Novel microbit
By designing a linear secondary chip drain on the PCB micro drill bit, the problem of untimely elimination of cutting objects is solved, the chip drainage ability is enhanced, the friction heat is reduced, and the hole wall and hole position accuracy is improved.
Patent Information
- Application Number
- CN202420905897.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-04-28
- Publication Date
- 2025-07-01
- Estimated Expiration
- 2034-04-28
AI Technical Summary
The secondary chip drain grooves of the existing PCB micro drill bits are opened in an arc shape, which makes the cutting objects unable to be removed in time and the chip drainage ability is weak, resulting in the contact between the drill bit and the hole wall to form pulling and friction heat, resulting in the problems of black lines in the hole, rough hole walls and needle breakage.
A new micro drill bit is designed, with two main chip drain grooves and two pairs of chip drain grooves on the drill blade. The starting edge of the secondary chip drain groove is changed to a straight line, with an angle α of 45°-86° to enhance chip drainage capability. Cutting objects are discharged in time through the main and secondary chip drainage grooves to reduce the contact between the drill back and the hole wall.
Improve the quality of the hole wall and the accuracy of the hole position, avoid the problems of black lines, rough hole walls and needle breakage in the hole, and reduce friction heat.
Smart Images
Figure CN223053188U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of printed circuit board drilling, in particular to a novel micro drill bit. Background Art
[0002] A PCB board is a support for electronic components and a carrier for the electrical interconnection of electronic components. Since it is manufactured by electronic printing technology, it is called a printed circuit board. During the production process of a PCB board, drilling is required to make via holes for copper plating to form circuits or for making positioning holes. With the development of high integration and precision of electronic products, PCB boards are gradually developing in the direction of small aperture, narrow line pitch, high density and multi-layers. As Figure 5 shown, the secondary chip flutes of existing PCB micro drill bits are all opened in an arc shape, resulting in the inability to timely remove the cuttings generated during drilling, with weak chip removal ability, and the contact between the drill bit and the hole wall is prone to form pulling and frictional heat, leading to problems such as black lines in the hole, rough hole walls and broken needles. Content of the Utility Model
[0003] The technical problem to be solved by the utility model is that the secondary chip flutes of existing PCB micro drill bits are all opened in an arc shape, resulting in the inability to timely remove the cuttings generated during drilling, with weak chip removal ability, and the contact between the drill bit and the hole wall is prone to form pulling and frictional heat, leading to problems such as black lines in the hole, rough hole walls and broken needles.
[0004] To solve the above problems, the utility model provides a novel micro drill bit, including a drill edge, on which two main chip flutes and two secondary chip flutes are spirally arranged circumferentially. At the tip of the drill edge, two main cutting surfaces and two secondary cutting surfaces are arranged at an included angle and are connected. The main cutting surface and the secondary cutting surface intersect to form a center line and a chisel edge respectively. The secondary chip flute intersects with the secondary cutting surface to form a side line, and the side line is set as a straight line and forms an included angle α with the center line.
[0005] The novel micro drill bit provided by the utility model further has the following technical features:
[0006] The included angle α is 45° - 86°.
[0007] The center line and the chisel edge intersect to form a drill point angle.
[0008] The secondary chip flute is parallel to the main chip flute and has the same spiral angle, and the length of the secondary chip flute is less than that of the main chip flute.
[0009] The diameter of the drill edge is 0.10 mm - 0.45 mm, and the length is 1.20 mm - 7.00 mm.
[0010] It further includes a drill shank, which is connected to the end of the drill edge far from its tip.
[0011] The utility model has the following beneficial effects: By changing the starting edge line of the secondary chip removal groove from the traditional arc shape to a straight line shape, the contact between the drill back and the hole wall during drilling can be reduced, and the frictional heat can be lowered; at the same time, the chip removal ability is enhanced, so that the cutting debris generated when the drill edge 10 is cutting at high speed can be discharged in time through the main chip removal groove 11 and the secondary chip removal groove 12, reducing the pulling and frictional heat formed by contact with the hole wall, improving the hole wall quality and hole position accuracy, and avoiding the generation of problems such as black lines in the drilled hole, rough hole walls, and broken needles. Brief Description of the Drawings
[0012] Figure 1 is the front view of the utility model;
[0013] Figure 2 is Figure 1 the partial enlarged view of;
[0014] Figure 3 is Figure 2 the side view of;
[0015] Figure 4 is the schematic diagram of the grinding wheel structure;
[0016] Figure 5 is the schematic diagram of the structure of the existing drill bit. Detailed Description of the Preferred Embodiments
[0017] The present utility model will be described in detail below with reference to the drawings and in conjunction with the embodiments. It should be noted that, without conflict, the embodiments in the present utility model and the features in the embodiments can be combined with each other.
