Encapsulation and packaging of biosensor

Smart biosensors integrated with signal processing circuitry have technical advantages for medical diagnostics. The ion-selective field effect transistor (ISFET) biosensor presented in this paper will be used to detect temperature and pH values of liquid solutions, e.g. human serum. To make a contact hole for the sensing area as small as 250 mum times 350 mum on the biosensor chip is one of the challenges for packaging process. The key factors to consider in the biosensors packaging are biocompatibilities, water absorption and chemical resistance. Ceramic substrate as a carrier for the biosensor chip can meet both requirements of biocompatibility and chemical resistance. Two biosensor packaging methods are demonstrated for making a tiny contact hole for sensing area on biosensor chip. The methods of packaging biosensor presented in this paper have combined the lithography process at wafer level and chip-on-board (COB) techniques. The wire bonding and encapsulation techniques are mature processes for microelectronic devices packaging. As the protective material for the sensing area of biosensor were formed in wafer level, these packaging methods will be suitable for use in mass production of biosensor packaging