Sources of VOC in the electronics industry

The electronics manufacturing industry can generally be divided into several major parts, including electronic components and parts, printed circuit boards, vacuum devices, semiconductor manufacturing (semiconductor discrete devices and integrated circuits), flat panel displays, and electronic terminal product assembly.
Electronic components are the foundation of the electronics industry, and products include capacitors, resistors, potentiometers, electrical connection components, control components, as well as sensitive components and sensors. There are many types of electronic component products, and the structures and production processes vary greatly. The processing technology generally involves a combination of multiple processes such as machinery, chemicals, thermal processing or formulation. The main volatile organic pollutant emissions from electronic components come from some volatile organic solvents such as toluene and xylene used to clean parts or materials during the production of electronic components.

Circuit boards are basic products of the electronics industry and are widely used in high-tech fields such as computers, communication network equipment, new display products, and new generation audio-visual products. Circuit boards are divided into flexible circuit boards and rigid circuit boards. Typical production processes for circuit boards include:substrate cutting, drilling, copper deposition, graphic electroplating, etching, solder mask printing, text printing, tin spraying, and other processes. The organic waste gas in the production process of circuit boards mainly comes from the large amount of ink used and the volatile organic compounds used for dilution and cleaning, and its main components are benzene, toluene and xylene.

The electric vacuum device is mainly represented by CRT color picture tubes. The production process of electric vacuum devices can be divided into parts purification, parts coating, electrode manufacturing, welding, sealing, assembly, sealing, exhaust, aging and testing. The volatile organic compounds produced by electric vacuum devices mainly come from the emission of toluene and other volatile organic compounds in the organic film coating of the screen glass.

Flat panel display devices (FPD) mainly include TN/STN-LCD, TFT-LCD (thin film transistor liquid crystal display device) and PDP (plasma display device). The manufacturing process of TFT-LCD mainly consists of array preparation, color filter preparation, liquid crystal box preparation and module assembly. A variety of chemical reagents and organic solvents are used in the production process of TFT-LCD. The waste gas discharged from the production of TFT-LCD is divided into four types:acidic gas, alkaline gas, organic waste gas and toxic gas. It is mainly produced in the main process of substrate cleaning, chemical vapor deposition (CVD), photolithography, etching, stripping (stripping), and coating of oriented films.

Electronic terminal products are divided into electronic computer products, communication products, home audio-visual products, instrumentation and equipment products, and other products. The assembly of electronic terminal products mainly includes the preparation of electronic components, surface mounting of printed circuit boards (PCBs), testing, aging, packaging, assembly of complete machines, and product debugging. The main sources of volatile organic compounds in the assembly of electronic terminal products are organic waste gas from cleaning and paint mist and volatile organic compounds generated during the product spray painting production process.