A method of laser additive manufacturing of a freeform surface circuit
By dividing the freeform surface circuit into a galvanometer processing area and dynamically matching the laser parameters, the problem of spot distortion caused by the laser not being incident along the normal is solved, and high-precision and high-adhesion freeform surface circuit processing is achieved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- SOUTHWEST CHINA RES INST OF ELECTRONICS EQUIP
- Filing Date
- 2024-02-20
- Publication Date
- 2026-08-04
AI Technical Summary
Efficiently and precisely controlling lasers to strike at small incident angles and perform highly consistent processing on complex freeform surfaces is a challenge that current technologies struggle to address, as lasers do not strike along the normal, leading to issues such as spot distortion and weakened circuit bonding.
By dividing the freeform surface circuit into multiple galvanometer processing areas, the optimal processing posture is determined using the principle of minimum normal angle, and laser parameters are dynamically matched to ensure that the laser is incident at a small angle and performs S-shaped reciprocating processing.
This improves the processing accuracy and adhesion consistency of freeform surface circuits, ensuring efficient and high-quality laser micro-additive manufacturing.
Smart Images
Figure CN117961264B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of freeform surface processing technology, and more specifically, to a laser additive manufacturing method for freeform surface circuits. Background Technology
[0002] With the development of the electronic information industry, in order to meet the three-dimensional integration requirements of electronic products, it is necessary to manufacture reliable electrical functional structures such as circuits and resistors on the surface of complex freeform substrates. Laser micro-additive manufacturing technology can complete the manufacturing of electrical functional structures on the surface of various substrates by laser etching reconstruction → coating of metal paste → laser cladding. However, in the face of complex freeform surface processing scenarios, how to efficiently and accurately control the laser to complete the high consistency processing of various regions of complex freeform surfaces under different incident angles has become a new challenge. Chinese patent, publication number CN111375899A, specifically discloses a laser processing and forming method for large curvature curved surfaces. The processing equipment includes five mechanical motion axes, including the X-axis, Y-axis, Z-axis, the A-axis and C-axis of the central turntable. The laser spot moves along the X-axis, Y-axis and Z-axis by controlling the deflection and zoom of the galvanometer. Chinese patent, publication number CN105365531A, specifically discloses a laser processing method for forming large curvature surfaces, which is used for efficient and high-precision laser forming of large curvature surfaces of complex surface tools; the above patent shows that it is feasible to complete the laser processing of free-form surfaces using an eight-degree-of-freedom laser processing device, and it has significant advantages in improving efficiency and precision. However, the processing effect of laser micro-additive manufacturing is very sensitive to the interaction between the laser and the surface. When the laser does not incident along the normal, the ideal circular spot will be deformed into an elliptical spot, causing the laser energy distribution to be distorted. This ultimately leads to the interaction effect between the laser and the surface deviating from the ideal effect, resulting in weakened bonding force of the additive manufacturing circuit and deterioration of edge pattern accuracy. To reduce the negative impact of the laser not incident along the normal, on the one hand, it is necessary to make the laser incident at the smallest possible angle while taking efficiency into account. On the other hand, it is necessary to adjust the laser power, scanning speed and other related parameters for different laser incident angles. Summary of the Invention
[0003] The technical problem to be solved by this invention is to provide a laser additive manufacturing method for freeform surface circuits. By controlling the position between the laser and the freeform surface circuit, the laser is ensured to enter each processing area at the smallest possible incident angle. At the same time, by dynamically linking and controlling the laser parameters and the incident angle, efficient, high-precision, and high-reliability laser micro-additive manufacturing of freeform surface circuits can be guaranteed. The solution adopted by this invention to solve the technical problem is: A laser additive manufacturing method for freeform surface circuits specifically includes the following steps: Step S1: Extract the curved metal conductor model to be additively manufactured from the dielectric substrate; Step S2: Divide the curved metal conductor model into multiple quadrilateral meshes, calculate the curvature of each vertex in each quadrilateral mesh, and obtain the average curvature at each vertex position; Step S3: Divide the curved metal conductor model into multiple galvanometer processing areas based on the average curvature value; Step S4: Set positioning points at the boundary of each galvanometer processing area and on the dielectric substrate; Step S5: Based on the principle of minimum normal angle, solve for the optimal machining posture of each galvanometer machining area and calculate the parameters of the five mechanical motion axes; Step S6: Within each galvanometer processing area, determine the laser incident angle for all quadrilateral mesh vertices in the area under the optimal processing posture; match the laser parameters according to the laser incident angle, and perform laser additive manufacturing by planning the laser motion path in an S-shaped reciprocating pattern.
