitable for fast cutting into high hardness base plate, improves cutting efficiency, and the rear end small rake angle strengthens the blade edge strength, avoids the phenomenon of chipping in the cutting process, and significantly improves the durability and stability of drill needle.

Description

Technical Field

[0001] This utility model relates to the field of PCB drill bit technology, specifically a PCB drill bit for PCB board processing. Background Technology

[0002] With the rapid development of the electronics and information industry towards higher frequency, higher speed, and miniaturization, the application scenarios of PCB boards are constantly expanding, extending from traditional consumer electronics to 5G base stations, automotive electronics, MiniLED displays, servers, and other fields. The substrate materials and structural designs are also exhibiting new characteristics of "high hardness, high multilayering, and high precision," which places more stringent demands on the performance of PCB drill bits, the core tool for PCB processing. However, current traditional PCB drill bits on the market are no longer sufficient to meet the processing needs of new PCB boards in terms of processing adaptability, cutting efficiency, hole wall quality, and service life, mainly exhibiting the following technical pain points: Traditional PCB drill bits typically employ a fixed rake angle design, resulting in a single rake angle parameter. While a larger rake angle can reduce cutting resistance and increase cutting speed, it significantly reduces the edge strength. When machining high-hardness substrates, the high hardness and shear strength of the substrate can easily cause the edge to chip. Conversely, a smaller rake angle can enhance edge strength and prevent chipping, but it greatly increases cutting resistance. This not only reduces drilling efficiency but also makes the drill bit prone to vibration due to excessive cutting force, leading to hole position deviations and affecting the circuit connection accuracy of the PCB board.

[0003] Traditional PCB drill bits typically employ a fixed-pitch spiral groove structure, with only a single main spiral groove cooperating with the main cutting edge for chip removal. On one hand, a fixed pitch makes it difficult to balance "cutting stability" and "chip removal efficiency." If the pitch is too small, while ensuring drill bit rigidity during insertion, it results in a narrow chip removal channel, causing chips to accumulate and clog within the spiral groove. If the pitch is too large, while it widens the chip removal channel, it weakens the rigidity of the drill bit's cutting edge, leading to increased vibration during cutting. On the other hand, traditional drill bits rely solely on the main cutting edge to generate chips of a single size. These chips are large and irregular in shape, further increasing chip removal resistance. Especially when machining multilayer PCBs, where the hole depth is large and heat dissipation space is limited, accumulated chips not only scratch the machined hole walls but also cause a sudden temperature rise due to frictional heat, accelerating drill bit wear and causing thermal deformation of the substrate material, affecting the flatness of the hole walls.

[0004] In the traditional PCB drill bit processing flow, cutting and drilling are completed only by the main cutting edge, lacking a special hole wall finishing structure: because burrs and scratches are easily left on the hole wall after the main cutting edge is cut, and it is affected by cutting vibration, it cannot meet the requirements of high-frequency and high-speed PCB boards for hole wall smoothness. Utility Model Content

[0005] The purpose of this invention is to provide a PCB drill bit for PCB board processing, so as to solve the problems mentioned in the background art.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a PCB drill bit for PCB board processing, comprising a drill bit body, wherein a cemented carbide substrate is disposed at the center inside the drill bit body, and a drill bit section, a variable pitch helical section, a drilling section, a polishing section and a connecting section are sequentially disposed on the surface of the drill bit body outside the cemented carbide substrate. The drill bit section includes a drill bit integrally formed with a cemented carbide substrate. High-strength cutting edges are provided on both sides of the drill bit. The tail end of the drill bit is connected to a variable pitch helical section, and the variable pitch helical section has a gradual change from small to large. The outer side of the cemented carbide substrate of both the variable pitch helical section and the drilling section is spirally provided with a main cutting edge and a secondary cutting edge. The polishing section includes a support post provided at one end of the drilling section. The surface of the support post is uniformly distributed with finishing edges in a ring.

[0007] Furthermore, a main spiral groove and an auxiliary spiral groove are respectively provided between adjacent main cutting edges and between secondary cutting edges of the variable pitch spiral section and the drilling section, and the width of the main spiral groove and the auxiliary spiral groove of the drilling section is greater than the width of the main spiral groove and the auxiliary spiral groove of the variable pitch spiral section.

[0008] Furthermore, micro-protrusions are uniformly provided on the surface of the cemented carbide substrate between the main spiral groove and the auxiliary spiral groove.

