A laser zoom punching method for a wire drawing die

Abstract

The application discloses a laser zoom punching method for a wire drawing die, wherein the height of each processing area of the wire drawing die is preset, and one or more of a focus processing method, an upper defocus processing method or a lower defocus processing method is adopted to punch and finish the height area where the wire drawing die is located according to actual requirements of different height positions; the method punches the surface of the workpiece through a laser beam, and then finishes the punching according to requirements, so that the smoothness of the workpiece after punching is improved, and the carbonized layer generated during laser punching can be removed.

Description

Technical Field

[0001] This invention relates to the field of laser wire drawing die drilling technology, and particularly to a laser zoom drilling method for wire drawing dies. Background Technology

[0002] Wire drawing dies refer to various dies used for drawing wires, including those for drawing optical fibers. All wire drawing dies have a hole of a specific shape in the center—round, square, octagonal, or other special shapes. As the material being processed is drawn through the die hole, its size decreases, and even its shape may change.

[0003] In laser processing of hard and brittle materials (such as diamond), high-frequency, narrow-pulse laser beams are generally used. Each pulse has a high energy density, but the total energy is not large. This allows material in a tiny area to be reliably vaporized in an instant, leaving a micro-pit on the mold. During laser processing, numerical control scanning is often used, and a large number of micro-pits are connected to form a three-dimensional hole.

[0004] For precision lead wire drawing dies for integrated circuits, the hole shape generally includes an inlet, lubrication, compression, sizing, tapered, and outlet area, such as... Figure 1 As shown.

[0005] Traditional laser drilling models use the contour forming method, which is currently the most commonly used laser drilling method. Its basic principle is as follows: Figure 2 As shown.

[0006] The laser beam is focused on the mold surface, and the workpiece rotates along the Z-axis at a certain speed. The laser beam scans radially from the center to the edge of the mold. R is the scanning radius, and its composite trajectory is an Archimedean spiral. After one layer of material is removed, the laser focal length decreases by ΔZ, and the scanning radius is reduced to R - ΔR. The laser then removes another layer of material until the entire thickness H of material is etched away.

[0007] Because the removal process involves etching pits, it leaves corresponding pit marks on the inner wall of the machined hole, such as... Figure 3 As shown.

[0008] In existing technologies, laser focus is usually used to perform rapid drilling according to the above method. However, due to the high energy density of the focus, when drilling, the outline of the laser spot will be formed at the edge of each drilling layer. At the same time, a stepped structure will be formed between adjacent drilling layers. Both of these factors will affect the surface finish of the wire drawing die, thereby affecting the forming quality of precision leads of integrated circuits. Summary of the Invention

[0009] The purpose of this invention is to provide a laser zoom drilling method for wire drawing dies, which addresses the above-mentioned shortcomings and solves the problem of low surface finish of wire drawing dies using laser focal point drilling in the prior art.

[0010] This invention is achieved through the following scheme:

[0011] A clamping batch grinding system presets the height of each processing area of ​​the wire drawing die. For different height positions, one or more processing methods, such as focal point processing, upper defocusing processing, or lower defocusing processing, are used to drill and refine the height area of ​​the wire drawing die at different height positions according to actual needs.

[0012] The wire drawing die to be processed is divided into an inlet area, a compression area, and a sizing area, with heights of H1, H2, and H3 respectively, and processing angles of A1, A1, and A3 for each segment. In the inlet area, the upper defocusing processing method is used to drill holes on the surface of the workpiece at an angle of A1, and the upper defocusing processing method is also used to refine the hole shape after drilling.

[0013] In the compression zone, the workpiece surface is drilled at an angle of A2 using the focal point machining method, and the hole shape is refined using the upper defocusing or lower defocusing machining method.

[0014] In the sizing zone, the workpiece surface is drilled at an angle of A3 using the lower defocusing or focal point machining method; at the same time, the hole shape after drilling is refined using the lower defocusing machining method.

[0015] When machining the sizing zone, the drilling method is selected according to the diameter of the hole in the sizing zone being machined; when the machining size of the sizing zone is greater than 30μm, the defocusing machining method is selected to machine the sizing zone; when the machining size of the sizing zone is less than 30μm, the focus machining method is selected to machine the sizing zone.

