Linked Electronics sometimes receives quality compliant from customer that the vias colors on the PCB board turns red.

See above picture please.

This is not quality issue. 

The vias is open,the and soldermask is liquid condition during soldermask process. 

When the soldermask is printed on the PCB board and the soldermask around the vias will fall inside the holes and the soldermask will be very thin around the vias. In this way, the color around the vias turns red. And this is unpreventable in PCB Board manufacturing industry.

But we can do a little bit change for the holes to prevent this. 

If you do not accept this.

Please ask our engineer or sales team to change vias open to vias plugged. 

For traditional PCB Factories, they will ignore your vias requirement, if gerber files are uploaded. Their engineer will just follow your gerber files. But at Linked, we are different, if you have any special requirements for the vias, such as vias open, vias tented or vias plugged, just let us know, our engineer will follow your request.

If you do not accept vias to be red color, please ask us to plug the vias, thank you!

And please design the vias size smaller than 0.5mm or else it will not be fully plugged and you will see vias turn red too.

Contact Linked Electronics and discuss about your PCB demand today.