Circuit board ultra-short slot hole processing method and processing equipment

Abstract

The application discloses a kind of circuit board ultra-short slot hole processing method and processing equipment.Processing method includes the following steps: determining the processing area of ultra-short slot hole on circuit board, processing area has two semicircular arc segments with same radius;Determine the center line of the center of two semicircular arc segments;The processing area is divided into first area and second area, first area is formed by the circle of one semicircular arc segment complement, and the second area is the area in the processing area except the first area;Several first holes are opened in the first area;Second hole is opened in the processing area, and the second hole is tangent to the semicircular arc segment of the second area, the center of the second hole is located on the center line, and the second hole intersects with the first area;After opening first hole and second hole, drill through the first area;After drilling through the first area, drill through the second area to form ultra-short slot hole.The application improves the problems of the ultra-short slot hole obtained by the existing processing method, such as poor flatness, deformation and large length deviation.

Description

Technical Field

[0001] This invention relates to the technical field of circuit board processing, and in particular to a method and equipment for processing ultra-short slots in circuit boards. Background Technology

[0002] With the arrival and rapid development of the 5G era, circuit boards are trending towards miniaturization, high integration, and high performance. This also places increasingly stringent requirements on the diameter and quality of drilled holes, especially for short slots, with ultra-short slots being a major challenge. An ultra-short slot is defined as a slot whose length L is less than 1.5 times its width D. The width D of ultra-short slots on circuit boards is typically 0.6mm-2.0mm.

[0003] The principle of machining short slots using mechanical drilling is to connect holes to form a complete slot. Therefore, during the machining of short slots, after one end is drilled, continuing to drill down the other end results in a portion of the area being drilled into an "empty" state. Because this part is "empty," there is no point of force application. Due to the lack of a force point, under the action of cutting resistance, the drill bit will shift towards this "empty" part during the drilling process, leading to problems such as poor straightness, deformation, and large length deviations in the machined ultra-short slots. Summary of the Invention

[0004] In view of this, the present invention provides a method and equipment for processing ultra-short slots on circuit boards, which improves the problems of poor straightness, deformation and large length deviation of ultra-short slots obtained by existing processing methods.

[0005] To solve the above-mentioned technical problems, the first technical solution adopted by the present invention is as follows:

[0006] A method for processing ultra-short slots on a circuit board, the method comprising the following steps:

[0007] The processing area for ultra-short slots is defined on the circuit board, the processing area having two semi-circular arc segments with the same radius;

[0008] Determine the centerline passing through the centers of the two semicircular arc segments;

[0009] The processing area is divided into a first area and a second area. The first area is a circle formed by completing one of the semicircular arc segments. The second area is the processing area excluding the first area.

[0010] Several first holes are opened in the first area;

[0011] A second hole is made in the processing area. The second hole is tangent to the semicircular arc segment of the second area. The center of the second hole is located on the center line. The second hole intersects with the first area.

[0012] After the first hole and the second hole are made, the first area is drilled through;

[0013] After drilling through the first region, the second region is drilled to form the ultra-short slot.

[0014] In some embodiments of the circuit board ultra-short slot processing method, the step of opening a plurality of first holes in the first region includes:

[0015] Obtain the rotation direction of the drill bit;

[0016] Using the center line as a dividing line, the first region is divided into a third region and a fourth region;

[0017] According to the rotation direction of the drill bit, a plurality of first holes are drilled, and the plurality of first holes form an empty space in the first region;

[0018] When the drill bit rotates in the direction from the third region to the fourth region, the area of ​​the airspace occupying the fourth region is greater than the area it occupies in the third region.

[0019] When the drill bit rotates in the direction that the fourth region turns into the third region, the area of ​​the airspace occupying the third region is greater than the area it occupies in the fourth region.

[0020] In some embodiments of the circuit board ultra-short slot processing method, when there are multiple first holes, the edge distance between two adjacent first holes is 0-20 μm.

[0021] In some embodiments of the circuit board ultra-short slot processing method, the center of one of the plurality of first holes is located on the center line, and the distance between the first hole whose center is located on the center line and the semi-circular arc segment forming the first region is 0-20 μm.

[0022] In some embodiments of the method for processing ultra-short slots on the circuit board, the difference between the radius of the second hole and the radius of the semicircular arc segment is 0-0.2 mm.