[0004] This invention utilizes a galvanometer processing area segmentation method based on surface curvature to ensure controllable overall undulation of each galvanometer processing area. Positioning points are used to locate each galvanometer processing area, ensuring reliable splicing between adjacent areas with a splicing accuracy of ±20μm. The minimum normal angle principle is used to determine the processing posture of each galvanometer processing area, ensuring that the laser acts on the processing position at the most perpendicular angle possible during processing within each galvanometer processing area. A method based on dynamic matching of process parameters according to the incident angle improves the consistency of laser action on the curved surface and mitigates the negative impact of spot deformation. This method can solve the laser control problem applicable to freeform surface laser micro-additive manufacturing, improve the consistency of adhesion in each area, and enhance circuit edge accuracy, laying the foundation for efficient and high-quality freeform surface micro-additive manufacturing.
[0005] In some possible implementations, The side length of the quadrilateral grid is L, where 0.1 ≤ L ≤ 1 mm.
[0006] In some possible implementations, The average curvature is H. ; Where k1 is the maximum curvature of the tangent lines of all smooth curves passing through this vertex; k2 is the minimum curvature of the tangent lines to all smooth curves passing through this vertex.
[0007] In some possible implementations, The sum of the absolute values of the average curvature of all vertices in each galvanometer processing region is A. , of which 0.5mm -1 ≤K≤2mm -1 L is the side length of the quadrilateral grid.
[0008] In some possible implementations, The positioning point can be any one or more of blind holes and scribing lines.
[0009] In some possible implementations, The minimum normal angle principle in step S5 specifically refers to the fact that, under the processing posture, the sum of the angles between the incident direction of the laser and the normal direction of the corresponding vertex at each vertex of the galvanometer processing area is the smallest.
[0010] In some possible implementations, The laser parameters matching based on the laser incident angle in step S6 specifically refers to matching the laser parameters based on the laser incident angle and the material of the curved metal conductor model to obtain the optimal laser power, repetition frequency, scanning speed, scanning line spacing, and number of repetitions at that laser incident angle.
[0011] In some possible implementations, The laser parameters are stored in the laser process database and established after preliminary process experiments.
[0012] Compared with the prior art, the beneficial effects of the present invention are as follows: This invention utilizes the minimum angle rule to determine the processing posture of each galvanometer processing area, enabling the laser to process each region of the freeform surface with the smallest possible incident angle; This invention ensures the processing accuracy of the laser on the galvanometer processing area by using positioning points, and calls upon a laser process database established for specific materials to ensure processing quality; This invention determines the processing posture of each galvanometer processing area by using the principle of minimum normal angle to ensure that the laser can act on the position to be processed at the most perpendicular angle during processing in each position within the galvanometer processing area. It improves the consistency of the laser's action on the curved surface and reduces the negative impact of spot deformation by using a method of dynamically matching process parameters based on the incident angle. This invention can solve the laser control problem applicable to laser micro-additive manufacturing of freeform surfaces, improve the consistency of adhesion in different areas, improve the accuracy of circuit edges, and lay the foundation for efficient and high-quality freeform surface micro-additive manufacturing. Attached Figure Description
[0013] Figure 1 This is a schematic diagram of the curved circuit in Embodiment 1 of the present invention; Figure 2 This is a schematic diagram of the structure of the curved metal conductor model extracted in this invention; Figure 3This is a schematic diagram illustrating the division of a curved metal conductor model into multiple quadrilateral grids in this invention; Figure 4 This is a schematic diagram illustrating the division of the curved metal conductor model into multiple galvanometer processing areas in this invention; Figure 5 This is a schematic diagram showing the location of the positioning points in this invention; Figure 6 This is a schematic diagram of laser processing performed within a galvanometer processing area in this invention; Figure 7 This is a schematic diagram of the galvanometer processing posture in each galvanometer processing area of the present invention; Among them: 1. Dielectric substrate; 11. Positioning point; 2. Curved surface metal conductor model; 21. Quadrilateral mesh; 22. Galvanometer processing area. Detailed Implementation
[0014] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. The terms "first," "second," and similar terms used in this application do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Similarly, "a" or "one," etc., do not indicate a quantity limitation, but rather indicate the existence of at least one. In the implementation of this application, "and / or" describes the association relationship of related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. In the description of the embodiments of this application, unless otherwise stated, "multiple" means two or more. For example, multiple positioning posts refer to two or more positioning posts. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.
[0015] The present invention will now be described in detail.
