PCB board processing methods

Abstract

This application discloses a PCB board processing method, including the following steps: First, based on the total thickness of the PCB board stack, and adding a preset safety distance, the first starting coordinate of the PCB board in the processing direction is automatically set. The coordinate of the tool when it reaches the upper processing surface of the PCB board from the first starting coordinate is used as the second starting coordinate of the PCB board in the processing direction. The second starting coordinate is used as the starting processing point of each processing position on the PCB board for processing. At the same time, processing pauses are performed during the processing according to the calculated cutting pause thickness. The length of the chips is controlled by the cutting depth to avoid chips wrapping around the tool. Compared with the technical solution of manually setting parameters to continuously process the PCB board, the technical solution of this invention has higher processing efficiency and can solve the problem of continuous chip wrapping around the tool during PCB board processing.

Description

Technical Field

[0001] This application relates to the field of PCB board technology, and in particular to a PCB board processing method. Background Technology

[0002] During mechanical drilling, the drill bit must first be manually moved to a safe distance before the material is processed. For some materials, continuous chips are generated during cutting, which can become entangled on the drill bit and drill shank during the process.

[0003] When chips get tangled around the drill bit or shank, continuing to cut will result in a larger hole diameter and a rougher hole wall, leading to a low yield of finished products. Summary of the Invention

[0004] Therefore, the purpose of this application is to provide a PCB board processing method with high processing efficiency and high yield.

[0005] To achieve one or more of the above objectives or other objectives, this application provides a PCB board processing method, including the following steps: based on the total thickness of the PCB board stack to be processed, adding a preset safety distance to the total thickness of the PCB board stack to serve as the first starting coordinate of the PCB board in the processing direction;

[0006] The coordinates at which the cutting tool arrives at the upper machining surface of the PCB board from the first starting coordinate are taken as the second starting coordinates of the PCB board in the machining direction.

[0007] Calculate the cutting thickness per spindle revolution based on the machining parameters of the selected tool, and calculate the cutting pause thickness based on the cutting thickness per spindle revolution;

[0008] The cutting process begins from the second starting coordinate of the PCB board in the processing direction, and the cutting pause is performed according to the calculated cutting pause thickness to avoid chips entangled in the tool.

[0009] According to the set processing path, the second starting coordinate is used as the starting processing point for each processing position on the PCB board.

[0010] Optionally, the step of adding a preset safety distance to the total thickness of the PCB stack to be processed, and using this as the first starting coordinate of the PCB in the processing direction, includes:

[0011] The total thickness of the PCB stack is detected by a sensor, and the corresponding total thickness information of the PCB stack is sent to the controller.

[0012] Optionally, the first starting coordinate of the PCB board in the processing direction is set based on the total thickness of the PCB board stack plus a safety distance, including:

[0013] The controller will receive the PCB board stack thickness value detected by the sensor and add it to the preset safety distance in the controller, and use it as the first starting coordinate of the PCB board in the processing direction.

[0014] Optionally, when the tool reaches the upper machining surface of the PCB board from the first starting coordinate, the second starting coordinate in the machining direction is recorded, including:

[0015] The controller records the second starting coordinates of the tool as it arrives at the upper machining direction of the PCB board.

[0016] Optionally, the cutting tool arrives at the upper machining surface of the PCB board from the first starting coordinate in the following manner:

[0017] The photoelectric switch is used to detect whether the cutting tool has reached the upper surface of the PCB board.

[0018] Optionally, the cutting pause thickness during tool processing is calculated based on the second starting coordinate of the PCB board in the processing direction, including:

[0019] Based on the cutting thickness per revolution of the tool, the controller calculates the thickness of the tool's pause during each machining process.

[0020] Optionally, the cutting pause thickness is less than the cutting thickness per revolution of the tool;

[0021] Alternatively, the cutting pause thickness satisfies the following relationship:

[0022] ;

[0023] Where T represents the cutting pause thickness, D represents the tool diameter, D1 represents the tool holder diameter, and f represents the cutting thickness per spindle revolution.

