CIRCUIT FORMATION BOARD AND MANUFACTURE THEREOF

摘要

PURPOSE: To provide a method for manufacturing a high mounting density circuit board. CONSTITUTION: Through holes 4 of insulating substrates 1a-1c are made into the shape of a taper and the sizes of lands on and under the through holes 4 are changed according to the taper. Then, conductive paste 4 is injected into the through holes from a larger diameter section. By this method, even if the size of the through holes 3 is made small, the through holes 3 can be filled with conductive paste successfully. Therefore, a very reliable circuit board on which components can be mounted at high density can be obtained.