Image sensor and manufacturing method thereof

Abstract

An image sensor has a three-dimensional structure in which a sensor element array having a plurality of sensor elements consisting of CdTe, arranged in a two-dimensional matrix, is mounted to an IC substrate via a connection layer. The connection layer has a plurality of stud bumps and a plurality of thin film layers. The stud bumps are formed on an electrode of each IC and are provided in the connection layer in order to fetch a signal detected by each sensor element. The thin film layers are formed at the distal end of each stud bump, and are electrically connected with an electrode of each sensor element.

What is claimed is:  
     
         1 . An image sensor comprising: 
 a sensor element array having a plurality of sensor elements arrayed in a two-dimensional matrix;    an IC substrate laminating said sensor element array and provided with a plurality of ICs for amplifying an electric signal based on radiation incident on any of the plurality of said sensor elements; and    a connection layer interposed between said sensor element array and said IC substrate, and electrically connecting each electrode of said sensor elements with each electrode of said ICs.    
     
     
         2 . The image sensor according to  claim 1 , wherein said connection layer has a plurality of stud bumps formed on an electrode of each of the plurality of said ICs; 
 and a plurality of thin film layers formed at the distal end of each of the plurality of said stud bumps and electrically connected with the electrode of each of the plurality of said sensor elements.    
     
     
         3 . The image sensor according to  claim 2 , wherein each of said stud bumps is made of gold; and 
 each of said thin film layers is made of indium.    
     
     
         4 . The image sensor according to  claim 2 , wherein said connection layer has an insulating layer which buries said stud bumps and said thin film layers.  
     
     
         5 . The image sensor according to  claim 1 , wherein said connection layer has a plurality of multi-layer bumps formed in a manner that at least two-layer stud bump is laminated on the electrode of each of the plurality of said ICs, and a plurality of thin film layers formed at the distal end of said multi-layer bump and electrically connected with the electrode of each of the plurality of said sensor elements.  
     
     
         6 . The image sensor according to  claim 5 , wherein each of said multi-layer bumps is made of gold; 
 and each of said thin film layers is made of indium.    
     
     
         7 . The image sensor according to  claim 5 , wherein said connection layer has an insulating layer which buries said stud bumps and said thin film layers.  
     
     
         8 . The image sensor according to  claim 1 , wherein said sensor element is a CdTe element.  
     
     
         9 . A method of manufacturing an image sensor comprising: 
 forming stud bumps on each electrode pad of the predetermined number of IC chips provided in a first substrate;    carrying out indium plating with respect to a second substrate;    transferring said plated indium to said second substrate to the distal end of each of said stud bumps so that a plurality of thin film layers can be formed;    connecting each of said thin film layers with the electrode of each of sensor elements so that a sensor element array having the plurality of said sensor elements arrayed like two-dimensional matrix is mounted to each of IC chips of said first substrate by flip chip mounting; and    injecting an insulating resin between said first substrate and said sensor element array, and thereafter, hardening said insulating resin.    
     
     
         10 . The method of manufacturing said image sensor, according to  claim 9 , wherein each of said stud bumps is made of gold, and each of said thin film layers is made of indium.