Patent ID: 8471375

Claim:
A high-density fine line circuit structure, comprising: a first board, comprising: a first fine line circuit layer; a first insulating layer, formed on a same surface as the first fine line circuit layer; and a first semiconductor device, installed on the first fine line circuit layer; a second board, comprising: a second fine line circuit layer; a second insulating layer, formed on a same surface as the second fine line circuit layer; and a second semiconductor device, installed on the second fine line circuit layer; and a dielectric layer formed between the first board and the second board for combining the first board and the second board to be a combined single board with the first and second semiconductor devices being embedded in the dielectric layer between the first and second boards; wherein the first or second fine line circuit layer of the first board or the second board has portions exposed on an outer surface of the combined single board for serving as tin ball pads on which tin balls are formed.