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Application filed by Mitsui Mining & Smelting CofiledCriticalMitsui Mining & Smelting Co
Priority to MYPI9900338priorityCriticalpatent/MY125649A/en
Publication of MY125649ApublicationCriticalpatent/MY125649A/en
AN ALKALINE REFRACTORY METAL (2) WHICH IS INSOLUBLE IN ALKALINE ETCHING SOLUTIONS, IS ELECTRODEPOSITED ON THE SURFACE OF COPPER FOIL (1), THEN A THERMOSETTING RESIN IS APPLIED TO THE SURFACE AND SEMI- CURED TO OBTAIN A COATED COPPER FOIL(1). THE COATED COPPER FOIL (1) IS BONDED TO ONE OR BOTH FACES OF AN INNER LAYER BOARD HAVING WIRINGS (4) ON ONE OR BOTH OF ITS FACES. THEN, THE COPPER FOIL (1) ON A SURFACE OF THIS LAMINATE IS REMOVED BY ALKALINE ETCHING, WILE SELECTIVETY LEAVING THE ALKALINE REFRACTORY METAL (2) LAYER. A LASER BEAM IS USED TO FORM VIA HOLES (6) IN BOTH THE ALKALINE REFRACTORY METAL (2) LAYER AND THE THERMOSETTING RESIN LAYER (3) SIMULTANEOUSLY. WITH THE ABOVE METHOD, VIA HOLES (6) OF THE MULTI- LAYERED PRINTED WIRING BOARD CAN BE EASILY FORMED USING A LASER, AND ADHESION BETWEEN THE OUTER WIRINGS (8) MADE FROM THE PLATED COPPER AND THE INSULATING RESIN IS IMPROVED.(FIGURE 1)
MYPI99003381999-01-301999-01-30Method for producing multi-layer printed wiring boards having blind vias
MY125649A
(en)