• Control of bypass cycle
• Monitoring vacuum

Wafer bonding is a procedural step in semiconductor technology, in which two wafers are joined. For certain applications, such as the encapsulation of chip sensors, this process takes place in a vacuum.

Requirements

After loading, the bond chamber is first evacuated via a bypass by the backing pump. Once a set vacuum level is reached, a smooth switchover to the high vacuum pump follows. The actual bonding process is then performed under high vacuum conditions. During pump-down, the absolute pressure in the bypass-line must be accurately controlled in order to prevent damage to the high vacuum system. Whilst the actual bonding process, the vacuum inside the chamber must also be monitored to ensure the desired results.

Suitable Products

VSC43MA4: Bypass control is performed with a VSC43MA4 rough vacuum transmitter. The ceramic sensor measures pressure with the required accuracy and is virtually maintenance-free.

VSM: The process pressure is measured by a VSM vacuum transmitter from the Smartline product family with a sensor combination of Pirani and cold cathode.