Laser processing method, controller, laser processing apparatus, and single-wire blind slot

Abstract

The application provides a laser processing method, a controller, a laser processing device and a single-line blind slot, wherein the method mainly adopts a processing method containing forward and reverse bidirectional cutting and laser opening and scanning motion synchronization, so as to compensate for the energy deposition difference caused by laser energy dynamic response and one-way scanning at both ends of the track, and effectively improve the laser processing quality.

Description

Technical Field

[0001] This application belongs to the field of laser processing technology, and particularly relates to a laser processing method, controller, laser processing equipment, and single-line blind groove. Background Technology

[0002] Laser processing technology, due to its advantages such as high precision and non-contact operation, is widely used in the processing of microstructures in various materials, such as printed circuit boards (PCBs) or packaging substrates, where it is often necessary to fabricate high-precision micro-groove structures on their surfaces. The dimensional uniformity of these structures is a key factor affecting device performance, and in particular, it requires a high degree of consistency in the processing morphology of the groove along its length.

[0003] In related technologies, using lasers for the aforementioned micro-machining is a common method. The typical laser processing method involves controlling the laser beam to perform unidirectional, repeated scanning cuts along the desired line trajectory. However, in actual processing, due to the interaction between the dynamic characteristics of laser energy and the beam scanning motion control, this conventional unidirectional repeated cutting method easily leads to the morphology of the processed lines in the starting and ending regions of the trajectory being significantly different from the morphology in the middle region, severely affecting the processing quality of the structure. Summary of the Invention

[0004] This application provides a laser processing method, controller, laser processing equipment, and single-line blind groove, which can improve the quality of laser processing.

[0005] A first aspect of this application provides a laser processing method, comprising: determining a target processing trajectory on a workpiece to be processed, and determining a total number of cuts N on the target processing trajectory, wherein the target processing trajectory includes a first endpoint and a second endpoint, and N is an integer greater than 1; performing a first-direction cutting operation, the first-direction cutting operation comprising: controlling a laser beam acting on the workpiece to be processed to perform M cuts along the target processing trajectory from the first endpoint to the second endpoint, wherein M is a positive integer less than N, and during each first-direction cutting operation, the laser's activation time is synchronized with the time when the laser beam begins scanning along the target processing trajectory; and performing a second-direction cutting operation, the second-direction cutting operation comprising: controlling the laser beam to perform NM cuts along the target processing trajectory from the second endpoint to the first endpoint, wherein during each second-direction cutting operation, the laser's activation time is synchronized with the time when the laser beam begins scanning along the target processing trajectory.

[0006] In the technical solution of this application, a processing method that includes bidirectional cutting and synchronous laser activation and scanning motion is mainly adopted to compensate for the energy deposition difference caused by the dynamic response of laser energy and unidirectional scanning at both ends of the trajectory, thereby effectively improving the quality of laser processing.

[0007] Optionally, in one possible implementation of the first aspect, determining the total number of laser cuts N on the target processing trajectory includes: performing multiple laser cuts along a preset test processing trajectory on a test workpiece of the same specifications as the workpiece to be processed, using laser processing parameters; measuring the processing morphology of the middle region of the test processing trajectory after multiple laser cuts along the test processing trajectory; and determining the minimum number of cuts required to meet the preset target processing morphology requirements as the total number of cuts N. Thus, by determining the minimum number of cuts N required to achieve the target based on the morphology of the middle region during testing, a precise technological basis is provided for subsequent formal processing, ensuring processing quality while avoiding unnecessary repeated cuts and improving processing efficiency.

[0008] Optionally, in another possible implementation of the first aspect, before performing the first direction cutting operation, the method further includes: performing multiple forward and reverse cutting number tests based on the total number of cuttings N. Each forward and reverse cutting number test includes: on a test workpiece of the same specifications as the workpiece to be processed, using laser processing parameters, performing K cuts from the third endpoint to the fourth endpoint of the test workpiece along a preset test processing trajectory, and performing NK cuts from the fourth endpoint to the third endpoint along the test processing trajectory, to obtain the test result of the forward and reverse cutting number test, wherein the third endpoint corresponds to the first endpoint of the workpiece to be processed, the fourth endpoint corresponds to the second endpoint of the workpiece to be processed, K is a positive integer less than N, the number of cuttings K in each forward and reverse cutting number test is different, and the test result of the forward and reverse cutting number test is obtained by measuring the processing morphology of the test area corresponding to the third endpoint on the test processing trajectory, and measuring the processing morphology of the test area corresponding to the fourth endpoint on the test processing trajectory; and determining the number of cuttings M in the first direction from the number of cuttings K in each forward and reverse cutting number test based on the test result of the multiple forward and reverse cutting number tests. Therefore, by performing multiple tests with different cutting ratios based on the total number of cuttings N, and selecting the optimal number of cuttings M in the first direction based on the test results, the distribution of the number of forward and reverse cuttings in the formal processing can be balanced to the greatest extent to achieve energy deposition at both ends and optimize the consistency of the end-point morphology.

[0009] Optionally, in another possible implementation of the first aspect, before performing the first-direction cutting operation, the method further includes: setting a first shutdown delay time corresponding to the first endpoint and setting a second shutdown delay time corresponding to the second endpoint; the first-direction cutting operation further includes: when the laser beam scans to the second endpoint, controlling the laser to shut down with a delay according to the second shutdown delay time; the second-direction cutting operation further includes: when the laser beam scans to the first endpoint, controlling the laser to shut down with a delay according to the first shutdown delay time. Thus, by setting independent shutdown delay times for the two endpoints of the trajectory and applying them at the corresponding cutting direction endpoints, differentiated and precise control of endpoint energy accumulation caused by scanning deceleration can be achieved, directly and specifically improving the problem of over-etching or under-etching of endpoints.

