METHOD FOR FABRICATING SOLDER ON PAD OF FINE BUMP USING PHOTORESIST AND PRINTED-CIRCUIT-BOARD FABRICATED USING THE SAME

摘要

PURPOSE: A method for forming solder-on-pad(SOP)s of micro bumps based on photo-resist is provided to easily adjust the height of bumps by forming an electric copper or tin plated bump layer in a recessed region. CONSTITUTION: A printed circuit board includes a core layer(100), an inner circuit(110) formed on the upper side of the core layer, and bumps(115). A pre-preg layer(120) is arranged to insulate the circuit. Printed circuit patterns are formed on the upper side of the pre-preg layer. A solder mask(145) is formed on the upper side of the bumps and the printed circuit board. A conductive seed layer(150) is formed on the upper side of the solder mask. An electric plated bump layer(170) is formed at a SOP forming region on the upper side of the seed layer. SOPs(185) are formed on the upper side of the electric plated bump layer.