A method for processing slots of printed circuit boards

Abstract

The present invention belongs to the technical field of printed circuit board processing and discloses a method for processing slots in printed circuit boards. The method for processing slots in printed circuit boards uses a stepped drill comprising at least a first-stage drill and a second-stage drill to process the slots, including drilling a pre-drilled hole and drilling a slotted hole. The pre-drilled hole is located on the centerline of the slot along its length, and the pre-drilled hole diameter is equal to the first-stage drill diameter and smaller than the slot width. Drilling the slotted hole includes drilling a first hole and drilling a second hole. The first hole and the second hole are both located on the centerline and have diameters equal to the slot width. The first hole and the second hole are respectively matched with both ends of the slot in its length. After at least one of the first hole and the second hole is concentrically matched and positioned with the first-stage drill and the pre-drilled hole, the second-stage drill is used to complete the processing. The method for processing slots in printed circuit boards provided by the present invention can keep the drill stable when drilling the slots, avoid drill offset problems, and improve the drilling quality of the slots.

Description

Technical Field

[0001] The present invention relates to the technical field of printed circuit board processing, and in particular to a method for processing slots of a printed circuit board. Background Art

[0002] PCB board is a printed circuit board, also known as printed circuit board. As the support body of electronic components, PCB board is an important electronic component and also the carrier of electrical connection of electronic components.

[0003] PCBs are currently developing towards higher density and greater functionality. This has led to an increasing number of PCB layers and smaller apertures in PCB components. This has also led to increasingly stringent requirements for the shape of drilled holes, particularly short slots. However, with this growing demand for short slots, processing challenges are becoming increasingly apparent.

[0004] Due to the increasing number of PCB boards stacked together and the significant overlap between holes during multiple drilling, after completing one hole, the tip of the drill bit can easily fall into the area of ​​the already processed hole during subsequent drilling, making it impossible to center the drill bit. Furthermore, since the previously processed hole has already removed some material, there is a problem of local force imbalance during subsequent drilling, which causes the drill bit to deform and deflect. This leads to quality problems such as increased slot width, reduced slot length, and hole shape deviation in short slot holes, affecting the performance of the PCB board.

[0005] Some existing techniques employ pre-drilled holes on the PCB to provide reverse eccentricity compensation for subsequently drilled holes and maintain drill bit stability. However, because the pre-drilled holes are not concentric with the drilled holes, the position of the pre-drilled holes must be determined based on operator experience to achieve the reverse compensation effect, making the operation difficult and demanding. Other techniques employ a method where a small-diameter hole is first drilled, followed by concentrically machining holes of progressively larger diameters, using the small-diameter hole to position the drill tip for subsequent holes. However, because the diameter of the drill bit during subsequent drilling is larger than the previous hole, the drill tip hangs suspended in the small-diameter hole, resulting in insufficient drill bit stability and a tendency for drill bit deflection, which compromises the machining quality of short slot holes. Summary of the Invention

[0006] The object of the present invention is to provide a slot hole processing method for a printed circuit board, which can keep the drill bit in a stable position when drilling the slot hole, avoid the problem of drill bit deviation, and improve the drilling quality of the slot hole.

[0007] To achieve this object, the present invention adopts the following technical solutions:

[0008] A method for processing a slot hole of a printed circuit board, wherein the slot hole is processed by a step drill, wherein the step drill includes at least a first-step drill bit and a second-step drill bit, and the method for processing a slot hole of a printed circuit board comprises:

[0009] Drilling a pre-drilled hole, wherein the pre-drilled hole is provided on the center line of the slotted hole along the length direction, and the diameter of the pre-drilled hole is equal to the diameter of the first-stage drill bit and is smaller than the width of the slotted hole;

[0010] Drilling a slot hole includes drilling a first hole and drilling a second hole. The first hole and the second hole are both located on the center line and have diameters equal to the width of the slot hole. The first hole and the second hole are respectively matched with both ends of the slot hole in the length direction. At least one of the first hole and the second hole is completed by the second-stage drill after the first-stage drill is concentrically matched and positioned with the pre-drilled hole.

[0011] Optionally, two pre-drilled hole positions are provided on the printed circuit board, and one or two of the pre-drilled holes can be selectively processed, and the two pre-drilled holes are arranged along the center line.

[0012] Optionally, if the two pre-drilled holes are spaced apart, the first hole and the second hole can correspond to the two pre-drilled holes respectively through the first-step drill, so that the pre-drilled holes position the step drill so that the second-step drill can process the first hole and the second hole.

