Method for etching PCB (Printed Circuit Board) based on laser and machinery

Abstract

The invention relates to the technical field of printed circuit board manufacturing, in particular to a method for etching a PCB based on laser and machinery. Comprising the steps of S1, material preparation; s2, graphic design; s3, shunt design is carried out; s4, setting laser parameters; s5, performing laser etching; s6, mechanical carving; according to the laser and mechanical two-in-one PCB etching method, large-area copper removal or copper removal with a large line width and a large line spacing is realized by using mechanical polishing and cutting through process division, and a fine line with a small line width and a small line spacing is completed by laser engraving, so that the efficiency, the precision and the environmental protection are considered, and the two-in-one realization efficiency is higher; chemical liquid medicine is not needed in the whole process, discharge of heavy metal and organic waste liquid is avoided, the method is green and environment-friendly, mask and wet process processes are omitted, and the cost is saved; and the short-pulse ultraviolet laser is adopted to directly etch the circuit pattern on the copper-clad substrate, so that the method has the advantage of high precision, and is suitable for manufacturing high-end PCBs such as high-density interconnection boards, flexible boards, high-frequency and high-speed boards and the like.

Description

Technical Field

[0001] This invention relates to the field of printed circuit board manufacturing technology, and in particular to a method for PCB circuit boards based on dual laser and mechanical etching. Background Technology

[0002] With the development of the electronics industry, electronic products have entered a stage of functional and intelligent development. To meet the demands for high integration, miniaturization, and micro-miniaturization of electronic products, circuit boards are also developing towards lighter, thinner, shorter, and smaller designs, while ensuring good electrical and thermal performance. As design dimensions gradually decrease, the interconnection density of all products at the design level is constantly increasing. That is, within increasingly limited area, more input and output signal lines need to be designed, and the circuit board lines also require increasingly fine precision.

[0003] Existing patent CN202011627732.5 provides a method for manufacturing circuit board circuits using laser etching, including laminating conductive copper foil onto a substrate to form a copper-clad laminate; laser etching the copper-clad laminate using a laser engraving machine, whereby the conductive copper foil is laminated to form a conductive copper layer, grooves are etched into the conductive copper layer, and a certain thickness of conductive copper layer is retained at the bottom of the grooves; the laser-etched copper-clad laminate is placed in a vacuum two-fluid etching device to etch away the conductive copper layer, forming circuit spacers. By using a laser engraving machine, grooves with fine circuits are formed on the conductive copper layer; by using a vacuum two-fluid etching device, the residual conductive copper layer in the grooves is etched away to form circuit spacers, completing the required circuit pattern. This method reduces the steps of film fabrication, photosensitive film application, exposure and development, electroplating, and film removal; resulting in a simpler circuit board manufacturing process, lower material consumption, and a shorter production cycle.

[0004] However, the aforementioned technologies require etching solutions during processing, and this chemical etching can affect the desired circuitry. Furthermore, the initial etching process cannot guarantee the etching thickness and circuit precision, necessitating a secondary etching step. This results in complex processes, limited precision, significant pollution, and poor flexibility. As electronic products evolve towards higher density, miniaturization, and higher speeds, the requirements for PCB circuit pattern precision and green manufacturing are becoming increasingly stringent. Therefore, developing a new laser etching process that is high-precision, low-pollution, and digitally controllable has become a new trend in technological development. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a method for etching PCB circuit boards based on laser and mechanical dual etching that is highly accurate, low-pollution, and digitally controllable.

[0006] To solve the above-mentioned technical problems, the technical solution of the present invention is: a method for etching PCB circuit boards based on laser and mechanical dual etching, the innovation of which is: including the following steps: S1. Material preparation: Provide copper-clad laminate substrate and clean the surface of the substrate. S2. Graphic Design: Generate graphic data using CAD software based on the circuit board design requirements; S3, Branch Design: Import the graphic data into the control system. The control system is used to load the graphic file and control the laser parameters and scanning path. It is easy to integrate digitally and intelligently. When the line spacing or line width in the graphic data is >100 micrometers, execute S6. When the line spacing or line width in the graphic data is ≤100 micrometers, execute S4. S4. Laser parameter settings: Select a short-pulse ultraviolet laser and set the appropriate wavelength, power, frequency, scanning speed and path; S5, Laser Etching: The laser is precisely scanned on the copper surface by a high-speed galvanometer or motion platform to directly etch away the copper layer to form circuit patterns, and then S7 is executed; S6. Mechanical engraving: The copper foil is removed by mechanical polishing to form the circuit pattern, and the engraving depth is 0.05–0.15mm. Then, S7 is executed. S7. Online Inspection: Automatically inspects the size and quality of the graphic and automatically adjusts the laser path for compensation processing to achieve closed-loop control of the graphic.

