Separating wafers coated with plastic films

Abstract

The method of protecting micromechanical structures during a wafer fabrication process. A protective layeris deposited to protect the fragile microstructures during a wafer separation process and a post separation cleanup process. Suitable protective layerstypically are plastic and tend to deform or delaminate when the wafer is sawn. The deformation of the protective overcoat during the saw process destroys the structures it is intended to protect. To prevent deformation of the protective layera brittle layeris deposited on the protective layerto hold the protective layer in place during the saw process. Cured photoresist is a suitable protective layer. The photoresist can be applied to the protective layer using standard processes and cured, typically by baking the photoresist. Once the wafer is separated, the brittle layer may be removed. After the debris created during the saw process is removed, the protective overcoat may be removed. The brittle layerand the protective overcoatmay be removed at the same time. The preceding abstract is submitted with the understanding that it only will be used to assist in determining, from a cursory inspection, the nature and gist of the technical disclosure as described in 37 C.F.R. § 1.72(). In no case should this abstract be used for interpreting the scope of any patent claims.