[0013] Optionally, if the positions of the two pre-drilled holes partially overlap, only one pre-drilled hole is processed. After processing the first hole, the first-stage drill is positioned in conjunction with the pre-drilled hole so that the second-stage drill can process the second hole.

[0014] Optionally, the pre-drilled hole is machined by a pre-drilling tool.

[0015] Optionally, if the pre-drilled hole is located at the overlapping position of the first hole and the second hole, after machining one pre-drilled hole and machining the first hole thereon, the second hole is machined by the step drill.

[0016] Optionally, the pre-drilled hole is machined by the first-stage drill.

[0017] Optionally, after drilling the slotted hole, the method further includes:

[0018] Flattening is performed to improve the accuracy and surface quality of the slot.

[0019] Optionally, the aspect ratio of the slot is less than 2.

[0020] Optionally, the second-stage drill is set with a preset taper.

[0021] Optionally, the slot is processed in steps along the thickness direction of the printed circuit board, and the depth of each step is less than the length of the first-stage drill.

[0022] Beneficial effects:

[0023] The present invention provides a method for processing slot holes in a printed circuit board. This method comprises a step-by-step process of pre-drilling a hole on the printed circuit board and then processing the slot hole with a step drill. The pre-drilled hole is arranged on the center line of the slot hole in the longitudinal direction, so that the first hole and the second hole can form the two ends of the slot hole, respectively, ensuring the processing accuracy of the slot hole shape. Since the diameter of the pre-drilled hole is equal to the diameter of the first-step drill bit of the step drill, when processing the slot hole, the first-step drill bit can be inserted into the pre-drilled hole, and then the first hole and the second hole can be processed by the second-step drill bit, thereby forming the slot hole together. Due to the cooperation between the first-step drill bit and the pre-drilled hole, the step drill can be stably positioned, effectively reducing the risk of the step drill deflecting and other problems, thereby improving the processing quality of the slot hole. The method for processing slot holes in a printed circuit board provided by the present invention can keep the drill bit in a stable position when drilling the slot hole, avoid the problem of drill bit offset, and improve the drilling quality of the slot hole. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a schematic diagram of a step drill provided by the first embodiment of the present invention during machining;

[0025] Figure 2 1 is a schematic structural diagram of a step drill provided in the first embodiment of the present invention;

[0026] Figure 3 This is a flow chart of a method for processing a slot of a printed circuit board provided in the first embodiment of the present invention;

[0027] Figure 4 Schematic diagram of a method for processing slots in a printed circuit board provided in Example 1 of the present invention;

[0028] Figure 5 Schematic diagram of a method for processing slots in a printed circuit board provided in a second embodiment of the present invention;

[0029] Figure 6 Schematic diagram of a method for processing slots in a printed circuit board provided in the third embodiment of the present invention.

[0030] In the picture:

[0031] 100, step drill; 110, first-step drill; 120, second-step drill;

[0032] 1. Slotted hole; 11. First hole; 12. Second hole; 2. Pre-drilled hole. DETAILED DESCRIPTION

[0033] The present invention will be further described in detail below with reference to the accompanying drawings and examples. It will be understood that the specific embodiments described herein are intended only to illustrate the present invention and are not intended to limit the present invention. It should also be noted that, for ease of description, the accompanying drawings only illustrate portions relevant to the present invention, not all structures.

[0034] In the description of the present invention, unless otherwise expressly specified or limited, the terms "connected," "connected," and "fixed" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integration; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention in specific circumstances.

[0035] In the present invention, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may include the first and second features being in direct contact, or may include the first and second features being in contact not directly but through another feature between them. Furthermore, a first feature being "above," "above," and "above" a second feature may include the first feature being directly above or obliquely above the second feature, or may simply mean that the first feature is higher in level than the second feature. A first feature being "below," "below," and "below" a second feature may include the first feature being directly below or obliquely below the second feature, or may simply mean that the first feature is lower in level than the second feature.

[0036] In the description of this embodiment, the terms "upper," "lower," "right," and other orientations or positional relationships are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely for ease of description and simplified operation. They do not indicate or imply that the devices or components referred to must have, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on the present invention. Furthermore, the terms "first" and "second" are used solely for descriptive purposes and have no special meanings.

[0037] Example 1

[0038] like Figures 1-4 As shown, this embodiment provides a method for machining slots in a printed circuit board. A slot 1 is machined using a step drill 100, which includes at least a first-step drill bit 110 and a second-step drill bit 120. It is understood that the diameter of the first-step drill bit 110 is smaller than that of the second-step drill bit 120. A step drill 100 with multiple-step drill bits can be selected based on actual conditions to meet the machining requirements for the slot 1.

