Abstract: A method of forming thick film resistor circuits whereby a non-hole metal, such as copper, requiring a reducing atmosphere is included with resistor material requiring an oxidizing atmosphere. A fritless conductor paste with a small percentage of silver is deposited and fired in air at a low temperature. Resistors are then deposited and fired in air. Subsequently, the conductor material is reduced at a sufficiently low temperature so as not to adversely affect the resistors.

Abstract: A method of forming thick film resistor circuits whereby non-noble metals (11, 12) requiring a reducing firing atmosphere are included with resistor material (13) requiring an oxidizing atmosphere. The conductor metallization is capable of adhering to the substrate at a low firing temperature in air. The resistors are printed and fired in air after conductor formation. The metal oxide can then be reduced at a sufficiently low temperature so as not to significantly affect the resistor material. In one embodiment, the conductor paste includes copper and glass frits which can adhere to a ceramic substrate by firing at a temperature of less than 1100 degrees C.

Abstract: Disclosed is a method of fabricating bi-level circuits which include metallization of via holes (14 and 15) in insulating subustrates (10). A thick film metal paste (13) is prepared which according to one embodiment comprises copper, glass frit and an organic vehicle including a low molecular weight ethyl cellulose binder and solvents of butyl carbitol acetate and alpha terpineol. The paste is deposited onto the substrate and through the holes. The structure is baked with the printed surface (12) down in order to establish a solvent concentration gradient in the paste which results in solid material accumulating away from the printed surface to form the contact pad (16). The material is then fired to establish the desired conductivity.