Semiconductor package, method for fabricating the same, and semiconductor device

Abstract

A semiconductor device includes a semiconductor chip, leads for sending and receiving signals between the semiconductor chip and an external device, fine metal wires, an encapsulant for sealing the leads, and a lid member. On the surface of each of the leads, a metal oxide film is formed by an oxidation treatment. The metal oxide film has a thickness larger than a natural oxide film and no more than 80 nm.

1 - 4 . (canceled) 
   
   
       5 . A method for fabricating a semiconductor package, comprising the steps of:
 (a) preparing a leadframe having a frame body and a plurality of leads which are connected at the proximal ends to the frame body and the distal ends of which are to face a region for mounting a semiconductor chip;   (b) forming a metal oxide film having a thickness of no less than 1.7 nm and no more than 80 nm on the surface of the leadframe by subjecting the leadframe to an oxidation treatment; and   (c) forming an encapsulant with a molding material to seal parts of the plurality of leads.   
   
   
       6 . The method of  claim 5 , wherein in the step (b), the leadframe is held in an atmosphere having an oxygen concentration of 20%±5% at a temperature of 200 to 260° C. for one hour. 
   
   
       7 . The method of  claim 5 , wherein in the step (b), the metal oxide film is formed to have a thickness of 10 nm or less.