[0039] Printed circuit board slot processing methods include:

[0040] S1. Drill a pre-drilled hole 2. The pre-drilled hole 2 is located on the center line of the slotted hole 1 along the length direction. The diameter of the pre-drilled hole 2 is equal to the diameter of the first-stage drill bit 110 and is smaller than the width of the slotted hole 1.

[0041] S2. Drilling the slotted hole 1. Drilling the slotted hole 1 includes drilling a first hole 11 and a second hole 12. The first hole 11 and the second hole 12 are both located on the centerline and have diameters equal to the width of the slotted hole 1. The first hole 11 and the second hole 12 are respectively aligned with the ends of the slotted hole 1 in the longitudinal direction. At least one of the first hole 11 and the second hole 12 is completed by the second-stage drill 120 after the first-stage drill 110 is concentrically aligned with the pre-drilled hole 2.

[0042] The pre-drilled hole 2 is positioned along the longitudinal centerline of the slotted hole 1. This facilitates the alignment of the first hole 11 and the second hole 12 with the ends of the slotted hole 1 during machining, thereby serving as the ends of the slotted hole 1. This improves the machining quality of the slotted hole 1 and reduces errors. The diameter of the pre-drilled hole 2 is equal to that of the first-stage drill 110, facilitating the insertion of the first-stage drill 110 into the pre-drilled hole 2. The coordination between the pre-drilled hole 2 and the first-stage drill 110 ensures stable positioning of the step drill 100, preventing deflection of the step drill 100 during machining and affecting the machining accuracy of the slotted hole 1. After the first-stage drill 110 is positioned, the second-stage drill 120 is used to machine the first hole 11 and the second hole 12, thereby forming the slotted hole 1. Since the diameters of the first hole 11 and the second hole 12 are equal to the width of the slotted hole 1, after machining the first hole 11 and the second hole 12, the ends and most of the middle portion of the slotted hole 1 have been substantially machined on the printed circuit board. The pre-drilled hole 2 is concentrically arranged with the first-step drill bit 110, ensuring that the drill tip of the step drill 100 maintains good centering performance. Compared to pre-drilling methods with reverse compensation, this method facilitates determining the position of the pre-drilled hole 2, reduces the operator's experience requirements, and makes it easier to achieve a stable drill bit. This method for processing slot holes in printed circuit boards ensures that the step drill 100 maintains stable positioning when drilling the slot hole 1, preventing deviation of the step drill 100 and improving the drilling quality of the slot hole 1.

[0043] Optionally, after S2, drilling the slot hole 1, the method further includes:

[0044] S3. Flattening to improve the accuracy and surface quality of slot 1.

[0045] After machining the first hole 11 and the second hole 12, some residual material remains in the slot 1 on the printed circuit board. In this case, the drilling tool can be used to repeat the drilling process by changing the horizontal position to complete the slot 1. Smoothing can improve the surface quality of the slot 1 while completing the machining of the slot 1, thereby improving the connection of electronic components.

[0046] Optionally, the aspect ratio of the slot 1 is less than 2.

[0047] This method for machining slots in printed circuit boards effectively solves the problem of uneven force applied to the drill bit during machining, which can lead to inaccurate drill tip positioning and deflection due to the short length of the slot 1. Furthermore, this method is also applicable to thicker-to-diameter plates, similar situations where uneven force applied during drilling can make it difficult for the drill bit to maintain balance, and other applicable scenarios.

[0048] Optionally, the second-stage drill 120 is set at a preset taper.

[0049] Optionally, the slot 1 is processed in steps along the thickness direction of the printed circuit board, and the depth of each step is less than the length of the first-stage drill 110 .

[0050] The lengths of the first-stage drill 110 and the second-stage drill 120 can be determined as needed, but the depth of each machining operation by the second-stage drill 120 must be less than the length of the pre-drilled hole 2. Furthermore, the depth of each step-by-step machining operation must also be less than the length of the first-stage drill 110 to ensure that the first-stage drill 110 can function as a positioning support. Furthermore, when processing multiple layers of stacked printed circuit boards, a distributed machining process can be performed layer by layer until the slot 1 is completed along the thickness of the printed circuit board. Because the pre-drilled hole 2 has a large aspect ratio, the desired length can be achieved through multiple drillings, avoiding the increased difficulty of machining the pre-drilled hole 2 due to the required length of the thick printed circuit board. Accordingly, the first hole 11 and the second hole 12 are also completed through step-by-step machining. Step-by-step machining can reduce drilling deviations caused by thick printed circuit boards, improving machining quality while also avoiding vibration, deformation, and breakage caused by a large aspect ratio, which can weaken the drill's rigidity and increase its sensitivity to unbalanced forces. The problem of reduced efficiency caused by multi-step processing can be alleviated by increasing the number of printed circuit board stacks and increasing the drilling depth, so as to improve the processing quality while reducing the impact on processing efficiency.

