| abstract |
A substrate having an ultrafine pitch flip chip bump for attaching a chip to a substrate having an outer layer with via pillars embedded in a dielectric, such as a solder mask. A multilayer composite electronic structure comprising a feature layer extending in an XY plane, wherein each adjacent pair of feature layers is separated by an inner via layer, the via layer being in relation to the XY plane. Via pillars connecting feature layers adjacent to each other in the vertical Z direction, wherein the via pillars are embedded in an inner layer dielectric, and the multilayer composite structure 100 includes at least one end portion including at least one micro bump 130. Further comprising an outer layer 132, at least one microbump 130 comprises via posts that are covered by a solderable material. [Selection] Figure 1 (xvi) |