Integrated circuits contg. thick and thin films - where ceramic substrate is coated by screen printing with thick film conductors and resistors, and then with thin films by electroplating

摘要

The screen printing of a substrate is employed to deposit both a thick film conductor pattern and thick film resistors both being baked. A photolacquer mask (I) is then applied to part of the structure, followed by sputter etching for cleaning, and depositing a layer (II) aiding the adhesion of a conductor layer (III). A second photolacquer mask (IV) is deposited, and electroplating is used to thicken layer (III), thus obtaining a thick Cu layer, and also to deposit a metal preventing corrosion and used for making joints to bonding wires. An organic solvent and ultrasonic energy are next used to remove the two photolacquer masks (I), (IV), so that the zones of layers (II), (III) resting on mask (I) are also removed. Layer (II) is pref. 90% W, 10% Ti, and ca. 1200 angstroms thick. Thick film resistors occupying small areas can be deposited and integrated with other components.