When the surface mount pcb assembly, because there are many large equipments in the workshop, such as reflow and wave soldering equipment, there are exhaust and flue gas emission requirements, and the exhaust fan should be configured according to the equipment requirements. For a full hot blast stove, the minimum flow rate for the exhaust duct is generally required to be 500 cubic feet per minute (14.15 m³/min).
Surface mount pcb assembly The air pollution source at the production site mainly comes from the wave generated by wave soldering, reflow soldering and manual soldering. The main components of soot are lead vapor, tin vapor, nitrogen oxides, ozone, carbon monoxide and other harmful gases. Lead vapor is the most serious hazard to human health. Therefore, effective measures must be taken to purify the air at the smt production site. Smoke filters are installed at some stations to absorb and filter harmful gases. Dispose of waste generated in production, such as waste gasoline, ethanol, cleaning fluid, discarded solder paste, patch glue, flux, solder slag, component packaging bags, etc., and hand over to the ability to process and meet The unit of national environmental protection requirements.
"Industrial "three wastes" emission standards" (GBJ4-73): The lead emission concentration of harmful substances is less than 34mg / m³.
"Sanitary Standards for Industrial Enterprises Design" (TJ36-90): The concentration of lead smoke in hazardous substances is less than 0.03mg/m³.
Sanitary Standards for Lead and Inorganic Compounds in the Atmosphere (GB7355-87): The daily average maximum allowable concentration of lead and its inorganic compounds in the living atmosphere is 0.001 5 mg/m³.