[0010] Optionally, in another possible implementation of the first aspect, setting the first closing delay time corresponding to the first endpoint and the second closing delay time corresponding to the second endpoint includes: performing multiple laser cuts along a preset test processing trajectory on a test workpiece of the same specifications as the workpiece to be processed, using laser processing parameters; after performing multiple laser cuts along the test processing trajectory, measuring the processing morphology of the test area corresponding to the first endpoint on the test processing trajectory, and measuring the processing morphology of the test area corresponding to the second endpoint on the test processing trajectory; and setting the first closing delay time and the second closing delay time based on the processing morphology of the test area at the first endpoint and the test area at the second endpoint. Thus, by setting the closing delay time by cutting on a test workpiece of the same specifications as the actual workpiece and measuring the endpoint morphology, the set delay parameters are based on real processing feedback, improving the accuracy and reliability of the parameter settings.

[0011] Optionally, in another possible implementation of the first aspect, setting the first shutdown delay time and the second shutdown delay time based on the processing topography of the test area at the first endpoint and the test area at the second endpoint includes: reducing the first shutdown delay time when the processing topography of the test area at the first endpoint is over-etched, and increasing the first shutdown delay time when the processing topography of the test area at the first endpoint is under-etched; reducing the second shutdown delay time when the processing topography of the test area at the second endpoint is over-etched, and increasing the second shutdown delay time when the processing topography of the test area at the second endpoint is under-etched. Thus, by establishing a clear adjustment rule of "reducing delay for over-etching and increasing delay for under-etching," a direct and effective operational basis is provided for setting the shutdown delay parameter.

[0012] Optionally, in another possible implementation of the first aspect, the laser processing parameters of the first direction cutting operation and the second direction cutting operation are the same, and the scanning paths of the laser beams overlap.

[0013] Optionally, in another possible implementation of the first aspect, when the total number of cuts N is even, the number of cuts M in the first direction is N / 2; when the total number of cuts N is odd, the number of cuts M in the first direction is (N+1) / 2.

[0014] A second aspect of this application provides a controller, including a memory, a processor, and a computer program stored in the memory and executable on the processor; when the processor executes the computer program, it implements the steps of the laser processing method of the first aspect described above.

[0015] A third aspect of this application provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the steps of the laser processing method described in the first aspect.

[0016] The fourth aspect of this application provides a computer program product that, when run, causes the laser processing method of the first aspect described above to be executed.

[0017] The fifth aspect of this application provides a laser processing apparatus, comprising: a laser for emitting a laser beam; a beam control device including a beam deflection mechanism for transmitting, controlling, and deflecting the laser beam; a processing platform for carrying a workpiece to be processed; and a controller for controlling the laser, the beam control device, and the processing platform to work together to achieve the steps of the laser processing method of the first aspect.

[0018] The sixth aspect of this application provides a single-line blind groove, which is obtained by laser processing method of the first aspect or by laser processing equipment based on the fifth aspect.

[0019] It is understood that the beneficial effects of the second to sixth aspects mentioned above can be found in the relevant descriptions in the first aspect mentioned above, and will not be repeated here. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of this application, 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.

[0021] Figure 1 This is a schematic flowchart of a laser processing method provided in an embodiment of this application; Figure 2This is a comparative schematic diagram of blind groove processing before and after, provided in an embodiment of this application; Figure 3 This is a comparative schematic diagram of another blind groove before and after processing, provided in an embodiment of this application; Figure 4 This is a comparative schematic diagram of another blind groove before and after processing, provided in an embodiment of this application; Figure 5 This is a comparative schematic diagram of another blind groove before and after processing, provided in an embodiment of this application; Figure 6 This is a comparative schematic diagram of another blind groove before and after processing, provided in an embodiment of this application; Figure 7 This is a schematic diagram of the structure of a controller provided in an embodiment of this application; Figure 8 This is a schematic diagram of the structure of a laser processing device provided in an embodiment of this application. Detailed Implementation

[0022] In the following description, specific details such as particular system architectures and techniques are set forth for illustrative purposes and not for limitation, in order to provide a thorough understanding of the embodiments of this application. However, those skilled in the art will understand that this application may also be implemented in other embodiments without these specific details. In other instances, detailed descriptions of well-known systems, apparatuses, circuits, and methods have been omitted so as not to obscure the description of this application with unnecessary detail.

[0023] It should be understood that, when used in this application specification and the appended claims, the term "comprising" indicates the presence of the described features, integrals, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or a collection thereof.

[0024] It should also be understood that the term “and / or” as used in this application specification and the appended claims means any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0025] As used in this application specification and the appended claims, the term "if" may be interpreted, depending on the context, as "when," "once," "in response to determination," or "in response to detection." Similarly, the phrase "if determined" or "if detected [the described condition or event]" may be interpreted, depending on the context, as meaning "once determined," "in response to determination," "once detected [the described condition or event]," or "in response to detection [the described condition or event]."

[0026] Furthermore, in the description of this application and the appended claims, the terms "first," "second," "third," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0027] References to "one embodiment" or "some embodiments" as described in this specification mean that one or more embodiments of this application include a specific feature, structure, or characteristic described in connection with that embodiment. Therefore, the phrases "in one embodiment," "in some embodiments," "in other embodiments," "in still other embodiments," etc., appearing in different parts of this specification do not necessarily refer to the same embodiment, but rather mean "one or more, but not all, embodiments," unless otherwise specifically emphasized. The terms "comprising," "including," "having," and variations thereof mean "including but not limited to," unless otherwise specifically emphasized.

[0028] It should be understood that the sequence number of each step in this embodiment does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of this application embodiment.

[0029] In related technologies, laser processing for microstructure fabrication is a common method. The typical laser processing approach involves controlling the laser beam to perform unidirectional, repeated scanning cuts along the desired line trajectory. However, in actual processing, due to the interaction between the dynamic characteristics of laser energy and the beam scanning motion control, this conventional unidirectional repetitive cutting method often results in the morphology of the processed lines at the beginning and end of the trajectory being significantly different from the morphology in the middle region, severely impacting the processing quality of the structure.

