| 摘要 |
PROBLEM TO BE SOLVED: To provide a multilayered printed wiring board that has a constitution having very high laying space of wiring and is improved in component mounting reliability at the time of mounting a component on a small-diameter land represented by the narrow-pitch BGA. SOLUTION: Conductor patterns for inner-layer material are formed on both sides of an insulating substrate having a conductive hole packed with conductive paste. Then a non-through hole 7 is obtained by superposing base materials impregnated with the same resin as that of an inner-layer material upon both surfaces of the inner-layer material obtained by superposing insulating substrates upon another by the same method and metal foil 6 upon the base materials, and working the metal foil 6 for external layer by heating and pressuring by heat pressing after the foil 6 is oxidized and directly working the foil 6 with a laser beam. Then, after the hole 7 is formed, metal plating is performed on the whole surface and, thereafter, the multilayered printed wiring board on which surface-layer IVH and a conductive pattern for external layer are formed is obtained. COPYRIGHT: (C)2006,JPO&NCIPI |
