Double-edged helical milling cutter for smooth edge treatment of PCB board

Abstract

The present invention discloses a double-edge spiral milling cutter based on the smooth edge treatment of a PCB board, which is provided with a plurality of spiral cutting edges. The spiral cutting edges are all spiraled around the axis in the length direction of the milling cutter. The spiral cutting edge includes a milling cutter cutting edge and a milling cutter back. The edge of the milling cutter cutting edge is composed of alternately spaced inwardly concave arc groove edges and straight outer edges. There is an arc-transition plane between the arc groove edge and the adjacent milling cutter back. The milling cutter back has a straight edge. This new type has arc groove edges, which can assist in guiding and discharging the end chips after the milling cutter processes the board, avoiding reducing the tool life. At the same time, the setting of the tooth grooves can greatly reduce the heat generated during the rotation process, and it has good heat dissipation performance, which better meets the temperature processing environment requirements of the PCB board. Moreover, under the guidance of the arc grooves, the multi-layer laminated board can achieve the purpose of buffering the impact force and preventing warping, so the smoothness of the board edge can be improved.

Description

Technical Field

[0001] The present invention relates to the field of cutting tools, and specifically to a double - helix milling cutter. Background Art

[0002] At present, the application proportion of high - end boards in the PCB industry is increasing. Therefore, the proportion of milling cutters in their production and sample making is also increasing. Application No.: 201910338038.2 discloses a design method for a chip - breaking type milling cutter, which is designed for a right - hand rotating milling cutter, and the designed milling cutter has the characteristic of double - sided cutting edges. With the development of PCB boards, they are now refined into various types according to different uses, such as flexible boards, rigid - flexible boards, halogen - free boards, high - TG boards, HDI boards, and ceramic boards, etc. High - TG boards refer to boards whose glass transition temperature is greater than 170 degrees when heated at high temperatures. When grinding the edges of such boards to obtain good quality, a lower rotational speed is required to avoid excessive temperature. For HDI boards, the outer surface needs to be laminated with copper foil using back glue for wiring, and at the same time, micro - via technology needs to be applied to achieve miniaturization of the board. During the miniaturization process, considering factors such as dense wiring, it is necessary to consider rigidity to prevent bending and deformation, prevent the end chips from hitting the circuit surface, prevent high temperature from affecting the firmness of the nearby circuit lamination, and the original performance of components. Edge treatment becomes extremely careful. Summary of the Invention

[0003] The purpose of the present invention is to provide a double - edge spiral milling cutter for smooth edge treatment of PCB boards to solve the above problems.

[0004] The present invention realizes the above - mentioned purpose through the following technical solutions:

[0005] A double - edge spiral milling cutter for smooth edge treatment of PCB boards is provided with a plurality of spiral cutting edges. The spiral cutting edges are all spiraled around the axis in the length direction of the milling cutter. The spiral cutting edge includes a milling cutter cutting edge and a milling cutter back. The edge of the milling cutter cutting edge is composed of alternately spaced inwardly concave arc - shaped groove edges and straight outer edges. There is an arc - shaped transition plane between the arc - shaped groove edge and the adjacent milling cutter back. The milling cutter back has a straight edge.

[0006] As a further description of the above double - edge spiral milling cutter for smooth edge treatment of PCB boards, the spiral cutting edges are separated from each other, and the edges of the milling cutter backs of the spiral cutting edges are parallel to each other, and the edges of the milling cutter cutting edges of the spiral cutting edges are parallel to each other.

[0007] As a further - more description of the above double - edge spiral milling cutter for smooth edge treatment of PCB boards, the outer edge of the milling cutter cutting edge is parallel to the edge of the milling cutter back.

[0008] As a further description of the above double-edged helical milling cutter for PCB board smooth edge treatment, the distances from the cutting edges of each helical cutting edge to the axis of the milling cutter are the same, the distances from the back of the milling cutter to the axis of the milling cutter are the same, and the distance from the cutting edge of the milling cutter to the axis of the milling cutter is greater than the distance from the back of the milling cutter to the axis of the milling cutter.

