PRINTED CIRCUIT BOARD HAVING MEANS FOR PREVENTING WARPAGE

摘要

A printed circuit board having a warpage preventing unit is provided to reduce a warpage phenomenon of PCB significantly by enabling first and second warpage preventing units to compensate a stress caused by a warpage property. In a printed circuit board having a warpage preventing unit, an etching-treated conductive pattern is formed on upper and lower surfaces of a resin layer. A wire bonding conductive pattern is included in the conductive pattern. A solder mask is coated on a lower surface of the resin layer except for ball land. A first warpage preventing unit(10) formed by laminating a material with a low thermal expansion coefficient and the material with a high thermal expansion coefficient up and down, is attached to a space between an upper surface of the resin layer and the solder mask, except for the conductive pattern. A second warpage preventing unit(12) formed by laminating the material with the high thermal expansion coefficient and the material with the low thermal expansion coefficient up and down, is attached to a space between a low surface of the resin layer and the solder mask, except for the ball land.