Method for controlling solder bump height and volume for substrates containing both pad-on and pad-off via contacts

摘要

An method for depositing solder onto the pad-on and pad-off via contacts of a substrate is disclosed. In one embodiment the present invention includes positioning a mask having a first opening of a first diameter and a second opening of a second diameter over a substrate having both pad-on and pad-off via contacts. The substrate is positioned over the substrate such that the first opening is positioned over the pad-on via contact and the second opening is positioned over the pad-off via contact. Solder of a first volume and solder of a second volume are deposited onto the pad-on and pad-off via contacts, respectively, by forcing a solder paste through the mask openings. In this manner, solder bumps having a uniform height and volume above the pad-on via contact plane is established after reflowing the deposited solder.