Patent ID: 6271478
Filing Date: 2001-08-07
Classification: H01L,H05K

Abstract:
A multi-layer circuit board formed by laminating a plurality of circuit boards, each circuit board comprising a substrate having its surface, a plurality of lands or vias and circuit patterns formed on said surface of the substrate, each of said circuit patterns having one end connected to said land or via and the other end extending outwardly from a land area where said plurality of lands or vias are arranged under such a condition that at least one circuit pattern can pass through a first space between two adjacent lands or vias and at least four circuit patterns can pass through a second space between lands or vias at both ends by removing an intermediate one from consecutively arranged three lands or vias;a first of said circuit boards having a plurality of said lands or vias arranged equidistantly in column and row directions to form an area array corresponding to an arrangement of electrodes of an electronic part which is to be mounted on said circuit board so that said electrodes are electrically connected to said respective lands or vias;said first circuit board comprising said circuit patterns which are connected to all the lands or vias positioned on a first, outermost row of the area array, and are connected to alternatively selected lands or vias positioned on second and third rows;a second of said circuit boards having a plurality of said lands or vias arranged so as to correspond to said lands or vias of the first circuit board to which no circuit patterns on the first circuit board are connected;said second circuit board comprising said circuit patterns which are connected to all the lands or vias positioned on the second row, corresponding to said lands or vias of the first circuit board, to which no circuit patterns on the first circuit board are connected, and are connected to all the lands or vias positioned on forth and fifth rows;a third of said circuit boards having a plurality of said lands or vias arranged so as to correspond to said lands or vias of the second circuit board to which no circuit patterns on the second circuit board are connected;said third circuit board comprising said circuit patterns which are connected to all the lands or vias positioned on the third row, corresponding to said lands or vias of the second circuit board, to which no circuit patterns on the second circuit board are connected, and are connected to all the lands or vias positioned on sixth and seventh rows; anda fourth of said circuit boards having a plurality of said lands or vias arranged so as to correspond to said lands or vias of the third circuit board to which no circuit patterns on the third circuit board are connected;said fourth circuit board comprising said circuit patterns which are connected to all the lands or vias positioned on eighth and ninth rows.