Printed circuit board and flip chip package using the same with improved bump joint reliability

Abstract

A printed circuit board and a flip chip package using the same are designed to minimize thermal stress due to different thermal coefficients present in areas having metal lines and solder resist versus other areas on the printed circuit board. The printed circuit board includes an insulation layer; a first metal line formed on one surface of the insulation layer and having at one end thereof a bump land and a projection which integrally extends from the bump land; a second metal line formed on the other surface of the insulation layer and having at one end thereof a ball land; a via metal line formed through the insulation layer to connect the first and second metal lines to each other; and solder resists formed on the upper and lower surfaces of the insulation layer to expose the bump land and the ball land.

1 . A flip chip package comprising:
 a printed circuit board comprising;   an insulation layer,   a first metal line formed on one surface of the insulation layer, the first metal line comprising: a bump land at one end thereof; and a projection which integrally extends from the bump land;   a second metal line formed on the other surface of the insulation layer;   a via metal line electrically connecting the first and second metal lines; and   solder resist formed at least on the upper surface of the insulation layer to expose the bump land;   a semiconductor chip bonded to one surface of the printed circuit board through bumps such that the semiconductor chip is electrically connected to the first metal line;   a filler material filled between the printed circuit board and the semiconductor chip;   a molding material for molding one surface of the printed circuit board including the semiconductor chip; and   solder balls attached to the ball lands of the printed circuit board.   
     
     
         2 . The flip chip package according to  claim 1 , wherein the first metal line, the second metal line, and the via metal line are made of copper. 
     
     
         3 . The flip chip package according to  claim 1 , wherein the projection of the first metal line extends toward an edge of the insulation layer. 
     
     
         4 . The flip chip package according to  claim 1 , wherein the first metal line has at least one projection. 
     
     
         5 . The flip chip package according to  claim 1 , wherein the projection of the first metal line extends from the bump land by a length of 5˜100 μm. 
     
     
         6 . The printed circuit board according to  claim 1 , wherein the solder resist is formed on the surface of the insulation layer to expose the ball land. 
     
     
         7 . The printed circuit board according to  claim 1 , wherein the semiconductor chip is electrically connected to the first metal line in a face-down manner.