PRINTED CIRCUIT BOARD AND ITS MANUFACTURING METHOD

摘要

PROBLEM TO BE SOLVED: To provide a printed circuit board which can stand repetitive heating and cooling cycles for a long term and is improved in continuity between wiring patterns on its front and rear surfaces. SOLUTION: As the material of the via holes 16 of his printed circuit board, highly heat-resistant oxygen free copper, phosphorus deoxidized copper, and/or toughpitch copper is used. Plated copper layers 18 are formed so that the layers 18 may come into contact with both ends of the via holes 16.