[0016] This solution also provides a laser zoom drilling method for wire drawing dies; it includes a laser control system and a workpiece control system;

[0017] The wire drawing die to be processed is divided into an inlet area, a compression area, and a sizing area, with heights of H1, H2, and H3 respectively. The ratio of each processing area to the workpiece is set according to requirements, and the processing angles for each segment are A1, A1, and A3. The processing angles for each segment are set according to the requirements of the workpiece, and the horizontal and rotational speeds of the workpiece are set for each step. A variable power processing method is used to control the laser power, ensuring a constant frequency of laser bombardment on the workpiece surface from its center to its edge. The step distance between each processing level is set according to different laser powers.

[0018] The workpiece is fixed in the workpiece control system, which controls the workpiece to rotate. The laser outputs laser light at a fixed position, and at the same time, the workpiece control system moves the workpiece horizontally. The laser bombards the workpiece surface to form an Archimedean spiral. The laser stays at a preset position for a preset time at the edge. When the current level of processing is completed, the edge of the hole is finely finished using the upper or lower defocusing method. Then, the workpiece control system moves the center position of the workpiece to the lower side of the laser. At this time, the laser control system moves the laser down one step to perform the next level of processing, until the entire workpiece is processed according to the preset parameters.

[0019] The laser frequency is linearly controlled. When the laser beam is located at the center of the workpiece, the laser beam frequency is set to the minimum value. When the laser beam is located at a predetermined position on the edge of the workpiece, the laser beam frequency is set to the maximum value. The laser power changes linearly between the minimum and maximum values, and the rate of change is adaptively corrected according to the different diameters of the workpieces.

[0020] When processing each sizing zone, when processing to the outermost edge of the sizing zone, the dwell time is set according to the size of the circular surface. During the dwell time, the workpiece only rotates and does not move in steps, so that the laser can process the edge of the sizing zone into a complete circular surface.

[0021] When using the upper or lower defocusing method for fine finishing, parameters such as the step distance of each laser descent, the workpiece rotation speed, the minimum laser frequency, the maximum laser frequency, the dwell time, and the power are modified according to actual needs in the entrance zone, compression zone, and sizing zone to complete the fine finishing of the contour.

[0022] The laser wavelengths used are 10.6μm, 1.064μm, 10.6μm, 0.532μm, 0.355μm, and 0.266μm.

[0023] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0024] 1. This method uses a laser beam to drill holes in the surface of a workpiece. After drilling, the surface is then defocused and refined as needed to improve the smoothness of the workpiece after drilling and remove the carbonized layer generated during laser drilling.

[0025] 2. When using the upper defocusing processing method to process the sizing area, this solution not only utilizes the lower defocusing processing method, but also, from the perspective of laser drilling principles, ensures that the focal point reaches the layer to be drilled first, thus creating the hole shape first. This avoids affecting the next area and guarantees the accuracy of drilling. Using the upper defocusing processing method in the entry area can prevent damage to the layered hole shape between the entry area and the compression area. The upper defocusing processing method, with its focal point above the interface to be drilled, can prevent the focal point from damaging the processing interface and affecting the hole shape in the next area. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the workpiece structure in the prior art;

[0027] Figure 2 This is a schematic diagram of a workpiece processing method in the prior art;

[0028] Figure 3 This is a schematic diagram of an erosion pit in the prior art;

[0029] Figure 4 A schematic diagram of the focal laser rotary cutting and drilling method;

[0030] Figure 5 This is a schematic diagram of the focal processing method;

[0031] Figure 6 This is a schematic diagram of the upper defocusing process;

[0032] Figure 7 This is a schematic diagram of the overall processing method of this scheme; Detailed Implementation

[0033] All features disclosed in this specification, or all steps in all disclosed methods or processes, may be combined in any way, except for mutually exclusive features and / or steps.

[0034] Any feature disclosed in this specification (including any appended claims and abstract) may be replaced by other equivalent or similar features, unless specifically stated otherwise. That is, unless specifically stated otherwise, each feature is merely one example of a series of equivalent or similar features.

[0035] In the description of this invention, it should be understood that the terms "upper", "lower", "left", "right", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0036] Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature.

[0037] First, we will introduce the small-focus laser rotary cutting and drilling method, which can control the hole shape and roundness more precisely than the large-focus method (e.g., Figure 4 When machining with the focal point as the working interface, the etch pits are smaller and the surface finish is relatively higher. However, because the etch pits are small, the machining time is longer than with larger focal points, resulting in lower efficiency. Furthermore, although the etch pits formed by small focal points have a smaller diameter, they have a greater depth, making it impossible to further improve the surface finish (e.g., ...). Figure 5 ).

