SMT producing needs ESD products
What is SMT
SMT is the surface mount technology (Surface Mounted Technology) (abbreviation of Surface Mounted Technology), which is currently the most popular technology and process in the electronics assembly industry.
What are the characteristics of SMT
High assembly density, small size and light weight of electronic products. The volume and weight of chip components are only about 1/10 of that of traditional plug-in components. Generally, after SMT is adopted, the volume of electronic products is reduced by 40%~60%, and the weight is reduced by 60%~ 80%.
High reliability and strong anti-vibration ability. The defect rate of solder joints is low.
Good high frequency characteristics. Reduce electromagnetic and radio frequency interference.
It is easy to realize automation and improve production efficiency. Reduce costs by 30%~50%. Save materials, energy, equipment, manpower, time, etc.
Why use SMT electronic products to pursue miniaturization? The perforated plug-in components used before can no longer be reduced
Electronic products have more complete functions, and the integrated circuits (ICs) used have no perforated components, especially large-scale, highly integrated ICs, so surface mount components have to be used
Mass production of products and automation of production. The factory must produce high-quality products with low cost and high output to meet customer needs and strengthen market competitiveness.
The development of electronic components, the development of integrated circuits (IC), the diversified application of semiconductor materials
Electronic technology ** is imperative, chasing the international trend
SMT basic process components: printing (or dispensing) --> placement --> (curing) --> reflow soldering --> cleaning --> inspection --> repair
Printing: Its function is to print solder paste or patch glue onto the PCB pads to prepare for the soldering of components. The equipment used is a printing machine (a solder paste printing machine), which is located at the *front end of the SMT production line.
Dispensing: Since most of the circuit boards used now are double-sided patches, in order to prevent the components on the input surface from falling off due to the remelting of the solder paste during the second return to the furnace, a dispenser is installed on the input surface, which drops the glue to In the fixed position of the PCB, its main function is to fix the components on the PCB board. The equipment used is a glue dispenser, located at the front end of the SMT production line or behind the testing equipment. Sometimes because customers require that the output surface also needs to be glued, many small factories now do not use the glue machine, if the input surface components are large, manual dispensing is used.
Mounting: Its role is to accurately mount surface mount components to a fixed position on the PCB. The equipment used is a placement machine, located behind the printing machine in the SMT production line.
Curing: Its function is to melt the patch glue, so that the surface mount components and the PCB board are firmly bonded together. The equipment used is a curing oven, located behind the placement machine in the SMT production line.
Reflow soldering: Its function is to melt the solder paste, so that the surface mount components and the PCB board are firmly bonded together. The equipment used is a reflow oven, located behind the placement machine in the SMT production line.
Cleaning: Its function is to remove the solder residues such as flux that are harmful to the human body on the assembled PCB board. The equipment used is a washing machine, and the location may not be fixed, it may be online or offline.
Inspection: Its function is to inspect the welding quality and assembly quality of the assembled PCB board. The equipment used includes magnifying glass, microscope, online tester (ICT), flying probe tester, automatic optical inspection (AOI), X-RAY inspection system, functional tester, etc. The location can be configured in a suitable place on the production line according to the needs of the inspection.
Rework: Its function is to rework the PCB boards that have been detected to be faulty. The tools used are soldering iron, rework station, etc. Configured at any position in the production line.