Laser was born out of both theoretical preparation and urgent practical production needs. Since its invention, it has developed extraordinarily rapidly. The development of laser technology has not only revitalized the ancient science and technology of optics but also led to the emergence of a whole new scientific and technological field—laser technology. Today, laser technology has been widely and deeply applied in industry, agriculture, military, medicine, and all aspects of society, playing an increasingly important role in human progress. It has become one of the leading technologies in the current new technological revolution.
1. Advantages of Laser Processing Technology
Processing is the largest application field of laser technology.
Laser processing technology utilizes the interaction between laser beams and materials to perform cutting, welding, surface treatment, drilling, micro-processing, and also serves as a light source for object recognition. It has become a key technology in industrial automation. The valuable characteristics of lasers—good coherence, good monochromaticity, good directionality, and high brightness—determine the advantages of lasers in processing:
① Non-contact processing. No direct impact on the workpiece, thus no mechanical deformation. The energy of the high-energy laser beam and its moving speed can be adjusted to achieve various processing purposes;
② Can process various metals and non-metals, especially materials with high hardness, high brittleness, and high melting points;
③ Can process workpieces inside sealed containers through transparent media;
④ In laser processing, the laser beam has high energy density, fast processing speed, and local processing, with little or no effect on areas not irradiated by the laser. Therefore, it has a small heat-affected zone, minimal thermal deformation of the workpiece, and reduced post-processing;
⑤ No tools are worn during laser processing, and no cutting force acts on the workpiece;
⑥ Laser beams are easy to guide and focus, allowing directional changes. They easily integrate with CNC systems to process complex workpieces, making it a highly flexible processing method;
⑦ Laser processing offers high production efficiency, reliable quality, and good economic benefits.
2. Applications of Laser Processing Technology in the Electronics Industry
Laser processing is a non-contact method that produces no mechanical extrusion or stress, particularly meeting the processing requirements of the electronics industry. Additionally, due to its high efficiency, pollution-free nature, high precision, and small heat-affected zone, laser processing is widely used in electronics.
2.1 Laser Trimming
Laser trimming technology can automatically perform precise micro-adjustments on specified resistors with accuracies ranging from 0.01% to 0.002%, which is higher and more cost-effective than traditional methods. Resistors in integrated circuits and sensors are thin resistor films that can have manufacturing errors up to 15–20%. Only by correcting these errors can the yield of high-precision devices be improved. The laser can be focused into a very small spot with concentrated energy, causing minimal thermal impact on adjacent components without pollution. It is also easy to control by computer, making it suitable for rapid trimming of resistors to precise preset values. During processing, the laser beam is focused on the resistor film to vaporize the material. First, the resistor is measured, and data are sent to a computer. The computer commands the beam locator to position the laser to cut the resistor along a certain path until the resistance value reaches the set value. Similarly, laser technology can be used for capacitance correction of chip capacitors and trimming of hybrid integrated circuits. The excellent positioning accuracy of laser trimming systems improves yield and circuit functions in miniaturized precision linear combination signal devices.
2.2 Laser Dicing
Laser dicing technology is a key technique in integrated circuit manufacturing. It features fine, high-precision lines (line width of 15–25 μm, groove depth of 5–200 μm), fast processing speed (up to 200 mm/s), and yields above 99.5%. In integrated circuit production, thousands of circuits are fabricated on a wafer, which must be diced into individual chips before packaging. Traditional methods use diamond grinding wheels, which cause radial cracks on the silicon wafer surface due to mechanical stress. Laser dicing uses a laser beam focused on the wafer surface to generate high temperatures that vaporize material and form grooves. Adjusting pulse overlap precisely controls groove depth, enabling the wafer to be cleanly broken along the grooves, or directly cut by multiple passes. Because the laser beam is focused into a very small spot, the heat-affected zone is minimal. When cutting 50 μm deep grooves, temperature rise 25 μm from the groove edge does not affect the performance of active devices. Laser dicing is non-contact processing, so the wafer is free from mechanical stress and cracks. This improves silicon wafer utilization, yields, and cutting quality. It is also used for dicing single-crystal, polycrystalline, and amorphous silicon solar cells, as well as dicing and cutting silicon, germanium, gallium arsenide, and other semiconductor substrate materials.
2.3 Laser Precision Welding
Laser welding uses a laser beam to irradiate material, melting it without vaporization. After cooling, it forms a continuous solid structure. Welding speed is fast, with a high depth-to-width ratio and minimal workpiece deformation. It is unaffected by electromagnetic fields and can weld at room temperature, in vacuum, air, or certain gas environments. It can weld through glass or materials transparent to the beam; weld refractory materials such as quartz and ceramics; weld dissimilar materials; perform micro-welding; and enable non-contact remote welding in