[0038] The above method is the conventional focus processing method.

[0039] When the laser focus is moved upward, it is equivalent to the laser focus becoming larger. At the same time, because it is upward defocusing, the etch pits formed by the laser are shallower and flatter, resulting in a better surface finish. This is the upward defocusing processing method.

[0040] Similarly, when the laser focus is lowered, it's equivalent to the laser focus becoming larger. Simultaneously, because it's a downward defocusing process, the etched pits formed by the laser are shallower and flatter, resulting in a better surface finish. This is the downward defocusing processing method. For example... Figure 6 As shown.

[0041] Example 1

[0042] like Figure 7 As shown, the present invention provides a technical solution:

[0043] A laser zoom drilling method for wire drawing dies involves pre-setting the height of each processing area of ​​the wire drawing die, and then using one or more processing methods, such as focal point processing, upper defocus processing, or lower defocus processing, to drill and refine the height areas of the wire drawing die at different height positions according to actual needs.

[0044] Based on the above structure, this method uses a laser beam to drill holes on the surface of the workpiece. After drilling, the surface is then defocused and refined as needed to improve the smoothness of the workpiece after drilling and remove the carbonized layer generated during laser drilling.

[0045] When lasers process diamond, different laser powers produce different effects. When the laser power is below the diamond's energy threshold breaking point, the laser will not damage the diamond. When the laser power is above the diamond's energy threshold breaking point, the laser will vaporize the diamond. After vaporization, the affected area will form a carbonized layer due to the decrease in temperature or even burn directly. Therefore, a black carbon layer usually forms on the surface after laser drilling. One of the purposes of this finishing method is to remove this carbon layer.

[0046] As an example, in this method, the wire drawing die to be processed is divided into an inlet area, a compression area and a sizing area, with heights of H1, H2 and H3 respectively, and processing angles of each segment of the die being A1, A1 and A3.

[0047] In the entry zone, the upper defocusing machining method is used to drill holes on the workpiece surface at an angle of A1. At the same time, the upper defocusing machining method is used to refine the hole shape after drilling. When drilling in the entry zone, a high-power laser is used to efficiently process the shape. When refining in the entry zone, a low-power laser is used to efficiently remove the carbon layer on the hole surface and correct the edge hole diameter.

[0048] During laser drilling, drilling is typically performed layer by layer. The laser remains stationary while external moving parts rotate the workpiece and then move it in a certain direction, causing the laser to form an Archimedean spiral on the current processing layer of the workpiece. Due to the use of high-power lasers for rapid drilling, contour points will be formed at the outermost drilling points, and the larger the laser drilling spot, the more obvious the contour points will be. At this point, it is necessary to remove the drilling contour points of the corresponding layer for smoothing, as well as to process the carbon layer of the corresponding layer.

[0049] After the current layer is processed, the next layer is processed in the same way as described above. At the edge, a stepped structure will appear between adjacent layers. One of the advantages of using top defocus for drilling is that it can remove the stepped structure between adjacent processed layers, making the transition between adjacent layers smooth and improving the overall smoothness of the hole.

[0050] As an example, in this method, the workpiece surface is drilled at an angle A2 using the focal point machining method in the compression zone, while the hole shape is refined using the upper defocus or lower defocus machining method; when refining in the compression zone, a low-power laser is used to efficiently remove the carbon layer on the hole surface, while the edge hole diameter is corrected.

[0051] In the sizing zone, the workpiece surface is drilled at an angle of A3 using the defocusing or focus machining method; at the same time, the hole shape after drilling is refined using the defocusing machining method; during the refinement in the sizing zone, a low-power laser is used to efficiently remove the carbon layer on the hole surface, and the edge hole diameter is corrected.

[0052] In this solution, the entry area does not have high requirements for shape and roundness, but requires high-efficiency removal while maintaining a smooth finish. Therefore, a large defocused spot is used to rapidly process the shape with high power, followed by edge scanning and polishing with low power defocusing.

[0053] In the compression zone, precise machining of angles and shapes is required, so a small focal point is used for precise machining. Defocusing and low-power polishing can be performed as required.

