Why was my circuit area identified as a via opening design error?

It is possible that in the Gerber files you submitted, we noticed that some of the traces have also been exposed through the solder mask, just like the pads. From an engineering perspective, this approach is not recommended, so the order will be blocked during the engineering review stage.

In simple terms, the system identified that "the entire copper line is not covered by solder mask", not just the pad opening. This is usually considered to be risky.

Usually, areas such as regular wiring, conductors, and text should be protected by solder mask ink. If the entire wiring section is completely exposed, it will easily oxidize and turn black, and over time, this will affect the electrical performance and reliability of the board.

PCBasic suggests:

Please only open the solder mask for the solder pads that require soldering. Do not expose the entire traces. If this design is intentionally done by you, please clearly inform your PCBasic sales representative, “this is not a file error, but your process requirement. “ After confirming the risks, we can produce according to the original Gerber files you submitted.