Yeah it's a trend that's been going on for several years, I remember hearing about it in 2006 or 7...Copper has a different coefficient of expansion than gold and thus when driven real hard tended to part at the ultrasonic weld to the breakout pad on the die...Was a lot of talk about ti... Seems to me that it was National Semi. that started the research...God Bless Bob Pease... Wherever he is... Bob and Bob (Robert Widlar... inventor of the Band Gap device) WERE National Semiconductor and National folded right about the time that Bob Pease died...Bob
@ codlink.. Yes because of it's softness and work-ability... Not much perhaps a mm or so per lead but real easy to ultrasonic weld.