1.3 SMT production line toward "green" direction of people's lives today Earth has been met with people of different degrees of damage, based SMT equipment, SMT production line as part of industrial production, without exception, will destroy our environment. SMT process from packaging materials, electronic components, glue, solder paste, flux and other materials to the production process of the SMT production lines, all to the environment such as pollution more SMT production line, the greater the scale of this pollution more serious, therefore, the latest SMT production lines are moving in the direction of development of green production line. Green production line concept refers to the beginning of the SMT production, we must consider the environmental requirements and analysis of pollution sources and pollution levels will appear in the SMT production, to select the appropriate SMT equipment and processes, materials, and formulate appropriate process specifications in a timely , scientific, rational approach to management to maintain the operation of the management of SMT production lines to meet production requirements and environmental requirements. This suggests that SMT production line not only to consider the scale of production and production capacity, but also consider the environmental impact of SMT production, designed to build line from SMT, SMT equipment selection, process materials, environmental and logistics management, process waste disposal and a full range of process management, and take full account of the requirements of environmental protection. Green production line is also the future direction of development of the SMT production line.
SMT equipment, updating and development of the SMT equipment represents the level of surface mount technology, the development of new SMT equipment towards efficient, flexible, intelligent, and environmental protection direction.
2.1 screen printing equipment, solder paste printing is one of the key processes in SMT production, and control directly affects the quality of the pcb board assembly. Currently showing a new technology:
(1) closed-end printing technology. Traditional solder paste printing process, solder paste prolonged exposure in an open environment is an important reason to cause printing defects. MPM flow pump "print head can effectively solve the above problem, its working principle is shown in Figure 2. Rolling in an open environment with the solder paste and solder paste rheological pump is installed in the sealed printing head, the only hole solder paste before contact with the stencil, standard solder paste package folder tube by applying pressure to fill the paste, and dynamic pressure, the paste into the openings. "Rheology pump" technology to fundamentally eliminate the solder paste printing variable factors, so that users do not need to consider printing an intermittent or machine time to get satisfactory results.pcb assembly services in China.