[0018] As Figures 1 to 5 shown, the novel micro drill bit of the present utility model includes a drill edge 10, on which two main chip removal grooves 11 and two secondary chip removal grooves 12 are circumferentially spirally formed, and at the tip of the drill edge 10, two main cutting surfaces 13 and two secondary cutting surfaces 14 are provided and are arranged at an included angle and connected. The main cutting surface 13 and the secondary cutting surface 14 intersect to form a center line 15 and a web 16 respectively. The secondary chip removal groove 12 intersects with the secondary cutting surface 14 to form an edge line 21, and the edge line 21 is arranged as a straight line and forms an included angle α with the center line 15.
[0019] By changing the starting edge line of the secondary chip removal groove 12 from the traditional arc shape to a straight line shape, the present utility model can reduce the contact between the drill back and the hole wall during drilling, and lower the frictional heat; at the same time, the chip removal ability is enhanced, so that the cutting debris generated when the drill edge 10 is cutting at high speed can be discharged in time through the main chip removal groove 11 and the secondary chip removal groove 12, reducing the pulling and frictional heat formed by contact with the hole wall, improving the hole wall quality and hole position accuracy, and avoiding the generation of problems such as black lines in the drilled hole, rough hole walls, and broken needles.
[0020] Wherein, the secondary chip removal groove 12 is a curved surface obtained by twisting the edge line 21 along a spiral line.
[0021] Among them, the depth of the edge line 21 is controlled by dressing the inclined surface of the grinding wheel for grinding the micro drill bit. The grinding wheel is formed by three surfaces. Refer to Figure 4 , that is, the angles a / b / c are 30 degrees / 87 degrees / 35 degrees respectively. The angles b and c mainly participate in the grinding of the secondary chip flutes 12 of the micro drill bit to form the edge line 21. The grinding wheel is installed on the grinding equipment. The center point of the grinding surface of the grinding wheel is horizontally opposed to the center of the micro drill bit. The installation angle of the grinding wheel is between 50° and 55°, and this installation angle is set correspondingly according to the different thread angles of the micro drill bit.
[0022] Preferably, the included angle α is 45° - 86°.
[0023] Preferably, the center line 15 intersects with the chisel edge 16 to form the drill point angle 17.
[0024] Preferably, the secondary chip flutes 12 are parallel to the primary chip flutes 11 and have the same spiral angle. The length of the secondary chip flutes 12 is less than the length of the primary chip flutes 11.
[0025] Preferably, the diameter of the drill edge 11 is 0.10 mm - 0.45 mm, and the length is 1.20 mm - 7.00 mm.
[0026] Preferably, it further includes a drill shank 18, which is connected to one end of the drill edge 10 away from its tip.
[0027] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.
Claims
1. A novel micro drill comprises a drill blade (10), wherein two main chip removal grooves (11) and two auxiliary chip removal grooves (12) are spirally formed on the drill blade (10) in a circumferential direction, and the tip of the drill blade (10) is provided with two main cutting surfaces (13) and two auxiliary cutting surfaces (14) arranged at an angle and connected to each other, wherein the main cutting surfaces (13) and the auxiliary cutting surfaces (14) intersect to form a center line (15) and a chisel edge (16), respectively, and characterized in that: The secondary chip removal groove (12) intersects with the secondary tool surface (14) to form a side line (21), and the side line (21) is arranged as a straight line and forms an angle α with the center line (15).
2. The novel micro drill according to claim 1 is characterized in that: The angle α is 45°-86°.
3. The novel micro drill according to claim 1 is characterized in that: The center line (15) intersects with the chisel edge (16) to form a drill point angle (17).
4. The novel micro drill according to claim 1 is characterized in that: The secondary chip removal groove (12) is parallel to the primary chip removal groove (11) and has the same spiral angle, and the length of the secondary chip removal groove (12) is smaller than the length of the primary chip removal groove (11).
5. The novel micro drill according to claim 1 is characterized in that: The diameter of the drill blade (10) is 0.10 mm-0.45 mm, and the length is 1.20 mm-7.00 mm.
6. The novel micro drill according to claim 1, characterized in that: The utility model also comprises a drill shank (18) which is connected to an end of the drill blade (10) away from the tip thereof.