Methods and pad structures to test via accuracy are provided. A method according to the present disclosure includes forming a first pad and a second pad on a device component, wherein the second pad includes a via landing area and a clearance opening, providing a core substrate that includes a cavity, placing the device component in the cavity, forming a build-up film over the device component and the core substrate, forming a first contact via extending through the build-up film to contact the landing area and a second contact via extending through build-up film and the clearance opening, and performing a continuity test to determine whether the second contact via is in contact with the second pad.