Abstract: An array for light-detecting diodes is inserted into a cavity in an electally insulating substrate with trimmable resistances on the substrate. The substrate is cooled, the diodes are connected to the resistances and are energized via electrical conductors on the substrate and in the cavity, and their individual near infrared light detectivities are measured. The resistors are trimmed by a laser beam such that all diodes have the same amount of detectivity. The substrate is allowed to return to ambient temperature, is mounted on a cold finger, and electrical conductors are made between the resistance-diode combinations and connectors on the cold finger.

Abstract: A modular trim resistive network providing adjustable in-circuit resistance. The network essentially consists of multiple parallel connected single or double branched series divided resistive elements of which the elements may be separate and distinct or diffused onto or into the surface of an integrated circuit. In either instance the elements are interconnected by conductive leads in such a manner that the selective severing of various leads results in the desired matching network resistance.