"Green" and "environmentally friendly" in PCB manufacturing
"Green" and "environmentally friendly" are important signs of PCB manufacturing technology progress. In addition to finding ways to use revolutionary clean production technologies such as printed electronics and 3D printing, improvements in existing PCB manufacturing technologies to clean production are ongoing. Such as looking for alternatives to toxic and hazardous materials, reduce processing steps, and reduce the consumption of chemicals, as well as reduce the use of water and energy, and the recycling of materials, etc..
Specifically, halogen free substrates are used as flame retardants with non-toxic inorganic materials, which also improve electrical properties, thermal conductivity and thermal expansion coefficient. Using direct laser imaging to reduce working procedure and material consumption; The consumption of copper electroplating and etching is reduced by half addition method. Adopt direct metallization hole technology and eliminate toxic and harmful substances in chemical copper precipitation solution; Conductive paste printing is used to clean the connecting hole.
Direct metallization technology has existed for a long time and has matured over the years. Direct metallization processes include carbon black system and conductive polymer system, replacing palladium activation with carbon or graphite and conductive polymer, removing toxic formaldehyde, cyanide and refractory EDTA complexing agent in chemical copper precipitation solution.
The technique of direct hole metallization of colloidal graphite has stable dispersion and good adsorption with various resins. Colloid graphite direct metallization process has been applied in rigid PCB manufacturing for many years. It can be applied to HDI board, flexible board and rigid board with complicated blind hole, buried hole and any interconnect layer.
PCB production process used to be called waste or even hazardous waste, but it is no longer "waste". For example, the surplus copper etching solution, micro-etching treatment solution and electroplating cleaning solution tend to be recycled online. Some new design of production line equipment, etching line or vertical line and horizontal electroplating electroplating line, consider the online recycling device configuration, there are like air knife block reasonable configuration, circulating pump energy saving, automatic analysis add extend the service life of liquid liquid, both to improve quality, and is conducive to energy conservation and environmental protection.