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Laser soldering has attracted attention as an alternative soldering process for microsoldering due to its localized and noncontact heating, a rapid rise and fall in temperature, fluxless and easy automation compared to reflow soldering.

In this study, the metallurgical and mechanical properties of the Sn3.0Ag0.5Cu/Ni-P joints after laser and reflow soldering and isothermal aging were compared and analyzed.

In the as-soldered Sn3.0Ag0.5Cu/Ni-P joints, a small granular and loose (Cu,Ni)6Sn5 intermetallic compound (IMC) structure was formed by laser soldering regardless of the laser energy, and a long and needlelike (Cu,Ni)6Sn5 IMC structure was generated by reflow soldering. During aging at 150°C, the growth rate of the IMC layer was faster by laser soldering than by reflow soldering. The shear strength of as-soldered joints for reflow soldering was similar to that of laser soldering with 7.5 mJ, which sharply decreased from 0 to 100 h for both cases and then was maintained at a similar level with increasing aging time.

Laser soldering with certain energy is effective for reducing the thickness of IMCs, and ensuring the mechanical property of the joints was similar to reflow soldering.

The purpose of this paper is to present a novel laser pointer for manual coating robot teaching. The laser pointer has simple structure and no physical contact with substrate in teaching work. The sensitivity of visual detection in the design accuracy is guaranteed.

The strategy adopts two laser sources to form a triangle to achieve a fixed distance detection pointer for manual robot teaching. After optimizing the source, spot size and the incident angle of the lasers, the sensitivity of fixed-distance judgment is analyzed and compared with traditional pointers. In addition, the laser pointer adds the functions to simulate coating atomizer, including posture and overlap pitch. Finally, the laser pointer verified by coating application and measurement system analysis evaluation.

The laser pointer has been successfully applied to coating robot teaching by the authors’ team. From the simulation and experimental results, it can be concluded that the proposed approach is effective at improving manual teaching of coating robot, especially for the complex geometry.

The main function of the laser pointer often used for manual teaching in other purposes; for example, sealer etc. The paper innovatively considered and tested the laser pointer on robotic coating process.

Compared with the traditional hard straight stick pointer, the paper proposes a very simple construction for teaching pointer with laser feature. At the same time, the requirement of coating process simulation is considered.

Selective laser sintering (SLS) is an essential technology in the field of additive manufacturing. However, SLS technology is limited by the traditional point-laser sintering method and has reached the bottleneck of efficiency improvement. This study aims to develop an image-shaped laser sintering (ISLS) system based on a digital micromirror device (DMD) to address this problem. The ISLS system uses an image-shaped laser light source with a size of 16 mm × 25.6 mm instead of the traditional SLS point-laser light source.

The ISLS system achieves large-area image-shaped sintering of polymer powder materials by moving the laser light source continuously in the x-direction and updating the sintering pattern synchronously, as well as by overlapping the splicing of adjacent sintering areas in the y-direction. A low-cost composite powder suitable for the ISLS system was prepared using polyether sulfone (PES), pinewood and carbon black (CB) powders as raw materials. Large-sized samples were fabricated using composite powder, and the microstructure, dimensional accuracy, geometric deviation, density, mechanical properties and feasible feature sizes were evaluated.

The experimental results demonstrate that the ISLS system is feasible and can print large-sized parts with good dimensional accuracy, acceptable geometric deviations, specific small-scale features and certain density and mechanical properties.

This study has achieved the transition from traditional point sintering mode to image-shaped surface sintering mode. It has provided a new approach to enhance the system performance of traditional SLS.

This paper aims to discuss the effect of surface treatment on the wettability between copper and a lead-free solder paste. The industrial applications of laser technologies are increasing constantly. A specific laser treatment can modify the surface energy of copper and affect the wetting properties.

The surfaces of copper plates were treated using an Nd:YAG laser with varying laser powers. After laser surface treatment, wetting experiments were performed between the copper plates and SAC305 lead-free solder paste. The effect of laser treatment on copper surface was analysed using optical microscopy and scanning electron microscopy (SEM).

The experimental results showed that the wetting contact angles changed with the variation in laser power. Furthermore, it means that the surface energy of copper plates was changed by the laser treatment. The results demonstrated that the contact angles also changed when a different soldering paste was used.

Previous laser surface treatment can be a possible way to optimize the wettability between solders and substrates and to increase the quality of the soldered joints.

