Process for mounting electronic device and semiconductor device

Abstract

An electronic device comprising a semiconductor chip which is fixed to the mounting face of a wiring board through an adhesive and in which external terminals are electrically connected with electrode pads of the wiring board through bump electrodes. Recesses are formed in the electrode pads, and in the recesses the electrode pads and the bump electrodes are connected. The electrode pads are formed over the surface of a soft layer, and the recesses are formed by elastic deformation of the electrode pads and the soft layer.

What is claimed is:  
     
         1 . An electronic device comprising a semiconductor chip which is fixed to the mounting face of a wiring board through adhesive and in which external terminals are electrically connected with electrode pads of said wiring board through bump electrodes, 
 wherein recesses are formed in said electrode pads and in said recesses said electrode pads and said bump electrodes are connected.    
     
     
         2 . An electronic device according to    claim 1   , 
 wherein said electrode pads are formed over the surface of a soft layer, and    wherein said recesses are formed by elastic deformation of said electrode pads and said soft layer.    
     
     
         3 . An electronic device according to    claim 2   , 
 wherein said soft layer is formed over the surface of a rigid board.    
     
     
         4 . An electronic device according to    claim 2   , 
 wherein said soft layer is made of a material having a smaller coefficient of thermal expansion than that of said adhesive.    
     
     
         5 . An electronic device according to    claim 1   , 
 wherein said bump electrodes are fixed to the external terminals of said semiconductor chip and pressed to the electrode pads of said wiring board.    
     
     
         6 . An electronic device according to    claim 1   , 
 wherein said bump electrodes are constructed to have a stud bump structure.    
     
     
         7 . An electronic device according to    claim 1   , 
 wherein said adhesive is made of an anisotropic conductive resin film.    
     
     
         8 . A data processor comprising an electronic device according to any of the    claims 1    to    7    and assembled therein.  
     
     
         9 . A process for mounting a semiconductor device comprising a semiconductor chip which is fixed to the mounting face of a wiring board through adhesive and in which external terminals are electrically connected with electrode pads of said wiring board through bump electrodes, comprising: 
 the step of preparing a wiring board having electrode pads over a rigid board through a soft layer, and a semiconductor chip having bump electrodes formed over external terminals;    the step of arranging said semiconductor chip over the mounting face of said wiring board through adhesive and the bump electrodes of said semiconductor chip over the electrode pads of said wiring board; and    the step of forming recesses in said electrode pads by depressing the bump electrodes of said semiconductor chip thereby to cure said adhesive in this state.    
     
     
         10 . A process for manufacturing a semiconductor device, comprising: 
 a) the step of preparing a semiconductor chip having a plurality of semiconductor elements and a plurality of bonding pads over a major face, and bump electrodes over the individual surfaces of said bonding pads;    b) the step of preparing a wiring board having a plurality of first wirings, and a mounting board including an insulating film having a lower modulus of elasticity than that of said wiring board and a plurality of second wirings formed over said insulating layer;    c) the step of mounting said semiconductor chip over said mounting board in such a way that said bump electrodes are arranged over the second wirings of said mounting board; and    d) the step of joining the major face of said semiconductor chip to said mounting board through adhesive interposed therebetween.    
     
     
         11 . An electronic device manufacturing process according to    claim 10   , 
 wherein said bump electrodes are gold bumps.    
     
     
         12 . An electronic device manufacturing process according to    claim 10   , 
 wherein said wiring board is made by impregnating glass fibers with resin, and    wherein said insulating layer is made of resin.    
     
     
         13 . An electronic device manufacturing process according to    claim 10   , 
 wherein said adhesive contains conductive particles in an insulating resin, and    wherein said bump electrodes and said second wirings are electrically connected through said conductive particles.