Printed circuit board fabrication

Abstract

Abstract A NOVEL METHOD OF PRODUCING A PRINTED CIRCUIT BOARD MATERIAL HAVING A SUBSTRATE CARRYING SUPERPOSED RESISTIVE MATERIAL AND CONDUCTIVE METAL LAYERS WHICH COMPRISES DEPOSITING THE RESISTIVE LAYER ON A PREFORMED CONDUCTIVE METAL FILM, THE IMPROVEMENT WHEREIN THE RESISTIVE LAYER IS DEPOSITED ON SAID PREFORMED CONDUCTIVE METAL LAYER IN A PLATING BATH HAVING AN ANODE AND WHEREIN THE PREFORMED CONDUCTIVE METAL FILM IS THE CATHODE, AND WHEREIN THE RESISTIVE MATERIAL IS DEPOSITED SLOWLY FROM A DILUTE PLATING SOLUTION IN A QUIESCENT STATE BY THE USE OF A TUNNEL POSITIONED WITHIN THE BATH BETWEEN THE ANODE AND CATHODE TO REGULATE TURBULENCE WITHIN THE BATH BETWEEN SAID ANODE AND CATHODE, AND PREVENT DIFFUSION INTO THE ENCLOSED AREA OF THE BATH. THE PRESENT INVENTION FURTHER COMPRISES THE NOVEL APPARATUS FOR CARRYING OUT THE FOREGOING PROCESS WHICH COMPRISES A PLATING BATH HAVING A RESISTIVE METAL ANODE AND A PREFORMED CONDUCTIVE METAL FILM CATHODE, A PLATING SOLUTION WITHIN SAID BATH COMPRISING A SALT OF SAID RESISTIVE MATERIAL, POSITIONED BETWEEN SAID ANODE AND CATHODE, A TUNNEL COMPRISING A BOX-LIKE STRUCTURE OPEN AT THE ENDS IN PROXIMITY TO SAID ANODE AND CATHODE AND OTHERWISE CLOSED BY GENERALLY PARALLEL, HORIZONTAL AND VERTICAL SHEET MEMBERS WHICH ABUT AT THE EDGE, SAID TUNNEL BEING ADAPTED TO CONTROL THE TURBULENCE OF THE PLATING SOLUTION WITHIN SAID BATH, AND TO PREVENT DIFFUSION INTO THE ENCLOSED AREA OF SAID BATH.

Inventors

• 👤 R Castonguay

Bibliographic Details