[0030] In view of this, embodiments of this application provide a laser processing method, controller, laser processing equipment, and single-line blind groove. First, a target processing trajectory on the workpiece to be processed is determined, and the total number of laser cuts N on the target processing trajectory is determined. The target processing trajectory includes a first endpoint and a second endpoint, and N is an integer greater than 1. Then, a first-direction cutting operation is performed, comprising: controlling the laser beam acting on the workpiece to perform M cuts along the target processing trajectory from the first endpoint to the second endpoint, where M is a positive integer less than N. During each first-direction cutting operation, the laser's activation time is synchronized with the time the laser beam begins scanning along the target processing trajectory. Finally, a second-direction cutting operation is performed, comprising: controlling the laser beam to perform NM cuts along the target processing trajectory from the second endpoint to the first endpoint. During each second-direction cutting operation, the laser's activation time is synchronized with the time the laser beam begins scanning along the target processing trajectory. The laser processing parameters for the first-direction cutting operation and the second-direction cutting operation are the same, and the scanning paths of the laser beams overlap. Therefore, by adopting a processing method that includes bidirectional cutting and synchronous laser activation and scanning motion, the energy deposition difference caused by the dynamic response of laser energy and unidirectional scanning at both ends of the trajectory is compensated, effectively improving the quality of laser processing.

[0031] To illustrate the technical solution of this application, specific embodiments are described below.

[0032] Reference Figure 1 The diagram illustrates a flow chart of a laser processing method provided in an embodiment of this application. This method can be applied to a controller, which can be installed on a laser processing device, to process a target processing structure, such as a single-line blind groove, on the workpiece to be processed. The single-line blind groove is an elongated groove structure.

[0033] like Figure 1 As shown, the laser processing method may include the following steps: Step 101: Determine the target machining trajectory on the workpiece to be processed, and determine the total number of laser cutting operations N on the target machining trajectory.

[0034] The workpiece to be processed refers to the packaging substrate used to carry and realize the interconnection of different chips and / or electronic components, which needs to be processed by laser to form specific microstructures on its surface. Specifically, the workpiece to be processed can include various PCB boards such as ordinary boards, multilayer boards, high-density interconnect (HDI) boards, and flexible printed circuit boards (FPCs), as well as IC carrier boards made of organic substrates, ceramic substrates, glass substrates, or other novel substrates. The surface of the workpiece to be processed is usually covered with a material layer that needs to be selectively removed, such as a solder resist layer, to expose the underlying pads or form specific window structures.

[0035] In this embodiment, the target machining trajectory refers to a predetermined path planned on the surface of the workpiece to be processed, which needs to be formed by laser beam scanning or etching. Geometrically, this trajectory defines a line segment with a clearly defined first and second endpoint. Taking a single-line blind groove as an example, the target machining trajectory typically corresponds to the centerline of the blind groove or the desired groove wall contour. When a blind groove with a width of 10 to 100 micrometers needs to be machined on the solder resist layer of the workpiece, the target machining trajectory is the centerline of the blind groove along its length, and its first and second endpoints correspond to the predetermined start and end positions of the blind groove, respectively.

[0036] In this embodiment, determining the total number of laser cuts N on the target processing trajectory is the basis for subsequent processes. The total number of cuts N refers to the number of times the laser beam needs to be repeatedly scanned along the complete trajectory to process a blind groove that meets the requirements for depth, width, and morphology, and N is an integer greater than 1. For laser sources such as flat-top lasers, a single scan often cannot remove all the material required to reach the target depth, or the morphology of the groove wall formed by a single scan may not meet requirements such as perpendicularity. Therefore, multiple repeated scans are required to optimize the morphology.

[0037] In one embodiment, the total number of cuts N can be determined as follows: On a test workpiece of the same specifications as the workpiece to be processed, multiple laser cuts are performed along a preset test processing trajectory using laser processing parameters; after multiple laser cuts along the test processing trajectory, the processing morphology of the middle region of the test processing trajectory is measured; the minimum number of cuts required to meet the preset target processing morphology requirement is determined as the total number of cuts N. Therefore, by determining the minimum number of cuts N required to achieve the target based on the morphology of the middle region during testing, a precise technological basis is provided for subsequent formal processing, ensuring processing quality while avoiding unnecessary repeated cuts and improving processing efficiency.

[0038] It should be noted that the process of determining the total number of cuts N is to establish a core process benchmark that ignores the endpoint effect and is based solely on the processing quality of the intermediate stable section. Specifically, the test workpiece must be completely identical to the workpiece to be processed in terms of material, thickness, and surface coating. Laser processing parameters, including laser power, pulse frequency, and scanning speed, must be kept constant during the test. During operation, a test processing trajectory that is representative of the target processing trajectory in length and direction is selected on the test workpiece, and the laser beam is controlled to make the first cut along the trajectory with the set parameters. Then, using measuring equipment such as an optical microscope, confocal microscope, or profilometer, the processing morphology of the middle area of ​​the test trajectory after this cut (usually referring to the stable section at least tens of micrometers away from the start and end points of the trajectory) is observed, including but not limited to groove depth, groove width, and bottom flatness. If the morphology after this cut does not meet the preset target requirements (e.g., the depth is not up to standard), a second cut is made on the same test trajectory (or on another parallel trajectory of the test workpiece) with the exact same parameters, and the morphology of the middle area is measured again. This process is repeated until, after a certain cut, the measurement results show that the key morphological indicators such as the processing depth and width of the intermediate area simultaneously meet the preset target requirements for the first time. At this point, the accumulated number of cuts is identified as the "minimum number of cuts required to meet the preset target processing morphological requirements," and is ultimately determined as the total number of cuts N for subsequent formal processing.

[0039] In this embodiment, to accurately measure the processed morphology, the laser processing equipment includes a measurement unit. The measurement unit is communicatively connected to a controller and is used to measure the processed morphology of the workpiece surface after test processing or formal processing, acquiring measurement data including processing depth, width, and morphological features. The measurement unit may include high-precision non-contact measurement devices such as cameras, optical microscopes, confocal microscopes, interference microscopes, or laser profilometers. The measurement results can be used to provide feedback for adjusting process parameters.

