Patent ID: 7402758

Claim:
An interlayer interconnection unit for a printed circuit board (PCB), comprising: a plurality of interstitial bridge pads, each of said plurality of interstitial bridge pads having a first side and a second side, wherein said first side of each of said interstitial bridge pads physically contacts a first dielectric layer and said second side of each of said plurality of_interstitial bridge pads physically contacts a second dielectric layer; a corresponding first blind via disposed on said first side of each of said plurality of_interstitial bridge pads, wherein said first blind via extends through said first dielectric layer; and a corresponding second blind via disposed on said second side of each of said plurality of_interstitial bridge pads, wherein said second blind via extends through said second dielectric layer, wherein each of said plurality of_interstitial bridge pads electrically connects corresponding first blind vias to corresponding second blind vias, wherein each of said plurality of interstitial bridge pads is coaxial in a z direction with said corresponding first blind via and with said corresponding second blind via, wherein, in between interstitial bridge pads, at least a portion of said first dielectric layer is fused to at least a portion of said second dielectric layer, said corresponding first blind vias extend from corresponding first capture pads to said first side of each of said plurality of interstitial bridge pads, said corresponding second blind vias extend from corresponding second capture pads to said second side of each of said plurality of interstitial bridge pads, and said corresponding first capture pad and said corresponding second capture pad each have a diameter less than a diameter of said interstitial bridge pad therebetween.