[0016] like Figures 1-7 As shown: A laser additive manufacturing method for freeform surface circuits, based on an eight-degree-of-freedom laser processing device, specifically includes the following steps: Step S1: Extract the curved metal conductor model 2 to be additively manufactured on the dielectric substrate 1, and establish a laser process database storing laser parameters. The establishment of the laser process database is based on the previous process experiments. Step S2: Divide the curved metal conductor model 2 into multiple quadrilateral meshes 21, calculate the curvature of each vertex in each quadrilateral mesh 21, and obtain the average curvature at each vertex position; The side length of the quadrilateral grid 21 is L, where 0.1mm ≤ L ≤ 1mm; The average curvature is H. ; Where k1 is the maximum curvature of the tangent lines of all smooth curves passing through this vertex; k2 is the minimum curvature of the tangent lines to all smooth curves passing through this vertex; Step S3: Divide the curved metal conductor model 2 into multiple galvanometer processing regions 22 based on the average curvature; specifically, the sum of the absolute values of the average curvature of all vertices in each galvanometer processing region is A. , of which 0.5mm -1 ≤K≤2mm -1 L is the side length of the quadrilateral grid; The galvanometer processing area 22 described in this invention refers to the area where no mechanical movement occurs during processing; the processing of this area is completed solely by the laser movement controlled by the galvanometer. The overall qualitative relationship of the galvanometer processing area 22 division standard is as follows: the larger the curvature of the surface, the smaller the area of the galvanometer processing area 22 and the more numerous it is, to ensure that the undulation of a single processing area is not too large, to ensure the effect of laser interaction with the surface and improve accuracy; the smaller the curvature of the surface, the larger the area of the galvanometer processing area 22 and the fewer it is, to ensure processing efficiency. Step S4: Set a positioning point 11 at the boundary of each galvanometer processing area 22 and on the medium substrate 1; the positioning point 11 is any one or more of blind holes and scribing lines; the positioning point 11 is used as the positioning point 11 for the processing posture of each galvanometer in subsequent processing, and the positioning point 11 needs to be shared by adjacent galvanometer processing areas 22 to greatly improve the splicing accuracy between areas. Step S5: Based on the principle of minimum normal angle, solve for the optimal machining posture of each galvanometer machining area 22, and calculate the parameters of the five mechanical motion axes; The minimum normal angle principle in step S5 specifically refers to the fact that, under the processing posture, the sum of the angles between the incident direction of the laser and the normal direction of the corresponding vertex at each vertex of the galvanometer processing area 22 is the smallest. Step S6: Within each galvanometer processing area 22, determine the laser incident angle at the optimal processing posture for all vertices of the quadrilateral mesh 21 within that area; match the laser parameters according to the laser incident angle, and perform laser additive manufacturing by planning the laser motion path in an S-shaped reciprocating pattern. The laser parameters matching based on the laser incident angle in step S6 specifically refers to matching the laser parameters based on the laser incident angle and the material of the curved metal conductor model 2 to obtain the optimal laser power, repetition frequency, scanning speed, scanning line spacing, and number of repetitions at that laser incident angle.
[0017] This invention utilizes a galvanometer processing area 22 segmentation method based on surface curvature to ensure controllable overall undulation of each galvanometer processing area 22. Positioning points 11 are used to locate each galvanometer processing area 22, ensuring reliable splicing between adjacent processing areas with a splicing accuracy of ±20μm. The minimum normal angle principle is used to determine the processing posture of each galvanometer processing area 22, ensuring that the laser acts on the processing position at the most perpendicular angle possible during processing within each galvanometer processing area 22. A method based on dynamic matching of process parameters according to the incident angle improves the consistency of laser action on the curved surface and mitigates the negative impact of spot deformation. This method can solve the laser control problem applicable to free-form surface laser micro-additive manufacturing, improve the consistency of adhesion in each area, and enhance circuit edge accuracy, laying the foundation for efficient and high-quality free-form surface micro-additive manufacturing.
