Micro-injection moulding: Factors affecting the replication quality of micro features

Abstract

Micro-injection molding is one of the key technologies for micromanufacture because of its mass-production capability and relatively low component cost. The surface quality in replicating microfeatures is one of the most important process characteristics and constitutes a manufacturing constraint in applying injection molding in a range of micro-engineering applications. This chapter investigates the effects of three processing and one geometric factors on the surface quality of microfeatures in three different polymer materials. The factors considered are barrel temperature, mold temperature, injection speed, and placement density of microfeatures. The mold temperature is set in the conventional range. This investigation reveals that, in general, increasing the barrel temperature, mold temperature, and the injection speed improves the polymer melt fill in microcavities. However, the effects of these factors on the process replication capabilities are not consistent for different polymer materials and could be adverse in specific conditions. Varying the placement density of microfeatures does not affect the melt fills.