[0023] In some embodiments of the circuit board ultra-short slot processing method, the formula for calculating the diameter of the first hole is:

[0024] D1 = L - D2 - AB;

[0025] Wherein, D1 is the diameter of the first hole, L is the length of the ultra-short slot, D2 is the diameter of the second hole, A ranges from 0 to 20 μm, and B ranges from 60 μm to 100 μm.

[0026] In some embodiments of the method for processing ultra-short slots on circuit boards, drilling through the first region includes:

[0027] Multiple circuit boards are stacked sequentially, with each circuit board aligned with the first hole and the second hole as references;

[0028] The first region is drilled through along the thickness direction of the plurality of circuit boards.

[0029] In some embodiments of the circuit board ultra-short slot processing method, drilling through the second region to form the ultra-short slot includes:

[0030] Multiple circuit boards are stacked sequentially, and each circuit board is aligned with the drilled area in the processing area 1 as a reference.

[0031] The second region is drilled through along the thickness direction of the plurality of said circuit boards.

[0032] In some embodiments of the method for processing ultra-short slots on a circuit board, the radius of the drill bit used to drill through the first region is the same as the radius of the semicircular arc segment.

[0033] To solve the above-mentioned technical problems, the second technical solution adopted by the present invention is as follows:

[0034] A processing device for implementing the ultra-short slot hole processing method for circuit boards described in the above embodiments.

[0035] Implementing the embodiments of the present invention will have at least the following beneficial effects:

[0036] The aforementioned method for processing ultra-short slots on circuit boards has the technical effect of improving the flatness, deformation, and large length deviation of ultra-short slots. Specifically, the processing method of the present invention divides the processing area into a first region and a second region, and opens a first hole and a second hole in the processing area. The first hole can reduce the cutting resistance during the drilling process of the first region, while the position and size of the second hole are such that after drilling through the first region, the waste material left in the second region is opposite on the upper and lower sides and the middle is empty. With this setting, drilling "holes" can be avoided and reduced during the drilling process of the second region, thereby avoiding deviation and improving the problems of poor flatness, deformation, and large length deviation of ultra-short slots obtained by existing processing methods.

[0037] The processing equipment described above for implementing the above-mentioned circuit ultra-short slot processing method belongs to the same concept as the corresponding circuit ultra-short slot processing method embodiment, and thus has the same technical effect as the corresponding circuit ultra-short slot processing method, and will not be described again here. Attached Figure Description

[0038] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0039] Figure 1 This is a flowchart of a method for processing ultra-short slot holes on a circuit board in one embodiment;

[0040] Figure 2 This is a schematic diagram illustrating the structural changes in the formation of ultra-short slots in one embodiment;

[0041] Figure 3 This is a force analysis diagram of the first region being drilled out;

[0042] Figure 4 This is a schematic diagram illustrating the structural changes during the formation of existing ultra-short slots.

[0043] Among them: 1. Processing area; 11. First area; 111. Third area; 112. Fourth area; 12. Second area; 2. First hole; 3. Second hole. Detailed Implementation

[0044] To facilitate understanding of the present invention, a more complete description will be given below with reference to the accompanying drawings. Preferred embodiments of the invention are shown in the drawings. However, the invention can be implemented in many other different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a thorough and complete understanding of the disclosure of the invention.

[0045] It should be noted that when a component is said to be "fixed to" another component, it can be directly attached to the other component or there may be an intervening component. When a component is said to be "connected to" another component, it can be directly connected to the other component or there may be an intervening component. The terms "vertical," "horizontal," "left," "right," and similar expressions used in this document are for illustrative purposes only.

[0046] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0047] Reference Figure 4 As shown, Figure 4 The diagram illustrates the existing machining method for ultra-short slots. During machining, a circular hole is first drilled through a semi-circular arc segment at one end of the ultra-short slot machining area, leaving a crescent-shaped waste material. Then, the other semi-circular arc segment is drilled through part of the crescent-shaped waste material. Finally, the remaining waste material in the middle is drilled away to form the ultra-short slot. When drilling away the crescent-shaped waste material, because the crescent shape does not match the circular shape of the drill bit, and the area of ​​the crescent-shaped waste material is smaller than the cross-sectional area of ​​the drill bit, the drill bit will cover the circular hole drilled on the right side. This means there is a "hollow" area on the right side, which is called drilling a "hollow." Drilling a "hollow" means that part of the drill bit has no stress point. Due to the lack of a stress point, under the action of cutting resistance, the drill bit will shift towards the "hollow" area during drilling, resulting in problems such as poor straightness, deformation, and large length deviations in the machined ultra-short slot.