[0024] Optionally, the cutting thickness per revolution of the tool satisfies the following relationship:

[0025] f = F * 1000 / S;

[0026] Where f represents the cutting thickness per revolution of the tool, F represents the feed rate of the machine tool, and S represents the spindle speed of the machine tool.

[0027] Optionally, when the machine tool spindle speed is 20,000 revolutions per minute, a 1-millisecond cutting pause is performed every 2.05 revolutions until the machining is completed.

[0028] Optionally, the cutting process starting from the second starting coordinate of the PCB board in the processing direction, and the cutting pause according to the calculated cutting pause thickness, includes:

[0029] The cutting tool controls the point at which the spindle pauses each time by controlling the machining depth, and the millisecond-level pause time blocks the generation of continuous cutting filaments.

[0030] Implementing the embodiments of this application will have the following beneficial effects:

[0031] In the embodiments of this application, the first starting coordinate of the PCB board in the processing direction is automatically set based on the total thickness of the PCB board stack plus a preset safety distance. The coordinate of the tool when it arrives at the upper processing surface of the PCB board from the first starting coordinate is used as the second starting coordinate of the PCB board in the processing direction. The cutting thickness per spindle revolution is obtained according to the processing parameters of the selected tool. The cutting pause thickness is calculated based on the second starting coordinate. In this way, the tool can process according to the set processing path, with the second starting coordinate as the starting processing point of each processing position on the PCB board. At the same time, the processing pause is performed according to the calculated cutting pause thickness. The length of the chips is controlled by the cutting depth to avoid chips wrapping around the tool. Compared with the technical solution of manually setting parameters to continuously process the PCB board, the technical solution of this invention has higher processing efficiency and can solve the problem of continuous chip wrapping around the tool during PCB board processing. Attached Figure Description

[0032] To more clearly illustrate the technical solutions in the embodiments of this application 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 this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0033] Figure 1 This is a flowchart illustrating one embodiment of the PCB board processing method of this application;

[0034] Figure 2 This is a diagram showing the relationship between the chip filaments and the total length of the tool when the tool becomes entangled. Detailed Implementation

[0035] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0036] It should be noted that if the embodiments of this application involve directional indications (such as up, down, left, right, front, back, etc.), the directional indications are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indications will also change accordingly.

[0037] Furthermore, if the embodiments of this application involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, features defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the technical solutions of various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. If the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed in this application.

[0038] PCB board processing involves a board structure composed of epoxy resin, fiberglass cloth, copper foil, and other fillers. During processing, an aluminum sheet is added to the surface for protection and heat dissipation. Copper foil and aluminum sheets, due to their high ductility, are subjected to continuous cutting by the tool during processing, inevitably producing long, continuous chips. These chips are discharged from the hole through the drill bit's chip evacuation groove. Under the centrifugal force generated by the high-speed rotation of the machine tool spindle, discontinuous chips are thrown out and then sucked away by the dust extraction system. However, the continuous long chips, after being discharged from the hole, do not have their roots still inside the hole. Instead, the continuous chip filaments, driven by the spindle's centrifugal force, tend to wrap around the drill bit / drill shank, creating a tangling problem. To solve these technical problems, the inventive concept of this application was developed, which will be explained through the following embodiments.

[0039] refer to Figure 1 The PCB board processing method of the present invention is based on the total thickness of the PCB board stack to be processed. Specifically, the thickness parameter to be processed of the PCB board is obtained by detecting the total thickness of the PCB board stack. The total thickness of the PCB board stack plus a safety distance is used as the first starting coordinate of the PCB board in the processing direction. That is, the position of the first starting coordinate is the safe position for the tool to process the PCB board. By setting the safety distance, the PCB board processing method of the present application can be applied to PCB boards of various specifications. This eliminates the need for manual adjustment of the process steps when processing each type of PCB board, thereby improving the processing efficiency of the PCB board.