[0009] Furthermore, the circular diameter of the polishing section formed by the uniformly distributed finishing blades is equal to the circular diameter of the main blade and the secondary blade of the drilling section.

[0010] Furthermore, the connecting section includes a mating hexagonal prism connected to the bearing column, and the surface of the mating hexagonal prism is uniformly provided with anti-slip grooves.

[0011] Furthermore, a TiCN transition coating is uniformly disposed on the surface of the drill bit body, and an AlCrN-SiN nanocomposite coating is uniformly disposed on the outer side of the TiCN transition coating.

[0012] Furthermore, the main blade adopts a variable rake angle design, with the front end of the main blade having a rake angle of 15°-18° and the rear end transitioning to 10°-12°.

[0013] Furthermore, the secondary blade and the main blade are staggered at 30°-45°.

[0014] This utility model provides a PCB drill bit for PCB board processing, which has significant advantages over the prior art, as follows: 1. The main cutting edge of this invention adopts a variable rake angle design, which effectively reduces cutting resistance due to the large rake angle at the front end, making it suitable for rapid cutting into high-hardness substrates and improving cutting efficiency. The small rake angle at the rear end enhances the edge strength, preventing chipping during cutting and significantly improving the drill bit's durability and stability. The secondary cutting edge further breaks down the large chips generated by the main cutting edge into smaller chips, effectively solving the problem of easy clogging during chip removal in traditional drill bits. This reduces heat accumulation inside the hole, further improving drilling efficiency and hole wall quality. The finishing cutting edge is evenly distributed in a ring on the surface of the bearing pillar in the polishing section, and the diameter of the circle formed by them is equal to the diameter of the circle formed by the main and secondary cutting edges in the drilling section. After the main and secondary cutting edges complete the cutting, the finishing cutting edge performs fine finishing and polishing on the hole wall, ensuring the smoothness and precision of the hole wall and significantly improving the overall processing quality of the PCB board.

[0015] 2. The variable pitch helical section gradually increases from small to large pitch. The small pitch at the front end ensures stability during the cutting process and avoids instability caused by excessive pitch. The large pitch at the end accelerates chip removal, reduces the residence time of chips in the hole, effectively reduces heat accumulation and cutting resistance in the hole, and improves drilling efficiency and hole wall quality. Attached Figure Description

[0016] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this utility model and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the overall structure of this utility model; Figure 2 This is a cross-sectional structural diagram of the cemented carbide substrate of this utility model. Figure 3 This is a schematic diagram of the micro-protrusion distribution structure of this utility model; Figure 4 This is a schematic diagram of the polishing blade distribution structure of this utility model; Figure 5 This is a schematic diagram of the coating structure of this utility model; In the diagram: 1. Connecting section; 2. Polishing section; 3. Drilling section; 4. Variable pitch helical section; 5. Drill bit section; 6. High-strength cutting edge; 7. Drill bit; 8. Carbide substrate; 9. Main cutting edge; 10. Secondary cutting edge; 11. Finishing edge; 12. Bearing column; 13. Anti-slip groove; 14. Main helical groove; 15. Auxiliary helical groove; 16. TiCN transition coating; 17. Micro-bumps; 18. Drill bit body; 19. Butt joint hexagonal prism; 20. AlCrN-SiN nanocomposite coating. Detailed Implementation

[0018] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present utility model without creative effort are within the scope of protection of the present utility model.

[0019] Please see Figure 1-5 One embodiment of this utility model is a PCB drill bit for PCB board processing, comprising a drill bit body 18, a TiCN transition coating 16 uniformly disposed on the surface of the drill bit body 18, and an AlCrN-SiN nanocomposite coating 20 uniformly disposed on the outer side of the TiCN transition coating 16.

[0020] The center of the drill bit body 18 is provided with a cemented carbide substrate 8, and the surface of the drill bit body 18 outside the cemented carbide substrate 8 is provided with a drill bit section 5, a variable pitch helical section 4, a drilling section 3, a polishing section 2 and a connecting section 1 in sequence.

[0021] The surface of the drill bit body 18 is uniformly provided with a TiCN transition coating 16. The main function of this coating is to alleviate the hardness difference between the surface layer and the substrate and prevent the coating from cracking. On the outside of the TiCN transition coating 16, an AlCrN-SiN nanocomposite coating 20 is further uniformly provided. This composite coating has excellent hardness and thermal stability, which can significantly improve the working performance of the drill bit under high temperature and high pressure environment.

