PCB Chemical Reagents Face New Challenges
The application of new materials, RoHS restrictions on hazardous materials, lead-free soldering and multiple reflow soldering requirements, as well as energy-saving emission reduction requirements for green production, make the most important chemical syrup applied in the PCB production process - from More than 20 processes, such as oxidation of the inner layer to the final coating of the surface, are facing new changes and challenges.
1. The chemical syrup provided must meet the requirements of various specifications of domestic and foreign green products such as WEEE, RoHS, and does not contain any prohibited substances. A corresponding inspection/inspection report must be provided that meets the requirements. The original lead and cyanide-containing syrup must be renewed, such as the development of products such as non-cyanide gold, lead-free nickel, formaldehyde-free and chemical-free copper without EDTA (ethylenediaminetetraacetic acid).
2. Halogen-free materials, low CTE (thermal expansion coefficient) materials and high Tg (glass transition temperature) applications of various types of materials, the traditional black oxygen and brown oxidation process is difficult to ensure that halogen-free materials can be provided multiple times Lead-free reflow soldering, post-oxidation processing and new oxidation processes will be the best choice. Substrates containing various filler materials and high Tg materials, in addition to challenging the slag and chemical copper deposition process, must improve existing product processes to completely remove the drill slag, improve the coverage of the chemical immersion copper and the walls of the hole The combination of strength. The pore metallization direct plating process of the palladium system is not only suitable for various materials, but also has high coverage and high reliability of inner layer interconnection, and does not contain formaldehyde, EDTA and cyanide, and is one of the best choices for green production.
3. Lead-free and lead-free high-temperature soldering and multiple reflow soldering requirements PCB surface coating must be free of lead, and still have good solderability after high temperature soldering and multiple reflow soldering. The traditional leaded HASL (hot air solder leveling) process will be completely replaced by lead-free HASL, OSP (organic solder protection), chemical nickel gold, chemical nickel palladium gold, chemical tin and chemical silver. At the same time, in order to meet lead high temperature welding and multiple reflow soldering, the products and processes of OSP, chemical tin and chemical silver are also constantly improving.
4. Develop new chemical products and optimize processes to reduce process flow and improve product quality to meet energy saving, emission reduction and waste reduction requirements: The metallized hole process of conductive polymer is not only formaldehyde-free and EDTA-free, and does not contain any metal ( Such as copper) and complexing agents, easy to clean, less waste water discharge and easy to handle, thus truly achieving the goal of green production. The chemical tin process of tetravalent tin regeneration and divalent copper treatment system can not only reduce the waste liquid discharge by 50%, but also the quality is stable, the product qualification rate is high, and the production cost can be reduced by 30%.
5. Develop physical methods or physical plus chemical methods to meet the needs of green production, such as printing technology, nanotechnology, etc.