tape 12 the tape 12 with the dies attached thereto is fed through a second machine which thermal compression bonds the outer portions of the interconnect leads 16 to the inner ends of the lead frame members 43 see fig5 and 6 in case the lead frame 43 is made of copper it is first plated with a barrier layer material 44 as of nickel which is then selectively plated over with a layer of gold 45 to which the copper interconnect lead 16 is to be thermally compression bonded the upper surface of the interconnect lead 16 which is to be bonded to the selectively plated gold layer 45 is preferably coated with an antioxidant coating as of gold chromate or copper phosphate to a thickness sufficiently thin to permit thermal compression bonding therethrough a thermal compression tool 46 is brought up against the lower side of the interconnect lead 16 for pressing the upper surface of the interconnect lead 16 into engagement with the lower surface of the gold layer 45 in a typical example the temperature of the bonding tool 46 is 450 u00b0 c and is held in engagement with the interconnect lead 16 for approximately 0 15 seconds the bonding pressure per square mil is typically approximately three times the pressure utilized for bonding the inner ends of the interconnect lead 16 to the gang bonding bumps 21 i e 10 30 grams per square mil the selective gold plating layer 45 has an area of for example 225 square mils interfacing with the interconnect lead 16 bond strengths achieved between the copper interconnect lead 16 and the gold layer 45 on the lead frame 43 are usually greater than 50 grams.