Methods are described for addressing the bowing and/or warping of flexible substrates, attached to a rigid carrier, which occurs as a result of the thermal challenges of semiconductor processing. In particular, viscoelastic adhesives are provided which can bond a flexible substrate to a rigid carrier and mediate the thermal mismatch which often is present due to the distinctly different materials properties of most flexible substrates, such as plastic films, with respect to rigid carriers, such as silicon wafers. Assemblies are also provided which are produced according to the methods described herein.