in a manner so as to cover all the resistant paste dabs but to leave exposed at least a portion of each of the pads the chip resistors were then laser trimmed by use of a laser trimming technique such as disclosed in the e i du pont deneumors amp co publication no e 10690 1 1976 34 laser trimming techniques for thick film resistors 34 a yag laser with a q value of 427 and a power of approximately 1 to 3 watts being employed by this means the resistor chips were trimmed to a resistance of about 1 000 ohms with tolerances of u00b1 0 5 by a still further silk screening step a thin protective epoxy layer of a thickness of approximately 9 microns was applied to all areas of the substrate bearing the chip resistors except the exposed areas of the pads the resultant epoxy layer was then hardened by heating at a temperature of 200 u00b0 c by the use of a laser scribing technique employing a co 2 laser fragmentation lines were scribed in the surface of the substrate between each chip resistor the substrate was then broken into strips of single rows of chip resistors along fragmentation lines separating the rows of chip resistors a number of the strips of the chip resistor were then.