Supposedly gold ball bonding can be performed at room temperature with a high frequency ultrasonic generator. There was just an article in one of the trade journals (Semiconductor International, August Issue) regarding room temperature bonding. Haven't tried it yet. One can make a bond stick at room temperature with a normal ultrasonic generator, but I would question the reliability of that bond. There would probably be mechanical forces holding the bond down, but not a true weld. As for the capillary, I'm not sure that you can get one with those dimensions. K & S Micro-Swiss (and others I imagine) sell bottleneck capillaries, but I think their standard bottleneck height is 18 mils with a tip diameter of 6 mils. This capillary can handle 0.7 - 1.3 mil wire. I have a 1990 catalog, so maybe there have been improvements since then, but 50 mils would be a stretch I think. Dave Anderson >>> <[log in to unmask]> 08/15/97 12:54pm >>> Hello Everybody, I had a couple questions concerning gold ball bonding. First I was wondering about the feasability of gold ball bonding without using heat. Second, What is the finist tip on a capillary that can be made for a deep access application The diameter can not be greater than 9.5 mils at 50 mils up from the tip. If such a cap is possible to make what diameter wire would be used. Thanks for the help, Peter Scott