PCB chemicals face new challenges

- Aug 18, 2018-

The application of new materials, the limitation of RoHS on hazardous substances, the requirements of lead-free welding and repeated reflow welding, as well as the requirements of energy conservation and emission reduction of green production, make the chemical potion applied in the PCB production process with the largest proportion -- from the oxidation of the inner layer to the final coating on the surface -- more than 20 processes face new changes and challenges.1. The chemical solution provided must meet the requirements of various specifications of green products such as WEEE and RoHS at home and abroad, without any banned substance.The corresponding test/inspection report that meets the requirements must be provided.The original lead and cyanide solutions must be updated, such as the development of non-cyanide gold, lead-free nickel, formaldehyde-free and EDTA(EDTA) systems of chemical precipitation copper products.

2. Application of various types of materials such as halogen free materials, low CTE(thermal expansion coefficient) materials and high Tg(glass state conversion temperature), traditional black oxygen and brown oxidation processes are difficult to ensure that halogen free materials can be provided through multiple lead-free reflux welding, and oxidation post-treatment and new oxidation processes will be the best choice.The substrate containing various filling materials and high Tg materials pose a challenge to the plastic slag and chemical copper sinking technology. The existing product technology must be improved to completely remove the plastic slag of borehole, improve the coverage rate of chemical copper sinking and the binding force with the hole wall.The direct electroplating process for pore-metallization of palladium system can not only adapt to various materials, but also have high coverage and reliable interconnection of inner layers. Moreover, it does not contain formaldehyde, EDTA and cyanide, which is one of the best choices for green production.

3. Lead-free and lead-free high-temperature welding and repeated reflow soldering require the surface coating of PCB to be lead-free, and it still needs to have good soldering performance after high-temperature welding and repeated reflow soldering.The traditional lead HASL(hot air solder leveling) process will be completely replaced by lead free HASL, OSP(organic solder shielding), chemical nickel gold, chemical nickel palladium, chemical tin and chemical silver.At the same time, OSP, chemical tin and chemical silver products and processes are being improved to meet the requirements of high-temperature lead soldering and multiple reflow soldering.

4. The development of new chemical products and optimize the process to reduce the technological process, improve product quality in order to achieve the requirements of energy conservation and emissions reduction, waste minimization, hole metallization process of conductive polymer formaldehyde-free and EDTA not only, and does not contain any metal such as copper and complexing agent, easy to clean, less waste water discharge and easy to handle, so as to truly achieve the goal of green production.The four-price tin recycling and two-price copper treatment system of chemical tin process can not only reduce the discharge of waste liquid by 50%, but also stabilize the quality, high product qualification rate and reduce the production cost by 30%.

5. Develop physical methods or physical plus chemical methods to meet the requirements of green production, such as printing technology, nano technology, etc