OSP PCB process also very complex

Organic Solderability Preservative, or OSP is a method for Coating printed circuit boards. 
PCB OSP process means the Printed Circuit Boards' Organic Solderability Preservative process.
Circuit boards making is a very complex process.
Some the reason is during to Organic Solderability Preservative process very complex.
Not only during to Organic Solderability Preservative requires many steps.
But also the OSP technology.

If your purchaser choose one new PCB supply.
Even OSP is very normal surface finish types.
No produce experience may can't produce OSP park PCBs.

HTD circuits as a leading PCB manufacturer from China, have rich experience in OSP finish PCBs.
Experience PCB OSP process engineers introduce Jim many informantion of this process.
But during the article limited.
I just share you something I think very important of the PCB OSP process.

First is using film cover the PCBs during the PCB OSP process.
Open small window in the surface finish process.
This process design may by the PCB designer.
Because most of open window must match the circuit board wires or pads.

Second is the theory of PCB OSP process.
In fact this point we also mention before.
But not related to the detail PCB OSP process.
It uses a water-based organic compound that selectively binds to copper and protects the copper until soldering.
And this point is a very important factor, also very complex for the production PCB OSP process.

Third factor is the detail operation of the PCB OSP process.
During to the first fact fine cove the circuit boards.
So the water-based organic compound can only work in the open window.
It comprises the small local deviations of a surface from the perfectly flat ideal (a true plane).