Laser milling is a recent process in mould making, providing several advantages over traditional mould making technologies by reducing manufacturing time, shortening the number of machining operations and avoiding expensive electrodes. This paper investigates the influence of the operating conditions on both the surface quality and material removal for two types of materials commonly used in mould making.

Laser scanning strategies and operating parameters like scanning speed and laser frequency and power were tested, regarding surface quality and material removal rate. The most representative parameter of the real surface quality, R_k, the core roughness parameter, is used to characterise the surface finishing on all cavities.

The findings of this research work suggest that it is possible to significantly reduce processing time by increasing the hatch spacing up to a value close to the laser beam spot diameter, without compromising surface quality. Lower pulse frequencies and laser power are more appropriate whenever surface quality is an issue. Higher material removal rates are achieved by increasing both the pulse frequency till an optimum value and laser power. The increase of scanning speed reduces the material removal rate by decreasing the overlap degree between individual laser pulses.

The originality is to correlate the influence of the operating conditions of laser milling on both the surface quality and material removal for different types of materials.

Photoresist imaging traditionally uses silver halide or diazo based phototools for contact exposure to an actinic UV light source. By contrast, laser direct imaging uses digital imaging data to control a laser beam scanner to write directly on to the photoresist, therefore eliminating the need for phototools. In the past, even though the benefit of a UV system was recognised, laser direct imaging was mainly limited to the use of a visible laser as early UV lasers were low in power, unreliable and expensive. So far, no visible systems have gained commercial recognition because of the inherent deficiencies of the visible system. Recent advantages in UV laser equipment and UV sensitive photoresist have now made UV laser direct imaging a viable alternative to traditional contact imaging. As new UV laser imaging systems start to emerge, interest and attention are also growing among printed circuit board manufacturers. This paper discusses various attributes of a UV laser direct imaging system and fundamental differences in photophysics between laser direct imaging and conventional UV imaging.

Conventional processes for cleaning, stripping and surface preparation mainly use solvents or abrasives which can be harmful for the environment, and can also damage the surface of the material. Moreover, the use of these products generates a large quantity of waste that needs to be reprocessed or discarded. In many cases, laser is the solution to these problems. Its possibilities are still under‐exploited but they are growing with the improvement of the performances of the CO₂, YAG and Excimer lasers. This paper describes the laser cleaning process and the benefits which can be obtained.

The latest developments in the use of lasers for welding plastics are reviewed. Lasers were demonstrated as being suitable for welding plastics in 1970. However, it is only now that they are finding wide application following technical developments in transmission laser welding and ClearWeld™, and the availability of small, economic diode laser systems.

The purpose of this paper is to form good cutting qualities in glass-epoxy material for opening flexible areas of rigid-flex printed circuit boards (PCB) by ultraviolet (UV) laser cutting.

The cut width and cut depth of glass-epoxy materials were both observed to evaluate their cutting qualities. The heat affected zone (HAZ) of the glass-epoxy material was also investigated after UV laser cutting. The relationships between the cut width and the parameters of various factors were analyzed using an orthogonal experimental design.

The cut width of the glass-epoxy material gradually increased with the increment of the laser power and Z-axis height, while cutting speed and laser frequency had less effect on the cut width. Optimal parameters of the UV laser process for cutting glass-epoxy material were obtained and included a laser power of 6W, a cutting speed of 170 mm/s, a laser frequency of 50 kHz and a Z-axis height of 0.6 mm, resulting in an average cut width of 25 μm and small HAZ.

Flexible areas of rigid-flex PCBs are in good agreement with the cutting qualities of the UV laser. The use of a UV laser process could have important potential for cutting glass-epoxy materials used in the PCB industry.

Many small holes need to be drilled in printed circuit boards to achieve a high packing density of circuit components. Even with NC control, conventional mechanical techniques are relatively slow and holes smaller than 035 mm diameter are difficult to achieve in production. Laser drilling has been suggested as a potentially fast technique capable of drilling small holes, so trials have been conducted on thin, flexible kapton board, and on 08 mm and 16 mm thick epoxide woven glass fabric board with 12 and 36 micron thick copper cladding. Using a 600 W CO2 laser, the proposed technique was to pre‐etch holes in the copper which would then act as a mask to the beam, so drilling only where etched holes existed. This technique was feasible on the flexible board, but not on the thicker boards because of damage to the copper. Using a pulsed Nd‐YAG laser to drill through both copper and laminate gave good results, but more work is necessary to eliminate occasional delamination of the copper around the hole. Through‐hole plating of the drilled holes appeared to present no special problems.