[0022] The center of the drill bit body 18 is provided with a cemented carbide substrate 8. The cemented carbide substrate 8 has the characteristics of high strength and high hardness and is the core support material of the drill bit body 18. On the outside of the cemented carbide substrate 8, the surface of the drill bit body 18 is provided with a drill bit section 5, a variable pitch helical section 4, a drilling section 3, a polishing section 2, and a connecting section 1 in sequence.

[0023] Drill section 5 is located at the very tip of the drill bit. Its main function is to perform initial drilling on the PCB board. The geometry of drill section 5 is designed as a pointed cone to facilitate rapid penetration of the PCB board material. The surface of drill section 5 is also covered with a TiCN transition coating 16 and an AlCrN-SiN nanocomposite coating 20 to ensure excellent wear resistance and corrosion resistance during the drilling process.

[0024] The variable pitch helical section 4 is located after the drill bit section 5. Its main function is to guide the drill cuttings to be discharged smoothly. The design feature of the variable pitch helical section 4 is that the pitch gradually increases. This design can effectively reduce the accumulation of drill cuttings during the drilling process and improve drilling efficiency. The surface of the variable pitch helical section 4 is also covered with a TiCN transition coating 16 and an AlCrN-SiN nanocomposite coating 20 to enhance its wear resistance and corrosion resistance.

[0025] Drilling section 3 is located after variable pitch helical section 4. Its main function is to continue to expand the drilling diameter and ensure the accuracy and smoothness of the drilling. The surface treatment of drilling section 3 is the same as that of drill bit section 5 and variable pitch helical section 4, and it is covered with TiCN transition coating 16 and AlCrN-SiN nanocomposite coating 20.

[0026] The polishing section 2 is located after the drilling section 3. Its main function is to polish the inner wall of the drill hole to improve the smoothness and quality of the drill hole. The surface treatment of the polishing section 2 also includes a TiCN transition coating 16 and an AlCrN-SiN nanocomposite coating 20 to ensure that it has excellent wear resistance and corrosion resistance during the polishing process.

[0027] The connecting section 1 is located at the very end of the drill bit. Its main function is to cooperate with the connecting device of the drilling machine or other processing equipment to ensure the stability and accuracy of the drill bit during the processing. The surface treatment of the connecting section 1 is the same as that of the other sections, and it is covered with a TiCN transition coating 16 and an AlCrN-SiN nanocomposite coating 20.

[0028] When using this PCB drill bit for PCB board processing, the drill bit is first connected and fixed to the drilling machine or other processing equipment through the connecting section 1. After starting the equipment, the drill bit section 5 first contacts the PCB board surface and quickly penetrates the board material using its pointed conical design. As the drill bit goes deeper, the variable pitch spiral section 4 starts to work, guiding the drill chips to be discharged smoothly and avoiding the accumulation of drill chips that affects the drilling efficiency.

[0029] When the drilling section 3 enters the working state, it continues to expand the drilling diameter to ensure the accuracy and smoothness of the drilling. Finally, the polishing section 2 polishes the inner wall of the drilling to improve the smoothness and quality of the drilling. Throughout the drilling process, the TiCN transition coating 16 and the AlCrN-SiN nanocomposite coating 20 play an important role in ensuring that the drill bit has excellent wear resistance and corrosion resistance under high temperature and high pressure environment.

[0030] The drill bit section 5 includes a drill bit 7 integrally formed with the cemented carbide substrate 8. High-strength cutting edges 6 are provided on both sides of the drill bit 7. The tail end of the drill bit 7 is connected to the variable pitch helical section 4, and the variable pitch helical section 4 is in a gradual transition state from small to large. The outer sides of the cemented carbide substrate 8 of the variable pitch helical section 4 and the drilling section 3 are both spirally provided with a main cutting edge 9 and a secondary cutting edge 10. The main cutting edge 9 adopts a variable rake angle design. The rake angle of the front end of the main cutting edge 9 is 15°-18°, and the rear end of the main cutting edge 9 transitions to 10°-12°. The secondary cutting edge 10 is staggered with the main cutting edge 9 at 30°-45°.

[0031] The drill bit 7 has high-strength cutting edges 6 on both sides. The material selection and heat treatment process of the cutting edges 6 give them extremely high hardness and wear resistance, and they can remain sharp during high-load cutting.