[0048] To improve upon the problems of poor straightness, deformation, and large length deviation in ultra-short slots obtained by existing processing methods, this invention provides a method and equipment for processing ultra-short slots on circuit boards, including the following embodiments:

[0049] like Figure 1-3 As shown in one embodiment of a method for processing ultra-short slots on a circuit board, the processing method includes the following steps:

[0050] S100. Determine the processing area 1 of the ultra-short slot on the circuit board. The processing area 1 has two semi-circular arc segments with the same radius.

[0051] S200, Determine the center line passing through the centers of the two semicircular arc segments.

[0052] S300, the processing area 1 is divided into a first area 11 and a second area 12. The first area 11 is a circle formed by completing one of the semicircular arc segments. The second area 12 is the area in the processing area 1 excluding the first area 11.

[0053] S400, several first holes 2 are opened in the first area 11.

[0054] S500. A second hole 3 is opened in the processing area 1. The second hole 3 is tangent to the semicircular arc segment of the second area 12. The center of the second hole 3 is located on the center line. The second hole 3 intersects with the first area 11.

[0055] S600: After opening the first hole 2 and the second hole 3, drill through the waste material in the first area 11.

[0056] S700: After drilling through the first region 11, drill through the waste material in the second region 12 to form an ultra-short slot.

[0057] In this embodiment, the processing method divides the processing area 1 into a first area 11 and a second area 12. A first hole 2 and a second hole 3 are formed in the processing area 1. The first hole 2 can reduce the cutting resistance during the drilling of the first area 11. The position and size of the second hole 3 are such that after drilling through the first area 11, the waste material left in the second area 12 is opposite on the top and bottom sides and empty in the middle. With this setting, drilling through the second area 12 can avoid and reduce drilling "holes", thereby avoiding deviation and improving the problems of poor straightness, deformation and large length deviation of ultra-short slots obtained by existing processing methods.

[0058] It is understandable that the center of the second hole 3 and the center of the first region 11 are both on the center line. Therefore, in order for the outer edge of the second hole 3 to extend into the first region 11, the sum of the diameter of the second hole 3 and the diameter of the first region 11 only needs to be greater than the length of the ultra-short slot. Combining the definition of an ultra-short slot, which is that the slot length is less than 1.5 times the slot width, and the slot width is the diameter of the first region 11, the diameter of the second hole 3 only needs to be greater than the radius of the semicircular arc segment.

[0059] It should be noted that both the first hole 2 and the second hole 3 are pre-drilled holes. The drilling method for the first hole 2 and the second hole 3 is not limited and can be obtained by any means such as punching or drilling.

[0060] In one embodiment of a method for processing ultra-short slots on a circuit board, the step of creating a plurality of first holes 2 in the first region 11 specifically includes:

[0061] S401, Obtain the rotation direction of the drill bit.

[0062] S402. Using the center line as the dividing line, the first region 11 is divided into the third region 111 and the fourth region 112.

[0063] S403. According to the rotation direction of the drill bit, a number of first holes 2 are drilled, and the number of first holes 2 form an empty space in the first region 11.

[0064] When the drill bit rotates from the third region 111 to the fourth region 112, the area of ​​the airspace occupying the fourth region 112 is greater than the area it occupies in the third region 111.

[0065] When the drill bit rotates from the fourth region 112 to the third region 111, the area of ​​the airspace occupying the third region 111 is greater than the area it occupies in the fourth region 112.

