Lasers are capable of engraving on copper surfaces. Traditionally, this is done by chemical etching to produce complex conductive paths. Instead, a new process application is PCB laser engraving on thin copper sheets, improving quality and efficiency.
Laser engraving and laser marking are often confused,handheld laser marking machine but in reality, they are two different processes. Engraving is generally accompanied by a process of physical removal of the material, with a change in the contour of the substrate being processed.
Engraving is used in a wide range of applications, from steel engraving to stone engraving, and touches every aspect of daily life. When you sit in your car and run your hands over the dashboard and interior trim, you will feel that these faux leather materials have nothing to do with animal fur. These interiors are processed, usually by first carving floral patterns on steel molds with nanosecond pulsed fiber optic excitation, and then using these abrasives to create the faux leather material. The manufacture of coin and medal molds also falls into the field of laser engraving. Laser engraving of precious metals is also becoming more common in the jewelry industry. The traditional way of craftsmen engraving patterns with punches and hammers is slowly disappearing. Today, everything can be done with laser processing.
While ultrafast lasers and continuous (CW) lasers can also be used for engraving applications, it is the nanosecond pulsed fiber laser that is used the most. Nanosecond laser pulses are short and have high peak power, making them particularly suitable for PCB laser engraving. The design of the Master Oscillation Power Amplification (MOPA) allows the user to freely select the pulse width and the repetition frequency is up to 4 MHz. e.g. SPI Laser's PulseTune technology, which allows the pulse width to be adjustable in the range of 3ns~2µs, gives the user the opportunity to optimize the pulse performance, thus improving the quality or efficiency of the laser engraving.
New Process Improves PCB Laser Engraving Productivity, Ensures Quality
Lasers are capable of engraving on copper surfaces. A new process application (nanosecond pulsed lasers) is the engraving of printed circuit boards (PCBs) on thin sheets of copper, whereas traditionally complex conductive paths are created by chemical etching. The copper layer is relatively thin, typically 40 to 100µm thick, but the metal layer can be easily removed by the engraving technique to expose the FR4 substrate. As with the VIN marking example, varying the laser parameters can remove any remaining debris from the FR4 substrate. In addition, the laser can also cut thin copper sheets to the desired size. While laser engraved circuit boards are not well suited for mass production, they can be used for rapid PCB prototyping.
Laser engraving is essentially material removal, and a laser process removes only a few tens of micrometers in depth.little pecker laser engraver The material removal process is therefore relatively slow, with currently achieved removal rates measured in cubic millimeters per minute and removal efficiencies determined by average power. The key to achieving both high quality laser engraving and efficient material removal is the use of optimized processing solutions. Since raster scanning typically creates furrows, there are problems with low removal depth and residual roughness, so this process is generally not recommended unless the engraving requirements are not high.
The principle of PCB laser engraving is relatively simple. The laser pulse acting on the material causes the material to melt, forming a molten pool. After a certain amount of heat is reached, the surface of the material is vaporized and recoil pressure is generated on the melt, resulting in the ejection of the melt, which is the main mechanism of laser engraving to remove the material. There may be some misconceptions about laser engraving, for example, that the higher the pulse energy, the more material is removed; the higher the peak power and the shorter the pulse width, the better the quality of the laser engraving. In fact, the laser engraving process is extremely complex, and there is no fixed processing solution that can guarantee engraving quality. Since engraving quality and material removal rate are mutually dependent, it is important for the user to optimize the pulse characteristics, optics and processing/scanning parameters in order to ensure a good balance between quality and efficiency.
Alternatively, if only lines and simple text need to be engraved, laser dithering can be used. This technology is ideally suited for Vehicle Identification Number (VIN) marking, where the engraved VIN remains visible even after painting and is difficult to rub off, making it safer. In addition, thanks to the powerful functional selectivity of the laser system, oxides and surface spatters generated during the laser engraving process can be effectively removed by simply changing the laser parameters, e.g., by shortening the pulse width and cranking up the repetition frequency.
However, in the case of large areas and complex shapes, if the laser scanning is continuously maintained in a fixed direction, inhomogeneous effects can gradually build up!
精選文章:
The development advantages and future trends of laser engraving and cutting equipment
The application of laser engraving machine in various industries