[0032] The tail end of the drill bit 7 is connected to the variable pitch helical section 4. The design of the variable pitch helical section 4 is unique. Its pitch gradually changes from small to large. Specifically, the pitch at the front end of the variable pitch helical section 4 is smaller and gradually transitions to a larger pitch at the rear end. This design helps to provide stable cutting force in the early stage of drilling and effectively remove chips and reduce cutting resistance when drilling is deep.

[0033] Both the variable pitch helical section 4 and the drilling section 3 have a main cutting edge 9 and a secondary cutting edge 10 spirally arranged on the outer side of the cemented carbide substrate 8.

[0034] The main cutting edge 9 adopts a variable rake angle design, with a rake angle of 15°-18° at the front end and gradually transitioning to 10°-12° at the rear end. This variable rake angle design can provide a larger cutting force in the early stage of cutting, while reducing cutting resistance and improving cutting efficiency when cutting deeper.

[0035] The secondary cutting edge 10 and the main cutting edge 9 are staggered at 30°-45°. This staggered distribution design helps to disperse the cutting force, reduce the load on a single cutting edge, and extend the service life of the drill bit.

[0036] When using the drill bit of this invention for drilling operations, first align the drill bit section 5 with the surface of the material to be drilled, start the drill to rotate the drill bit and gradually apply pressure. The high-strength cutting edge 6 of the drill bit 7 first contacts the material and begins cutting. As the drill bit penetrates deeper, the pitch of the variable pitch helical section 4 gradually increases, effectively removing chips and maintaining a smooth cutting process.

[0037] The staggered distribution of the main cutting edge 9 and the secondary cutting edge 10 ensures a uniform distribution of cutting force, avoiding edge damage caused by local stress concentration. The main cutting edge 9 with its variable rake angle design provides a suitable cutting angle at different cutting stages, further improving cutting efficiency.

[0038] A main spiral groove 14 and an auxiliary spiral groove 15 are respectively provided between adjacent main cutting edges 9 and secondary cutting edges 10 of the variable pitch spiral section 4 and the drilling section 3, and the width of the main spiral groove 14 and the auxiliary spiral groove 15 of the drilling section 3 is greater than the width of the main spiral groove 14 and the auxiliary spiral groove 15 of the variable pitch spiral section 4.

[0039] The variable pitch helical section 4 is designed to provide different propulsion forces and cutting efficiencies under different geological conditions. The main cutting edge 9 and the secondary cutting edge 10 of this section are arranged at a certain helical angle. The main cutting edge 9 is mainly used to cut waste, while the secondary cutting edge 10 assists in cutting and provides a stable drilling direction.

[0040] In the variable pitch helical section 4, the widths of the main helical groove 14 and the auxiliary helical groove 15 are relatively small. Specifically, the smaller groove width design helps to improve the rigidity and strength of the helical section and reduce deformation and wear during drilling. The larger groove width design helps to increase the amount of waste material discharged and reduce blockage during the waste discharge process, thereby improving drilling efficiency. At the same time, the main cutting edge 9 and the secondary cutting edge 10 of the drilling section 3 are also arranged according to a certain helical angle to ensure a smooth transition with the variable pitch helical section 4.

[0041] Micro-bumps 17 are uniformly arranged on the surface of the cemented carbide substrate 8 between the main spiral groove 14 and the auxiliary spiral groove 15. The micro-bumps 17 reduce the contact area between the chips and the groove wall, thus preventing the chips from sticking together. On the other hand, they form an air flow channel to accelerate heat dissipation in the processing area and extend the service life of the drill bit.

[0042] The polishing section 2 includes a support column 12 disposed at one end of the drilling section 3, and the surface of the support column 12 is uniformly distributed with polishing blades 11 in a ring.

[0043] The diameter of the circular polishing blades 11 evenly distributed in the polishing section 2 is equal to the diameter of the circular blades 9 and 10 formed by the main blade and secondary blade in the drilling section 3.

[0044] The bearing column 12 of the polishing section 2 is set at one end of the drilling section 3. The surface of the bearing column 12 is uniformly distributed with polishing blades 11 in a ring. The polishing blades 11 are designed to polish the hole wall after drilling to improve the smoothness of the hole wall.

[0045] Specifically, the number and distribution of the polishing blades 11 are carefully designed to maximize the polishing effect. The polishing blades 11 are made of high-hardness, high-wear-resistant materials, such as diamond or cemented carbide, to ensure their durability and effectiveness during the polishing process.

