Patent ID: 6867121

Claim:
A method of electrically interconnecting a bump of a bumped fine pitch circuit layer trace to a portion of an outer conductive layer separated from the bumped fine pitch circuit layer trace by an insulating layer, comprising the steps of: positioning a portion of the outer conductive layer to be connected generally over the bumped fine pitch circuit layer, the bumped fine pitch circuit layer having at least one bump having a center at an x-y location relative to the outer conductive layer, the bump having an approximate width orthogonal to the z-dimension, removing conductive material from the portion of the outer conductive layer generally over the bump to make an opening in the conductive layer, the opening having a width substantially greater than the width of the bump, the opening being disposed generally above the x-y location of the bump; removing sufficient insulating material from the insulating layer within the opening and over the bump to expose at least a portion of a top of the bump; and filling at least a portion of the opening with sufficient conductive paste or solder to electrically interconnect the bump to the portion of the outer conductive layer.