[0018] Example 1: This embodiment uses a free-form surface model to be processed as an example, such as... Figures 1-7 As shown, this is a conformal circuit with a curved surface to be processed. The conformal circuit consists of a non-metallic dielectric body and a thin layer of metallic conductor. The non-metallic dielectric body is a free-form surface and is manufactured by machining. Figure 1 For a curved circuit, the non-metallic dielectric body is dielectric substrate 1. Figure 1 The shaded area is a thin layer of metallic conductor, which is conformally arranged with the dielectric surface and is directly processed on the surface of the non-metallic dielectric body by laser micro-addition manufacturing. Specifically, a three-dimensional model of the thin metal conductor layer is extracted using computer-aided design software. This three-dimensional model is the curved metal conductor model 2. The three-dimensional model is then divided into multiple quadrilateral grids 21, with each grid having a side length of L, where L is 0.5 mm. The surface curvature of all vertices of the quadrilateral grids 21 is calculated, and the average curvature of each vertex is obtained. Based on the obtained average curvature values, the area is divided into 32 galvanometer processing regions 22; the sum A of the absolute values of the average curvature values of the vertices contained in each galvanometer processing region 22 satisfies... The value of K is related to the desired machining accuracy; K = 0.5mm -1 ; A blind hole with a diameter of 0.2 mm and a depth of 0.1 mm is set at the boundary of the galvanometer processing area 22 and on the surface of the non-metallic medium as a positioning point 11; According to the principle of minimum normal angle, the sum of the angles between the incident direction of the laser and the normal direction of the corresponding vertex in the region is minimized under the machining posture of Azi. The corresponding machining posture at this time is the optimal machining posture for the galvanometer machining region 22. Figure 6 As shown, The angle between the incident direction of the laser at a vertex and the normal to that vertex; Obtain the parameters of the five mechanical motion axes required for optimal machining posture, including the parameters of the X-axis, Y-axis, Z-axis, A-axis (rotary axis), and C-axis (rotary axis). Within each galvanometer processing area 22, the laser incident angle is determined for the vertices of all quadrilateral grids 21 within that area. Based on the laser incident angle, the corresponding laser parameters are matched in the laser process database, and the laser motion path is planned in an S-shaped reciprocating manner. The laser process database is a collection of parameters such as laser incident angle, optimal laser power, optimal repetition frequency, optimal scanning speed, optimal scanning line spacing, and optimal number of repetitions, which was established through previous process experiments. The parameters of the five mechanical motion axes, the laser motion path within the galvanometer processing area 22, and the laser process parameters (laser power, optimal repetition frequency, optimal scanning speed, optimal scanning line spacing, and optimal number of repetitions) are bound together into a processing parameter group for one region. The parameter groups for each region are then packaged into the final processing file. This enables effective control of laser additive manufacturing of freeform surfaces. By controlling the position between the laser and the freeform surface substrate, the laser is ensured to enter each region at the smallest possible incident angle. At the same time, by dynamically linking and controlling the laser parameters and the incident angle, efficient, high-precision, and high-reliability laser micro-additive manufacturing of freeform surface circuits can be guaranteed.
[0019] The manufacturing methods of the present invention were compared experimentally with those in the prior art, and the results are shown in Table 1.
[0020] Table 1 It is evident that the freeform surface circuit prepared by the manufacturing method of this invention enables the laser to enter each processing area at the smallest possible incident angle. At the same time, the laser parameters and incident angle can be dynamically correlated and controlled to ensure efficient, high-precision, and high-reliability laser micro-additive manufacturing of the freeform surface circuit.
[0021] This invention is not limited to the specific embodiments described above. The invention extends to any new feature or combination disclosed in this specification, as well as any new method or process step or combination disclosed herein.
Claims
1. A method of laser additive manufacturing of a freeform surface circuit, characterized in that, Specifically, the following steps are included: Step S1: Extract the curved metal conductor model to be additively manufactured from the dielectric substrate; Step S2: Divide the curved metal conductor model into multiple quadrilateral meshes, calculate the curvature of each vertex in each quadrilateral mesh, and obtain the average curvature at each vertex position; the average value of the curvature is H, ; Where k1 is the maximum curvature of the tangent lines of all smooth curves passing through this vertex; k2 is the minimum curvature of the tangent lines to all smooth curves passing through this vertex; Step S3: Divide the curved metal conductor model into multiple galvanometer processing areas based on the average curvature value; Step S4: Set positioning points at the boundary of each galvanometer processing area and on the substrate; each set of positioning points is shared by adjacent galvanometer processing areas; Step S5: Based on the principle of minimum normal angle, solve for the optimal processing posture of each galvanometer processing area and calculate the parameters of the five mechanical motion axes; the principle of minimum normal angle specifically means that under the processing posture, the sum of the angles between the incident direction of the laser at each vertex of the galvanometer processing area and the normal direction of the corresponding vertex is minimized. Step S6: Within each galvanometer processing area, determine the laser incident angle for all quadrilateral mesh vertices in the area under the optimal processing posture; match the laser parameters according to the laser incident angle, and perform laser additive manufacturing by planning the laser motion path in an S-shaped reciprocating pattern.
2. The method of claim 1, wherein, each of the four quadrilateral meshes has a side length of L, .
3. The method of claim 1, wherein, The positioning point can be any one or more of blind holes and scribing lines.
4. The method of claim 1, wherein, The laser parameters matching based on the laser incident angle in step S6 specifically refers to matching the laser parameters based on the laser incident angle and the material of the curved metal conductor model to obtain the optimal laser power, repetition frequency, scanning speed, scanning line spacing, and number of repetitions at that laser incident angle.
5. The method of claim 4, wherein the method further comprises: The laser parameters are stored in the laser process database and established after preliminary process experiments.