[0040] In practical applications, after setting the first starting coordinate, when the tool reaches the upper machining surface of the PCB board from the first starting coordinate, the second starting coordinate of the tool in the machining direction of the PCB board is recorded. Optionally, the tool can pause feeding or retract a small distance at this time, and the recorded second starting coordinate is used as the starting coordinate in the machining direction when the tool actually starts machining. For example, the material is in the xyz coordinate system, and the tool moves in the xyz coordinate system to machine the PCB board. The machining direction of the material is the Z-axis direction, the machining endpoint coordinate of the material is Z0=0, the second starting coordinate is Z1=d, and the first starting coordinate is Z2=d+h, where d and h are both positive numbers. The initial position of the tool before machining is Z2. After that, the tool feeds to the Z1 position and enters the initial machining position. After that, the starting machining coordinate of all machining positions on the PCB board is Z1, and the endpoint machining coordinate is Z0, realizing automatic and efficient machining of the PCB board.

[0041] Optionally, a sensor is used to detect the total thickness of the PCB stack and send the total thickness information to the controller for processing. The total thickness is added to the set safety distance to obtain the first starting coordinate of the PCB in the processing direction, so as to realize the automated acquisition of the total thickness of the PCB stack and the setting of the first starting coordinate.

[0042] Furthermore, when the cutting tool arrives at the machining surface on the PCB board from the first starting coordinate, specifically, the distance between the cutting tool and the machining surface on the PCB board is detected directly or indirectly by a photoelectric sensor. The controller then determines the next step of the operation based on the information detected by the photoelectric sensor. When the photoelectric sensor detects that the cutting tool is located on the machining surface on the PCB board, the coordinates at that location are set as the second starting coordinate in the PCB board machining direction. More often, the cutting tool can be mounted on a machine tool. After the sensor collects data, the data is sent to the machine tool, where the controller compares the information and determines the next step of the operation, thus achieving automated operation.

[0043] After obtaining the second starting coordinates, the cutting pause thickness during the machining process is calculated based on the second starting coordinates of the PCB board in the machining direction. During machining, the length of the chips is controlled according to the calculated cutting pause thickness to prevent continuous chips from being generated and wrapped around the tool during PCB board machining, thus affecting machining quality. Specifically, based on the chip thickness per revolution of the tool, the pause thickness of the tool in each machining process is calculated by the controller. Optionally, the pause thickness is less than the cutting thickness per revolution of the tool. Alternatively, the cutting pause thickness T, tool diameter D, tool holder diameter D1, and cutting thickness f per spindle revolution satisfy the following relationship: For example, the cutting thickness f per revolution of the tool, the feed rate F of the machine tool, and the spindle speed S of the machine tool satisfy the following relationship: f = F * 1000 / S. The cutting pause thickness T, the tool diameter D, the tool holder diameter D1, and the cutting thickness f per revolution of the spindle satisfy the following relationship: .

[0044] More specifically, in one embodiment, the total layer thickness of the product to be processed is value A, the required processing depth is Z, the drill bit diameter is D=3.1mm, the drill shank diameter is D1=3.17mm, the drill bit processing parameters are rotation speed S=20000 rpm, feed F=1.0 m / min, and the feed speed F can be selected with reference to the tool's own processing parameters; based on the drill bit processing parameters, the thickness f=0.05mm / Rev cut per spindle revolution can be calculated; therefore, based on the drill bit diameter D and L=D*π, the length L of the cutting wire generated per revolution of the drill bit can be calculated as 9.73mm; and the shortest length L1 of the cutting wire wrapped around the drill shank is calculated as 9.969mm, thus preventing the cutting wire from wrapping around the tool. Furthermore, the centrifugal force during high-speed spindle rotation prevents the cutting wire from wrapping around the tool.

[0045] In practical application scenarios, you can refer to Figure 2 In actual drilling operations, half of the long, continuous cutting filaments generated by the cutting tool remain inside the hole, while the other half, after exiting the hole, is wound onto the tool shank by the spindle's rotation. The length of the filament wrapped around the drill bit / shank is often more than three times the calculated length. Twice the cutting filament length is 19.94 mm, and the amount of cutting filaments cut per spindle revolution is 9.73 mm. Based on this data, it can be concluded that by pausing the cutting process for 1 ms after every two spindle revolutions, preventing continuous cutting, continuous chips can be eliminated, thus fundamentally solving the problem of tool filament entanglement.

