Approaches to the Screen - Printing of Fine Holes in the Ceramic Insulating Layers of Multilayer Hybrid Arrays

摘要

In the construction of multi-layer hybrid circuitry by the screen-printing technique it is necessary to be able to interconnect the conductor planes at predetermined points through the insulating layer of ceramic separating them. The through-holes are necessarily small (of the order of 10 thou across) because of the geometrical limitation imposed by the high density of packing of the conductors. This report discusses ways in which these fine holes may be produced by printing with AWRE zero-flow glass paste. After normal printing, very fine holes, 10 thou diameter, tend to close up due to flow of the paste. Three suggested approaches to avoid this effect are discussed:-n(1) Modifications of existing printing techniques and circuit design.n(2) The use of auxiliary physical methods to restrict flow of the "wet" paste after printing.n(3) Modification of the paste itself by modification of the liquid carrier.