PCB Board OSP Surface Finish Process
Principle: An organic film is formed on the copper surface of the circuit board to firmly protect the fresh copper surface and prevent oxidation and contamination at high temperatures. The OSP film thickness is generally controlled to be 0.2-0.5 microns.
Process: degreasing → washing → micro-etching → washing → pickling → pure water washing → OSP → pure water washing → drying.
OSP material types: Rosin, Active Resin and Azole. The OSP material used in the deep-connected circuit is the most widely used azole OSP.
Features: flat surface, no IMC formation between OSP film and copper on the circuit board pad, allowing solder and circuit board copper to be soldered directly during soldering (good wettability), low temperature processing, low cost (less than HASL) ), less energy use during processing, and so on. It can be used on low-tech boards or on high-density chip package substrates. PCB proofing board features insufficient points: 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
Storage method and time: vacuum packaging for 6 months (temperature 15-35 ° C, humidity RH ≤ 60%).
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, assembly begins within 48 hours after OSP packaging unpacking; 2 single-sided It is recommended to use within 48 hours after the first piece is recommended, and it is recommended to save it in a low temperature cabinet without vacuum packaging; 3DMT is recommended to complete DIP within 24 hours after completion.