[0051] The first-stage drill bit 110 is primarily used for positioning and support, and can be designed without a taper. The second-stage drill bit 120 is used for drilling and can be set with a preset taper or a surface ring cut of a certain length. The second-stage drill bit 120, which is closer to the first-stage drill bit 110, is configured with a larger end. This reduces friction between the rear end of the second-stage drill bit 120 and the wall of the slotted hole 1, improving the surface processing quality of the hole wall. The slotting of the step drill 100 adopts a small helix angle, which not only facilitates the discharge of machining chips, but also enhances the rigidity of the step drill 100 and reduces deformation.

[0052] Optionally, continue with reference to Figures 1-4 Two pre-drilled holes 2 are provided on the printed circuit board, and one or two pre-drilled holes 2 can be selectively processed. The two pre-drilled holes 2 are arranged along the center line of the length direction of the slot 1.

[0053] The processing position and diameter of the pre-drilled hole 2 can be determined based on factors such as the size of the slotted hole 1 and processing requirements. If the diameter of the pre-drilled hole 2 is set too large, it is easy to cause the overlap between the two pre-drilled holes 2 to be too large, which is not conducive to subsequent processing. If the diameter of the pre-drilled hole 2 is too small, the aspect ratio of the drill used in processing will be too large, which will reduce the rigidity of the drill and easily affect the accuracy of the pre-drilled hole 2, thereby causing the slotted hole 1 to shift.

[0054] Optionally, in this embodiment, the two pre-drilled holes 2 are spaced apart, and the first hole 11 and the second hole 12 can correspond to the two pre-drilled holes 2 respectively through the first-step drill 110, so that the pre-drilled holes 2 position the step drill 100 so that the second-step drill 120 can process the first hole 11 and the second hole 12.

[0055] When two pre-drilled holes 2 can be spaced apart, if the center of the second hole 12 falls within the first hole 11, to prevent the drill tip of the step drill 100 from falling into the first hole 11 during machining of the second hole 12 and affecting the stability of the step drill 100, and to improve the positioning and support effect, two pre-drilled holes 2 can be machined so that the first hole 11 and the second hole 12 can be positioned through the corresponding pre-drilled holes 2, completing the machining of the slotted hole 1. It is understood that this method is also applicable when the center of the first hole 11 falls within the second hole 12.

[0056] Optionally, the pre-drilled hole 2 is processed by a pre-drilling tool. This method for processing slots in a printed circuit board can effectively reduce the deformation of the step drill 100 by coordinating and positioning the first-step drill 110 with the pre-drilled hole 2, enhance the anti-deformation performance of the step drill 100, and reduce the rigidity requirements for the step drill 100.

[0057] Example 2

[0058] This embodiment provides a method for processing slots in a printed circuit board, which is substantially the same as the method for processing slots in the printed circuit board in the first embodiment, except that the processing of the pre-drilled holes 2 is different.

[0059] Alternatively, as Figure 1-Figure 3 and Figure 5 As shown, if the positions of the two pre-drilled holes 2 partially overlap, only one pre-drilled hole 2 is processed. After processing the first hole 11, the first-stage drill 110 is positioned in conjunction with the pre-drilled hole 2 so that the second-stage drill 120 can process the second hole 12.

[0060] In this embodiment, the center of the first hole 11 falls outside the pre-drilled hole 2, ensuring balanced force during drilling. To avoid uneven force during drilling of the second hole 12, a pre-drilled hole 2 is first provided at the corresponding position of the second hole 12. After the first hole 11 is machined, the first-stage drill 110 is positioned in conjunction with the pre-drilled hole 2 to ensure the machining accuracy of the second hole 12.

[0061] Optionally, the pre-drilled hole 2 is machined by a pre-drilling tool.

[0062] Example 3

[0063] This embodiment provides a method for processing slots in a printed circuit board, which is substantially the same as the method for processing slots in the printed circuit board in the first embodiment, except that the processing of the pre-drilled holes 2 is different.

[0064] Alternatively, as Figure 1-Figure 3 and Figure 6 As shown, if the pre-drilled hole 2 is located at the overlapping position of the first hole 11 and the second hole 12 , after machining a pre-drilled hole 2 and machining the first hole 11 thereon, the second hole 12 is machined by the step drill 100 .