[0046] Furthermore, the spindle rotates at 20,000 revolutions per minute, or 333.3 revolutions per second, or 0.333 revolutions per millisecond, which is sufficient to break the cutting filaments. As can be seen from the above embodiment, with A as the machining point and Z as the machining endpoint, the spindle makes a 1-millisecond cutting pause every 2.05 revolutions until the PCB board is machined, thus solving the problem of cutting filaments entangled in the tool.

[0047] After setting the cutting pause thickness via the controller, the cutting path is followed, with the second starting coordinate as the starting point for each machining position on the PCB board. The tool controls the spindle's pause point each time by controlling the machining depth, using millisecond-level pause times to prevent the generation of continuous chips.

[0048] The various technical features of the above embodiments can be combined arbitrarily. For the sake of brevity, not all possible combinations of the various 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.

[0049] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, 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 this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A method of processing a PCB board, characterized by, The method comprises the following steps: Based on the total thickness of the PCB board to be processed, the total thickness of the PCB board is added to a preset safety distance as the first starting coordinate of the PCB board in the processing direction; The coordinate of the cutter when it reaches the upper processing surface of the PCB board from the first starting coordinate is taken as the second starting coordinate of the PCB board in the processing direction; The cutting stop thickness is determined according to the processing parameters of the selected cutter, and the cutting stop thickness is an interval point in the processing direction for controlling the length of the cutting chip; The cutting processing is started from the second starting coordinate of the PCB board in the processing direction, and the cutting stop is performed according to the cutting stop thickness; The processing is performed according to the set processing path, and the second starting coordinate is taken as the starting processing point of each processing position on the PCB board.

2. The PCB board processing method of claim 1, wherein, The total thickness of the PCB board is detected by a sensor, and the total thickness information of the PCB board is sent to a controller. The total thickness of the PCB board is detected by a sensor, and the total thickness information of the PCB board is sent to a controller.

3. The PCB processing method of claim 2, wherein, The total thickness of the PCB board is detected by a sensor, and the total thickness information of the PCB board is sent to a controller. The controller adds the preset safety distance to the total thickness value of the PCB board detected by the sensor and sends it to the controller as the first starting coordinate of the PCB board in the processing direction.

4. The PCB processing method of claim 3, wherein, When the cutter reaches the upper processing surface of the PCB board from the first starting coordinate, the second starting coordinate in the processing direction at this time is recorded, which comprises: The second starting coordinate of the cutter reaching the upper processing surface of the PCB board is recorded by the controller.

5. The PCB processing method of claim 4, wherein, The cutter reaches the upper processing surface of the PCB board from the first starting coordinate by the following method: Whether the cutter reaches the upper processing surface of the PCB board is detected by a photoelectric switch.

6. The PCB processing method of claim 4, wherein, The cutting stop thickness in the processing of the cutter is calculated according to the second starting coordinate of the PCB board in the processing direction, which comprises: The stop thickness of the cutter in each processing process is calculated by the controller according to the cutting thickness of the cutter per revolution.

7. The PCB processing method of claim 6, wherein, The cutting stop thickness is less than the cutting thickness of the cutter per revolution. Alternatively, the cutting stop thickness satisfies the following relationship: ； Wherein, T represents the cutting stop thickness, D represents the cutter diameter, D1 represents the shank diameter, and f represents the cutting thickness of the spindle per revolution.

8. The PCB processing method of claim 7, wherein, The cutting thickness of the cutter per revolution satisfies the following relationship: f=F*1000 / S; Wherein, f represents the cutting thickness of the cutter per revolution, F represents the feed speed of the machine tool, and S represents the spindle speed of the machine tool.

9. The PCB processing method of claim 8, wherein, When the spindle speed of the machine tool is 20,000 revolutions per minute, the cutting stop of 1 millisecond is made every 2.05 revolutions until the processing is completed.

10. The PCB processing method according to any one of claims 1-9, wherein, The cutting processing is started from the second starting coordinate of the PCB board in the processing direction, and the cutting stop is performed according to the calculated cutting stop thickness, which comprises: The cutter controls the point of the spindle stop by the processing depth, and the continuous cutting chip is blocked by the millisecond level stop time.

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