Julia L Johnson

US Patent:

51621444, Nov 10, 1992

Filed:

Aug 1, 1991

Appl. No.:

7/739269

Inventors:

Vernon L. Brown - Barrington IL
Julia S. Johnson - Schaumburg IL
Yaroslaw A. Magera - Arlington Heights IL

Assignee:

Motorola, Inc. - Schaumburg IL

International Classification:

B32B 300
B05D 512
B44C 122
B29C 3700

US Classification:

428209

Abstract:

A unique process metallizes a substrate surface using a reducing agent including a borohydride to reduce, in a starved reaction, metal oxide particles (300) substantially uniformly distributed and at a controlled concentration in a particle-filled resin (204) to produce catalytic island areas (301). The catalytic island areas (301) formed have a surface resistivity greater than 10. sup. 6 ohms per square. These catalytic island areas (301) are then electrolessly metallized to a predetermined thickness, such that adjacent catalytic island areas (301) are interconnected and form metallic features, such as pads, vias (213), and conductors (210, 211 and 212). The starved reaction limits the reduction of metal oxide particles (300) to catalytic island areas (301) and prevents migration of reduced metal beyond each of the exposed surfaces of particle-filled resin (204) which are to be metallized.