[0040] Furthermore, before executing step 102, multiple forward and reverse cutting count tests can be performed based on the total number of cuts N. Each forward and reverse cutting count test includes: on a test workpiece of the same specifications as the workpiece to be processed, using laser processing parameters, K cuts are made from the third endpoint to the fourth endpoint along a preset test processing trajectory, and NK cuts are made from the fourth endpoint to the third endpoint along the test processing trajectory to obtain the test results of the forward and reverse cutting count test. Here, the third endpoint corresponds to the first endpoint of the workpiece to be processed, the fourth endpoint corresponds to the second endpoint of the workpiece to be processed, K is a positive integer less than N, and the number of cuts K in each forward and reverse cutting count test is different. The test results of the forward and reverse cutting count test are obtained by measuring the processing morphology of the test area corresponding to the third endpoint on the test processing trajectory, and measuring the processing morphology of the test area corresponding to the fourth endpoint on the test processing trajectory. Based on the test results of multiple forward and reverse cutting count tests, the number of cuts M in the first direction is determined from the number of cuts K in each forward and reverse cutting count test. Therefore, by performing multiple tests with different cutting ratios based on the total number of cuttings N, and selecting the optimal number of cuttings M in the first direction based on the test results, the distribution of the number of forward and reverse cuttings in the formal processing can be balanced to the greatest extent to achieve energy deposition at both ends and optimize the consistency of the end-point morphology.

[0041] It should be noted that the purpose of the above operation is to optimize the ratio of the number of cuts in the forward and reverse directions (i.e., M and NM) to compensate for the differences in end-point morphology caused by energy dynamic response and scanning motion control in the subsequent formal processing.

[0042] In the specific implementation process, based on the already determined total number of cuts N (e.g., N=5), it is necessary to test the effect of different combinations of forward cuts K (corresponding to reverse cuts NK) on the endpoint morphology. The test needs to be conducted on multiple independent test tracks to avoid mutual interference between different tests. For example, to conduct the first forward and reverse cut test: select a test track where the third endpoint corresponds to the first endpoint of the actual processing (both are starting points), and the fourth endpoint corresponds to the second endpoint (both are ending points). On this test track, first control the laser beam to continuously scan and cut K1 times from the third endpoint to the fourth endpoint (e.g., K1=1), and then immediately control the laser beam to continuously scan and cut N-K1 times from the fourth endpoint to the third endpoint (i.e., 5-1=4 times). After completing this combined processing, use a measuring device to accurately measure the processing depth and morphological characteristics of the areas adjacent to the third endpoint (representing the starting point morphology) and the areas adjacent to the fourth endpoint (representing the ending point morphology) on the test track, and record these as the test results for this test (K1=1). Subsequently, a second test is conducted on a new test trajectory, selecting a different K value (e.g., K2=2). Cuts are performed twice in the forward direction and then three times in the reverse direction (5-2=3), with the morphology of the two endpoint regions measured again. This process is repeated, trying multiple different K values ​​(e.g., K=1, 2, 3, 4). Finally, all test results are compared, analyzing the morphological differences (e.g., depth differences) between the two endpoint regions of the test trajectory under different K values, and their degree of conformity to the target morphology. From these tried K values, the K value that best approximates the morphology of both endpoints and best meets the target requirements is selected. This value is chosen as the first direction cutting number M for formal processing. For example, if the test finds that the depth difference between the two endpoints is smallest when K=3, then M=3 is determined, meaning that during formal processing, cuts will be made three times from the first endpoint to the second endpoint, and then twice from the second endpoint to the first endpoint (NM=2).

[0043] In one embodiment, when the total number of cuts N is even, the number of cuts M in the first direction can be N / 2; when the total number of cuts N is odd, the number of cuts M in the first direction can be (N+1) / 2. It should be understood that this approach is an efficient and quickly executable solution. Its technical principle lies in making the number of cuts in the forward and reverse directions as equal as possible (completely equal when even, and slightly more in the forward direction when odd), providing a fundamentally optimal initial allocation for energy symmetry compensation at both ends of the trajectory without extensive testing. For example, if the total number of cuts N=4 (even) is determined using the method of the aforementioned embodiment, then the number of cuts M in the first direction can be directly set to N / 2=2, i.e., an equal allocation of 2 cuts in the forward direction and 2 cuts in the reverse direction (NM=2). If N=5 (odd), then M is directly set to (5+1) / 2=3, i.e., an allocation of 3 cuts in the forward direction and 2 cuts in the reverse direction (NM=2), making the number of cuts in the forward direction slightly more than the reverse direction. This rule is based on extensive process practice and can quickly provide a near-optimal allocation scheme for common material and parameter combinations, significantly improving the efficiency of process setup. It is especially suitable for situations where high endpoint consistency is required and the process needs to be determined quickly.

[0044] Step 102: Perform a first-direction cutting operation, which includes: controlling the laser beam acting on the workpiece to be processed to perform M cuts along the target processing trajectory from the first endpoint to the second endpoint.

[0045] Wherein, the number of cuts in the first direction M is a positive integer less than the total number of cuts N, as determined according to the aforementioned embodiment.

[0046] It is important to note that during each cutting operation in the first direction, the laser's activation moment must be synchronized with the moment the laser beam begins scanning along the target processing trajectory. In other words, the laser should be triggered to start outputting laser light the instant the galvanometer or other beam deflection mechanism controlling the beam scanning precisely moves the laser spot to the first endpoint of the trajectory and prepares to move towards the second endpoint. This zero-delay control strategy aims to fundamentally avoid the problems in traditional processes where setting a positive activation delay (delayed laser emission) results in the starting area being skipped and not processed, or setting a negative activation delay (early laser emission) results in erroneous processing of non-target areas before the trajectory's starting point. To achieve this precise synchronization, the system needs to integrate a high-precision timing control module to strictly align and calibrate the galvanometer's scanning trigger signal and the laser's emission trigger signal.

