A Random Trimming Approach for Obtaining High-Precision Embedded Resistors

Embedded resistors will potentially allow electronic applications to cost less and perform better. However, it is difficult to fabricate embedded resistors to the correct resistance value, so embedded resistors are often fabricated with a lower value and then trimmed to raise the resistance to the desired value. A computer simulation for the trimming process of an embedded resistor has been developed that has been verified and calibrated against experimental results. A study of embedded resistors containing random voids of varying size has been performed. A new trimming strategy in which the trims are made randomly (rather than conventional L-shaped trims) is proposed and the results of the analysis demonstrate that single-dive trimming combined with random trimming allows higher precision embedded resistors to be obtained than conventional trimming patterns.