Method of manufacturing a semiconductor device

Abstract

A method of manufacturing a semiconductor device, includes the steps of: grinding the rear surface of a semiconductor wafer to reduce its thickness; flattening the rear surface of the semiconductor wafer; dividing the semiconductor wafer into a plurality of semiconductor chips; forming gold bumps on the electrodes of the plurality of semiconductor chips; applying NCP to the front surface of a packaging board; and arranging the semiconductor chips over the packaging board through the NCP and pressing the back surfaces of the semiconductor chips to flip-chip bond the semiconductor chips to the packaging board. Therefore, it is possible to prevent NCP from rising onto the back surfaces of the semiconductor chips at the time of flip-chip bonding, whereby separation and cracking caused by a high-temperature treatment for assembly and mounting of a semiconductor device can be prevented and the reliability of the semiconductor device can be improved.

1 . A semiconductor device comprising: 
 a wiring substrate having a front surface and a rear surface; a first semiconductor chip which has a main surface and a back surface and is flip-chip bonded to the main surface of the wiring substrate through projecting electrodes;    a second semiconductor chip having a main surface and a back surface and mounted over the first semiconductor chip by bonding its back surface to the back surface of the first semiconductor chip with an adhesive;    a non-conductive resin adhesive interposed between the wiring substrate and the first semiconductor chip; and    a sealing body formed over the front surface of the wiring substrate, for resin sealing the first and second semiconductor chips,    wherein the first semiconductor chip is made thin by grinding its back surface and the back surface is made flat by polishing after grinding.    
     
     
         2 . The semiconductor device according to  claim 1 , wherein the projecting electrodes are gold bumps and the gold bumps are soldered to the flip-chip bonded portions.  
     
     
         3 . A method of manufacturing a semiconductor device, comprising the steps of: 
 (a) grinding a rear surface of a semiconductor wafer to reduce its thickness;    (b) after the step (a), flattening the rear surface of the semiconductor wafer;    (c) after the step (b), dividing the semiconductor wafer into a plurality of semiconductor chips;    (d) after the step (c), forming projecting electrodes over the plurality of semiconductor chips;    (e) applying a non-conductive resin adhesive to the front surface of a wiring substrate;    (f) arranging the semiconductor chips over the front surface of the wiring substrate through the resin adhesive and pressing a back surfaces of the semiconductor chips to flip-chip bond the semiconductor chips to the wiring substrate through the projecting electrodes; and    (g) sealing the semiconductor chips with a resin.    
     
     
         4 . The method of manufacturing a semiconductor device according to  claim 3 , wherein polishing is carried out in the step (b) to flatten the rear surface of the semiconductor wafer.  
     
     
         5 . The method of manufacturing a semiconductor device according to  claim 3 , wherein wet etching is carried out in the step (b) to flatten the rear surface of the semiconductor wafer.  
     
     
         6 . The method of manufacturing a semiconductor device according to  claim 3 , wherein the back surfaces of the semiconductor chips are pressed by a block through a sheet member in the step (f).  
     
     
         7 . The method of manufacturing a semiconductor device according to  claim 6 , wherein the sheet member is made of a fluororesin.  
     
     
         8 . The method of manufacturing a semiconductor device according to  claim 3 , wherein a first semiconductor chip is flip-chip bonded to the front surface of the wiring substrate in the step (f), and a second semiconductor chip is mounted over the back surface of the first semiconductor chip through an adhesive, and the back surface of the first semiconductor chip and a back surface of the second semiconductor chip are bonded together by the adhesive after the step (f).  
     
     
         9 . The method of manufacturing a semiconductor device according to  claim 3 , wherein the non-conductive resin adhesive is a thermosetting resin.  
     
     
         10 . The method of manufacturing a semiconductor device according to  claim 8 , wherein the adhesive for bonding the first semiconductor chip to the second semiconductor chip is a thermosetting resin.  
     
     
         11 . The method of manufacturing a semiconductor device according to  claim 3 , wherein the sealing resin used in the resin sealing of the step (g) is a thermosetting resin.  
     
     
         12 . The method of manufacturing a semiconductor device according to  claim 3 , wherein a plurality of solder balls are formed as external terminals over the rear surface of the wiring substrate after the step (g).  
     
     
         13 . The method of manufacturing a semiconductor device according to  claim 3 , wherein solder is pre-coated over a plurality of electrodes to be flip-chip bonded over the front surface of the wiring substrate before the step (e).  
     
     
         14 . The method of manufacturing a semiconductor device according to  claim 13 , wherein the pre-coated solder is used to connect goldbumps as the projecting electrodes for flip-chip bonding.  
     
     
         15 . The method of manufacturing a semiconductor device according to  claim 3 , wherein a paste non-conductive resin adhesive is applied to the front surface of the wiring substrate in the step (e).  
     
     
         16 . A method of manufacturing a semiconductor device, comprising the steps of: 
 (a) grinding the rear surface of a semiconductor wafer to reduce its thickness;    (b) after the step (a), planishing the rear surface of the semiconductor wafer;    (c) after the step (b), dividing the semiconductor wafer into a plurality of semiconductor chips;    (d) after the step (c), forming projecting electrodes over the plurality of semiconductor chips;    (e) applying a non-conductive resin adhesive to the front surface of a wiring substrate;    (f) arranging the semiconductor chips over the front surface of the wiring substrate through the resin adhesive;    (g) after the step (f), pressing a planished back surfaces of the semiconductor chips to flip-chip bond the semiconductor chips to the wiring substrate through the projecting electrodes; and    (h) sealing the semiconductor chips with a resin.    
     
     
         17 . The method of manufacturing a semiconductor device according to  claim 16 , wherein polishing is carried out to planish the rear surface of the semiconductor wafer in the step (b).  
     
     
         18 . The method of manufacturing a semiconductor device according to  claim 16 , wherein a first semiconductor chip is flip-chip bonded to the front surface of the wiring substrate in the step (g), and after the step (g), a second semiconductor chip is mounted over the back surface of the first semiconductor chip through an adhesive, and the back surface of the first semiconductor chip and a back surface of the second semiconductor chip are bonded together through the adhesive.  
     
     
         19 . A method of manufacturing a semiconductor device, comprising the steps of: 
 (a) preparing a plurality of semiconductor chips, each having a main surface and a back surface, the back surface being ground to be made thin, and being flattened by flattening after grinding;    (b) forming projecting electrodes over the electrodes of the plurality of semiconductor chips;    (c) applying a non-conductive resin adhesive to the front surface of a wiring substrate;    (d) arranging the semiconductor chips over the front surface of the wiring substrate through the resin adhesive;    (e) pressing the flattened rear surfaces of the semiconductor chips to flip-chip bond the semiconductor chips to the wiring substrate through the projecting electrodes; and    (f) sealing the semiconductor chips with a resin.