Multi-part lead frame with dissimilar materials

Abstract

A multi-part lead frame semiconductor device assembly is disclosed including a die bonded to a die paddle. A second lead frame including leads is superimposed and bonded onto the first lead frame. Also disclosed is a method for fabricating the multi-part lead frame semiconductor device assembly which utilizes equipment designed for single lead frame processing. If desired, the materials for the multi-part lead frame may be dissimilar.

1 . A semiconductor device assembly having a semiconductor device therein, the semiconductor device having an active surface having at least one bond pad thereon, the semiconductor device assembly manufactured by the process comprising the steps of: 
 forming a first lead frame including a die paddle, first carriers each having a first alignment member therein, a plurality of tie bars, and at least one attachment tab extending from a tie bar of the plurality of tie bars, a tie bar of the plurality of tie bars interconnecting the die paddle and a carrier of the first carriers;    attaching the semiconductor device to the die paddle;    forming a second lead frame including second carriers each having an attachment tab receiving portion affixed thereto and having a second alignment member therein and a plurality of leads, at least one lead of the plurality of leads having an inner lead portion and an outer lead portion;    aligning the first alignment member of a carrier of the first carriers of the first lead frame and the second alignment member of a carrier of the second carriers of the second lead frame;    securing the attachment tabs of the first lead frame to the attachment tab receiving portions of the second lead frame;    cutting the plurality of tie bars at a point between the attachment tabs and the first carriers.    
   
   
       2 . The semiconductor device assembly of  claim 1 , further manufactured by the process comprising the step of: 
 connecting at least one of the inner lead portions and the at least one bond pad to the semiconductor device.    
   
   
       3 . The semiconductor device assembly of  claim 1 , further manufactured by the process wherein the step of securing consists of welding the attachment tabs of the first lead frame to the attachment tab receiving portions of the second lead frame.  
   
   
       4 . The semiconductor device assembly of  claim 1 , further manufactured by the process wherein the step of securing comprises adhesively bonding the attachment tabs of the first lead frame and the attachment tab receiving portions of the second lead frame.  
   
   
       5 . The semiconductor device assembly of  claim 1 , further manufactured by the process wherein the first lead frame further includes tie bar cut zones located between the attachment tabs and the first carriers, and wherein the step of cutting the tie bars consists of cutting the tie bar cut zones.  
   
   
       6 . The semiconductor device assembly of  claim 1 , further manufactured by the process wherein the first lead frame further includes tie bar cut zones located between the attachment tabs and the first carriers, and wherein the step of cutting the tie bars consists of severing the tie bar cut zones.  
   
   
       7 . The semiconductor device assembly of  claim 1 , further manufactured by the process, further comprising the step of: 
 applying an insulating film to a portion of the active surface of the semiconductor device.    
   
   
       8 . The semiconductor device assembly of  claim 1 , further manufactured by the process, further comprising the step of: 
 applying an insulating film between a portion of the active surface of the semiconductor device and at least one of the inner lead portions of the plurality of leads.    
   
   
       9 . The semiconductor device assembly of  claim 1 , further manufactured by the process, further comprising the step of: 
 molding the semiconductor device in a plastic body.