Smif interface

Acronym For Standard Mechanical InterFace.

An Isolation technology developed in the 1980s by group known as "micronauts" at Hewlett-Packard in Palo Alto. The system is used in semiconductor wafer fabrication and cleanroom environments.

Its purpose is to isolate the wafers from contamination by providing a mini environment with controlled airflow, pressure and particle count. SMIF Pods can be accessed by automated mechanical interfaces from production equipment. The wafers therefore remain in a carefully controlled environment whether in the SMIF pod or in a tool, without being exposed to the surrounding airflow.

Each SMIF pod contains a wafer cassette in which the wafers are stored horizontally. The bottom surface of the pod is the opening door, and when a SMIF pod is placed on a load port the bottom door and cassette are lowered into the tool so that the wafers can be removed.

SMIF is typically used for wafers no larger than 200mm, the equivalent for 300mm wafers being the FOUP (Front Opening Unified Pod). The greater flexibility of 300mm wafers means that it is not feasible to use SMIF technology and designs for 300mm, hence the reason for the emergence of FOUPs.