" Conductive Adhesives – the High Tech Solution in Medical Electronics

Conductive inks and adhesives were used in the earliest electronics. Thomas Edison was the first to propose conductive adhesives as a way to replace wires all the way back in 1904. Today, adhesives are used with conventional etched copper circuit boards and also with other Polymer Thick Film (PTF) materials to produce electronic products that can be built very efficiently. Safe, reliable and low cost circuitry is being manufactured in high volume by printing conductors, resistors and dielectrics onto all kinds of substrates. Thin, pliable and extremely versatile flex circuits are efficiently made with PTF technology using film substrate. However, the temperature-sensitive nature of many plastic films precludes soldering. Conductive adhesives have become the ideal joining solution. The complete system of various types of polymer-based inks and adhesives make up today’s state-of-the-art Polymer Thick Film Technology Modern medical electronics has embraced PTF during the past few years with great success, especially in the disposable product area. Given the choice of etched copper and solder vs. non-toxic PTF, many designers have selected the polymer-based approach. Electronic blood-oxygen sensors, for example, are now built using PTF flexible circuits with components assembled employing conductive adhesives. Such products, produced efficiently in high volume, are used extensively in the medical world. Reliable and accurate oxygen level sensing is provided for both routine and lifethreatening medical situations. PTF-based medical products have an excellent record here. Several other medical sensors and input devices are also beginning to use PTF. This paper will review the progress made in PTF technology with a focus on conductive adhesives and discus its use especially as applied to the medical field. Advantages and limitations will be highlighted with case histories used for examples. First, we will provide the background to help you better understand and appreciate Polymer Thick