Spherical shaped semiconductor device, a flexible printed wiring substrate, and mounting method thereof

Abstract

A spherical shaped semiconductor device has a protective insulating film thereon and input/output connection openings that are located along a intersected portion on the protective insulating film where a plane face running through a center of the spherical shaped semiconductor device intersects the protective insulating film. More input/output connection openings are provided on the spherical shaped semiconductor device compared with a conventional square semiconductor device. The spherical shaped semiconductor device is connected to a flat circuit substrate through a flexible printed wiring substrate. A lower portion of the flexible printed wiring substrate is cut into divided sections for connecting input/output terminals of the flat circuit substrate. Connection between the spherical shaped semiconductor device and the flat circuit substrate does not cause any cracks or disconnection due to flexibility of the flexible printed wiring substrate.

What is claimed is:  
     
         1 . A spherical shaped semiconductor device electrically connected to a flat circuit substrate, comprising: 
 a protective insulating film formed on an outer surface of the spherical shaped semiconductor device; and    a plurality of input/output connection openings which are disposed along a intersected portion of the protective insulating film where a plane face orthogonal to an axis running through a center of the spherical shaped semiconductor device intersects the protective insulating film.    
     
     
         2 . The spherical shaped semiconductor device according to    claim 1   , wherein 
 the axis running through the center of the spherical shaped semiconductor device is orthogonal to the flat circuit substrate.    
     
     
         3 . The spherical shaped semiconductor device according to    claim 2   , wherein 
 the input/output connection openings are disposed along a intersected portion of the protective insulating film where a plane face running through the center of the spherical shaped semiconductor device intersects the protective insulating film.    
     
     
         4 . A flexible printed wiring substrate, comprising of: 
 a flexible resin layer; and    a flexible metallic foil layer stacked on the resin layer, wherein    the metallic foil layer forms circuit patterns to electrically connect a spherical shaped semiconductor device to a flat circuit substrate on which the spherical shaped semiconductor device is mounted.    
     
     
         5 . The flexible printed wiring substrate according to    claim 4   , wherein 
 the resin layer is made of polyimide.    
     
     
         6 . The flexible printed wiring substrate according to    claim 4   , wherein 
 the metallic foil layer is made of aluminum.    
     
     
         7 . The flexible printed wiring substrate according to    claim 4   , wherein 
 a lower portion of the flexible printed wiring substrate located on a side of the flat circuit substrate is cut into a plurality of divided sections to be connected to input/output terminals of the flat circuit substrate.    
     
     
         8 . The flexible printed wiring substrate according to    claim 4   , wherein 
 an upper portion of the flexible printed wiring substrate located on a side of the spherical shaped semiconductor device is cut into a plurality of divided sections to be connected to input/output terminals of the spherical shaped semiconductor device.    
     
     
         9 . The flexible printed wiring substrate according to    claim 7   , wherein 
 the flexible printed wiring substrate has a divided section longer than other divided sections.    
     
     
         10 . The flexible printed wiring substrate according to    claim 8   , wherein 
 the flexible printed wiring substrate has a divided section longer than other divided sections.    
     
     
         11 . The spherical shaped semiconductor device according to    claim 3   , wherein 
 the spherical shaped semiconductor device is electrically connected to the flat circuit substrate through the flexible printed wiring substrate of    claim 7   .    
     
     
         12 . A mounting method of a spherical shaped semiconductor device on a flat circuit substrate, comprising the steps of: 
 winding an upper portion of a flexible printed wiring substrate around an outer surface of the spherical shaped semiconductor device;    connecting the upper end portion of the flexible printed wiring substrate to input/output terminals of the spherical shaped semiconductor device through input/output openings of the spherical shaped semiconductor device;    expanding in radial directions a plurality of divided sections formed by cutting a lower portion of the flexible printed wiring substrate; and    connecting the divided sections of the flexible printed wiring substrate to input/output terminals of the flat circuit substrate.