Abstract

Because of interaction of resistor and conductor material and variation of film thickness due to different resistor geometries, square resistance becomes a function of resistor length and width. Additional to the square resistance one paste parameter or two parameters must be introduced if the influence of both length and width on the square resistance is to be taken into account. From resistance measurements of a test pattern all paste parameters can be calculated as numerical functions of resistor length by a computer programme using the method of least squares. Beside the layout of thick film resistors, the data are suitable to give a computer plot of square resistance in relation to length and width. This representation can play an important part in paste evaluation and process control. It shows at a glance what relationship will be present with various combinations of conductor and resistor materials or by changed process conditions.