Low pressure lamination of ceramic green tapes by gluing at room temperature

Abstract

An advanced method to laminate ceramic green tapes is described. In contrast to the well-known thermo-compression method, in which a junction is produced at elevated temperatures and pressures, this method allows the laminates to be produced at room temperature under very low pressures. To aid the joining of the tapes, an adhesive system was utilised: a double-sided adhesive tape, consisting of an acrylate adhesive and a carrier film made of polyethyleneterephthalate (PET). The studies were carried out on two alumina-based green tapes having different grain sizes. The laminates were characterised in the sintered state using a scanning electron microscope. The polymeric reactions occurring during heat treatment were revealed by optical microscopy experiments, thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and viscosity measurements. It was found that for a successful joining, a low viscosity polymer melt is necessary. At elevated temperatures it functions as a flux for the ceramic particles, allowing them to rearrange. Due to capillary actions the flux creates a drag on the ceramic layers, leading to interpenetration and a homogeneous body.