[0054] In the sizing zone, precise aperture positioning and high surface finish are required. Therefore, a small focal spot is used, with precise machining at the focal spot, followed by fine polishing with low power and defocusing.

[0055] As an example, in this solution, when machining the sizing zone, the drilling method is selected according to the diameter of the hole in the sizing zone being machined; when the machining size of the sizing zone is greater than 30μm, the defocusing machining method is selected to machine the sizing zone; when the machining size of the sizing zone is less than 30μm, the focus machining method is selected to machine the sizing zone.

[0056] Since defocusing cannot be used to process micropores smaller than 30μm, only focused processing can be used.

[0057] When using the upper defocusing method to process the sizing area, not only because the lower defocusing method is used, but also because, from the principle of laser drilling, the focal point reaches the layer to be drilled first, the hole shape can be drilled first, and the influence on the next area can be avoided, thus ensuring the accuracy of drilling.

[0058] Similarly, using the upper defocusing processing method in the entrance area can avoid damaging the layered hole pattern between the entrance area and the compression area. The upper defocusing processing method has its focus above the interface to be drilled, which can avoid the focus damaging the processing interface and affecting the hole pattern in the next area.

[0059] Example 2

[0060] Based on the method of Embodiment 1 above, this embodiment provides a laser zoom drilling method for wire drawing dies; it includes a laser control system and a workpiece control system;

[0061] The wire drawing die to be processed is divided into an inlet area, a compression area, and a sizing area, with heights of H1, H2, and H3 respectively. The ratio of each processing area to the workpiece is set according to requirements, and the processing angles for each segment are A1, A1, and A3. The processing angles for each segment are set according to the requirements of the workpiece. The horizontal movement speed and rotation speed of the workpiece are set for each step. A variable power processing method is used to control the laser power, ensuring a constant frequency of laser bombardment on the workpiece surface from its center to its edge. The step distance between each processing level is set according to different laser powers.

[0062] Therefore, the laser frequency needs to be linearly controlled. When the laser beam is located at the center of the workpiece, the laser beam frequency is set to the minimum value, and when the laser beam is located at a predetermined position on the edge of the workpiece, the laser beam frequency is set to the maximum value. The laser power changes linearly between the minimum and maximum values, and its rate of change is adaptively corrected according to the different diameters of the workpieces.

[0063] Since the rotational speed of the workpiece is constant and the angular velocity of each area of ​​the circular workpiece is the same, but the linear velocity increases with the distance from the center, if a constant power laser is used to bombard the workpiece surface, it is impossible to bombard each surface. Therefore, it is necessary to gradually and linearly increase the laser power so that the bombardment frequency can bombard the entire workpiece uniformly until the current level of hole is processed.

[0064] When processing each sizing zone, the dwell time is set according to the size of the circular surface when processing the outermost edge of the sizing zone. During the dwell time, the workpiece only rotates and does not move in steps, so that the laser can process the edge of the sizing zone into a complete circular surface, thereby ensuring the accuracy of the entire dimension of the sizing zone after processing.

[0065] Its processing procedure is as follows:

[0066] The workpiece is fixed in the workpiece control system, which controls the workpiece to rotate. The laser outputs laser light at a fixed position, and at the same time, the workpiece control system moves the workpiece horizontally. The laser bombards the workpiece surface to form an Archimedean spiral. The laser stays at a preset position for a preset time at the edge. When the current level of processing is completed, the edge of the hole is finely finished using the upper or lower defocusing method. Then, the workpiece control system moves the center position of the workpiece to the lower side of the laser. At this time, the laser control system moves the laser down one step to perform the next level of processing, until the entire workpiece is processed according to the preset parameters.

[0067] When using the upper or lower defocus method for fine finishing, parameters such as the step distance of each laser descent, the rotation speed of the workpiece, the minimum laser frequency, the maximum laser frequency, the dwell time, and the power can be modified in the entry zone, compression zone, and sizing zone according to actual needs, thereby completing the fine finishing of the contour.

[0068] In this scheme, the laser wavelengths used are 10.6μm, 1.064μm, 10.6μm, 0.532μm, 0.355μm, and 0.266μm.

[0069] The laser can be a solid-state laser, a gas laser, or a fiber laser.

[0070] The materials to be processed include natural diamonds, rubies, sapphires, silicon nitride, ceramics, as well as common wire drawing die materials such as artificial single crystals, polycrystalline, high-crystal, and CD.