[0046] The drilling section 3 mainly includes a main cutting edge 9 and a secondary cutting edge 10. The main cutting edge 9 and the secondary cutting edge 10 are arranged in a ring and together form a circular cutting edge, which is used to realize the drilling operation on the workpiece. The main cutting edge 9 is mainly responsible for the main cutting work, while the secondary cutting edge 10 assists the main cutting edge 9 to ensure the accuracy of the hole diameter and the smoothness of the hole wall.

[0047] The circular diameter of the polishing section 2, which is composed of uniformly distributed finishing blades 11, is equal to the circular diameter of the main blade 9 and the secondary blade 10 of the drilling section 3. This design ensures that the polishing section 2 can accurately enter the hole drilled by the drilling section 3 for efficient polishing.

[0048] The connecting section 1 includes a docking hexagonal prism 19 connected to the bearing column 12, and the surface of the docking hexagonal prism 19 is uniformly provided with anti-slip grooves 13.

[0049] The hexagonal prism 19 is designed in a hexagonal shape, with all six sides being flat and adjacent sides forming a 120-degree angle. This design not only facilitates docking with other components but also effectively disperses stress at the connection points, improving the overall structural stability.

[0050] In the detailed description of the mating hexagonal prism 19, special attention should be paid to the anti-slip grooves 13 evenly distributed on its surface. The anti-slip grooves 13 are designed to increase the friction when the mating hexagonal prism 19 comes into contact with other components, and to prevent sliding or displacement caused by external forces.

[0051] In this embodiment of the application, the connecting section 1 of the PCB drill bit is first connected to the chuck of the drilling machine or other PCB processing equipment. The hexagonal structure of the connecting hexagonal prism 19 in the connecting section 1 is used to achieve precise positioning and ensure that the drill bit is coaxial with the output shaft of the equipment. At the same time, the anti-slip grooves 13 uniformly arranged on the surface of the connecting hexagonal prism 19 increase the friction with the chuck and prevent the drill bit from slipping during high-speed rotation. After the assembly is completed, the drill bit is firmly fixed by the locking mechanism of the equipment chuck.

[0052] Based on the material, thickness, and target hole diameter of the PCB board to be processed, the drill bit speed, feed rate, and drilling depth are set in the processing equipment control system. Then, the moving equipment worktable is moved so that the drill bit section 5 is aligned with the target drilling position on the PCB board, ensuring that the tip of the drill bit 7 coincides with the center point of the hole to be drilled.

[0053] The processing equipment is started, and the drill bit begins to rotate at high speed and feeds along the axial direction toward the PCB board. The drill bit section 5 first contacts the surface of the PCB board. The drill bit head 7, which is integrally formed with the cemented carbide substrate 8 in the drill bit section 5, is cone-shaped. The high-strength cutting edges 6 on both sides of the drill bit quickly cut into the PCB board material using their own high hardness characteristics, completing the initial drilling positioning and penetration, laying the foundation for subsequent processing.

[0054] As the drill bit continues to feed, the variable pitch helical segment 4 connected to the tail end of the drill bit head 7 enters the drilling area of ​​the PCB board. The variable pitch helical segment 4 has a gradually increasing pitch, with the small pitch at the front end ensuring the stability of the drill bit during cutting and preventing hole displacement due to vibration. The gradually increasing pitch at the rear end accelerates chip removal. At the same time, the main cutting edge 9 and the secondary cutting edge 10, which are spirally arranged on the outer side of the variable pitch helical segment 4, work together. The main cutting edge 9 has a variable rake angle design of "15°-18° at the front end and 10°-12° at the rear end" to reduce cutting resistance. The secondary cutting edge 10 breaks the large chips generated by the main cutting edge 9 into smaller chips. The chips are discharged through the main helical groove 14 between the main cutting edges 9 and the auxiliary helical groove 15 between the secondary cutting edges 10. In addition, the micro-protrusions 17 on the surface of the cemented carbide substrate 8 between the main helical groove 14 and the auxiliary helical groove 15 reduce the contact area between the chips and the groove wall, prevent adhesion, and form an air flow channel to accelerate heat dissipation and prevent heat accumulation in the hole.

[0055] The drill bit continues to feed, and the drilling section 3 takes over from the variable pitch helical section 4 and enters the working state. The main cutting edge 9 and the secondary cutting edge 10 are also spirally arranged on the outside of the drilling section 3, and the width of its main helical groove 14 and auxiliary helical groove 15 is larger than that of the variable pitch helical section 4, which further improves the chip removal efficiency. The variable rake angle design of the main cutting edge 9 and the staggered distribution of the secondary cutting edge 10 continue to play a role in expanding the diameter and calibrating the precision of the drill hole, ensuring that the drill hole diameter meets the target requirements. At the same time, relying on the protection of the TiCN transition coating 16, the main cutting edge 9 and the secondary cutting edge 10 are prevented from chipping or wearing when cutting high hardness substrates, ensuring the initial flatness of the hole wall.

