PCB board OSP surface treatment process principle and introduction
Principle: An organic film is formed on the copper surface of the circuit board to firmly protect the surface of fresh copper and prevent oxidation and contamination at high temperatures. The OSP film thickness is generally controlled to be 0.2-0.5 microns.
1. Process: degreasing→water washing→micro-etching→water washing→acid washing→pure water washing→OSP→pure water washing→drying.
2. OSP material types: Rosin, Active Resin and Azole. The OSP material used in the deep-connected circuit is the currently widely used azole OSP.
What is the surface treatment process of PCB board OSP?
3, characteristics: flat surface is good, there is no IMC formation between the OSP film and the copper of the circuit board pad, allowing the solder and the circuit board copper to be directly soldered during soldering (good wettability), low temperature processing technology, low cost (low In HASL), less energy is used during processing. It can be used on low-tech boards or on high-density chip package substrates. PCB proofing excellent board tips: 1 visual inspection is difficult, not suitable for multiple reflow soldering (usually required 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 acid-filled environment, OSP packaging began to assemble within 48 hours after unpacking; 2 After the single-sided parts are recommended to be used within 48 hours, it is recommended to use a low-temperature cabinet to save without vacuum packaging; 3SMT is recommended to complete DIP within 24 hours after completion.