[0066] It is understandable that when drilling with a drill bit, the cutting resistance will cause a deviation, resulting in deformation and length deviation. Therefore, this embodiment correlates the arrangement range of the first hole 2 with the rotation direction of the drill bit when drilling through the first region 11. Different rotation directions of the drill bit result in different directions of cutting resistance from the waste material in the first region 11. The rotation direction of the drill bit is the direction from one of the third region 111 to the other, corresponding to clockwise and counterclockwise rotations of the drill bit, respectively. Taking clockwise rotation as an example, it corresponds to the direction from the third region 111 to the fourth region 112. The force analysis is as follows: Figure 3 As shown, the resistance of the scrap in the first region 11 to the drill bit can be decomposed into F1 and F2, which causes the drill bit to deflect to the upper left. In this embodiment, by setting several first holes 2 to form a void, when the drill bit rotates clockwise, the void area of ​​the fourth region 112 below the first region 11 is large, that is, there is less scrap in the fourth region 112, which can reduce the cutting component. Meanwhile, there is more scrap in the third region 111, which can resist the centripetal force when the drill bit is cutting, thereby reducing the influence of the cutting resistance on the drill bit. This can avoid deviation when drilling through the scrap in the first region 11 and improve the machining accuracy of the ultra-short slot.

[0067] It should be noted that in this embodiment, the main purpose of the plurality of first holes 2 is to form a void. The void refers to the hole formed by removing some waste material in the first region 11 by opening the first hole 2. The comparison is also made on the area of ​​the void in the third region 111 and the fourth region 112. Therefore, the size and shape of each first hole 2 are not limited in any way. In addition, the area occupied by the void in the third region 111 or the fourth region 112 can also be zero. For example, when the drill bit rotates clockwise, the void only occupies the fourth region 112.

[0068] Preferably, in order to facilitate the processing of the first hole 2, the shape of the first hole 2 can be a round hole. Unless otherwise specified, the following description will use the first hole 2 as a round hole.

[0069] Specifically, when there is only one first hole 2, the first hole 2 can be pressed on the center line, and the part of the center line passing through the first hole 2 constitutes a non-diameter chord on the first hole 2, so that the area occupied by the first hole 2 in the third region 111 and the area occupied in the fourth region 112 are not equal, so that it is possible to compare which region occupies more, the third region 111 or the fourth region 112.

[0070] In some embodiments, the number of first holes 2 may be multiple. When there are multiple first holes 2, the edge distance between two adjacent first holes 2 is 0-20 μm. By limiting the edge distance between two adjacent first holes 2, it is convenient to arrange two first holes 2. The specific edge distance between two first holes 2 can be 0 μm, 1 μm, 2 μm...20 μm. The smaller the edge distance, the higher the required processing precision, which is limited by the processing precision of the equipment itself. However, the effect is better when drilling through the first region 11, and the offset can be reduced. The specific design can be based on the processing precision and cost of different equipment to design the specific edge distance size.

[0071] It should be noted that the edge distance is not the center distance. The specific value is equal to the center distance between the two first holes 2 minus the radius of the two first holes 2.

[0072] In one embodiment of a circuit board ultra-short slot processing method, the center of one of the plurality of first holes 2 is located on the center line, and the distance between the first hole 2 whose center is located on the center line and the semi-circular arc segment forming the first region 11 is 0-20um.

[0073] Understandably, this embodiment determines the distance and positional relationship between a first hole 2 and the adjacent semicircular segment. With this setting, the position of the first hole 2 can be determined after setting its size parameters. Furthermore, regardless of its size, the first hole 2 is always set to the distance between it and the semicircular segment, thus avoiding the phenomenon of drilling a "hole" due to the first hole 2 being tangent to the semicircular segment. Additionally, by setting the center of the first hole 2 on the centerline, and combining this with the center of the second hole 3 in the previous embodiment also being located on the centerline, and with both positions determined, the first hole 2 and the second hole 3 can also form a positioning hole, facilitating the stacking of multi-layer circuit boards.

[0074] Preferably, all first holes 2 have the same diameter, and there are two first holes 2. With this configuration, combined with the limitation on the edge distance between two adjacent first holes 2 in the previous embodiment, and the center distance between two adjacent first holes 2, it is easy to directly determine the position of the first hole 2 adjacent to the first hole 2 on the adjacent center line. Its center is on the arc centered on the center of the first hole 2 on the center line. Further, considering the rotation direction of the drill bit when drilling through the first region 11, the arrangement range of the other first hole 2 can be determined. Figure 2 As shown.