[0009] As a further description of the above double-edged helical milling cutter for PCB board smooth edge treatment, there is a sunken tooth groove between the back of the milling cutter and the cutting edge of adjacent helical cutting edges, and the cutting edge of the milling cutter is connected to the edge of the tooth groove and is in a fault.

[0010] As a further description of the above double-edged helical milling cutter for PCB board smooth edge treatment, the edge of the back of the milling cutter forms a 30-degree angle with the axis of the milling cutter.

[0011] The design method of the chip-breaking milling cutter mentioned in the background technology Figure 1 shows a structure relatively similar to this solution, and the content mainly discloses the calculation process, adjustment and production of multiple parameters of the milling cutter, as well as the calculation steps of multiple parameters, including how to calculate the size of the cutting offset angle, how to calculate the slot length and slot pitch, but does not mention what the specific structure of the milling cutter is and what the specific functions of each structure are. Figure 1 It can only be used as an expression of a non-specific structure. And in the background technology Figure 1 there is no tooth groove left between the back of the milling cutter and the cutting edge of the milling cutter, there is no arc-shaped groove on the cutting edge of the milling cutter, and there is no arc-shaped transition plane between the edge of the arc-shaped groove and the back of the milling cutter. By comparing the above features, the uses of the tool itself and the effects brought by the features, the differences can be known.

[0012] The beneficial effects of the present invention are as follows: The tool has an edge of an arc-shaped groove, and this groove edge cooperates with the arc-shaped transition plane, which can assist in guiding and discharging the end chips after the milling cutter processes the board, avoiding directly hitting the tool head-on and reducing the tool life; at the same time, the setting of the tooth groove can greatly reduce the heat generated during the rotation process, and its heat dissipation performance is good, which better meets the low-temperature processing environment requirements of PCB boards; furthermore, under the guidance of the arc-shaped groove, the multi-layer laminated board can avoid direct linear full-area contact cutting, and its arc-shaped spiral structure can gradually contact multiple layers, achieving the purpose of buffering the impact force and preventing warping, so the smoothness of the edge can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 is a schematic diagram of the overall structure of the present invention;

[0014] Figure 2 is a schematic diagram of a partial structure of the positions of two adjacent helical cutting edges. DETAILED DESCRIPTION OF THE INVENTION

[0015] To make the above objects, features, and advantages of the present invention more obvious and understandable, the following provides a detailed description of the specific embodiments of the present invention with reference to the accompanying drawings. It should be noted that the accompanying drawings of the present invention are all in simplified forms and use non-precise ratios, only for conveniently and clearly assisting in explaining the purpose of the embodiments of the present invention.

[0016] As shown in Figure 1-2 , a double-edge spiral milling cutter for PCB board smooth edge treatment is provided with a plurality of spiral cutting edges. The spiral cutting edges are all spiraled around the axis in the length direction of the milling cutter. The spiral cutting edge includes a milling cutter cutting edge 11 and a milling cutter back 12. The edge of the milling cutter cutting edge 11 is composed of alternately spaced inwardly concave arc groove edges 13 and straight outer edges 14. There is an arc-shaped transition plane 15 between the arc groove edge 13 and the adjacent milling cutter back 12. The milling cutter back 12 has a straight edge. In the requirements of the number of multi-layer laminated boards, the edge treatment of the board edge needs to consider the force transition of the milling cutter cutting edge 11 during the advancing process. The above arc groove edge can effectively contact the board edge, and cutting can be performed during the contact process of the arc groove edge, and the end chips can be guided and transferred downward along the arc groove.

[0017] As a further description of the above double-edge spiral milling cutter for PCB board smooth edge treatment, the spiral cutting edges are separated from each other, and the edges of the milling cutter backs 12 of the spiral cutting edges are parallel to each other, and the edges of the milling cutter cutting edges 11 of the spiral cutting edges are parallel to each other.

