Nov 19, 2004 
A typical pressure sensor will have a Wheatstone Bridge printed onto an area of the steel, such that deflection of the steel either by applied pressure or mechanical force will cause a distortion of the resistors in the bridge and a consequent change in value. This change will cause a detectable output from the bridge.
Extec�s new advancements in steel pressure sensors allow for the particular advantage of e-beam welding to a variety of fixtures to suit any application. This e-beam welding effectively minimizes stress caused to the bridge�s diaphragm and has resulted in exceptional linearity with minimal to zero hysteresis. Frank Bellion, Extec�s Technical Director explains, "When we first saw the linearity results from the steel sensors, we did not believe the graph; it looked as though someone had drawn a straight line and then added the measurement points to it!". Peltier Coolers are another application where Extec has used Thick Film ink technology on steel. Extec has designed and fabricated many Peltier Coolers ranging in size from very small to several inches long to suit a variety of applications. One advantage of these Coolers is that the steel substrate becomes the heat sink, thus removing one layer of thermal resistance. Combining Thick Film printing onto the top face of a Cooler can provide an electronic circuit with its own heat dissipater. Chris Warne, Extec�s Managing Director, states "We have seen an enormous interest in providing tailor-made Peltier Coolers for our customer�s specific applications including Coolers for infrared diodes, high-dissipating electronic circuitry, and even beer dispensing pumps. We have been able to provide custom Peltiers of better efficiency, both in terms of mechanical effectiveness and superior specification, than those available off the shelf."
Another Extec advancement has been to use Thick Film technology to form 3-D structures on ceramic substrate by printing a release-layer as a first-process step. This release layer can cover the entire substrate (if the whole circuit is required to be released) or be printed only under isolated areas (if only parts of the structure are to be released). Printing of the substrate is then carried on as normal until the circuit has been built up, finally allowing the release layer to be removed. The remaining layers may be attached to the surrounding structure forming movable elements, or can be completely released forming a multi-layer circuit only microns thick. John Holliman, Extec�s Principal R & D Engineer, states, "When we discovered that we could release entire structures from the underlying ceramic we were very excited; the applications for this technique in the area of sensors are quite enormous. We have already successfully produced pressure sensors, accelerometers and Carbon Monoxide gas detectors and are finding new applications for our customer�s needs all the time."
Perllo, founded in 2002, is headquartered in St. Charles, Illinois. The company specializes in engineering design, manufacturing, product management, transportation, and warehousing to provide our clients the best possible product, service and delivery. For additional information, please visit our website: http://www.perllo.com.
Extec Integrated Systems was formed in 1986, and is headquartered in the United Kingdom. The company is an expert in providing design and manufacturing of Thick Film Hybrid microcircuits. With a strong emphasis on engineering, Extec is also able to offer innovative new products including ultra fine-line technology, power and optical products. For addition information, please visit http://www.extec.uk.co.