[0047] The beam deflection mechanism may include one or any combination of a galvanometer, a rotating mirror, an acousto-optic modulator (AOM), an acousto-optic deflector (AOD), an electro-optic modulator (EOM), an electro-optic deflector (EOD), a liquid crystal variable attenuator (LCVA), a micro-electro-mechanical systems (MEMS) based variable optical attenuator (VOA), and an optical attenuator wheel. Among these, the galvanometer and rotating mirror are beam deflection components controlled by mechanical motion, and their beam deflection control inevitably involves acceleration and deceleration during the start and end times of beam deflection. The AOM and AOD, on the other hand, are beam deflection components controlled by electrical signals, allowing for rapid, abrupt adjustments to the beam deflection process through parameter adjustments of the control information.

[0048] In one embodiment, before performing the first-direction cutting operation, a first shutdown delay time corresponding to the first endpoint and a second shutdown delay time corresponding to the second endpoint can be set. The first-direction cutting operation further includes controlling the laser to shut down according to the second shutdown delay time when the laser beam scans to the second endpoint. Thus, by setting independent shutdown delay times for the two endpoints of the trajectory and applying them at the corresponding cutting direction endpoints, differentiated and precise control of endpoint energy accumulation caused by scanning deceleration can be achieved, directly and specifically improving the problem of over-etching or under-etching of endpoints.

[0049] It should be noted that the above steps are a dynamic compensation scheme for the shutdown delay at the endpoint of the trajectory. During a single scan of the laser beam from the first endpoint to the second endpoint, when the beam deflection mechanism (such as a galvanometer) drives the spot to the second endpoint (geometric endpoint) of the target machining trajectory, the galvanometer needs to undergo a deceleration process until it stops due to mechanical inertia. During this deceleration phase, the actual residence time of the spot near the second endpoint will be prolonged. If the laser is turned off immediately upon the spot reaching the geometric endpoint, this segment may be under-etched due to the prolonged residence time; conversely, if the laser is turned off too late, the area will be over-etched due to excessive energy accumulation. Therefore, the second shutdown delay time is a parameter specifically set for the second endpoint (which serves as the cutting endpoint in this direction). It defines the period of time the laser continues to emit light after the spot has scanned to the geometric position of the second endpoint. By precisely setting this time, the effects of scanning deceleration can be compensated, the amount of energy deposition in the endpoint area can be actively controlled, and thus the machining morphology can be optimized.

[0050] In one embodiment, the first and second shutdown delay times can be determined as follows: On a test workpiece of the same specifications as the workpiece to be processed, multiple laser cuts are performed along a preset test processing trajectory using laser processing parameters; after multiple laser cuts along the test processing trajectory, the processing morphology of the test area corresponding to the first endpoint and the processing morphology of the test area corresponding to the second endpoint on the test processing trajectory are measured; based on the processing morphology of the test areas at the first and second endpoints, the first and second shutdown delay times are set. Thus, by setting the shutdown delay time by cutting on a test workpiece of the same specifications as the actual workpiece and measuring the endpoint morphology, the set delay parameters are based on real processing feedback, improving the accuracy and reliability of the parameter settings.

[0051] Specifically, the above steps detail how to obtain the optimized shut-off delay time for the two endpoints through experimental calibration. Multiple laser cuts here refer to performing a complete bidirectional cutting process on the test workpiece's test machining trajectory during the testing phase, using the same total number of cuts N and the number of cuts M in the first direction as in subsequent formal processing (i.e., the same forward and reverse cut allocation). After processing, high-precision measuring instruments are used to measure the morphology of the areas corresponding to the first endpoint (i.e., the test start area) and the areas corresponding to the second endpoint (i.e., the test end area) on the test trajectory, obtaining key data such as depth, width, and cross-sectional shape. The measurement results are compared and analyzed with the preset ideal morphology. If the measurement reveals processing defects (such as over-etching or under-etching) in the first endpoint area (test start area), the first shut-off delay time corresponding to the first endpoint in formal processing needs to be adjusted (this parameter mainly affects the processing effect when the first endpoint is used as the endpoint during reverse cutting); similarly, if defects are found in the second endpoint area (test end area), the second shut-off delay time corresponding to the second endpoint in formal processing needs to be adjusted. This calibration process ensures that the shut-off delay parameters are set based on actual processing feedback, possessing high specificity and accuracy.

[0052] Furthermore, the first and second shutdown delay times can be adjusted as follows: If the processing morphology of the test area at the first endpoint is over-etched, decrease the first shutdown delay time; if the processing morphology of the test area at the first endpoint is under-etched, increase the first shutdown delay time. Similarly, if the processing morphology of the test area at the second endpoint is over-etched, decrease the second shutdown delay time; if the processing morphology of the test area at the second endpoint is under-etched, increase the second shutdown delay time. Thus, by establishing a clear adjustment rule of "reducing delay for over-etching and increasing delay for under-etching," a direct and effective operational basis is provided for setting the shutdown delay parameters.

[0053] It should be noted that the above adjustment method clarifies the specific decision-making rules for adjusting the shutdown delay parameters based on measurement results. These rules are directly related to the energy deposition mechanism of laser processing: over-etching indicates that too much laser energy has accumulated in the endpoint region, so it is necessary to shorten the actual laser action time at that location by reducing the shutdown delay time, thereby reducing energy input; under-etching indicates insufficient energy, so it is necessary to extend the laser action time by increasing the shutdown delay time to supplement the energy.

[0054] For example, after a test machining, measurements reveal that the groove depth at the second endpoint region (corresponding to the second endpoint in the formal machining process) is significantly greater than that in the middle region, indicating over-etching. Therefore, when setting the second shut-off delay time for formal machining, the shut-off delay time should be adjusted to reduce it based on a certain benchmark value (e.g., a theoretically calculated value or the previously set value). This adjustment rule constitutes the core control logic of dynamic shut-off delay compensation, enabling process parameters to adaptively optimize towards eliminating endpoint morphology defects. In practice, the adjustment magnitude can be proportionally or empirically mapped based on the degree of over-etching or under-etching (e.g., depth deviation).

