PCB board OSP surface treatment process principle and introduction
Principle: An organic film is formed on the copper surface of the board to firmly protect the surface of fresh copper from oxidation and contamination at high temperatures. The OSP film thickness is typically controlled to be between 0.2 and 0.5 microns.
1. Process: degreasing → water washing → micro etching → water washing → pickling → pure water washing → OSP → pure water washing → drying.
2. OSP material types: rosin, reactive resin and azoles. The OSP material used in the deep connection circuit is the azole type OSP currently widely used.
What is the surface treatment process of the PCB board OSP?
3, characteristics: good plane, no IMC formation between OSP film and circuit board pad copper, allowing welding and circuit board copper to be directly soldered during soldering, low temperature processing technology, low cost (low HASL ), using less energy during processing. It can be used for low-tech boards or high-density chip package substrates. Excellent proof of PCB proofing: 1 visual inspection is difficult, not suitable for multiple reflow soldering (usually three times); 2OSP film surface is easy to scratch; 3 storage environment requirements are higher; 4 storage time is shorter.
4, storage method and time: vacuum packaging for 6 months (temperature 15-35 ° C, humidity RH ≤ 60%).
5, SMT site requirements: 1OSP circuit board must be stored in low temperature and low humidity (temperature 15-35 ° C, humidity RH ≤ 60%) and avoid exposure to acidic environment, start assembly and unpacking within 48 hours after OSP packaging; 2 recommendations After using single-sided parts within 48 hours, it is recommended to use a low temperature cabinet without vacuum packaging; 3SMT recommends completing DIP within 24 hours of completion.