Method of forming oversized solder bumps

摘要

Ball limited metallurgy is used in conjunction with defining a solder deposit volume using an aperture in a resist layer and reflow of electroplated solder materials deposited in that aperture, possibly with planarization after deposition to enhance volume accuracy, to develop solder deposits extending up to 10 mu m or more above the surface on which solder is deposited. Such deposits can be made at fine pitch and provide solder connections of high reliability even when the distance which must be bridged by the solder connection is not easily or reliably regulated.