Critical issues, processes and solutions in ISFET packaging

Purpose - To provide an insight of the intricacies of ion-sensitive field-effect transistor (ISFET) encapsulation and describe the presently available packaging solutions, indicating how the packaging requirements can be complied for various applications. Design/methodology/approach - ISFET packaging is a complete subject in itself. The paper includes examples of the different packaging strategies that have been offered by literature and company findings over the past few decades. Findings - ISFET packaging has progressed from the initial epoxy embedding of the wire bonds and contact pads to the more sophisticated techniques capable of automation wherein moulds are made for epoxy coating or the chip is tightened between contacting parts using elastomer gaskets. Research limitations/implications - The emerging packaging technologies have succeeded in making chip packaging more a science than an art, and the new methods are capable of large-scale manufacturing with greater precision. Practical implications - Packaging solutions for demanding applications of ISFETs have been provided by the upcoming technologies. Originality/value - The information provided in this paper is of immense value to researchers working on ISFET encapsulation.