In-mold micro assembly molding technology should be expected to be high efficiency low cost industrialized manufacturing technology of polymer micro-mechanical systems

but how to predict accurately and control precisely thermal-fluid-structure coupling deformation still is its industrialized technical bottlenecks of in-mold micro assembly molding technology. The theoretical prediction model of viscoelastic thermal-fluid-structure coupling deformation in molding process was established based on the boundary constraints of secondary viscoelastic melt filling flow. Research shows that viscoelastic thermal-fluid-structure coupling deformation is controlled by the coupling pressure

viscoelastic supporting normal stress

viscous friction drag shear stress on the micro assembly interface and anti-deformation stiffness

and will reduce with increasing of melt injection speed. The PMMA anti-deformation stiffness in near-surface local region exceeded 393 K will be drastically reduced

which is the key control factor of thermal-fluid-structure coupling deformation reducing with melt injection speed increasing.