Semiconductor device and a semiconductor device manufacturing method

Abstract

A semiconductor device for fingerprint sensors reduces a mounting area of the semiconductor device and improves a processing capacity of assembling and testing process. The semiconductor device has a functional surface that provides a predetermined function. A semiconductor element has a circuit formation surface on which a plurality of electrodes are formed and a back surface opposite to the circuit formation surface. A part of the circuit formation surface functions as the functional surface. Wiring is formed on the back surface of the semiconductor element. A plurality of connection parts extends between the circuit formation surface and the back surface of the semiconductor element so as to electrically connect the electrodes to the wiring. A plurality of external connection terminals are exposed outside the semiconductor device on a side of the back surface of the semiconductor element.

1 . A semiconductor device manufacturing method of manufacturing a plurality of semiconductor devices, each having a circuit formation surface on which a plurality of electrodes are formed and a back surface opposite to the circuit formation surface, a part of the circuit formation surface functioning as said functional surface, the manufacturing method comprising:
 forming a plurality of connection parts by an electrically conductive material in each of the semiconductor elements formed in a substrate, the connection parts electrically connected to the respective electrodes and extending between said circuit formation surface and said back surface of each of said semiconductor elements;   forming wiring connected to the connection parts on said back surface in each of said semiconductor elements;   forming external connection terminals connected to the wiring in each of the semiconductor elements;   resin-encapsulating said semiconductor elements in a state where said semiconductor elements are formed in the substrate so that said functional surface and said external connection terminals are exposed;   applying a electrical test to each of said semiconductor device in a state where said semiconductor devices are formed in the substrate; and   individualizing said semiconductor elements by cutting said substrate along boundaries between the semiconductor elements, thereby forming said plurality of semiconductor devices in a lump.   
     
     
         2 . The semiconductor device manufacturing method as claimed in  claim 1 , wherein said resin-encapsulation is carried out by compression resin molding using a mold die having a protruding part at a position corresponding to said functional surface, and a sheet material, which does not adhere to the resin, is interposed between the mold die and said substrate. 
     
     
         3 . The semiconductor device manufacturing method as claimed in  claim 1 , wherein the step of said resin-encapsulation includes:
 arranging a print mask on said circuit formation surface of each of said semiconductor elements formed in said substrate, the print mask having openings in portions other than a portion corresponding to said functional surface;   applying a liquid resin onto said circuit formation surface through the print mask in each of the semiconductor elements; and   removing said print mask after curing the liquid resin.   
     
     
         4 . The semiconductor device manufacturing method as claimed in  claim 1 , wherein an ashing process is performed on at least one of said functional surface and said external connection terminals after the step of said resin-encapsulation so as to remove resin burr formed by the seal resin. 
     
     
         5 . The semiconductor device manufacturing method as claimed in  claim 1 , wherein a recognition mark is formed on said functional surface simultaneously when forming the wiring on said circuit formation surface of each of said semiconductor elements, and individualizing said semiconductor devices by cutting said substrate while recognizing said boundaries using the recognition mark. 
     
     
         6 . The semiconductor device manufacturing method as claimed in  claim 5 , wherein before individualizing said semiconductor devices by cutting said substrate, a groove is formed along said boundaries while recognizing said boundaries using said recognition mark, the groove having a width larger than a part of said substrate to be cut off by said cutting for individualization. 
     
     
         7 . The semiconductor device manufacturing method as claimed in  claim 1 , wherein a recognition mark is formed on said back surface simultaneously when forming the wiring on said back surface of each of said semiconductor elements, and individualizing said semiconductor devices by cutting said substrate while recognizing said boundaries using the recognition mark. 
     
     
         8 . The semiconductor device manufacturing method as claimed in  claim 7 , wherein before individualizing said semiconductor devices by cutting said substrate, a groove is formed along said boundaries while recognizing said boundaries using said recognition mark, the groove having a width larger than a part of said substrate to be cut off by said cutting for individualization.