Method of high speed resistor trimming
AssigneeGeneral Radio
InventorMalcolm C. Holtje
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Abstract
This disclosure deals with a novel technique for trimming thin film resistors and the like by continually determining during relatively rapid anodizing whether the resistor has obtained a value greater than or less than a desired value without actually determining the resistance valve, and when the desired value is closely approached, more accurately making the determination while anodizing the resistor more slowly to the desired value.
Claims5
A method of trim-anodizing a thin-film resistor to a predetermined value, that comprises the sequential steps of applying anodizing current to said resistor during an anodizing period, removing said current and providing a settling period, and then determining whether said resistor is greater or less than the predetermined value, said sequential steps being repeated in a cyclic manner with each cycle being principally anodizing and to a minor extent settling and determining;
- and, when said resistor value approaches said predetermined value, automatically modifying such cycle to increase the settling period during the cycle.
Dependencies are inferred from the claim text.