The destruction of the atmospheric ozone layer is one of the important problems that harm the living environment of human beings. Our government solemn commitment, according to the International Convention on the phasing out of ozone depleting substances (ODS) production and consumption, to 2006 January 1, cleaning industry all stop using CFC-113 (CFC) and 1.1.1- trichloro ethane (TCA). This is information industry is facing the biggest challenge.
The destruction of the atmospheric ozone layer is one of the three global problems that harm the human living environment. The depletion of the ozone layer material phasing out the national plan has been approved by the State Council, China's Government solemn commitment, according to the International Convention on phasing out the production and consumption of ODS consumption of ozone depleting substances), to January 1, 2006 onwards cleaning industry all stop using CFC-113 (CFC) and 1.1.1- trichloro ethane (TCA), this is the information industry enterprises are facing the biggest challenge. According to the spirit of the United Nations Montreal Protocol, at the end of the eighties of the 20th century in the early 1990s industrial developed countries has developed washing technology, semi aqueous technology, non ODS organic cleaning solvents, free cleaning technology etc. four main alternative technology, and has been widely used in the electronic cleaning process.
In these alternative technologies, the equipment investment of washing and half washing is large, covers an area of large, power consumption, water consumption, but also to carry out water treatment and wastewater treatment. If the wastewater is discharged directly, it will cause a new pollution source. And non ODS organic cleaning solvents, the solvent itself cost high, volatile organic compounds (VOC) pollution and working operation safety problems, and HCFC is only a transitional substitute, has been listed as 2040 eventually eliminated all of the cleaning solvent. And free cleaning technology because of its simplified process, reducing the production cost (save the washing equipment and cleaning solvents, but also reduces the amount of flux), saving production man hour, shorten the production cycle, on the environment pollution-free advantages, by all countries widespread attention. Practice has proved that the three kinds of cleaning technology is a transitional phase, in the long run should be preferred free cleaning technology, in order to achieve the purpose finally without the use of ODS, for substitution of ODS cleaning it is one pace reachs the designated position technology. Non cleaning technology in the domestic and foreign electronic products have been the user's trust, has become a recognized alternative to ODS clean the effective way, will be more widely used, is the direction of future development.
Free cleaning technology is a new concept, new technology, different from cleaning. If it is said that when people realize that to improve the importance of the quality of the electronic products, by post weld cleaning development to cleaning is a leap in the wash, then now from cleaning to avoid cleaning will be a new leap, is never backwards, not to reduce the quality of the products for the price. Free cleaning process is compared with the traditional cleaning process, is established in order to ensure the requirements of the quality of the original products based on simplified process is a kind of advanced technology, it is never simply cancel the original cleaning process of cleaning. Free cleaning technology and application of new materials and new technology to achieve before welding is required after cleaning can achieve quality requirements, without cleaning only applies to in some low-end consumer electronics products, while eliminating the need for cleaning process, but relatively lower quality products.
Free cleaning technology, including the free cleaning wave soldering technology and free cleaning reflow soldering technology. The former by the conventional wave welding development and, through the original wave soldering equipment technology upgrading or wave soldering machine, with low solid content, does not contain any halide, after welding, only trace non corrosive residues and post weld surface insulation resistance high cleaning free soldering flux, in order to avoid cleaning effect, mainly to solve the through hole inserting components and mixed joint technology in curing surface components of wave soldering. The latter is an important process in the SMT assembly process, through the use of low solid content, not any halide, after welding, only trace of non corrosive residues. And after welding, insulation resistance of high free clean solder paste and process control to achieve free cleaning effect, mainly to solve the surface mount components of reflow soldering.
Free cleaning technology not only depends on the cleaning free soldering flux (solder paste), but also depends on the welding equipment, components, PCB board, the process and process parameters, process environment, process management, and many other factors. Cleaning free soldering technology is will combine together of materials, equipment, technology, environment and human factors, is a systematic project, its core content: choose the appropriate cleaning free soldering flux (paste), choose appropriate coating process and welding equipment, selection of suitable process parameters, to appropriate process planning and process management, should choose to avoid clean solder wire and supporting etc..
Select the appropriate cleaning flux free (paste)