[0055] Step 103: Perform a second-direction cutting operation, which includes controlling the laser beam to perform NM cuts along the target processing trajectory from the second endpoint to the first endpoint.

[0056] It should be noted that performing the second-direction cutting operation is another key part of the bidirectional cutting compensation method, working in conjunction with the first-direction cutting operation to achieve uniform processing of the entire target processing trajectory.

[0057] Wherein, NM is the number of cuts in the second direction determined based on the total number of cuts N and the number of cuts in the first direction M.

[0058] It is important to note that during each second-direction cutting operation, the laser's activation time must be synchronized with the start of the laser beam scanning along the target processing trajectory. The laser processing parameters for the first and second-direction cutting operations must be identical, and the laser beam scanning paths must overlap. This synchronization requirement is consistent with that for the first-direction cutting operation, aiming to eliminate the processing defect initiation problem introduced by laser emission delay at the second endpoint of the trajectory (which serves as the starting point in this direction). Simultaneously, the laser processing parameters (such as laser power, pulse frequency, scanning speed, and spot size) used in the second and first-direction cutting operations must be exactly the same, and the laser beam scanning paths in both directions must highly overlap. Parameter consistency is a prerequisite for ensuring comparable removal effects in both directions and for the superposition and cancellation of energy deposition; while path overlap ensures that both processing operations act on the same spatial location of the material, providing the geometric basis for precise energy compensation. Typically, this relies on a high-precision beam deflection mechanism (such as a galvanometer) and its calibration system, with repeatability accuracy within the micrometer range.

[0059] In one embodiment, the second-direction cutting operation may further include: controlling the laser to turn off with a first turn-off delay time when the laser beam scans to the first endpoint. This enables differentiated and precise control of endpoint energy accumulation caused by scanning deceleration, directly addressing the problem of over-etching or under-etching at the endpoint.

[0060] It should be noted that the above steps are the application of dynamic delay compensation in reverse cutting. When the laser beam scans from the second endpoint to the first endpoint to complete one reverse cut, the first endpoint becomes the end point of this cut. At this time, the beam deflection mechanism will also decelerate at the first endpoint, resulting in a longer spot dwell time. The first shutdown delay time is a compensation parameter specifically set for the first endpoint, which controls the duration for which the laser beam continues to emit light after reaching the geometric position of the first endpoint. By applying this parameter, the energy deposition in the first endpoint region at the end of the reverse cut can be precisely controlled, thereby compensating for the slight etching effect that may exist in this region (as the starting point) during forward cutting. For example, if the first endpoint has slight under-etching due to insufficient energy rise edge during forward cutting, then in reverse cutting, by setting an appropriate shutdown delay time for the first endpoint, it can obtain slightly more energy input, thereby canceling out the under-etching in forward cutting and improving the final morphology processing effect of that endpoint.

[0061] In this embodiment, a complete bidirectional cutting cycle is completed by sequentially executing a first-direction cutting operation and a second-direction cutting operation. This cycle can be repeated M times in the forward direction and NM times in the reverse direction, depending on the allocation of the total number of cuttings N and the number of cuttings M in the first direction. Its core process principle lies in energy symmetry compensation: the slight under-etching at the starting point (first endpoint) of the forward cutting cancels out the appropriate over-etching design at the corresponding point (as the endpoint) of the reverse cutting; the tendency for over-etching at the endpoint (second endpoint) of the forward cutting cancels out the tendency for under-etching at the corresponding point (as the starting point) of the reverse cutting. By dividing the total number of processing operations into two groups in opposite directions, and supplementing this with precise synchronization of the opening time and endpoint-specific closing delay time control, this embodiment transforms the systematic morphological errors accumulated at the same end of the trajectory in traditional unidirectional repetitive processing into spatially symmetrically distributed and mutually canceling error pairs. This significantly improves the consistency of processing depth and morphology across the entire target processing trajectory, such as the two ends of a 10-100 micrometer ultra-short blind groove, reducing the depth difference between the endpoint and the middle region from over 30% in traditional processes to less than 5%.

[0062] The laser processing method disclosed in the above embodiments of this application first determines the target processing trajectory on the workpiece to be processed and determines the total number of cuts N for laser processing on the target processing trajectory. The target processing trajectory includes a first endpoint and a second endpoint, and N is an integer greater than 1. Then, a first-direction cutting operation is performed, which includes controlling the laser beam acting on the workpiece to perform M cuts along the target processing trajectory from the first endpoint to the second endpoint. M is a positive integer less than N. During each first-direction cutting operation, the laser's activation time is synchronized with the time when the laser beam begins scanning along the target processing trajectory. Finally, a second-direction cutting operation is performed, which includes controlling the laser beam to perform NM cuts along the target processing trajectory from the second endpoint to the first endpoint. During each second-direction cutting operation, the laser's activation time is synchronized with the time when the laser beam begins scanning along the target processing trajectory. The laser processing parameters for the first-direction cutting operation and the second-direction cutting operation are the same, and the scanning paths of the laser beams overlap. Therefore, by adopting a processing method that includes bidirectional cutting and synchronous laser activation and scanning motion, the energy deposition difference caused by the dynamic response of laser energy and unidirectional scanning at both ends of the trajectory is compensated, effectively improving the quality of laser processing.

[0063] To more intuitively understand the effects of the embodiments of this application, Figure 2-6 The diagrams show a comparison of blind grooves of different sizes before and after processing. The upper part of the diagram shows the effect before processing, and the lower part shows the effect after processing. As can be seen from the diagrams, the laser processing method provided in this application creates a groove on the target processing trajectory on the surface of the workpiece with excellent characteristics such as uniform groove width, steep sidewalls, and consistent processing depth and morphology along the groove length from the first end point to the second end point. This makes it particularly suitable as a precision window for high-density PCB solder mask layers or a micro-line isolation groove on a packaging substrate.

