James A. Loughran

Thick Film Pastes for Multilayer Use

Suecessful multilayer processing requires careful selection of conductor and dielectric pastes. As pastes they must satisfy geometrical and processing needs; as conductors and dielectrics they must meet electrical and other requirements. Some dominating considerations for paste selection are reviewed. A method is described for evaluating paste performance with test patterns which simulate multileyer applications. Various popular conductor and dielectric pasteswere evaluated and the results are reported. Some frequently encountered processing problems and their causes are discussed. Although all pastes evaluated were found less than ideal, a satisfactory combination of conductor and dielectric pastes was selected.

Economic Considerations in Multilayer Thick Film Hybrids

Multilayer thick film hybrids are sometimes fabricated without adequate concern for their economics. Economy begins in design; it can suffer in processing and be lost in test and assembly: This paper treats some of the cost considerations applied to a large family of multilayer hybrids for use in computer equipment. Design rules for good yields are presented. Some materials selection and processing criteria are discussed. Paste consumption data, screen wear, and substrate yield experience, is given. An arrangement for automated electrical substrate testing is described. A mechanized process for silicon circuit chip attachment and connection is also described.