[0071] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A laser zoom drilling method for wire drawing dies, characterized in that: The height of each processing area of ​​the wire drawing die is preset. For different height positions, one or more processing methods such as focus processing, upper defocus processing or lower defocus processing are used to drill and refine the height area of ​​the wire drawing die at different height positions according to actual needs. The wire drawing die to be processed is divided into an inlet area, a compression area and a sizing area, with heights of H1, H2 and H3 respectively, and processing angles of A1, A1 and A3 for each segment; in the inlet area, the upper defocusing processing method is used to drill holes on the surface of the workpiece at an angle of A1, and the upper defocusing processing method is also used to refine the hole shape after drilling. In the compression zone, the workpiece surface is drilled at an angle of A2 using the focal point machining method, and the hole shape is refined using the upper defocusing or lower defocusing machining method. In the sizing zone, the workpiece surface is drilled at an angle of A3 using either the lower defocusing or focal point machining method; at the same time, the hole shape after drilling is refined using the lower defocusing machining method. When machining the sizing zone, the drilling method is selected according to the diameter of the hole in the sizing zone being machined; when the machining size of the sizing zone is greater than 30μm, the defocusing machining method is selected to machine the sizing zone; when the machining size of the sizing zone is less than 30μm, the focus machining method is selected to machine the sizing zone. When drilling in the entry area, a high-power laser is used to efficiently process the shape. When finishing the entry area, a low-power laser is used to efficiently remove the carbon layer on the hole surface and correct the edge diameter. When finishing the compression area, a low-power laser is used to efficiently remove the carbon layer on the hole surface and correct the edge diameter. When finishing the sizing area, a low-power laser is used to efficiently remove the carbon layer on the hole surface and correct the edge diameter.

2. A laser zoom drilling method for wire drawing dies, characterized in that: It includes a laser control system and a workpiece control system; The wire drawing die to be processed is divided into an inlet area, a compression area, and a sizing area, with heights of H1, H2, and H3 respectively. The ratio of each processing area to the workpiece is set according to requirements, and the processing angles for each segment are A1, A1, and A3. The processing angles for each segment are set according to the requirements of the workpiece, and the horizontal and rotational speeds of the workpiece are set for each step. A variable power processing method is used to control the laser power, ensuring a constant frequency of laser bombardment on the workpiece surface from its center to its edge. The step distance between each processing level is set according to different laser powers. The workpiece is fixed in the workpiece control system, which controls the workpiece to rotate. The laser outputs laser light at a fixed position, and at the same time, the workpiece control system moves the workpiece horizontally. The laser bombards the workpiece surface to form an Archimedean spiral. The laser stays at a preset position for a preset time at the edge. When the current level of processing is completed, the edge of the hole is finely finished using the upper or lower defocusing method. Then, the workpiece control system moves the center position of the workpiece to the lower side of the laser. At this time, the laser control system moves the laser down one step to perform the next level of processing, until the entire workpiece is processed according to the preset parameters.

3. The laser zoom drilling method for wire drawing dies as described in claim 2, characterized in that: The laser frequency is linearly controlled. When the laser beam is located at the center of the workpiece, the laser beam frequency is set to the minimum value. When the laser beam is located at a predetermined position on the edge of the workpiece, the laser beam frequency is set to the maximum value. The laser power changes linearly between the minimum and maximum values, and the rate of change is adaptively corrected according to the different diameters of the workpieces.

4. The laser zoom drilling method for wire drawing dies as described in claim 3, characterized in that: When processing each sizing zone, when processing to the outermost edge of the sizing zone, the dwell time is set according to the size of the circular surface. During the dwell time, the workpiece only rotates and does not move in steps, so that the laser can process the edge of the sizing zone into a complete circular surface.

5. The laser zoom drilling method for a wire drawing die as described in claim 4, characterized in that: When using the upper or lower defocusing method for fine finishing, the step distance of each laser descent, the rotation speed of the workpiece, the minimum laser frequency, the maximum laser frequency, the dwell time, and the power parameters are modified according to actual needs in the entrance area, compression area, and sizing area to complete the fine finishing of the contour.

6. The laser zoom drilling method for a wire drawing die as described in claim 5, characterized in that: The laser wavelengths used are 10.6μm, 1.064μm, 10.6μm, 0.532μm, 0.355μm, and 0.266μm.

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