[0064] It should be noted that, for the sake of simplicity, the aforementioned method embodiments are described as a series of actions. However, those skilled in the art should understand that this application is not limited to the described order of actions, because based on this application, some steps can be performed in other orders.

[0065] Figure 7 This is a schematic diagram of the controller provided in an embodiment of this application. Figure 7 As shown, the controller 700 of this embodiment includes: at least one processor 710 ( Figure 7The diagram shows only one processor, a memory 720, and a computer program 721 stored in the memory 720 and executable on the at least one processor 710, which, when executing the computer program 721, performs the steps described in the above-described laser processing method embodiments.

[0066] The controller 700 can be a computing device such as a desktop computer, laptop, handheld computer, or cloud server. The controller may include, but is not limited to, a processor 710 and a memory 720. Those skilled in the art will understand that... Figure 7 This is merely an example of controller 700 and does not constitute a limitation on controller 700. It may include more or fewer components than shown, or combine certain components, or different components, such as input / output devices, network access devices, etc.

[0067] The processor 710 may be a Central Processing Unit (CPU), or it may be other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor or any conventional processor.

[0068] In some embodiments, the memory 720 may be an internal storage unit of the controller 700, such as a hard disk or memory of the controller 700. In other embodiments, the memory 720 may be an external storage device of the controller 700, such as a plug-in hard disk, smart media card (SMC), secure digital (SD) card, flash card, etc., equipped on the controller 700. Furthermore, the memory 720 may include both internal storage units and external storage devices of the controller 700. The memory 720 is used to store operating systems, applications, boot loaders, data, and other programs, such as the program code of computer programs. The memory 720 can also be used to temporarily store data that has been output or will be output.

[0069] It should be noted that, for the sake of convenience and brevity, the structure of the controller described above can also be referred to the specific description of the structure in the method embodiment, which will not be repeated here.

[0070] Specifically, Figure 8 This application illustrates a laser processing apparatus, comprising: A laser, used to emit a laser beam; A beam control device, comprising a beam deflection mechanism, wherein the beam control device is used to transmit, control, and deflect the laser beam; The machining platform is used to support the workpiece to be processed; The controller is used to control the coordinated operation of the aforementioned laser, beam control device, and processing platform to achieve, for example... Figure 1 Laser processing methods.

[0071] In some embodiments of this application, the laser processing equipment may further include a measurement unit, which is communicatively connected to the controller. This measurement unit measures the surface morphology of the workpiece after test processing or formal processing, acquiring measurement data including processing depth, width, and morphological features. The measurement unit may include high-precision non-contact measurement devices such as cameras, optical microscopes, confocal microscopes, interference microscopes, or laser profilometers. The measurement results can be used to provide feedback for adjusting process parameters, such as determining the total number of cuts N, optimizing the number of forward cuts M and the number of reverse cuts NM, and calibrating the shutdown delay time.

[0072] In some embodiments of this application, the laser can be a solid-state laser (e.g., nanosecond laser, picosecond laser, femtosecond laser, etc.), a gas laser (e.g., a CO2 laser), or other types of lasers, and this application does not impose any limitations on this. A laser capable of providing suitable laser pulse wavelength and pulse frequency parameters can be selected according to processing requirements. The power, spot size, and pulse count of the laser beam emitted by the laser can all be set according to processing requirements.

[0073] In some embodiments of this application, the beam control device, in addition to the beam deflection mechanism, may also include, but is not limited to, a beam shaper (e.g., an aperture, a beam expander or beam shrinker, a shaping component that converts the intensity distribution of the laser beam from a Gaussian distribution to the desired shape), and a focusing lens. The beam shaper can be used to shape the laser beam to control the spot size and energy density distribution. The focusing lens can be used to control the focal length, thereby affecting the energy density distribution of the laser spot formed at the processing position of the workpiece. The various components within the beam control device cooperate to transmit, control, and deflect the laser beam, forming a spot with specific laser parameters to process the signal transmission substrate.

[0074] The beam deflection mechanism may include one or any combination of a galvanometer, a rotating mirror, an acousto-optic modulator (AOM), an acousto-optic deflector (AOD), an electro-optic modulator (EOM), an electro-optic deflector (EOD), a liquid crystal variable attenuator (LCVA), a microelectromechanical system (MEMS) based variable optical attenuator (VOA), and an optical attenuator wheel. Among these, the galvanometer and rotating mirror are beam deflection components controlled by mechanical motion, and their beam deflection control inevitably involves acceleration and deceleration during the start and end times of beam deflection. The AOM and AOD, on the other hand, are beam deflection components controlled by electrical signals, allowing for rapid, abrupt adjustments to the beam deflection process through parameter adjustments of the control information.

[0075] This application embodiment also provides a wire trough, the circuit board being based on... Figure 1 The described laser processing method or such Figure 8 It is produced by laser processing equipment.

[0076] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the above-described division of functional units and modules is merely an example. In practical applications, the above functions can be assigned to different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiments can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit. Furthermore, the specific names of the functional units and modules are only for easy differentiation and are not intended to limit the scope of protection of this application. The specific working process of the units and modules in the above system can be referred to the corresponding process in the foregoing method embodiments, and will not be repeated here.

[0077] In the above embodiments, the descriptions of each embodiment have different focuses. For parts that are not described in detail or recorded in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0078] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0079] In the embodiments provided in this application, it should be understood that the disclosed devices / controllers and methods can be implemented in other ways. For example, the device / controller embodiments described above are merely illustrative. For instance, the division of modules or units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between devices or units may be electrical, mechanical, or other forms.

[0080] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0081] Furthermore, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0082] If the integrated module / unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, all or part of the processes in the methods of the above embodiments can also be implemented by a computer program instructing related hardware. The computer program can be stored in a computer-readable storage medium, and when executed by a processor, it can implement the steps of the various method embodiments described above. The computer program includes computer program code, which can be in the form of source code, object code, executable files, or certain intermediate forms. The computer-readable medium can include: any entity or device capable of carrying the computer program code, recording media, USB flash drives, portable hard drives, magnetic disks, optical disks, computer memory, read-only memory (ROM), random access memory (RAM), electrical carrier signals, telecommunication signals, and software distribution media, etc. It should be noted that the content included in the computer-readable medium can be appropriately added or removed according to the requirements of legislation and patent practice in the jurisdiction. For example, in some jurisdictions, according to legislation and patent practice, computer-readable media do not include electrical carrier signals and telecommunication signals.

