Method for making multilayer circuits using embedded catalyst receptors

A method for making a laminate for the preparation of multilayer printed circuits by electroless plating of conductive metal thereon which comprises the sequential steps of

• (1) forming a conductive pattern on at least one surface of a substrate;
• (2) applying an adherent layer of tonable photodielectric material over the pattern and surrounding substrate areas;
• (3) toning the photodielectric material with finely divided particles of adsorbent so that they become partially embedded within and protrude from the layer surface away from the substrate, the surfaces of the protruding part of the particles being adsorptive with respect to electroless plating catalysts or reductive precursors thereof.

A laminate for the preparation of a multilayer printed circuit by electroless plating of conductive metal thereon which comprises

• (1) a substrate having formed on a surface thereof
• (2) a conductive pattern, and,
• (3) overlying the pattern and surrounding substrate areas, a layer of tonable photodielectric material having partially embedded therein finely divided particles of adsorbent which protrude from the layer surface away from the substrate, the protrusive surfaces of which have been rendered catalytic by adsorption thereon of an electroless plating catalyst.