[0075] It should be emphasized that when setting two first holes 2, in addition to the first hole 2 whose center is located on the center line, the other first hole 2 can only be set within the arrangement range.

[0076] In addition, for some ultra-short slots, such as those with a slot extension length of 1.3 times the diameter of the semicircular arc segment, the processing area 1 is limited, making it inconvenient to arrange multiple first holes 2. After arranging two first holes 2, there is no extra space to arrange a third first hole 2 within the arrangement range. However, if some ultra-short slots allow for arrangement, a third first hole 2 can be added according to the actual offset of the drill bit.

[0077] In one embodiment, the difference between the radius of the second hole 3 and the radius of the semicircular arc segment is 0-0.2 mm. By setting the variation range between the diameter of the second hole 3 and the two radii of the semicircular arc segment to be small, it can be ensured that the second hole 3 extends into the first region 11. At the same time, the small difference between the two can remove more waste material in the second region 12, thereby ensuring that it can connect with the remaining part of the second hole 3 after drilling through the first region 11. This can avoid and reduce drilling "holes" when drilling through the second region 12, prevent deviation, and improve the problems of poor straightness, deformation, and large length deviation of ultra-short slots obtained by existing processing methods.

[0078] Specifically, the difference between the radius of the second hole 3 and the radius of the semicircular arc segment can be any value among 0, 0.05mm, 0.1mm, 0.15mm, and 0.2mm. Preferably, the difference between the radius of the second hole 3 and the radius of the semicircular arc segment is 0.05mm-0.15mm.

[0079] In one embodiment, the formula for calculating the diameter of the first hole 2 is:

[0080] D1 = L - D2 - AB;

[0081] Where D1 is the diameter of the first hole 2, L is the length of the ultra-short slot, D2 is the diameter of the second hole 3, A ranges from 0 to 20 μm, and B ranges from 60 μm to 100 μm.

[0082] The value of A represents the distance between the first hole 2 on the center line and the adjacent semicircular arc segment. The value of B represents the distance between the circular edges of the first hole 2 and the second hole 3 on the center line. A and B are constants, and their specific values ​​can be designed according to the actual length L of the ultra-short slot. The goal is to ensure that the second hole 3 extends into the first region 11, while maintaining two first holes 2 and maximizing the diameter of the first hole 2. Furthermore, since the first hole 2 is a small hole, the closer the constant A is to zero, the larger the diameter of the first hole 2. However, the value of A is limited by the required precision. When the precision is insufficient, reserving a certain margin (i.e., a non-zero value for A) can prevent deviation of the small drill bit, thus avoiding sharp corners in the first hole 2 due to drilling out of the outline. To facilitate drilling through the second region 12 and improve the quality of the ultra-short slot, the value of D2 (the difference between the diameter of the second hole 3 and twice the radius of the semicircular arc segment) should be as small as possible. Based on this, referring to the formula above, the smaller the value of B, the larger the diameter of the first hole 2, so that there will be less waste in the first region 11 after the void is formed. However, the value of B cannot be too small, otherwise the first hole 2 and the second hole 3 will be too close, resulting in the drill bit having no force point when drilling through the first region 11, thus creating a "hole".

[0083] Specifically, the width of the ultra-short slot is defined as D, which is twice the radius of the semicircular arc segment.

[0084] Take, for example, an ultra-short slot with a limit of 0.6mm*0.78mm and an L:D ratio of 1.3;

[0085] When the slot length L of the ultra-short slot is 0.78 mm and the radius of the semicircular arc segment is 0.30 mm:

[0086] Example 1: The diameter of the second hole 3 is 0.50 mm, the value of A is 0, and the value of B is 60 μm. At this time, the diameter of the first hole 2 is 0.22 mm.

[0087] Example 2: The diameter of the second hole 3 is 0.50 mm, A is 20 μm, and B is 60 μm. In this case, the diameter of the first hole 2 is 0.20 mm. The diameter of the second hole 3 is fixed, and the diameter of the first hole 2 changes synchronously when the values ​​of A and B increase or decrease.

[0088] Specifically, take an ultra-short slot with a diameter of 0.6mm*0.90mm and an L:D ratio of 1.5 as an example;

[0089] When the slot length L of the ultra-short slot is 0.90mm and the radius of the semicircular arc segment is 0.30mm:

[0090] Example 3: The diameter of the second hole 3 is 0.50 mm, the value of A is 0 μm, and the value of B is 60 μm. At this time, the diameter of the first hole 2 is 0.34 mm.

