Micro-assembly technology is a high-density electronic assembly technology that utilizes connection and packaging processes on high-density multilayer interconnection circuit boards to assemble micro-small electronic components into high-density, high-speed, and high-reliability three-dimensional electronic products. The volume of these products is significantly smaller than conventional electronic products, and the reliability is also greatly improved due to the reduced number of solder joints.
The key to SMT lies in surface mount components, which include chip resistors, chip trimmer potentiometers, chip tantalum electrolytic capacitors, chip inductors, surface mount tactile switches, surface mount connectors, integrated circuits, hybrid integrated circuits, and more.
Currently, the development direction of surface mount components focuses on miniaturization and high performance, including high power, high precision, large capacity, high reliability, long life, and high frequency. For example, integrated circuits utilizing the four-side pin flat package (QFP) have achieved a minimum lead center distance of 0.5mm, with some devices featuring 0.406mm and 0.305mm distances in limited quantities. Chip tantalum electrolytic capacitors utilize 60000CV/g tantalum powder, with a capacity of 33μF and 1000 cycles of temperature at -55～+125℃, as well as high temperature and humidity characteristics of 85℃, 90%RH. Surface-mounted integrated circuits have seen rapid development in recent years, with various packaging forms such as four-side pin flat packages, thin small outline packages, and dual in-line packages.
As high-density, high-function, and high-speed circuit components continue to evolve, electronic components are moving towards greater micro-miniaturization and multi-pin narrow-pitch requirements, demanding more refined and precise SMT technology with controlled development. The surface mounting process encompasses soldering technology, placement equipment, and the design and production of printed circuit boards.
Soldering is a crucial process in circuit assembly technology that impacts the reliability of circuit components and enables narrow pitch technology. New welding processes developed in recent years include convection infrared reflow welding, vapor phase reflow welding, tool reflow welding, laser reflow welding, wash free soldering, vacuum reflow soldering, lead-free solder, and corresponding soldering technologies.
The placement machine is the most challenging and costly key equipment in the surface mount production system. Large-scale placement machines suitable for mass production of consumer electronics products can achieve mounting speeds of 0.1-0.4 seconds per component, with placement accuracy reaching ±0.01mm. With the addition of a CCD optical camera correction system, accuracy can extend to ±0.005mm.
Printed circuit boards not only serve as carriers for electronic components, interconnection lines, pads, and more, but also aid in heat dissipation. With the advancement of surface mounting technology for printed circuit boards, a trend towards high density, high frequency, ultra-thin designs has emerged, prompting changes in corresponding design and production technologies. Computer-aided design technology is widely utilized for automatic design processes, including circuit diagram network lists, digital input operations, component shape database creation, pad inspection, and computer-aided manufacturing data output operations.
Computer integrated manufacturing system technology has been implemented in surface mounting technology, while other key technologies related to printed circuit boards include wiring and plate making, metallization technology, holeization technology, lamination technology, and material technology. The screen printing machine is a vital equipment in surface mounting technology.
The key to SMT lies in surface mount components, which include chip resistors, chip trimmer potentiometers, chip tantalum electrolytic capacitors, chip inductors, surface mount tactile switches, surface mount connectors, integrated circuits, hybrid integrated circuits, and more.
Currently, the development direction of surface mount components focuses on miniaturization and high performance, including high power, high precision, large capacity, high reliability, long life, and high frequency. For example, integrated circuits utilizing the four-side pin flat package (QFP) have achieved a minimum lead center distance of 0.5mm, with some devices featuring 0.406mm and 0.305mm distances in limited quantities. Chip tantalum electrolytic capacitors utilize 60000CV/g tantalum powder, with a capacity of 33μF and 1000 cycles of temperature at -55～+125℃, as well as high temperature and humidity characteristics of 85℃, 90%RH. Surface-mounted integrated circuits have seen rapid development in recent years, with various packaging forms such as four-side pin flat packages, thin small outline packages, and dual in-line packages.
As high-density, high-function, and high-speed circuit components continue to evolve, electronic components are moving towards greater micro-miniaturization and multi-pin narrow-pitch requirements, demanding more refined and precise SMT technology with controlled development. The surface mounting process encompasses soldering technology, placement equipment, and the design and production of printed circuit boards.
Soldering is a crucial process in circuit assembly technology that impacts the reliability of circuit components and enables narrow pitch technology. New welding processes developed in recent years include convection infrared reflow welding, vapor phase reflow welding, tool reflow welding, laser reflow welding, wash free soldering, vacuum reflow soldering, lead-free solder, and corresponding soldering technologies.
The placement machine is the most challenging and costly key equipment in the surface mount production system. Large-scale placement machines suitable for mass production of consumer electronics products can achieve mounting speeds of 0.1-0.4 seconds per component, with placement accuracy reaching ±0.01mm. With the addition of a CCD optical camera correction system, accuracy can extend to ±0.005mm.
Printed circuit boards not only serve as carriers for electronic components, interconnection lines, pads, and more, but also aid in heat dissipation. With the advancement of surface mounting technology for printed circuit boards, a trend towards high density, high frequency, ultra-thin designs has emerged, prompting changes in corresponding design and production technologies. Computer-aided design technology is widely utilized for automatic design processes, including circuit diagram network lists, digital input operations, component shape database creation, pad inspection, and computer-aided manufacturing data output operations.
Computer integrated manufacturing system technology has been implemented in surface mounting technology, while other key technologies related to printed circuit boards include wiring and plate making, metallization technology, holeization technology, lamination technology, and material technology. The screen printing machine is a vital equipment in surface mounting technology.