[0056] After the drilling section 3 completes the hole diameter processing, the polishing section 2 of the drill bit enters the hole with the feed. The circular diameter of the uniformly distributed finishing blades 11 on the surface of the bearing column 12 connected to the drilling section 3 in the polishing section 2 is equal to the circular diameter of the main blade 9 and the secondary blade 10 of the drilling section 3, ensuring that the finishing blades 11 can completely fit the hole wall. The high-speed rotating finishing blades 11 perform fine polishing on the inner wall of the hole, removing the burrs and scratches left after the drilling section 3 is processed, reducing the roughness of the hole wall to the target value, eliminating the need for subsequent additional polishing processes. At the same time, the composite coating on the surface of the finishing blades 11 ensures its wear resistance and avoids the impact of blade wear on accuracy during the polishing process.

[0057] Obviously, the embodiments described above are only some embodiments of this utility model, and not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of this utility model.

[0058] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0059] It should be noted that the terms "first," "second," etc., used in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in sequences other than those illustrated or described herein.

[0060] The above are merely preferred embodiments of this utility model and are not intended to limit the scope of this utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A PCB drill bit for PCB board processing, comprising a drill bit body (18), characterized in that: The center of the drill bit body (18) is provided with a cemented carbide substrate (8), and the surface of the drill bit body (18) outside the cemented carbide substrate (8) is provided with a drill bit section (5), a variable pitch spiral section (4), a drilling section (3), a polishing section (2) and a connecting section (1) in sequence. The drill bit section (5) includes a drill bit (7) integrally formed with the cemented carbide substrate (8). High-strength cutting edges (6) are provided on both sides of the drill bit (7). The tail end of the drill bit (7) is connected to the variable pitch spiral section (4). The variable pitch spiral section (4) is in a state of gradual change from small to large. The outer sides of the cemented carbide substrate (8) of the variable pitch spiral section (4) and the drilling section (3) are spirally provided with a main cutting edge (9) and a secondary cutting edge (10). The polishing section (2) includes a support column (12) provided at one end of the drilling section (3). The surface of the support column (12) is uniformly distributed with polishing edges (11) in a ring.

2. A PCB drill bit for PCB board processing according to claim 1, characterized in that: A main spiral groove (14) and an auxiliary spiral groove (15) are respectively provided between the adjacent main cutting edges (9) and the secondary cutting edges (10) of the variable pitch spiral section (4) and the drilling section (3), and the width of the main spiral groove (14) and the auxiliary spiral groove (15) of the drilling section (3) is greater than the width of the main spiral groove (14) and the auxiliary spiral groove (15) of the variable pitch spiral section (4).

3. A PCB drill bit for PCB board processing according to claim 2, characterized in that: Micro-bumps (17) are uniformly arranged on the surface of the cemented carbide substrate (8) between the main spiral groove (14) and the auxiliary spiral groove (15).

4. A PCB drill bit for PCB board processing according to claim 1, characterized in that: The circular diameter of the polishing section (2) formed by the uniformly distributed polishing blades (11) is equal to the circular diameter of the main blade (9) and the secondary blade (10) formed by the drilling section (3).

5. A PCB drill bit for PCB board processing according to claim 1, characterized in that: The connecting section (1) includes a docking hexagonal prism (19) connected to the bearing column (12), and the surface of the docking hexagonal prism (19) is uniformly provided with anti-slip grooves (13).

6. A PCB drill bit for PCB board processing according to claim 1, characterized in that: The surface of the drill bit body (18) is uniformly provided with a TiCN transition coating (16), and an AlCrN-SiN nanocomposite coating (20) is uniformly provided on the outer side of the TiCN transition coating (16).

7. A PCB drill bit for PCB board processing according to claim 1, characterized in that: The main blade (9) adopts a variable rake angle design, with the front end of the blade (9) having a rake angle of 15°-18° and the rear end of the blade (9) transitioning to 10°-12°.

8. A PCB drill bit for PCB board processing according to claim 1, characterized in that: The secondary blade (10) and the main blade (9) are staggered at 30°-45°.

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