[0083] The implementation of all or part of the processes in the methods of the above embodiments can also be accomplished by a computer program product. When the computer program product is run on a controller, the controller can implement the steps in the various method embodiments described above.

[0084] The embodiments described above are only used to illustrate the technical solutions of this application, and are not intended to limit it. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be included within the protection scope of this application.

Claims

1. A laser processing method characterized by, include: Determine the target machining trajectory on the workpiece to be processed, and determine the total number of laser cutting operations N on the target machining trajectory, wherein the target machining trajectory includes a first endpoint and a second endpoint, and N is an integer greater than 1; Perform a first-direction cutting operation, which includes: controlling a laser beam acting on the workpiece to be processed to make M cuts along the target processing trajectory from the first endpoint to the second endpoint, where M is a positive integer less than N. During each first-direction cutting operation, the laser's activation time is synchronized with the time when the laser beam begins to scan along the target processing trajectory. Performing a second-direction cutting operation, the second-direction cutting operation includes: controlling the laser beam to make NM cuts along the target processing trajectory from the second endpoint to the first endpoint, wherein, during each second-direction cutting operation, the laser's activation time is synchronized with the time when the laser beam begins scanning along the target processing trajectory.

2. The method of claim 1, wherein, Determining the total number of laser cuts N on the target processing trajectory includes: On a test workpiece of the same specifications as the workpiece to be processed, the laser processing parameters are used to perform multiple laser cuts along a preset test processing trajectory. After performing multiple laser cuts along the test processing trajectory, the processing morphology of the middle region of the test processing trajectory is measured; The minimum number of cuts required to meet the preset target processing shape requirements is determined as the total number of cuts N.

3. The method of claim 1, wherein, Before performing the first-direction cutting operation, the method further includes: Based on the total number of cuts N, multiple forward and reverse cut count tests are performed. Each forward and reverse cut count test includes: on a test workpiece of the same specifications as the workpiece to be processed, using the laser processing parameters, K cuts are made from the third endpoint to the fourth endpoint along a preset test processing trajectory, and NK cuts are made from the fourth endpoint to the third endpoint along the test processing trajectory to obtain the test result of the forward and reverse cut count test. The third endpoint corresponds to the first endpoint of the workpiece to be processed, the fourth endpoint corresponds to the second endpoint of the workpiece to be processed, K is a positive integer less than N, and the number of cuts K in each forward and reverse cut count test is different. The test result of the forward and reverse cut count test is obtained by measuring the processing morphology of the test area corresponding to the third endpoint on the test processing trajectory, and measuring the processing morphology of the test area corresponding to the fourth endpoint on the test processing trajectory. Based on the test results of the multiple forward and reverse cutting tests, the number of cuts M in the first direction is determined from the number of cuts K in each forward and reverse cutting test.

4. The method according to claim 1, characterized in that, Before performing the first direction cutting operation, the method further includes: setting a first closing delay time corresponding to the first endpoint, and setting a second closing delay time corresponding to the second endpoint; The first directional cutting operation further includes: when the laser beam scans to the second endpoint, controlling the laser to turn off with a delay according to the second turn-off delay time; The second directional cutting operation further includes: when the laser beam scans to the first endpoint, controlling the laser to turn off with a delay according to the first shutdown delay time.

5. The method according to claim 4, characterized in that, The setting of a first shutdown delay time corresponding to the first endpoint and a second shutdown delay time corresponding to the second endpoint include: On a test workpiece of the same specifications as the workpiece to be processed, the laser processing parameters are used to perform multiple laser cuts along a preset test processing trajectory. After performing multiple laser cuts along the test processing trajectory, the processing morphology of the test area corresponding to the first endpoint on the test processing trajectory is measured, and the processing morphology of the test area corresponding to the second endpoint on the test processing trajectory is also measured. Based on the processing morphology of the test area of ​​the first endpoint and the processing morphology of the test area of ​​the second endpoint, the first shutdown delay time and the second shutdown delay time are set.

6. The method according to claim 5, characterized in that, The step of setting the first shutdown delay time and the second shutdown delay time based on the processing morphology of the test area of ​​the first endpoint and the test area of ​​the second endpoint includes: If the processing morphology of the test area at the first endpoint is over-etched, reduce the first shutdown delay time; if the processing morphology of the test area at the first endpoint is under-etched, increase the first shutdown delay time. If the processing morphology of the test area at the second endpoint is over-etched, the second shutdown delay time is reduced; if the processing morphology of the test area at the second endpoint is under-etched, the second shutdown delay time is increased.

7. The method according to any one of claims 1-6, characterized in that, The laser processing parameters for the first direction cutting operation and the second direction cutting operation are the same, and the scanning paths of the laser beams overlap.

8. The method according to any one of claims 1-6, characterized in that, When the total number of cuts N is even, the number of cuts M in the first direction is N / 2; when the total number of cuts N is odd, the number of cuts M in the first direction is (N+1) / 2.

9. A controller comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements the steps of the laser processing method as described in any one of claims 1 to 8.

10. A laser processing device, characterized in that, include: A laser, used to emit a laser beam; A beam control device, comprising a beam deflection mechanism, wherein the beam control device is used to transmit, control, and deflect the laser beam; The machining platform is used to support the workpiece to be processed; A controller is used to control the laser, the beam control device and the processing platform to work together to achieve the laser processing method as described in any one of claims 1 to 8.

11. A single-line blind slot, characterized in that, The single-line blind groove is obtained by the laser processing method according to any one of claims 1 to 8 or by processing based on the laser processing equipment according to claim 10.

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