[0018] As a further description of the above double-edge spiral milling cutter for PCB board smooth edge treatment, the outer edge of the milling cutter cutting edge 11 is parallel to the edge of the milling cutter back 12. The above structure can ensure high dimensional accuracy of the board processed by the milling cutter.

[0019] As a further description of the above double-edge spiral milling cutter for PCB board smooth edge treatment, the distances between the milling cutter cutting edges 11 of the spiral cutting edges and the milling cutter axis are the same, the distances between the milling cutter backs 12 and the milling cutter axis are the same, and the distance between the milling cutter cutting edge 11 and the milling cutter axis is greater than the distance between the milling cutter back 12 and the milling cutter axis. The thickness of the same spiral cutting edge gradually decreases from the milling cutter cutting edge 11 to the milling cutter back 12. The thickness relationship between the milling cutter cutting edge 11 and the milling cutter back 12 can cooperate with the end chips cut out by the arc groove of the milling cutter cutting edge 11 to be slapped to the milling cutter back 12 and ejected.

[0020] As a further description of the above double-edge helical milling cutter for PCB board smooth edge treatment, there is a concave tooth groove 2 left between the back 12 of the milling cutter and the cutting edge 11 of adjacent helical cutting edges. The cutting edge 11 of the milling cutter is connected to the edge of the tooth groove 2 and forms a fault 3. The tooth groove 2 penetrates the entire outer surface of the milling cutter, which can feed air and reduce the surrounding temperature through rapid air flow during the milling process, effectively improving the heat dissipation efficiency. It plays an important role for boards with low processing temperature requirements such as high TG boards and HDI boards. At the same time, the rapid air flow can support the chips cut out through the arc-shaped groove to a certain extent, assist in the transition to the adjacent back 12 of the milling cutter, realize effective chip discharge connection, and avoid blocking the tooth groove and affecting the ventilation and heat dissipation effect.

[0021] As a further description of the above double-edge helical milling cutter for PCB board smooth edge treatment, the edge of the back 12 of the milling cutter forms a 30-degree angle with the axis of the milling cutter.

[0022] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited by the above embodiments. What is described in the above embodiments and the specification only illustrates the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and these changes and improvements fall within the scope of the present invention claimed. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A double-edge helical milling cutter for smooth edge treatment of PCB boards, provided with a plurality of helical cutting edges, and the helical cutting edges are all helically wound around the axis in the length direction of the milling cutter. Characterized in that: The helical cutting edge includes a milling cutter cutting edge and a milling cutter back. The edge of the milling cutter cutting edge is composed of alternately spaced arcuate groove edges recessed inward and straight outer edges. The plane between the arcuate groove edge and the adjacent milling cutter back is an arcuate transition plane. The milling cutter back has a straight edge. There is a recessed tooth groove between the milling cutter back and the milling cutter cutting edge of adjacent helical cutting edges. The milling cutter cutting edge is connected to the edge of the tooth groove and is in a fault.

2. The double-edge helical milling cutter for smooth edge treatment of PCB boards according to claim 1. Characterized in that: Each helical cutting edge is separated from each other, and the edges of the milling cutter backs of each helical cutting edge are parallel to each other, and the edges of the milling cutter cutting edges of each helical cutting edge are parallel to each other.

3. The double-edge helical milling cutter for smooth edge treatment of PCB boards according to claim 2. Characterized in that: The outer edge of the milling cutter cutting edge is parallel to the edge of the milling cutter back.

4. The double-edge helical milling cutter for smooth edge treatment of PCB boards according to claim 1. Characterized in that: The distances from the milling cutter cutting edges of each helical cutting edge to the axis of the milling cutter are the same, the distances from the milling cutter backs to the axis of the milling cutter are the same, and the distance from the milling cutter cutting edge to the axis of the milling cutter is greater than the distance from the milling cutter back to the axis of the milling cutter.

5. The double-edge helical milling cutter for smooth edge treatment of PCB boards according to claim 1. Characterized in that: The edge of the milling cutter back forms a 30-degree angle with the axis of the milling cutter.

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