At SGA we have 3 vacuum soldering ovens used for high temperature solders – mainly AuGe and AuSn solders. Whilst soldering usually takes place using vacuum stages combined with inert or activated atmospheres, these machines also have the option to solder completely in a vacuum to obtain low pressure within a device/package. This can be particularly useful for the incorporation of MEMS devices.
Two of the machines are VSU28 models which were recently purchased from Invacu. They are capable of excellent temperature control which has improved our throughput for soldering processes and resulted in fewer rejections for defects such as voids in solder. They allow us to achieve high yield and repeatability in the production of soldered hermetic packages and devices.
The machines are capable of achieving up to 650°C on temperature and pressures down to 1x10-2 mbar and are halogen heated allowing fast ramp rates and process times. They also have auto-refill for formic acid which makes this process safer and less operator dependent.