Direct bonding of organic materials

Direct bonding of polymethylmethacrylate (PMMA) is described as an example of the applicability of direct bonding to organic materials such as polymers. Direct bonding of a PMMA wafer to itself and to silicon and fused silica wafers is realized. At room temperature, the value of the bond energy indicates the presence of weak chemical interactions at the bonded interface. Heating a bonded PMMA/PMMA wafer pair to the glass transition temperature of PMMA (105 °C) and higher temperatures causes the two surfaces to fuse and the interface to become bridged by polymer chains.