[0091] Example 4: The diameter of the second hole 3 is 0.50 mm, A is 20 μm, and B is 60 μm. At this time, the diameter of the first hole 2 is 0.32 mm. When the ultra-short groove ratio is increased to 1.5 times, the diameter of the short groove remains unchanged, so the diameter of the second hole 3 remains unchanged. When the values ​​of A and B remain unchanged, the diameter of the first hole 2 changes synchronously with the increase and decrease of the short groove ratio length.

[0092] Other possible embodiments:

[0093] Example 5: Taking the ultra-short slot with a slot length L of 0.90mm and a semi-circular arc radius of 0.30mm as an example, specifically, the diameter of the second hole 3 is 0.60mm, the value of A is 10um, and the value of B is 80um. At this time, the diameter of the first hole 2 is 0.21mm.

[0094] Example 6: Taking the ultra-short slot with a slot length L of 0.90mm and a semi-circular arc radius of 0.30mm as an example, specifically, the diameter of the second hole 3 is 0.40mm, the value of A is 20um, and the value of B is 100um. At this time, the diameter of the first hole 2 is 0.38mm.

[0095] Preferably, the difference between the radius of the second hole 3 and the radius of the semicircular arc segment is 0.1mm. At this time, the area of ​​the second hole 3 extending into the first region 11 can be better balanced, resulting in a good ultra-short slot effect.

[0096] In conjunction with the above embodiments, the position and size of the first hole 2 and the second hole 3 located on the center line are restricted. Correspondingly, the position of the first hole 2 and the second hole 3 on each circuit board is also determined, so as to be used for positioning when multiple circuit boards are stacked.

[0097] In one embodiment of a method for processing ultra-short slots on a circuit board, the step of drilling through the first region 11 includes:

[0098] S601. Stack multiple circuit boards in sequence, aligning each circuit board with the first hole 2 and the second hole 3 as a reference.

[0099] S602, Drill through the first region 11 along the thickness direction of multiple circuit boards.

[0100] In another embodiment of the circuit board ultra-short slot processing method, drilling through the waste material in the second region 12 to form an ultra-short slot hole includes the following steps:

[0101] S701. Stack multiple circuit boards in sequence, aligning each circuit board with the drilled area in processing area 1 as the reference.

[0102] S702, Drill through the second region 12 along the thickness direction of multiple circuit boards.

[0103] In both embodiments above, multiple circuit boards are stacked to process multiple circuit boards at once. The difference lies in the stacking steps: one is set in step S600, and the other in step S700. In existing circuit board processing technology, when the total number of stacked boards exceeds two, the existing processing method will cause the deviations to accumulate step by step. However, the present invention improves the problems of poor flatness, deformation, and large length deviations by setting the first hole 2 and the second hole 3 during the processing. Furthermore, the center, size, and position of the first hole 2 and the second hole 3 are determined, which can play a positioning role during stacking. With this setting, whether drilling through the waste material in the first area 11 or the second area 12, the problem of large deviations in drilling during stacking can be improved, so that the requirements can be met even under stacked processing. Moreover, the stacking method can also reduce time costs and improve processing efficiency.

[0104] It should be noted that when the stacking step is set in S600, step S700, which involves drilling through the second region 12, is also performed in the stacked state.

[0105] In one embodiment of a method for processing ultra-short slots on a circuit board, the radius of the drill bit used to drill the first region 11 is the same as the radius of the semi-circular arc segment.

[0106] In this embodiment, by using a drill bit with the same radius as the semicircular arc segment, the increased size of the drill bit will also improve its rigidity, which can reduce the offset during the cutting process.

[0107] In this embodiment, the drilling speed of the drill bit can be within the normal operating speed range of the spindle. The specific speed is related to the diameter of the drill bit; the larger the diameter of the drill bit, the lower the drilling speed is required because the drill bit will wear out rapidly at high speeds. Specifically, the drill bit speed can be 10K rpm-100K rpm. Preferably, the drill bit speed is 35K rpm, which is in the low-speed range and can reduce the influence of centripetal force to improve the accuracy of drilling through the first region 11. As the speed is further reduced, the cutting speed supplied to the tool is also lower. Theoretically, the lower the cutting speed, the less centripetal force is applied to the drill bit. However, the cutting speed cannot be infinitely low because the lower the cutting speed, the greater the axial force during the cutting process. Excessive axial force will increase the cutting resistance of the drill bit, causing it to break.