[0065] In this embodiment, the two pre-drilled holes 2 are spaced apart, and both pre-drilled holes 2 are located within the overlapping range of the first hole 11 and the second hole 12. In this case, one pre-drilled hole 2 can be processed first, and the first hole 11 can be processed using the step drill 100. Since the other pre-drilled hole 2 falls on the lower surface of the first hole 11, the step drill 100 can continue to be used to process the second hole 12. At this time, the drill tip of the first-stage drill 110 contacts the lower surface of the first hole 11, and the problem of uneven force will not occur. During processing, the processing depth of the second-stage drill 120 can be set to be less than the length of the first-stage drill 110, so that the first-stage drill 110 first contacts the lower surface of the first hole 11. After drilling to a certain depth, the second-stage drill 120 contacts the printed circuit board to begin drilling the second hole 12. The first-stage drill 110 can still play a positioning and support role.

[0066] Optionally, the pre-drilled hole 2 is machined by a first-stage drill 110 .

[0067] When processing the first pre-drilled hole 2, a step drill 100 is used to complete it, so that both the pre-drilled hole 2 and the slot hole 1 are completed using the step drill 100, which can reduce the number of tool changes, improve the processing accuracy and processing quality of the slot hole 1, and improve processing efficiency.

[0068] Obviously, the above embodiments of the present invention are merely examples for the purpose of clearly illustrating the present invention and are not intended to limit the embodiments of the present invention. A person skilled in the art would be able to make various obvious changes, readjustments, and substitutions without departing from the scope of protection of the present invention. It is not necessary and impossible to enumerate all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the claims of the present invention.

Claims

1. A method for processing slots in a printed circuit board, characterized in that: The slot hole (1) is processed by a step drill (100), wherein the step drill (100) comprises at least a first-step drill bit (110) and a second-step drill bit (120). The slot hole processing method of the printed circuit board comprises: Drilling a pre-drilled hole (2), wherein the pre-drilled hole (2) is arranged on the center line of the slot hole (1) along the length direction, the pre-drilled hole (2) is arranged concentrically with the first-stage drill bit (110), and the diameter of the pre-drilled hole (2) is equal to the diameter of the first-stage drill bit (110) and is smaller than the width of the slot hole (1); Drilling a slotted hole (1), comprising drilling a first hole (11) and drilling a second hole (12), wherein the first hole (11) and the second hole (12) are both located on the center line and have diameters equal to the width of the slotted hole (1), the first hole (11) and the second hole (12) are respectively matched with both ends of the slotted hole (1) in the length direction, and at least one of the first hole (11) and the second hole (12) is processed by the second-stage drill (120) after the first-stage drill (110) is concentrically matched and positioned with the pre-drilled hole (2); The slot (1) is processed in steps in the thickness direction of the printed circuit board, and the depth of each step is less than the length of the first-stage drill (110).

2. The method for processing slots in a printed circuit board according to claim 1, wherein: Two pre-drilled holes (2) are provided on the printed circuit board, and one or two of the pre-drilled holes (2) can be selectively processed. The two pre-drilled holes (2) are arranged along the center line.

3. The method for processing slots in a printed circuit board according to claim 2, wherein: If the two pre-drilled holes (2) are spaced apart, the first hole (11) and the second hole (12) can correspond to the two pre-drilled holes (2) respectively through the first-step drill (110), so that the pre-drilled holes (2) position the step drill (100) so that the second-step drill (120) can process the first hole (11) and the second hole (12).

4. The method for processing slots in a printed circuit board according to claim 2, wherein: If the positions of the two pre-drilled holes (2) partially overlap, only one of the pre-drilled holes (2) is processed. After processing the first hole (11), the first-stage drill (110) is positioned in conjunction with the pre-drilled hole (2) so that the second-stage drill (120) can process the second hole (12).

5. The method for processing slots in a printed circuit board according to claim 3 or 4, wherein: The pre-drilled hole (2) is machined by a pre-drilling tool.

6. The method for processing slots in a printed circuit board according to claim 2, wherein: If the pre-drilled hole (2) is located at the overlapping position of the first hole (11) and the second hole (12), after machining one pre-drilled hole (2) and machining the first hole (11) thereon, the second hole (12) is machined by the step drill (100).

7. The method for processing slots in a printed circuit board according to claim 6, wherein: The pre-drilled hole (2) is machined by the first-stage drill (110).

8. The method for processing slots in a printed circuit board according to claim 1, wherein: After drilling the slotted hole (1), the following steps are also included: Flattening is performed to improve the accuracy and surface quality of the slot (1).

9. The method for processing slots in a printed circuit board according to claim 1, wherein: The aspect ratio of the slot (1) is less than 2.

10. The method for processing slots in a printed circuit board according to claim 1, wherein: The second-stage drill bit (120) is arranged with a preset taper.

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