ENGINEERING ANSWER
Organic solderability preservative can be considered where the assembly process and exposed-copper requirements support it. Its suitability is product-specific and should not be reduced to an arbitrary frequency cutoff.
What to decide before release
Review the number of thermal cycles, handling exposure and the need for contact or test surfaces. Ask whether the planned assembly flow preserves solderability and whether any RF conductors require a different finish strategy.
Checks to put in your design brief
- Confirm reflow and handling conditions
- Identify exposed contacts
- Validate solderability after the intended process
Important distinction
A finish that works for one assembly flow may not survive another flow with additional heat or storage exposure.
Sources & basis
Material facts follow the cited source. Design checks are preliminary guidance, not supplier process instructions.