Virgil E Schuster

US Patent:

50008277, Mar 19, 1991

Filed:

Jan 2, 1990

Appl. No.:

7/459892

Inventors:

Virgil E. Schuster - Scottsdale AZ
Reginald K. Asher - Scottsdale AZ
Bhagubhai D. Patel - Tempe AZ

Assignee:

Motorola, Inc. - Schaumburg IL

International Classification:

C25D 502

US Classification:

204 15

Abstract:

A method and apparatus for electroplating metallized bumps of substantially uniform height on predetermined terminal areas of a substrate. Cup plating apparatus includes elements for adjusting parameters affecting the geometry of the substrate relative to the plating cup, as well as flow rate of the electroplating solution against the substrate surface. By achieving non-laminar flow of the electroplating solution near the substrate edges, the plating characteristics of the electroplating solution are altered in this region, substantialy offsetting "edge effect", so that the resulting plated bump height is substantially uniform across the substrate.