Lead Frame

Abstract

A lead frame includes a plurality of leads electrically connected to a semiconductor chip and a lead lock including a base layer disposed over the plurality of the leads and formed of a material having a coefficient of thermal expansion similar to that of inner leads. An adhesive layer is disposed between the base layer and the plurality of leads to fix the plurality of leads and adhere the base layer to the leads. At least one line electrically connects the semiconductor chip to the base layer of the lead lock. Since regions for bus bars are replaced by the lead lock and are removed, the lead frame can be miniaturized and has superior thermal stability and dimension stability.

1 . A lead frame, comprising:
 a plurality of leads electrically connected to a semiconductor chip; and   a lead lock including a base layer disposed over the plurality of the leads and an adhesive layer disposed between the base layer and the plurality of leads to fix the plurality of leads and adhere the base layer to the lead.   
   
   
       2 . The lead frame according to  claim 1 , wherein the base layer comprises a material having a coefficient of thermal expansion similar to that of the plurality leads. 
   
   
       3 . The lead frame according to  claim 2 , wherein the coefficient of thermal expansion of the base layer differs from the coefficient of thermal expansion by no more than about 10 ppm. 
   
   
       4 . The lead frame according to  claim 1 , wherein the lead lock further includes an insulating layer between the adhesive layer and the base layer. 
   
   
       5 . The lead frame according to  claim 4 , wherein the insulting layer comprises a cured portion of the adhesive layer. 
   
   
       6 . The lead frame according to  claim 1 , wherein the lead lock further includes a plating layer on at least one side of the base layer. 
   
   
       7 . The lead frame according to  claim 6 , wherein the plating layer comprises one of cooper, aluminum, silver, titanium, and stainless steel or a combination thereof. 
   
   
       8 . The lead frame according to  claim 1 , wherein the lead frame further comprises at least one line electrically connecting the semiconductor chip to the base layer of the lead lock. 
   
   
       9 . The lead frame according to  1 , wherein the lead frame further comprises an external connection terminal. 
   
   
       10 . The lead frame according to  9 , wherein the lead frame further comprises a line linking the lead lock to the external connection terminal.