What are the advantages and disadvantages of FPC using OSP process
Aug 29, 2022
Pure copper is easily oxidized if exposed to the air, and the outer layer of the circuit board must have a protective layer. Therefore, surface treatment is required in circuit board processing. OSP is a commonly used surface treatment process. So, what are the advantages and disadvantages of the OSP process of the FPC factory?
What makes OSP different from other surface treatments is that it acts as a barrier between copper and air.
The FPC factory tells you that, simply put, OSP is to chemically grow an organic film on the clean bare copper surface. Because it is organic, not metal, it is cheaper than tin spraying.
The function of this organic film is to ensure that the inner copper foil will not be oxidized before welding. As soon as it is heated during soldering, the film will volatilize, and the solder can weld the copper wire and the components together. However, this layer of organic film is not resistant to corrosion, and an OSP circuit board cannot be soldered after being exposed to the air for ten days.
Advantages and disadvantages of PCB circuit board OSP process
advantage:
With all the advantages of bare copper board soldering, expired boards can also be resurfaced.
shortcoming:
1. OSP is transparent and colorless, so it is difficult to check, and it is difficult to distinguish whether it has been treated by OSP.
2. OSP itself is insulating and non-conductive, which will affect the electrical test. Therefore, the test point must be opened with a stencil and printed with solder paste to remove the original OSP layer, so as to contact the pin point for electrical testing. OSP cannot be used to handle electrical contact surfaces, such as keyboard surfaces for keys.
3. OSP is easily affected by acid and temperature. When used for secondary reflow soldering, it needs to be completed within a certain period of time. Usually, the effect of the second reflow soldering will be poor. If the storage time exceeds three months, it must be resurfaced. Use within 24 hours after opening the package.
