C4NP Toolset
The tools described below are for full production capability of 150 wafer starts per day. A semiautomatic version is also available which is especially suited to process development work.
Mold Preparation
With the SUSS MFT (Mold Fill Tool), molten solder is filled into the cavities of the empty mold. The mold is a glass plate into which cavities have been etched representing the desired bump pattern for the wafer. The filled mold is then inspected by the SUSS MIT (Mold Inspect Tool) which uses a Cognex-based system to detect defects such as missing bumps. There is the possibility to repair defects (e.g. replacing a bump) before continuing to the transfer station.
Solder Transfer
In one easy step, the wafer with the Under Bump Metalization (UBM) is aligned to the filled mold, both are then heated slightly so that the solder balls up and then brought into close proximity for the transfer. A full production STT (Solder Transfer Tool) system has multiple transfer stations in one machine to enable 150 wafers to be bumped per day.
Mold Storage
Pre-Filled Molds can be stored ready for Solder Transfer to wafer whenever required, making the technology even more flexible. Various options and sizes are available