[0007] Furthermore, the short-pulse ultraviolet laser is an ultraviolet picosecond or femtosecond laser.

[0008] Furthermore, the motion platform is a two-dimensional galvanometer or an XY platform, which enables a processing accuracy of up to 20μm, making it suitable for high-density circuit fabrication.

[0009] Furthermore, it also includes an exhaust gas treatment system for collecting the metal fumes generated during the etching process.

[0010] Furthermore, the substrate is FR-4, polyimide, or ceramic.

[0011] Furthermore, the control system is a unified numerical control controller.

[0012] Furthermore, the short-pulse ultraviolet laser used in step S4 is an ultraviolet picosecond laser, and the relevant laser parameters are as follows: Laser wavelength: 355nm; Laser power: 30W; Laser pulse frequency: 300-2000kHz; Output pulse width: ≤15ps; Cutting efficiency: 800mm - 7000mm / s; The advantages of this invention are: This invention presents a laser-mechanical dual-process PCB etching method. Through process division, large-area copper removal or removal of copper foil with large line widths and spacing is achieved using mechanical polishing, while micro-line removal with small line widths and spacing is completed using laser engraving. This balances efficiency, precision, and environmental protection, with the dual-process achieving higher efficiency. Furthermore, the entire process eliminates the use of chemical solutions, preventing the discharge of heavy metals and organic waste liquids, making it green and environmentally friendly. It also eliminates the need for masking and wet processes, saving costs. Moreover, it uses short-pulse ultraviolet lasers to directly etch circuit patterns on copper-clad substrates, offering the advantage of high precision and making it suitable for high-end PCB manufacturing such as high-density interconnect boards, flexible boards, and high-frequency, high-speed boards.

[0013] This invention enables flexible manufacturing, allowing for rapid pattern switching, and is suitable for small-batch production of multiple varieties. Detailed Implementation

[0014] To further illustrate the technical means and effects of the present invention in achieving the intended purpose, the following detailed description of the specific implementation methods, structures, features and effects of the present invention, in conjunction with preferred embodiments, is provided below.

[0015] A method for etching PCB circuit boards using both laser and mechanical etching includes the following steps: S1. Material preparation: Provide copper clad laminate substrate, which is FR-4, polyimide or ceramic, and clean the surface of the substrate. Place the substrate on the processing platform, which is a vacuum adsorption type, to ensure that the board is fixed and level. S2. Graphic Design: Generate graphic data using CAD software based on the circuit board design requirements; S3. Path Design: The graphic data is imported into a unified CNC controller. The unified CNC controller is used to load the graphic file and control the laser parameters and scanning path, which is easy to integrate digitally and intelligently. When the line spacing or line width in the graphic data is >100 micrometers, the processing head switches to a mechanical head and executes S6. When the line spacing or line width in the graphic data is ≤100 micrometers, the processing head switches to a laser head and executes S4. The processing head in this embodiment includes a mechanical head and a laser head arranged in parallel. S4. Laser parameter setting: Select a short-pulse ultraviolet laser, which is an ultraviolet picosecond or femtosecond laser, focusing system, suitable for micro-line processing, and set appropriate wavelength, power, frequency, scanning speed and path; S5, Laser Etching: The laser is precisely controlled to scan the copper surface through a high-speed galvanometer or motion platform to directly etch and remove the copper layer to form a circuit pattern. Then, S7 is executed. The motion platform is a two-dimensional galvanometer or an XY platform, which makes the processing accuracy up to 20μm, suitable for high-density circuit fabrication. S6, Mechanical engraving: The CNC spindle carries a tiny engraving cutter or milling cutter to remove the copper foil with the required circuit through mechanical polishing to form a circuit pattern. The engraving depth is 0.05–0.15 mm. Only the copper layer is cut off without damaging the substrate. Then, S7 is executed. S7. Online Inspection: Automatically inspects the size and quality of the graphic and automatically adjusts the laser path for compensation processing to achieve closed-loop control of the graphic.

