Abstract: A precision voltage reference comprising an IC chip having a Zener diode connected to the input of an operational amplifier. Variations in output with temperature are minimized by selectively controlling the Zener current in accordance with temperature. The current is controlled by a resistive circuit including a thermistor connected in parallel with the Zener. A method of trimming the voltage reference is provided wherein an optimum quiescent operating current is determined based on voltage and current measurements at two different temperatures.

Abstract: A technique for enclosing microelectronic circuit elements in hermetically sealed packages comprising a planar ceramic substrate with a box-like ceramic cover sealed thereto by a fused glass coating. The glass sealant is applied to the substrate in the form of a paste which thereafter is fired at high temperature and cooled to produce a smooth glass coating. With the cover in place on the substrate, the glass coating is remelted by heat developed by infra-red radiation impinging on all sides of the package structure from heaters in an infra-red furnace. A reflective shield on top of the cover reduces the inflow of heat through that surface, and a heat sink beneath the substrate removes heat, thereby to reduce the temperature rise experienced by circuit elements in the package interior.

Abstract: A hybrid solid state package in which integrated circuits, precision resistor networks, capacitors and their interconnections are accommodated on a multi-layer process substrate while thick film resistors and interconnections provided on a separate substrate, which sub-assemblies are then sandwiched together using film epoxies are inserted within a single package, to thereby yield a structure of significantly smaller size and lighter weight and having minimal number of input-output interconnections as compared with conventional designs and without impairing quality or reliability.