Investigation of a Capacitor Array of a Composite Capacitive Touch Panel

Abstract

The work is devoted to studying a capacitor array of sensor and contactless identifier entry devices of the capacitive type on the example of sensory devices made from composite silver-containing materials on a ceramic substrate. The theoretical investigations involve calculations of the topology of the capacitor arrays, in particular, improved dimensions of the segments (3.5 × 3.5 mm) and the arrangement of array layers with the aim of more exactly recognizing input objects, reducing the malfunction of the controller, and increasing the electromagnetic pickup tolerance. In addition to searching for the dimensional parameters, the electrophysical parameters of the capacitive panel under study, namely, voltage, capacitance of 1.8 nF in the case of a matrix with square segments and 2.3 nF in the case of a matrix with round segments, and the charge before and after approaching the input objects (6 and 7 nC, respectively), are measured and calculated. Experimental investigations of the capacitor arrays are carried out, according to which it is determined that a round shape of the segments is preferable in order to increase the linearity of the dependence of the distance of the input objects from the centers of the sensor segments. It is also more effective to locate the integrated plate of a capacitor array from the bottom rather than the top. In this case, the set of holes in the array layers becomes unnecessary. The results of the calculations of the dimensional and electrophysical parameters and their experimental measurements help in the design of topologies of the arrays of the sensor elements of capacitive touch panels from materials which are an alternative to indium and tin oxides (ITOs) (silver nanowires, graphene, polymers, foil, silver-containing organic composites, etc.), as well as in the design of ADT diagrams and controllers for them.