[0016] Metal fumes generated during the etching process can also be collected through an exhaust gas treatment system.

[0017] The working principle of this patent: A laser etching method for HDI boards: S1. Material preparation: Select FR-4 copper-clad laminate with a thickness of 18μm copper foil, and clean the surface of the substrate. S2. Graphic Design: Generate graphic data using CAD software based on the circuit board design requirements; S3, Branch Design: Import the graphic data into the unified CNC controller. The unified CNC controller is used to load the graphic file and control the laser parameters and scanning path. It is easy to integrate digitally and intelligently. When the line spacing or line width in the graphic data is >100 micrometers, the processing head switches to the mechanical head and executes S6. When the line spacing or line width in the graphic data is ≤100 micrometers, the processing head switches to the laser head and executes S4. S4. Laser parameter settings: Select a picosecond laser with a wavelength of 355nm, set the scanning speed to 100mm / s, the power to 30W, the frequency to 2000KHZ, the output pulse width to ≤15ps, and the cutting efficiency to 800mm - 7000mm / s, to achieve high-density pattern etching with a line width of 30μm and a line spacing of 30μm. S5, Laser Etching: The scanning of the laser on the copper surface is precisely controlled by a two-dimensional galvanometer to directly etch away the copper layer and form the circuit pattern. Then, S7 is executed. The two-dimensional galvanometer can make the processing accuracy up to 20μm, which is suitable for high-density circuit fabrication. S6, Mechanical engraving: Remove copper foil to form circuit patterns through mechanical polishing, and then execute S7; S7. Online Inspection: Automatically inspects the size and quality of the graphic and automatically adjusts the laser path for compensation processing to achieve closed-loop control of the graphic.

[0018] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A method for etching PCB circuit boards using both laser and mechanical etching, characterized in that: Includes the following steps: S1. Material preparation: Provide copper-clad laminate substrate and clean the surface of the substrate. S2. Graphic Design: Generate graphic data using CAD software based on the circuit board design requirements; S3, Branching Design: Import the graphic data into the control system. When the line spacing or line width in the graphic data is >100 micrometers, execute S6. When the line spacing or line width in the graphic data is ≤100 micrometers, execute S4. S4. Laser parameter settings: Select a short-pulse ultraviolet laser and set the appropriate wavelength, power, frequency, scanning speed and path; S5, Laser Etching: The laser is precisely scanned on the copper surface by a high-speed galvanometer or motion platform to directly etch away the copper layer to form circuit patterns, and then S7 is executed; S6. Mechanical engraving: The copper foil is removed by mechanical polishing to form the circuit pattern, and the engraving depth is 0.05–0.15 mm. Then, S7 is executed. S7. Online Inspection: Automatically inspects the size and quality of the graphic and automatically adjusts the laser path for compensation processing.

2. The method for etching a PCB circuit board based on laser and mechanical dual etching according to claim 1, characterized in that: The short-pulse ultraviolet laser is an ultraviolet picosecond or femtosecond laser.

3. The method for etching a PCB circuit board based on laser and mechanical dual etching according to claim 1, characterized in that: The motion platform is a two-dimensional galvanometer or an XY platform, which enables a processing accuracy of up to 20μm, making it suitable for high-density circuit fabrication.

4. The method for etching a PCB circuit board based on laser and mechanical dual etching according to claim 1, characterized in that: It also includes an exhaust gas treatment system for collecting the metal fumes generated during the etching process.

5. The method for etching a PCB circuit board based on laser and mechanical dual etching according to claim 1, characterized in that: The substrate is FR-4, polyimide, or ceramic.

6. The method for etching a PCB circuit board based on laser and mechanical dual etching according to claim 1, characterized in that: The control system is a unified numerical control controller.

7. The method for etching a PCB circuit board based on laser and mechanical dual etching according to claim 2, characterized in that: The short-pulse ultraviolet laser used in step S4 is an ultraviolet picosecond laser, and the relevant laser parameters are as follows: Laser wavelength: 355nm; Laser power: 30W; Laser pulse frequency: 300-2000kHz; Output pulse width: ≤15ps; Cutting efficiency: 800mm - 7000mm / s.