The invention provides a new method and
chip scale
package is provided. The inventions starts with a substrate over which a contact point is provided, the contact point is exposed through an opening created in the layer of
passivation and a layer of
polymer or
elastomer. A barrier / seed layer is deposited, a first
photoresist mask is created exposing the barrier / seed layer where this layer overlies the
contact pad and, contiguous therewith, over a surface area that is adjacent to the
contact pad and emanating in one direction from the
contact pad. The exposed surface of the barrier / seed layer is electroplated for the creation of interconnect traces. The first
photoresist mask is removed from the surface of the barrier / seed layer. A second
photoresist mask, defining the solder bump, is created exposing the surface area of the barrier / seed layer that is adjacent to the contact pad and emanating in one direction from the contact pad. The solder bump is created in accordance with the second photoresist mask, the second photoresist mask is removed from the surface of the barrier / seed layer, exposing the
electroplating and the barrier / seed layer with the
metal plating overlying the barrier / seed layer. The exposed barrier / seed layer is etched in accordance with the pattern formed by the
electroplating, reflow of the solder bump is optionally performed.