the present invention relates to a structure of a composite lead frame generally having a die bonding layer and a solder layer and may further have an cohesive layer between the die bonding layer and the solder layer . the die bonding layer is made of flex substrate and the solder layer is made of traditional lead frame . thus , the composite lead frame structure is suitable for the flip chip or wire bonding packaging process of led and also suitable for semiconductor ic packaging process . it is good in electric and heat conductivity , and also with higher mechanical strength , resulting high pin counts and minimization of resulted ic .