[0108] Furthermore, the feed rate of the drill bit used to drill through the first region 11 is 0.3 m / min. In addition, the radius of the drill bit used to drill through the first region 11 is the same as the radius of the semicircular arc segment, the rotation speed of the drill bit is 35 rpm, and the feed rate is 0.3-0.5 m / min.

[0109] This invention also relates to a processing apparatus for implementing the circuit board ultra-short slot processing method in the above embodiments. It belongs to the same concept as the corresponding circuit ultra-short slot hole processing method embodiments, and thus has the same technical effects, which will not be elaborated further here.

[0110] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0111] The above embodiments merely illustrate several implementation methods of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this patent should be determined by the appended claims.

Claims

1. A method of processing an ultra-short slot hole of a circuit board, characterized by, The processing method comprises the following steps: determining a processing area of the ultra-short slot hole on the circuit board, the processing area having two semicircular arc segments with the same radius; determining a center line passing through the centers of the two semicircular arc segments; dividing the processing area into a first area and a second area, the first area being formed by a circle completed by one of the semicircular arc segments, and the second area being the area of the processing area except the first area; drilling a plurality of first holes in the first area; drilling a second hole in the processing area, the second hole being tangent to the semicircular arc segment of the second area, the center of the second hole being located on the center line, and the second hole intersecting the first area; after the first holes and the second hole are drilled, drilling through the first area; after the first area is drilled through, drilling through the second area to form the ultra-short slot hole.

2. The method of claim 1, wherein The step of drilling a plurality of first holes in the first area comprises: obtaining the rotation direction of the drill bit; dividing the first area into a third area and a fourth area with the center line as the dividing line; drilling a plurality of first holes according to the rotation direction of the drill bit, the plurality of first holes forming an empty area in the first area; when the rotation direction of the drill bit is the direction of the third area turning to the fourth area, the area occupied by the empty area in the fourth area is greater than the area occupied by the empty area in the third area; when the rotation direction of the drill bit is the direction of the fourth area turning to the third area, the area occupied by the empty area in the third area is greater than the area occupied by the empty area in the fourth area.

3. The method of claim 2, wherein the step of processing is performed by a computer. When the first holes are multiple, the circular edge distance between two adjacent first holes is 0-20um.

4. The method of claim 3, wherein the step of processing is performed by a computer. The center of one of the plurality of first holes is located on the center line, and the distance between the center on the center line and the semicircular arc segment forming the first area is 0-20um.

5. The processing method as described in claim 1, characterized in that, The difference between the radius of the second hole and the radius of the semicircular arc segment is 0-0.2mm.

6. The method of claim 5, wherein the step of processing is performed by a computer. The diameter of the first hole is calculated according to the formula: D1=L-D2-A-B; wherein D1 is the diameter of the first hole, L is the length of the ultra-short slot hole, D2 is the diameter of the second hole, A is 0-20um, and B is 60um-100um.

7. The processing method as described in claim 1, characterized in that, The step of drilling through the first area comprises: stacking a plurality of circuit boards in sequence, and aligning each circuit board based on the first holes and the second holes; drilling through the first area along the thickness direction of the plurality of circuit boards.

8. The processing method as described in claim 1, characterized in that, The step of drilling through the second area to form the ultra-short slot hole comprises: stacking a plurality of circuit boards in sequence, and aligning each circuit board based on the area drilled in the processing area; drilling through the second area along the thickness direction of the plurality of circuit boards.

9. A process according to any one of claims 1 to 8, wherein the process is carried out at a temperature of from 20 to 100°C. The radius of the drill bit used to drill through the first area is the same as the radius of the semicircular arc segment.

10. A processing apparatus characterized by comprising: A circuit board ultra-short slot hole processing method is provided. The circuit board ultra-short slot hole processing method is used to realize the circuit board ultra-short slot hole processing method according to any one of claims 1-9.

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