Mounting board and electronic device using the same

Abstract

Wiring electrodes are formed on a first principal surface of a base substrate. An insulation film partially covers the first principal surface of the base substrate and the wiring electrodes. The insulation film has opening portions where the base substrate and the wiring electrodes are not coated with the insulation film. An electronic component having bump electrodes is mounted on the mounting board by connecting the bump electrodes with the wiring electrodes in the opening portions. A gap between the first principal surface of the base substrate and the electronic component is filled with sealing resin. The opening portions are substantially orthogonal to the longitudinal direction of the wiring electrodes. The ratio of the minimum width of a portion of the base substrate exposed at each of the opening portions to the thickness of the insulation film may advantageously be greater than or equal to 2.

What is claimed is:  
     
         1 . A mounting board comprising: 
 a base substrate having a first principal surface;    a wiring electrode formed on the first principal surface of the base substrate; and    an insulation film which partially covers the first principal surface of the base substrate and the wiring electrode, the insulation film having a coated portion where the base substrate and the wiring electrode are coated with the insulation film, and an opening portion where the base substrate and the wiring electrode are not coated with the insulation film,    wherein L/T≧2 is satisfied, where L denotes the minimum width of a portion of the base substrate exposed at the opening portion and T denotes the thickness of the insulation film.    
     
     
         2 . The mounting board according to  claim 1 , wherein the opening portion straddles the wiring electrode and thereby forms a recess on each side of the wiring electrode.  
     
     
         3 . The mounting board according to  claim 1 , wherein the opening portion surrounds an end of the wiring electrode and thereby forms a U-shaped recess at the end of the wiring electrode.  
     
     
         4 . A mounting board comprising: 
 a base substrate having a first principal surface;    a wiring electrode formed on the first principal surface of the base substrate; and    an insulation film which partially covers the first principal surface of the base substrate and the wiring electrode, the insulation film having a coated portion where the base substrate and the wiring electrode are coated with the insulation film, and an uncoated portion where the base substrate and the wiring electrode are not coated with the insulation film,    wherein the coated portion of the insulation film includes a first coated portion and a second coated portion which extend substantially in parallel to each other with a predetermined spacing therebetween and which are substantially orthogonal to the wiring electrode, and    the uncoated portion between the first and second coated portions is open substantially orthogonally to the wiring electrode.    
     
     
         5 . A mounting board comprising: 
 a base substrate having a first principal surface;    at least one wiring electrode formed on the first principal surface of the base substrate; and    an insulation film which partially covers the first principal surface of the base substrate and the wiring electrode, the insulation film having a coated portion where the base substrate and the wiring electrode are coated with the insulation film, and an opening portion where the base substrate and the wiring electrode are not coated with the insulation film,    wherein the wiring electrode comprises a plurality of electrodes extending in parallel to each other, and    the opening portion is substantially orthogonal to the wiring electrodes, and extends over a plurality of the wiring electrodes.    
     
     
         6 . An electronic device comprising: 
 the mounting board according to  claim 1;     an electronic component having a bump electrode formed so as to correspond to the wiring electrode in the opening portion, via which the electronic component is mounted on the mounting board, and a gap between the first principal surface of the base substrate and the electronic component being filled with sealing resin,    the electronic component mounted on the mounting board by connecting the bump electrode with a portion of the wiring electrode exposed at the opening portion or the uncoated portion of the mounting board; and    the sealing resin filled and hardened in a gap between the first principal surface of the base substrate and the electronic component.    
     
     
         7 . The electronic device of  claim 6 , wherein said sealing resin has a viscosity range of 0.02 to 10 Pa·s before hardening.  
     
     
         8 . The electronic device of  claim 7 , wherein said viscosity range is 0.4 to 7.3 Pa·s.  
     
     
         9 . An electronic device comprising: 
 the mounting board according to  claim 4;     an electronic component having a bump electrode formed so as to correspond to the wiring electrode in the opening portion, via which the electronic component is mounted on the mounting board, and a gap between the first principal surface of the base substrate and the electronic component being filled with sealing resin,    the electronic component mounted on the mounting board by connecting the bump electrode with a portion of the wiring electrode exposed at the opening portion or the uncoated portion of the mounting board; and    the sealing resin filled and hardened in a gap between the first principal surface of the base substrate and the electronic component.    
     
     
         10 . An electronic device comprising: 
 the mounting board according to  claim 5;     an electronic component having a bump electrode formed so as to correspond to the wiring electrode in the opening portion, via which the electronic component is mounted on the mounting board, and a gap between the first principal surface of the base substrate and the electronic component being filled with sealing resin,    the electronic component mounted on the mounting board by connecting the bump electrode with a portion of the wiring electrode exposed at the opening portion or the uncoated portion of the mounting board; and    the sealing resin filled and hardened in a gap between the first principal surface of the base substrate and the electronic component.